JP2013125320A - Portable gas detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable gas detector which has a robust structure, can obtain desired explosion-proof property and desired waterproof property, and has high maintainability.
In this portable gas detector, a substrate assembly in which functional members related to a gas detection operation including a gas sensor are arranged together at one end side in the longitudinal direction of a flat main substrate is arranged in a casing main body and a casing main body. A gas detector main body disposed in a casing made of a top cover is provided. The casing main body communicates with the internal space, and a bottomed first tube in which one end side portion of the substrate assembly is accommodated. A flat second cylindrical portion that extends continuously outward in the axial direction of the first cylindrical portion, continuously from the outer surface of the bottom wall portion that defines the cylindrical portion and the first cylindrical portion, In the substrate assembly, the other end portion of the main substrate is inserted into the second cylindrical portion, and the other end portion of the main substrate is sandwiched between the substrate holding portions provided inside the second cylindrical portion. With a retained structure Yes.
[Selection] Figure 3

Description

  The present invention relates to a portable gas detector.

In general, for example, in underground construction sites, tunnels, places where people enter, work areas, etc., there is a risk that dangerous gases such as carbon monoxide gas or hydrogen sulfide gas may be contained in the air of the environment. In many cases, there is a possibility that the air in the environmental atmosphere is in a dangerous state or in a dangerous state, such as when the oxygen gas concentration in the air may be lowered.
And when it becomes dangerous to humans due to the high concentration of dangerous gas contained in the air or low oxygen gas concentration, it is necessary to immediately know that From such a demand, portable gas detectors having an alarm notification mechanism by an alarm sound from an alarm buzzer that operates when a detection target gas is detected by a gas sensor are widely used.

Thus, such portable gas detectors are used in an environment where ignition or explosion may occur due to the presence of an explosive atmosphere containing flammable gas or steam. It is necessary that the structure itself does not become an ignition source, that is, a structure that satisfies the so-called explosion-proof specification.
In addition, since it may be used to measure the state of air in a gas measurement target space such as a manhole where water is collected, water containing water droplets or the like in the atmosphere is inside the housing. It is desirable that a waterproof structure be adopted in order to prevent entry into the water.

  Usually, in such a portable gas detector, a rubber packing is mounted in a packing arrangement groove formed on one casing forming member, and the other casing forming member is formed on one casing via the rubber packing. The rubber packing is pressed and crushed by tightening the two casing forming members with a plurality of screws in contact with the member, and thereby the internal space in which the functional member related to the main substrate and the gas detection operation is accommodated. It is set as the structure in which the casing to form was formed (refer patent document 1).

JP 2005-134328 A

  However, in a configuration including a casing in which two casing forming members are joined to form an internal space in which the main board and the functional member are accommodated, it is difficult to obtain sufficiently high mechanical strength. There is a problem that it is difficult to obtain the desired waterproofness.

  The present invention has been made based on the circumstances as described above, has a robust structure, has the desired explosion-proof property and the desired waterproof property, and has high maintainability. The object is to provide a detector.

A portable gas detector according to the present invention is a casing in which a substrate assembly in which functional members related to a gas detection operation including a gas sensor are arranged and arranged at one end portion in the longitudinal direction of a flat main substrate is opened. A main body and a gas detector main body disposed in a casing made of a top cover that is detachably connected and fixed to the opening of the casing main body via a seal member;
The casing body has an inner space communicating with each other, and a bottomed first cylindrical portion in which the one end side portion of the substrate assembly is accommodated, and an outer surface of a bottom wall portion that defines the first cylindrical portion Comprising a flat second cylindrical portion that extends continuously outward in the axial direction of the first cylindrical portion, and is formed of an integral body without a joint portion,
In the substrate assembly, the other end portion of the main substrate is inserted into the second cylindrical portion, and the other end portion of the main substrate is provided in a substrate holding portion provided in the second cylindrical portion. It is sandwiched and held.

In the portable gas detector of the present invention, the functional member constituting the substrate assembly includes a display mechanism,
It is preferable that the casing body is made of a transparent resin material, and a protective window for the display mechanism is formed by a part of the front surface of the casing body.

