JP4428071B2 - Gas alarm - Google Patents

Description

  The present invention relates to a gas alarm.

  As a gas alarm device, there is a conventional gas leak detection unit and alarm unit, and a power source unit housed in separate units, and power is supplied from the power source unit to the gas leak detection unit and alarm unit by a cable ( Patent Document 1).

On the other hand, there is also provided a gas alarm having a structure capable of exchanging a cartridge containing a gas detection element and an EEPROM storing reference value data for gas detection (Patent Document 2).
Japanese Patent Laid-Open No. 5-166083 (see FIG. 1) Japanese Patent Laid-Open No. 9-1800080 (see FIG. 1)

  Since the gas alarm device described in Patent Document 1 connects the gas leakage detection unit and the alarm unit and the power supply unit with a cable, the power supply unit, the gas leakage detection unit and the alarm unit are connected to each other. If the distance between them is long, the wiring of the cable becomes long, and there is a problem that construction costs for wiring are also required. In addition, since the casing and power supply unit, which are composed of the gas leak detection unit and alarm unit, are both exposed, they are conspicuous in the room and the wiring such as the power supply line becomes unsightly, and the overall size is increased. There was also a problem with sex.

  In addition, the gas alarm device described in Patent Document 2 has a structure in which the sensor body on which the gas detection element is mounted is exposed on the wall surface or the like, so that it is conspicuous in the room, and the wiring of the power supply line is also in the room. There was a problem similar to that of the gas alarm of Patent Document 1 because it was exposed inside.

  The present invention has been made in view of the above-mentioned points. The object of the present invention is to provide a gas alarm device that can be reduced in size with a small portion exposed to the room and can be easily replaced. It is to provide.

In order to achieve the above object, according to the first aspect of the present invention, a gas detection circuit and a gas detection circuit for generating a gas detection output by determining the presence or absence of a detection target gas having a predetermined concentration from the detection output of the gas detection element. And a gas alarm having a power supply circuit for supplying operating voltages of the gas detection element and the gas detection circuit, and a means for issuing an alarm at the time of gas detection, a sensor body including at least the gas detection element, and the power supply circuit And a base body embedded in the construction body, wherein the power supply circuit transforms an AC power source into a predetermined voltage, and rectification rectifies the AC voltage transformed by the transformer element. Circuit, smoothing circuit for smoothing the output of the rectifier circuit, and microcomputer constituting the gas detection element and the gas detection circuit from the voltage smoothed by the smoothing circuit Is composed of a predetermined accuracy of the constant voltage element for obtaining the operating voltage, the base body has a holding means from the indoor side to hold the sensor body to freely mechanically detachable, and the sensor main body side circuit portion base provided with a connection means for electrically connecting the side circuit section comprising a portion of said power supply circuit including at least said transformer element, said sensor body includes said gas sensing element, electrical of the gas detection element And a microcomputer, and a remaining portion of the power supply circuit including at least the smoothing circuit and a constant voltage element .

According to the first aspect of the present invention, since the base body is embedded in the construction body, there are few portions where the base body is exposed to the indoor side, and as a result, the exposed portion of the entire gas alarm device including the sensor body exposed to the indoor side. Compared to the conventional one that is exposed as a whole, the power line can be downsized so that the presence of exposed parts on the indoor side is not conspicuous, and is also wired in advance on the back of the structure, etc. And the signal line can be connected to the base body side, so that the wiring is not exposed to the room, the aesthetics of the room is not impaired, and the sensor body equipped with the gas detection element is easily removed from the room side. Can be exchanged easily. In addition, by providing an element to be replaced on the sensor body side, it is not necessary to replace the base body side, and it is possible to correct errors inherent in the gas detection element by a microcomputer constituting the gas detection circuit. By replacing the gas detection element and the microcomputer programmed with error correction in advance, the adjustment process at the time of replacement becomes unnecessary, and among the components of the power supply circuit, there is also a smoothing circuit that needs to be replaced due to aging. Since the gas detection element can be replaced at the same time as a constant voltage element is provided on the sensor body side, the power supply voltage supplied from the base body side to the sensor body can be supplied to the secondary output of the power transformer with low accuracy or this The secondary output can be converted into a rectified output, which simplifies the manufacturing of the base body and reduces costs. By installing a large-sized power transformer on the body side that needs almost no replacement, the sensor body does not increase in size, there is almost no need to replace the base body that is embedded for a long period of time, and the life of the base body is extended. I can plan.

  According to a second aspect of the present invention, in the first aspect of the present invention, the outer shapes of the sensor body and the base body are formed in a columnar shape, and the base body is provided with a circular hole concentric with the central axis of the sensor body. The connecting means for detachably holding one end of the sensor main body inserted through the opening on the indoor side in the mounting portion and the electrical connecting means provided at the one end of the sensor main body The sensor main body is mounted in the mounting portion so that the gas inlet formed on the other end side of the sensor main body faces the indoor side.

  According to the invention of claim 2, since the embedded hole of the structure to which the sensor body is attached can be a circular hole, it can be easily drilled by using a hole saw or the like, resulting in improved workability and the construction. The installation area on the body can be reduced, and the sensor main body exposed to the indoor side is cylindrical, so that the same inflow characteristics can be obtained for gas diffusion from any direction. By making the central axis of the main body and the base main body the same, the shape of the sensor main body can be made to fill the entire opening surface of the mounting portion of the base main body. Since the exposed part of the sensor body and the base body seen from above looks circular, it is also aesthetically pleasing.

  In the present invention, since the base main body is embedded in the construction body, there are few portions where the base main body is exposed to the indoor side, and as a result, there are fewer exposed portions of the entire gas alarm device including the sensor main body exposed to the indoor side. Compared to the entire surface that is exposed like this, it can be downsized so that the presence of exposed parts on the indoor side is inconspicuous, and it is based on power lines and signal lines that are pre-wired on the back of the structure. Since it can be connected to the main body side, the wiring is not exposed to the room, the aesthetics of the room is not impaired, and the sensor body equipped with the gas detection element can be easily removed from the indoor side. There is an effect that the replacement can be easily performed.

  Embodiments of the present invention will be described below.

( Basic configuration )
A basic configuration of the gas alarm device X according to the present invention will be described. As shown in FIG. 1, the gas alarm device X includes a sensor body 1 having a cylindrical outer shape and a base body 2 having a cylindrical outer shape on which the sensor main body 1 is detachably mounted. Here, as shown in FIG. 2, on the sensor body 1 side, the gas detection element 3 of the semiconductor type and the reference value data for gas detection that corrects the variation in the electric characteristics of each gas detection element 3 to be used are written. An EEPROM 4 as a correction element is provided. The high temperature period to the base body 2 side perform conductible control of the heater of the internal gas detection element 3, when producing alternatively the cold phase and monitor the change in resistance of the gas-sensitive body of the gas detection element 3 incorporation at a predetermined timing hot period and low periods as a voltage change signal at the Turkey comparing the voltage value and the reference value data written in EEPROM4 taken, the detection target gas (e.g., CH4) corresponding to a high temperature period and A microcomputer (hereinafter abbreviated as a CPU section) 5 that is a gas detection circuit for performing a detection process for determining whether or not a detection target gas (CO) corresponding to a low temperature period is present at a predetermined concentration, and an AC power supply AC are connected to a power supply terminal 7a. 7a, a power transformer 60 that transforms (steps down) the voltage to a predetermined voltage, a rectifying / smoothing circuit 61 that rectifies and smoothes the alternating current transformed by the power transformer 60, and a regulator. A power supply circuit 6 comprising a high-precision constant voltage generating circuit 62 for obtaining a constant DC voltage from the DC voltage rectified and smoothed by the smoothing circuit 61, and when the gas detection signal is output from the CPU unit 5, the rectifying and smoothing circuit 61 A voltage output unit 8 for outputting the DC voltage of the output as a detection signal of a voltage from the pair of signal output terminals 7b and 7b to the outside, and a piezoelectric buzzer under the control of the CPU unit 5 in response to the gas detection of the CPU unit 5 And an alarm signal circuit 10 for driving an alarm 9 such as a piezoelectric speaker to issue an alarm and an LED display circuit 11 for displaying by an LED element. Note that a voice synthesis circuit may be provided as the warning signal circuit 10, and a warning message may be notified by voice from a warning device 9 including a speaker such as a piezoelectric speaker. Further, the alarm signal circuit 10 and the alarm device 9 may be omitted.