  In the portable gas detector of the present invention, the casing main body has an opening end surface of the first cylindrical portion from one end side to the other end side in the axial direction of the first cylindrical portion in a side view. It is preferable that the configuration has a configuration that inclines according to the above.

  Furthermore, in the portable gas detector according to the present invention, the casing body has a dimension in a direction perpendicular to a flat surface that constitutes a front surface of the second cylindrical part smaller than the dimension of the first cylindrical part. The second cylindrical portion has a form that is continuous with the first cylindrical portion so that the front surface and both side surfaces form a continuous surface, and the power supply unit mounting portion is on the back side of the second cylindrical portion. One of a rechargeable battery power supply unit including a rechargeable battery and a dry battery power supply unit including a dry battery is mounted to the power supply unit mounting portion in a replaceable manner. It is preferable to be configured.

  According to the portable gas detector of the present invention, substantially all of the substrate assembly in which all the functional members related to the gas detection operation are arranged and arranged at one end side portion in the longitudinal direction of the main substrate is accommodated. The casing body of the gas detector main body forming the internal space is continuous with the outer surface of the first cylindrical portion in which the one end side portion of the substrate assembly is accommodated and the bottom wall portion defining the first cylindrical portion. And a second cylindrical portion that extends outward in the axial direction of the first cylindrical portion and accommodates the other end portion of the main substrate for operation control in the substrate assembly, and is configured as an integrated body without a joint portion. As a result, the portable gas detector itself can be configured as having a robust structure, so that it can be configured as having the desired explosion-proof property and the desired waterproof property.

It is a front view which shows the structure in an example of the portable gas detector of this invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is an expanded sectional view which expands and shows a part in FIG. It is a disassembled perspective view which abbreviate | omits and shows a part of portable gas detector shown in FIG. It is a longitudinal cross-sectional view along the axial direction which shows the structure of the casing main body in the portable gas detector shown in FIG. The (a) top view which shows the structure of the rechargeable battery power supply unit in the portable gas detector shown in FIG. 1, (b) Front view, (c) The sectional view on the AA line in (b), (d) (b) It is a BB line sectional view in). (A) Top view which shows the structure of the dry battery power supply unit used in the portable gas detector shown in FIG. 1, (b) Rear view, (c) The sectional view on the AA line in (b), (d) (b It is a BB sectional view taken on the line in FIG.

Hereinafter, embodiments of the present invention will be described in detail.
1 is a front view showing a configuration of an example of a portable gas detector according to the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG. 4 is an enlarged sectional view showing a part of FIG. 3 in an enlarged manner, and FIG. 5 is an exploded perspective view showing a part of the portable gas detector shown in FIG.
This portable gas detector is configured, for example, as a portable gas alarm device having an alarm notification function by alarm sound and light emission, and is detachable from the gas detector body 10 and the gas detector body 10. For example, a rechargeable battery power supply unit 85 including a rechargeable battery 90 is mounted.
On the front surface of the gas detector main body 10, a display unit 11 is formed in the central region and an operation unit 12 is formed in a lower region of the display unit 11. In addition, an alarm light emitting unit 13 is formed in the upper region of the display unit 11 on the front surface of the gas detector body 10, the front surface region on the upper surface following this, and the front region on both side surfaces of the gas detector body 10. Has been.

  The gas detector body 10 includes a substrate assembly 20 in which functional members related to gas detection operations are arranged and arranged at one end portion in the length direction of a flat main substrate 21 elongated in one direction. Inside, the main board | substrate 21 is arrange | positioned and comprised so that it may extend in parallel with the front surface and back surface of a casing. Here, as functional members, there are a gas sensor 41, a pump unit 35 for supplying a gas to be detected to the gas sensor 41, an alarm notification mechanism such as an alarm light emitting element 23 and an alarm buzzer 30, and a display mechanism for displaying a gas detection result. Including.

On the front surface of the main board 21 constituting the board assembly 20, a panel-like display mechanism 22 is provided at the center position of one end side portion, and a plurality of warning light emitting elements are provided. For example, three warning light emitting elements 23 are provided at positions spaced apart from each other in the width direction at one end edge portion on the front surface of the main substrate 21, and the panel-like display mechanism 22 on both side edge portions on the front surface of the main substrate 21. Two alarm light emitting elements (only one alarm light emitting element is shown in FIG. 5) are provided at two positions between the main board 21 and the main board 21, respectively.
In addition, a plurality of switch elements 24 are disposed on the other end portion of the front surface of the main board 21.