  As shown in FIG. 3, the sensor body 1 has a cylindrical first housing 100a and a similar cylindrical bottomed second housing 100b attached to the opening side of the housing 100a with the opening side aligned. The housing 100a contains a circular circuit board 14 that is soldered to the ends of four pin-like terminals 12 that are inserted through the holes 13 from the outside. The four terminals 12 are arranged at equal intervals on a circumference concentric with the center of the bottom wall (ceiling wall) of the housing 100a. The flange 12a formed at the intermediate position of the terminal 12 hits the opening edge of the hole 13 and regulates the amount of insertion of the terminal 12. Further, a hole 15 provided in the circuit board 14 is for inserting the end of the terminal 12 and soldering to the circuit pattern.

  The gas detection element 3 and the EEPROM 4 are mounted on the circuit board 14, and two of the terminals 12... Are connected to a circuit pattern in which the detection electrodes of the gas detection element 3 are connected in FIG. One of the remaining two is connected to the circuit pattern to which the data terminal of the EEPROM 4 is connected, and the other is connected to the common ground pattern.

  As shown in FIG. 4, the housing 100 a is provided with a substantially L-shaped locking groove 16 whose upper end and side surfaces are open in the drawing. Although not visible in the figure, it is assumed that similar engagement grooves 16 are also provided at positions on the outer peripheral surface that are symmetrical with respect to the formation position and center of the engagement groove 16. These engaging grooves 16 are detachably engaged with two engaging projections 18 provided so as to correspond to a mounting portion 17 on the base body 2 side, which will be described later, to mechanically attach the sensor body 1 to the mounting portion 17. A held means for holding is configured. On the other hand, the bottom of the housing 100b is provided with a gas inlet 19 that faces the gas inlet 3a of the gas detection element 3 mounted on the circuit board 14 when attached to the housing 100a.

  Thus, when the housing 100a and the housing 100b are attached to each other with the openings facing each other, the sensor body 1 having a cylindrical outer shape is completed. In addition, the locking fixation is such that the outer diameter of the opening of one housing is formed to a diameter that fits into the other opening, and a locking claw (not shown) is provided on the outer peripheral surface of the one opening, and the other opening is provided. For example, a locking hole (not shown) for locking the locking claw from the inside is provided.

  As shown in FIG. 5, the base body 2 includes a cylindrical housing 200a and a cover 200b attached to one opening (upper side in the figure) of the housing 200a. Divided by the wall 201. In the figure, the upper space portion constitutes a housing portion 25 for housing the circuit board 20 on which circuit components such as the power transformer 60 on the base body 2 side are mounted, and the lower space portion is a hole portion of the sensor body 1. A mounting portion 17 for fitting and mounting the housing 100a portion is configured. An annular mounting flange 21 is integrally provided on the outer peripheral portion of the mounting portion 17 near the opening.

Wherein the inner diameter of the mounting portion 17 on the inner circumferential surface a little size rather than the outer diameter of the housing 100a so that it can fit the housing 100a is provided with engaging projections 18 described above. Further, the partition wall 201 serving as the ceiling surface of the mounting portion 17 is provided with an arcuate hole 22 through which the terminal 12 protruding from the housing 100a is inserted into the storage portion 25 side and is movable in the circumferential direction. 17 are provided at equal intervals on the circumference concentric with the center of 17 so as to correspond to the terminals 12.