An alarm buzzer 30 and a pump unit 35 are arranged at a position in the width direction of one end edge portion on the back surface of the main board 21.
The alarm buzzer 30 is a short columnar shape in which a piezoelectric vibrator 32 is disposed in a case 31 having a sound emission port 31A that is open on one side, and the sound emission port 31A is formed on the main board 21. It arrange | positions so as to oppose the formed opening 21A.
The pump unit 35 includes a diaphragm pump driven by a motor, for example, and has a performance capable of supplying air in an environmental atmosphere with a flow rate of 0.75 liter / min or more, for example.

  A flat sensor substrate 40 is provided on the back side of the alarm buzzer 30 so as to extend in the axial direction in parallel with the main substrate 21. On the back side of the sensor substrate 40, the types of detection target gases or the detection gases are mutually detected. A plurality of (5 in this example) button type gas sensors 41 having different levels are provided. Each gas sensor 41 is provided with a sensor cap 44 that is screwed and fixed to the casing main body 51 via the planar packing 43 in a state where a part of the gas sensor 41 is accommodated in the sensor holding portion of the sensor holder 42. Has been. A gas flow passage extending along the arrangement pattern of the gas sensor 41 is formed in the sensor cap 44.

  An example of the combination of the gas sensor 41 is a measurement of% LEL (explosive lower limit concentration) of a combustible gas such as a hydrocarbon gas comprising a hydrogen sulfide gas detection gas sensor comprising a constant potential electrolytic gas sensor and a contact combustion gas sensor. The first combustible gas sensor for detecting in the range, the carbon monoxide gas detecting gas sensor consisting of a constant potential electrolytic gas sensor, and the combustible gas such as hydrocarbon gas consisting of a heat conduction type gas sensor in the volume% measurement range Examples of the gas sensor for oxygen gas detection include a second combustible gas sensor for detection and a galvanic cell type gas sensor.

  In the casing, the casing main body 51 and the top cover 70 are detachably connected and fixed via a seal member made of a ring-shaped packing 80 disposed over the entire circumference of the contact surface between the casing main body 51 and the top cover 70. It is configured. The top cover 70 is fixed to the casing body 51 by a plurality of, for example, four fixing screws 81.

  Thus, the casing main body 51 in the portable gas detector is made of, for example, a transparent resin material and is configured as an integral body having no joint. Specifically, as shown in FIG. 6, the casing main body 51 has a bottomed structure in which one end side portion of the substrate assembly 20 in which the functional member is disposed is accommodated inside, and one side (upward in FIG. 6) opens. The first cylindrical part 60 and a flat bottomed second cylindrical part 61 whose dimension in the direction perpendicular to the flat surface constituting the front is smaller than the dimension of the first cylindrical part 60. The second cylindrical portion 61 defines the first cylindrical portion 60 in a state where the three circumferential surfaces, that is, the front surface and both side surfaces form a continuous surface with the front surface and both side surfaces of the first cylindrical portion 60, respectively. It is continuous with the outer surface of the bottom wall portion 54 so as to extend outward in the axial direction.

  The internal space of the first tubular portion 60 and the internal space of the second tubular portion 61 are in communication with each other, and the inner surface of the bottom wall portion 55 that defines the second tubular portion 61 is connected to the main space in the substrate assembly 20. A main board holding part 56 is formed to hold the other end edge of the board 21 and hold it. In addition, on the inner surface of the side wall portion defining the second cylindrical portion 61 in the both side walls 53 of the casing main body 51, a receiving guide portion 57 in which both side edges of the main substrate 21 in the substrate assembly 20 are guided as guided portions. It is formed to extend toward the other end side in the axial direction. Here, the guide surface 57A on the front side of the main board 21 of the receiving guide part 57 is continuous with the main board holding part 56 via a taper part 57B that is inclined inward from the one end side in the axial direction toward the other end side. doing.