  The mounting flange 21 is provided with two arcuate darling holes 23 concentric with the center of the housing 100a in point symmetry, and a normal type darling hole 24 is provided at a substantially intermediate position between the darting holes 23, 23. These daruma holes 23 and 24 constitute mounting holes for inserting mounting screws (not shown), and the base body 2 is embedded in the ceiling panel 30 as shown in FIG. 6 (a). As shown in FIG. 30B and FIG. 6B, the mounting flange 21 is provided around the opening edge of the embedded hole 30a and the embedded hole 31a when embedded in the embedded hole 31a provided in the wall panel 31 from the indoor side. The base main body 2 is fixed to the ceiling panel 30 or the wall panel 31 which is a construction body by screwing the mounting screw into the ceiling panel 30 or the wall panel 31 through the screw holes 23 or 24 in the contact state. It has become kill as.

  The circuit board 20 housed on the housing part 25 side has terminals 12 from the sensor body 1 side inserted into the housing part 25 side through the respective arc-shaped holes 22 on the surface facing the partition wall 201 side. Receiving terminals 26 made of leaf springs that are electrically connected by sandwiching the tip are mounted, respectively, and are attached via spacers (not shown) near the partition wall 201. The receiving terminal 26 has a blade receiving structure that sandwiches the terminal 12 inserted through the arc-shaped hole 22 and is in sliding contact when the terminal 12 is moved. Further, by adopting a configuration in which the terminal 12 is electrically connected in the shortest distance, the connection circuit between the sensor main body 1 side circuit and the base main body 2 side circuit can be shortened. Stable operation can be obtained.

  The cover 200b has a terminal block 27 provided with the power supply terminals 7a and 7a and the signal output terminals 7b and 7b on the outer surface side, and circuit patterns on the terminals 7a, 7a, 7b and 7b and the circuit board 20 side from the inner surface side. Are connected by wiring cables 28, and are placed between the end faces of the two mounting ribs 29 raised from the partition wall 201 to the vicinity of the opening along the inner peripheral wall of the storage portion 25. The tapping screw 33 is screwed and fastened from the insertion hole 32 on the cover 200b side to the attachment hole 29a opened on the end face of the attachment rib 29, and is fixedly attached to the opening of the storage portion 25.

When Thus by performing the mounting construction of the gas alarm device X with the FIG. 6 (a), the embedding of the circular through hole saw or the like to the erecting member such as a ceiling panel 30 and the wall panel 31 as shown in (b) Holes 30a and 31a are formed, the base main body 2 is fitted into the embedded holes 30a and 31a from the inside of the room, and the base main body 2 is fixed using the dart holes 23 and 24 of the mounting flange 21.
Then, the power supply line L1 is connected to the power supply terminals 7a and 7a of the terminal block 27 arranged on the back of the ceiling or the back of the wall, and the signal line L2 is connected to the signal output terminals 7b and 7b.

  After the construction work of the base body 2 is completed in this way, the gas alarm X attached to the ceiling or wall can be obtained by mounting the sensor body 1 to the mounting portion 17 of the base body 2 from the indoor side. become.

That the gas alarm device X, by in the form of embedding base body 2 in erecting member, it is possible to miniaturize the portion exposed to the indoor side as compared with the structure to expose the base body, also buried holes Since 30a and 31b can be opened with a hole saw, there is an advantage that construction can be performed efficiently, and wiring on the back of the ceiling or the back of the wall can be used, so that it is not visible to the residents and is attractive.

  Here, when the sensor body 1 is attached to the base body 2, the housing 100 a of the sensor body 1 is pushed into the attachment portion 17 toward the opening side of the attachment portion 17 of the base body 2. At this time, the engagement protrusion 18 in the mounting portion 17 is inserted into the vertical groove portion 16b of the engagement groove 16 from the opening 16a of the engagement groove 16, and the engagement protrusion 18 hits the inner end of the vertical groove portion 16b, that is, the terminal. The base body 2 is pushed into the mounting portion 17 until reaching the position where 12... Are sandwiched by the receiving terminals 26 in the storage portion 25 through the arc-shaped holes 22 of the partition wall 201. When the position is reached, the sensor body 1 is rotated in the direction of the lateral groove portion 16c, and the engagement protrusion 18 is moved from the vertical groove portion 16b into the horizontal groove portion 16c to engage the engagement protrusion 18 and the engagement groove 16. Let At this time, the terminals 12 move through the arc-shaped holes 22. However, since the terminals 12 slide while sandwiched between the receiving terminals 26, the electrical connection state is maintained. The lateral groove portion 16c may be tapered to increase the mechanical coupling force between the inner peripheral wall and the engagement protrusion 18.

Thus, the sensor main body 1 is mounted in a state in which the housing 100b of the sensor main body 1 protrudes on the indoor side in a state where it is mechanically and electrically connected and held to the mounting portion 17 of the base main body 2. The Here, since the housing 100b protruding to the indoor side is cylindrical, the gas inflow characteristics to the gas inlet 19 are almost the same for the diffusion of the gas from any direction, and the gas detection is ensured. .

Next will be described the operation of the gas alarm device X easily, power is supplied from the power supply circuit 6 microcomputer 5, chromatic voltage output unit 8, further alarm signal circuit 10 and the LE D Table示回path 11 during normal . In the semiconductor gas detecting element 3 controlled by the microcomputer 5, a predetermined voltage is applied to the gas sensitive body and a load resistance (not shown) is applied. Are made alternately. These drive voltages are high-accuracy voltages obtained by using a high-precision constant voltage element in the constant-voltage generation circuit 62 in order to perform gas detection with high accuracy.

  When the gas flowing into the housing 100b from the gas inlet 19 comes into contact with the gas sensitive body through the gas inlet 3a, the gas detecting element 3 changes the resistance value of the gas sensitive body according to the concentration of the gas. The microcomputer 5 takes in a voltage signal corresponding to the resistance change of the gas sensitive body at a predetermined timing in the low temperature period and the high temperature period from the A / D conversion port, and stores the level of the voltage signal in the EEPROM 4. A comparison is made with reference value (threshold value) data stored in advance, and it is determined whether or not the detection target gas is present at a predetermined concentration or more.

And when a predetermined concentration or more of the detection target gas is determined to be present, and outputs a detection signal of the chromatic voltage to the outside through the microcomputer 5 chromatic voltage output unit 8 to operate the alarm signal circuit 10, the notification An alarm is issued from the device 9. Further, the LED display circuit 11 is operated to perform light emission display by the LED element.

However because the detection ability decreases gas detection element 3 (in the case of the semiconductor gas detecting element about 5 years) fixed period exceeds, it is necessary to replace the gas detection element 3, in this configuration, the sensor body 1 Is removed from the mounting portion 17 of the base body 2 in a procedure reverse to the mounting procedure described above, so that only the sensor body 1 is replaced. That is, the cost is lower than when the entire gas alarm device X is replaced. Further, since the gas detection element 3 has a large variation among individuals in the electrical characteristics indicating the relationship between the detected gas concentration and the resistance change of the gas sensitive body, the reference value data for gas detection is also corrected according to the characteristics of the individual. Therefore, the replacement of the EEPROM 4 storing the reference value data indicating the relationship between the detected gas concentration and the resistance value of the gas-converted gas sensitive body makes the correction operation after the replacement unnecessary. .

Note The voltage level of the chromatic voltage signals 0V, 6V, 12V, there is 18V or the like, can also be used as a signal indicating, for example, during fault onset raw in addition to the gas detection.

( Reference example )
In the basic configuration , the gas detection element 3 and the EEPROM 4 that also constitutes the correction element are provided on the sensor body 1 side, and other circuit components including the power supply circuit 6 are provided on the base body 2 side. In this reference example , as shown in FIG. 7, only the power transformer 60 and the rectifying / smoothing circuit 61 among the circuit components constituting the power circuit 6 and the voltage output unit 8 are provided on the base body 2 side. The constant voltage generating circuit 62, the CPU 5, the alarm 9, the alarm signal circuit 10, and the LED display circuit 11 which are a part of the sensor are provided on the sensor body 1 side together with the gas detection element 3 and the EEPROM 4. There are features.