  The opening end surface 51A of the casing main body 51 (first tubular portion 60) is inclined to the front side from the one end side in the axial direction toward the other end side in a side view, and has such a configuration. Accordingly, a part of the substrate assembly 20 (for example, a region from one edge of the main substrate 21 to a position where the opening 21A is formed) is exposed to the outside of the casing body 51. The attachment and detachment with respect to 51 can be performed easily, and maintainability can be improved.

In the other end side portion (front wall portion defining the second cylindrical portion 61) of the front wall 52 of the casing body 51, positions facing the switch elements 24 in the substrate assembly 20 (immediately above the switch elements 24). In the position), a hole 52A is formed in which the switch element driving button 25 elastically displaced in a direction perpendicular to the surface thereof is mounted.
A protective film material 68 having a transparent deformability is attached to the entire area of the front surface of the casing main body 51, and each switch element driving button 25 is covered on the protective film material 68. There is a display indicating the type of switch in the part, and the operation unit 12 is configured thereby.
Further, the upper end side portion of the front wall 52 of the casing body 51 (the front wall portion that defines the first cylindrical portion 60 and the second cylindrical portion 61 that is continuous therewith) that is covered with the protective film material 68 is defined. A part of the front wall portion) functions as a protective window for protecting the panel-like display mechanism 22 in the substrate assembly 20, and thus the display unit 11 is configured. That is, the portable gas detector itself is more robust than the one in which the display unit 11 is formed by forming an opening in the casing body 51 itself and providing a separate protective window member in the opening. It can be configured as having a structure.

  On the back side of the second cylindrical portion 61 in the casing body 51, a space extending in the axial direction formed by a dimensional difference between the first cylindrical portion 60 and the second cylindrical portion 61 in a direction perpendicular to the front surface. A power supply unit mounting portion 65 is formed by the unit, and one of the rechargeable battery power supply unit 85 and the dry battery power supply unit 95 including the dry battery is the other of the power supply unit mounting portion 65. It can be exchanged for things. In this example, the state where the rechargeable battery power supply unit 85 is mounted is shown as described above.

In the power supply unit mounting portion 65, the axially lower end side of the outer surface of the bottom wall portion 54 defining the first cylindrical portion 60 is provided on each of both sides in the width direction on the back surface of the second cylindrical portion 61 of the casing body 51. A thin plate-shaped power supply unit guide portion 66 extending toward the surface is formed, and a groove portion 86 </ b> F formed on each side surface of the rechargeable battery power supply unit 85 and the dry battery power supply unit 95 on the inner surface of the power supply unit guide portion 66. , 96E (see FIGS. 7 and 8) is formed to extend in the axial direction.
Further, in the power supply unit mounting portion 65, a contact terminal in the board assembly 20 is exposed to form a connector portion (not shown) on the outer surface of the bottom wall portion 54 that defines the first cylindrical portion 60. Therefore, the rechargeable battery power supply unit 85 and the dry battery power supply unit 95 are electrically connected to the gas detector main body 10 by being slidably engaged with the power supply unit mounting portion 65.

In the top cover 70, a resonance space S is formed in the front region, which is partitioned so as to communicate with an internal space in which the substrate assembly 20 is disposed via a communication port 73A.
Specifically, the front wall 71 of the top cover 70 is formed with a recess 72 having an internal space extending in the width direction that opens in the front direction, and the front surface of the bottom wall portion 73 that defines the recess 72. A communication port 73A is formed at a position displaced in the direction of one side wall from the central position, that is, at a position facing the sound emission port 31A in the case 31 of the alarm buzzer 30 in the board assembly 20. And the buzzer cap 75 is provided in the cylindrical protrusion 71A formed so that the circumference | surroundings of the recess 72 in the front of the front wall 71 may be enclosed, and, thereby, the resonance space (resonance space) S is formed. .
A dustproof / waterproof filter 83 made of, for example, polypropylene is provided on the inner surface of the bottom wall 73 that defines the recess 72 so as to cover the communication port 73A.

The buzzer cap 75 has a notch 76 extending in the width direction at the center of the upper edge, thereby forming an alarm sound emitting opening 77 that opens the resonance space S to the outside. Accordingly, the alarm sound emitting opening 77 is positioned so as to be displaced upward in the axial direction with respect to the communication port 73A formed in the bottom wall 73 that defines the recess 72, and the alarm buzzer 30 generates an alarm sound. Are emitted in a predetermined direction with high directivity, and an alarm sound having a sufficiently high sound pressure level is obtained.
The buzzer cap 75 is formed with a plurality of buzzer sound adjustment holes 78 at positions displaced toward the other side wall in the width direction so as not to face the communication port 73A. Thereby, the sound pressure improvement effect of a buzzer sound can be obtained more reliably.

  As shown in FIG. 7, the rechargeable battery power supply unit 85 has a bottom that defines a second cylindrical portion 61 of the casing main body 51 that constitutes the gas detector main body 10 at the lower end edge of the flat surface that constitutes the front. The housing member 86 has a rectangular tubular housing member 86 that has an engaged portion 86E that is slidably engaged with an engaging portion 58 that is formed on the outer surface of the wall portion 55. One side wall 86A is formed by a lid member 89 that is attached to the opening of the housing member 86 to form a sealed space inside the housing member 86, and a battery support portion 87 that is formed in the side wall 86A side region inside the housing member 86. A rechargeable battery 90 having a cylindrical shape that is supported and disposed so as to extend along the front side, and a front side at a position on the other side wall 86B side of the rear side region inside the housing member 86. For example, an epoxy resin in which the rechargeable battery 90 and the power supply circuit board 91 are filled in the housing member 86. And embedded in a resin block 92 made of a thermosetting resin. Here, as the rechargeable battery 90, for example, a high-capacity secondary battery such as a lithium ion battery is used.

  A tapered portion 88 that is inclined inwardly from the opening end surface side of the housing member 86 toward the bottom surface side is formed at a position aligned with the battery support portion 87 on the inner surface of the front flat wall 86D of the housing member 86. With such a configuration, it becomes easy to fill the thermosetting resin, so that the state where the rechargeable battery 90 and the power supply circuit board 91 are embedded in the thermosetting resin can be reliably obtained. The explosion-proof property of the period can be reliably obtained, and the amount of the relatively expensive thermosetting resin can be suppressed to be small, so that it can be produced advantageously in terms of cost.

  On the outer surface of the lid member 89, a connector that is electrically connected to a connector part for connection formed on the bottom wall part 54 that defines the first cylindrical part 60 of the casing body 51 that constitutes the gas detector body 10. A portion 89A is formed.

As shown in FIG. 8, the dry battery power supply unit 95 has a common outer shape (flat box shape) with the rechargeable battery power supply unit 85, and a gas detector While having an engaged portion 96A that is slidably engaged with an engaging portion 58 formed on the outer surface of the bottom wall portion 55 that defines the second cylindrical portion 61 of the casing main body 51 that constitutes the main body 10, A connector portion 96B that is electrically connected to a connector portion for connection formed on the bottom wall portion 54 that defines the first cylindrical portion 60 of the casing body 51 that constitutes the gas detector body 10 is formed on the upper surface. Yes.
The dry battery power supply unit 95 in this example includes a housing member 96 having a battery receiving portion 96D having a battery mounting opening 96C that opens rearward on the back surface, and packing P in the opening of the battery insertion port 96C in the housing member 96. A battery receiving portion cover lid 97A that is airtightly mounted via the power supply circuit board 98 disposed on the front side of the battery receiving portion 96D, and a power supply that is airtightly mounted on the front surface of the housing member 96 via the packing P. A plate-shaped protective member 97B that protects the circuit board 98, and the battery receiving portion 96D has, for example, three cylindrical dry batteries (for example, AA type dry batteries (AA size)) 99 adjacent to each other. The negative electrode and the negative electrode are mounted in parallel so as to face in opposite directions, and are connected in series.

  In this portable gas detector, each of the gas detector main body 10 (the casing main body 51 and the top cover 70), the rechargeable battery power supply unit 85, and the dry battery power supply unit 95 includes, for example, an antistatic resin (antistatic resin). The protective cover 18 is integrally attached, and in the state where the protective cover 18 is attached, the size of the resin surface portion exposed to the outside is restricted to a predetermined size or less. Will have sufficient and reliable explosion-proof properties. In addition, the material constituting the protective cover 18 functions as a buffer material (protective material) for the portable gas detector due to the impact resistance of the material itself, so that the portable gas detector may fail or be damaged due to dropping or the like. It can be avoided.