That is, in this reference example , since the CPU unit 5 is provided on the sensor main body 1 side, when a part of the variation correction process of the gas detection element 3 is performed by the program of the CPU unit 5, the sensor main unit 1 side in advance. Adjustment is possible in advance, and adjustment after the sensor body 1 is mounted on the base body 2 is unnecessary. Further, the power supply voltage supplied to the sensor body 1 from the base body 2 side is set to an output voltage that does not require high accuracy, such as the rectifying and smoothing circuit 61, thereby facilitating the production of the power supply circuit configuration on the base body 2 side. with, we are working to decrease cutting costs.

Note that the number of terminals 12 and the number of terminals on the terminal block 27 are the same as the basic configuration , so the terminal structure does not change. However, it is necessary to provide the sound output hole of the alarm 9 and the display window of the LED display circuit 11 on the base body 2 side. is there. The number of mounted elements on the circuit boards 14 and 20 varies.

  Of course, the alarm 9 and the alarm signal circuit 10 may be provided on the base body 2 side. The voltage output unit 8 may be provided on the sensor body 1 side. In these cases, it is necessary to set the number of terminals 12 and the number of receiving terminals 26 according to the number of signal paths for signals transferred from the sensor body 1 to the base body 2 side.

(Embodiment 1 )
In the present embodiment, as shown in FIG. 8, a rectifier circuit 61 a is provided on the base body 2 side among the circuit components constituting the power transformer and the rectifying and smoothing circuit 61 of the power circuit 6, and the smoothing capacitor of the rectifying and smoothing circuit 61 is provided. There is a feature in that a smoothing circuit 61b composed of the above and other circuit components are provided on the sensor body 1 side.

  That is, since the power transformer 60 has a long life, it is hardly necessary to replace it, but the smoothing circuit 61b of the rectifying / smoothing circuit has a life and needs to be replaced after a predetermined period of use.

  On the other hand, in this embodiment, when the gas detection element 3 is replaced, there is an advantage that the life-smoothing circuit 61b can be replaced together. On the other hand, since only the long-life power transformer 60 and the rectifier circuit 61a need be provided on the base body 2 side, there is almost no need to replace the base body 2, and the base body 2 is attached in the form of being embedded in the construction body. The gas alarm device X of the present invention has an advantage that the replacement cost of the base body 2 can be reduced.

  Further, since the power supply voltage supplied from the base body 2 to the sensor body 1 may be a pulsating voltage obtained by rectification by the rectifier circuit 61a, the circuit configuration on the base body 2 side can be greatly simplified. Also in this case, since the power transformer 60, which is the largest circuit component, is on the base body 2 side, the downsizing of the sensor body 1 can be maintained. Of course, the same advantage can be obtained by providing the rectifying circuit 61a of the rectifying / smoothing circuit 61 on the sensor body 1 side and supplying the secondary voltage of the power transformer 60 from the base body 2 to the sensor body 1 side.

The alarm 9 and the alarm signal circuit 10 may be provided on the base body 2 side. The voltage output unit 8 may also be provided on the base body 2 side. Although it is necessary to change the number of terminals 12 and receiving terminals 26 connected to the base body 2 and the sensor body 1 at the positions where these circuits are provided, the number of terminals on the terminal block 27 is not different from the basic configuration .

By the way, in the basic configuration, the reference example, and the first embodiment, the configuration in which the sensor body 1 and the base body 2 are electrically connected has been described on the premise of the terminal 12 and the receiving terminal 26 corresponding thereto. It is good also as a structure connected using. Next, Embodiment 2 of this connector specification will be described.

(Embodiment 2 )
In this embodiment, as shown in FIGS. 9 to 11, the sensor body 1 is made of a cylindrical body of a synthetic resin molded product having a flat bottom and is attached to an opening of the housing 100 a having a columnar appearance. The disc-shaped cover 100c is attached to the back surface (lower surface) of the cover 100c as a spacer.

  The circuit board 14 has an insertion portion (female portion) 41a of an edge connector mounted on the lower surface (in FIG. 9), for example, at the center, and the gas detection element 3, the EEROM 4, the LED display circuit 11 and the LED element 11a, Two smoothing capacitors constituting the constant voltage generating circuit 62 of the power supply circuit 6 and the smoothing circuit 61b of the rectifying and smoothing circuit 61 are mounted. The gas inlet 3a of the gas detecting element 3 is opened at the bottom of the housing 100a. It is attached to the cover 100 c so as to be positioned above a certain gas inlet 19.