  Thus, the portable gas detector is configured by assembling the casing main body 51, the substrate assembly 20, the top cover 70, and, for example, the rechargeable battery power supply unit 85, which are configured as a single body. That is, the board assembly 20 is inserted from the opening of the first cylindrical portion 60 of the casing body 51 (the white arrow in FIG. 5 indicates the insertion direction), and the other end portion of the main board 21 is the second cylinder. In the state in which the one end side portion of the main substrate 21 is guided by the receiving guide portion 57 of the shape portion 61 and is accommodated in the first tubular portion 60, the other end portion of the sensor substrate 40 causes the first tubular portion 60. The inner surface of the bottom wall portion 55 that is sandwiched and held by the sensor substrate holding portion 54 </ b> A provided on the inner surface of the bottom wall portion 54 that is defined and the other end portion of the main substrate 21 defines the second cylindrical portion 61. Are held and held by a main board holding part 56 formed on the board. When the top cover 70 is attached to the opening of the casing body 51, one end of the main substrate 21 and one end of the sensor substrate 40 are respectively provided on the inner surface of the upper wall 74 of the top cover 70. In this state, the top cover 70 is fixed in a state of being hermetically sealed to the casing body 51 by the fixing screw 81. Further, the sensor cap 44 is mounted on the sensor cap mounting opening 59 formed on the back surface of the casing main body 51 and exposing the gas sensor arrangement area in the substrate assembly 20 to the outside, whereby the gas detector main body 10 is configured. The Then, the casing body 51 in which either one of the rechargeable battery power supply unit 85 and the dry battery power supply unit 95 is included in the gas detector body 10 with respect to the power supply unit mounting portion 65 in the gas detector body 10. The second cylindrical portion 61 is mounted so as to be slidably engaged along the back surface.

  According to the portable gas detector configured as described above, the casing main body 51 of the gas detector main body 10 that forms an internal space in which substantially the entire substrate assembly 20 is accommodated is a function related to the gas detection operation of the substrate assembly 20. The shaft of the first cylindrical portion 60 is continuous with the outer surface of the bottom wall portion 54 that defines the first cylindrical portion 60 and the first cylindrical portion 60 in which the one end side portion where the member is disposed is accommodated. A portable gas detector having a second cylindrical portion 61 that accommodates the other end portion of the main substrate 21 in the substrate assembly 20 that extends outward in the direction, and is configured as a single unit without a joint portion. Since itself can be configured as having a robust structure, it can be configured as having the desired explosion-proof property and the desired waterproof property.

  Further, since the casing main body 51 is made of a transparent resin material, it is not necessary to form an opening for forming the display portion in the casing main body 51, and a part of the front surface of the casing main body 51 is assembled on the substrate assembly. 20 can function as a protective window for the panel-like display mechanism 22 in this case, and in this respect as well, the portable gas detector itself can be reliably configured to have a robust structure. Furthermore, since a power supply unit including one of the rechargeable battery 90 and the dry battery 99 is configured independently of the gas detector main body 10, for example, both a rechargeable battery such as a lithium ion battery and a dry battery are used. However, the robustness can be improved also in that the casing body 51 does not need to be provided with a battery loading chamber or a battery insertion port for a dry battery.

  Furthermore, the substrate assembly 20 is held and fixed by simply inserting the substrate assembly 20 into the casing body 51, and the top cover 70 is mounted on the casing body 51 and fixed by the fixing screw 18. The sound emission port 31A in the alarm buzzer 30 is properly positioned with respect to the communication port 73A that allows the resonance space S formed in the top cover 70 to communicate with the internal space in which the substrate assembly 20 is accommodated. Therefore, the portable gas detector can be manufactured (assembled) very easily without complicated operations, and when a failure or the like occurs, the entire substrate assembly 20 can be assembled. High maintenance because it can be removed from the casing body 51 and the necessary functional members can be replaced. It is possible to obtain. The gas sensor 41 can be replaced by removing the sensor cap 44 from the casing body 51 without removing the top cover 70.