  In the present embodiment, the circuit components mounted on the circuit board 14 built in the sensor body 1 conform to the mounting structure shown in FIG. 8 except that the voltage output unit 8 is mounted on the circuit board 20 on the base body 2 side.

  Here, as shown in FIG. 11, the circuit board 14 has a window hole 43 that allows the insertion port of the insertion portion 41a of the edge connector on the lower surface side to face. Further, a rectangular window hole 44 is opened at the position of the cover 100c facing the window hole 43, and the insertion portion 41b of the edge connector on the base body 2 side is detachably inserted through these window holes 43, 44. It can be inserted into the portion 41a.

  A plurality of sound emitting holes 45 are formed in the center of the bottom of the housing 100 a, and an annular rib 46 is integrally formed on the inner bottom surface of the housing 100 a so as to surround the sound emitting holes 45. An alarm 9 made of a piezoelectric speaker is arranged in the opening. Reference numeral 55 denotes a light emitting hole of the LED element 11a.

  On the other hand, the base body 2 includes a housing 200a having a cylindrical shape with a bottom opening in FIG. 9 and having a columnar appearance, and a cover 200c attached to the opening of the housing 200a. The housing 200a accommodates the circuit board 20 on which the power transformer 60 of the power circuit 6, the rectifying circuit 61a of the rectifying and smoothing circuit 61, the voltage output unit 8, and the insertion portion 41b of the edge connector are mounted. Yes. Further, on the upper surface (in the drawing) of the housing 200a, a step portion 47 is provided on which the terminal block 27 provided with the power supply terminals 7a and 7a and the signal output terminals 7b and 7b is disposed. A mounting flange 21 is formed in the embedded hole 30a of the ceiling panel 30 (or the embedded hole 31a of the wall panel 31) for abutting against the surface on the indoor side when the housing 200a is fitted from the indoor side.

  The circuit board 20 is housed in the housing 200a so that the board surface is vertical, and the insertion edge 41c of the insertion part 41b of the edge connector mounted at the center part of the lower end protrudes downward from the lower end, and the wiring cable ( A wiring pattern in which the primary wiring pattern of the power transformer 60 is connected to the power terminals 7a and 7a of the terminal block 27 and the signal output terminal of the voltage output unit 8 is connected to the signal output terminals 7b and 7b. Is supposed to be connected.

  The cover 200c has a window hole 48 at the center for projecting the insertion edge 41c of the insertion portion 41b of the edge connector downward, and the window hole 46 of the cover 100c of the sensor body 1 is formed on the outer edge of the window hole 48. The peripheral wall 42 which fits in is formed.

  Thus, when the gas alarm device X of the present embodiment composed of the sensor main body 1 and the base main body 2 configured as described above is attached to the construction body, for example, on the back side of the ceiling panel 30 (or the wall panel 31). The power line L1 and the signal line L2 previously wired in advance are led out indoors through the switch box B0, the box cover B1, and a pre-filled hole 30a (or 31a), and the terminals of the terminal block 27 of the base body 2 are connected. Connect to 7a, 7a and 7b, 7b.

  Here, the switch box B0 is fixed to the box cover B1 by a fixing screw that is placed on the box cover B1 with the opening side and is inserted into a saddle hole 49 provided at the four corners of the box cover B1. Is fixed by a screw through which the mounting hole 50 is inserted into the back surface of the ceiling panel 30 (or the wall panel 31).

  Now, after connecting the power supply line L1 and the signal line L2 as described above, the base body 2 is inserted into the embedded hole 30a (or 31a) from the terminal block 27 side, and the mounting flange 21 is inserted into the embedded hole 30a (or 31a). ). After the contact, the mounting screws 54 are fastened to the ceiling panel 30 (or the wall panel 30b) through the mounting holes 51 formed in the mounting flange 21, and the base body 2 is attached to the ceiling panel 30 (or the wall panel 31). Fix it.