  Furthermore, since the seal portion formed on the joint surface between the casing main body 51 and the top cover 70 is a relatively small region, the original performance of the ring-shaped packing 80 is surely expressed and a highly reliable seal structure is achieved. Can be formed.

DESCRIPTION OF SYMBOLS 10 Gas detector main body 11 Display part 12 Operation part 13 Alarm light emission part 18 Protect cover 20 Board assembly 21 Main board 21A Opening 22 Panel-like display mechanism 23 Alarm light emitting element 24 Switch element 25 Switch element drive button 30 Alarm buzzer 31 Case 31A Sound outlet 32 Piezoelectric vibrator 35 Pump unit 40 Sensor substrate 41 Gas sensor 42 Sensor holder 43 Planar packing 44 Sensor cap 51 Casing body 51A Open end surface 52 Front wall 52A Hole 53 Side wall 54 Bottom wall portion 54A Sensor substrate holding portion 55 Bottom wall portion 56 Main board holding portion 57 Receiving guide portion 57A Guide surface 57B Taper portion 58 Engaging portion 59 Sensor cap mounting opening 60 First cylindrical portion 61 Second cylindrical portion 65 Power supply unit mounting portion 66 Power supply unit Guide part 66A protrusion 68 protective film material 70 top cover 71 front wall 71A protrusion edge 72 recess 73 bottom wall part 73A communication port 74 upper wall 74A, 74B board support part 75 buzzer cap 76 notch part 77 alarm Sound emission opening 78 Buzzer sound adjustment hole S Resonance space 80 Ring-shaped packing 81 Fixing screw 83 Dust / waterproof filter 85 Rechargeable battery power supply unit 86 Housing member 86A One side wall 86B The other side wall 86D Front side flat wall 86E Engaged portion 86F Groove portion 87 Battery support portion 88 Taper portion 89 Lid member 89A Connector portion 90 Rechargeable battery 91 Power supply circuit board 92 Resin block 95 Dry cell power supply unit 96 Housing member 96A Engaged portion 96B Connector portion 96C Battery mounting port 96D Battery receiving part 96E Groove part 97A Battery receiving part cover lid 97B Protective member 98 Power circuit board 99 Dry battery P Packing

Claims (4)

A substrate assembly in which functional members related to a gas detection operation including a gas sensor are arranged together on one end side in the longitudinal direction of a flat plate-like main substrate is sealed in a casing main body that is open on one side and the opening of the casing main body Comprising a gas detector body disposed in a casing made of a top cover that is detachably connected and fixed via a member;
The casing body has an inner space communicating with each other, and a bottomed first cylindrical portion in which the one end side portion of the substrate assembly is accommodated, and an outer surface of a bottom wall portion that defines the first cylindrical portion Comprising a flat second cylindrical portion that extends continuously outward in the axial direction of the first cylindrical portion, and is formed of an integral body without a joint portion,
In the substrate assembly, the other end portion of the main substrate is inserted into the second cylindrical portion, and the other end portion of the main substrate is provided in a substrate holding portion provided in the second cylindrical portion. A portable gas detector characterized in that it is sandwiched and held. The functional member constituting the substrate assembly includes a display mechanism,
The portable gas detector according to claim 1, wherein the casing body is made of a transparent resin material, and a part of the casing body on the front surface has a function as a protective window of the display mechanism.   The said casing main body has a form which inclines as the opening end surface of the said 1st cylindrical part goes to the other end side in the axial direction of the said 1st cylindrical part from a side view. 2. The portable gas detector according to 2. The casing body has a dimension in a direction perpendicular to a flat surface constituting the front surface of the second cylindrical part smaller than the dimension of the first cylindrical part, and the second cylindrical part is the first cylindrical part. The front and both side surfaces have a continuous form so as to form a continuous surface, and the power supply unit mounting portion is formed on the back side of the second cylindrical portion,
One of the rechargeable battery power supply unit having a rechargeable battery and the dry battery power supply unit having a dry battery is detachably attached to the power supply unit mounting portion so as to be exchangeable with the other. The portable gas detector according to any one of claims 1 to 3, wherein the portable gas detector is provided.

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