  When the sensor body 1 is attached to the base body 2 embedded in the ceiling panel 30 (or the wall panel 31) in this way, the edge connector insertion portion 41a exposed from the window hole 46 of the cover 100c. Further, the sensor body 1 is directed toward the ceiling panel 30 (or the wall panel 31) so as to push in the insertion edge 41 c of the insertion portion 41 b of the edge connector exposed to the indoor side from the window hole 48 of the cover 200 c of the base body 2. Move. The electrical connection between the insertion portion 41a and the insertion portion 41b is completed at the position where the peripheral wall 48a of the window hole 48 is fitted in the window hole 46 by the movement. On the other hand, the locking holes 52b provided in the pair of locking pieces 52, 52 formed on the periphery of the opening of the housing 100a of the sensor body 1 are formed so as to correspond to the periphery of the mounting flange 21 of the base body 2. The locking claw 53 is engaged while bending the locking piece 52, and the sensor body 1 is mechanically held with respect to the base body 2.

  At the time of replacement, the locking piece 52 is bent to release the locking state between the locking hole 52b and the locking claw 53, and when the sensor body 1 is pulled in this state, the insertion portion 41b is inserted from the inserted portion 41a of the edge connector. Thus, the sensor body 1 can be removed from the base body 2 mechanically and electrically.

It is a disassembled perspective view of the basic composition of the gas alarm device concerning the present invention . It is a circuit block diagram same as the above. It is a disassembled perspective view of a sensor main body same as the above. It is a side view of a decomposition | disassembly state same as the above. It is a disassembled perspective view of a base main body same as the above. It is attachment state explanatory drawing same as the above. It is a circuit block diagram of a reference example . 1 is a circuit configuration diagram of Embodiment 1. FIG. 6 is an exploded perspective view of Embodiment 2. FIG. It is an expanded sectional view same as the above. The circuit board of the base main body side is shown, (a) is a bottom view, (b) is a side view, (c) is a top view.

Explanation of symbols

X Gas alarm 1 Sensor body 100a, 100b Housing 2 Base body 200a Housing 200b Cover 201 Partition wall 12 Terminal 17 Mounting portion 18 Engagement protrusion 19 Gas inlet 22 Arc-shaped holes 23, 24 Daruma hole

Claims (2)

A gas detection circuit for generating a gas detection output by judging the presence or absence of a detection target gas having a predetermined concentration from a detection output of the gas detection element, and an operating voltage for the gas detection element and the gas detection circuit are supplied. A gas alarm device having a power supply circuit for performing an alarm when gas is detected, a sensor main body having at least the gas detection element, and a base main body having at least a part of the power supply circuit and embedded in a construction body And the power supply circuit comprises: a transformer element that transforms an AC power source to a predetermined voltage; a rectifier circuit that rectifies the AC voltage transformed by the transformer element; and a smoothing circuit that smoothes the output of the rectifier circuit; A constant voltage element having a predetermined accuracy for obtaining an operating voltage of the microcomputer constituting the gas detection element and the gas detection circuit from the voltage smoothed by the smoothing circuit; Made is, the base body includes a retaining means from the indoor side to hold the sensor body to freely mechanically detachable, the connecting means for electrically connecting the sensor body-side circuit portion and the base-side circuit section together, comprise a portion of said power supply circuit including at least said transformer element, said sensor body includes: the gas detection element, and a correction device for correcting the variation of the electrical characteristics of the gas detection element, the microcomputer And a remaining portion of the power supply circuit including at least the smoothing circuit and a constant voltage element . The outer shape of the sensor body and the base body is formed in a columnar shape, and the base body is provided with a mounting portion made of a circular hole in a cross section concentric with the central axis of the sensor body, and an opening on the indoor side is provided in the mounting portion The holding means for detachably holding one end portion of the sensor main body inserted from and the connecting means for connecting the electric connecting means provided at one end portion of the sensor main body are provided, and the other end of the sensor main body is provided. The gas alarm device according to claim 1, wherein the sensor main body is mounted in the mounting portion so that the gas inlet formed on the side faces the indoor side .

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