JP4711395B2 - Filter complex and gas detector - Google Patents

Description

  The present invention relates to a filter composite and a gas detector provided with the filter composite.

In general, for example, in underground construction sites, tunnels, and other areas, there is a risk that hazardous gases for the human body such as carbon monoxide gas or hydrogen sulfide gas may be contained in the air in the environment, There are many cases where the air in the environmental atmosphere may be in a dangerous state or may be in a dangerous state, such as when there is a possibility that the oxygen gas concentration in the air may decrease.
And when it becomes dangerous because the concentration of the dangerous gas contained in the air in the ambient atmosphere is high or the concentration of the oxygen gas is low, it is necessary to know immediately.

  To meet this demand, various types of gas detectors have been proposed so far, and some of these gas detectors are different from each other so that a plurality of types of gas can be detected simultaneously. It is set as the structure provided with the several gas sensor which detects this gas.

In the gas detector capable of detecting a plurality of types of gases as described above, for example, when detecting carbon monoxide gas, a gas sensor composed of a constant potential electrolytic gas sensor element is usually used. Is sensitive to an interference gas such as hydrogen sulfide gas, for example, a filter including an interference gas removal layer for removing an interference gas component is usually provided in the gas introduction opening.
Further, even for a gas sensor that is not sensitive to interference gas, it is necessary to provide a normal dust filter at the gas introduction opening.

As described above, in such a gas detector, it is necessary to arrange a relatively small filter in each gas introduction opening.
However, since the performance of these filters deteriorates with use, it is necessary to replace them at regular intervals, but it is necessary to individually arrange the corresponding filters for all gas sensors. Is complicated.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a filter required for all gas sensors by a simple operation in a gas detector having a plurality of different types of gas sensors. An object of the present invention is to provide a filter composite capable of realizing a state where an action can be obtained.
Another object of the present invention is to provide a gas detector provided with the above filter complex.

The filter composite of the present invention is a filter composite arranged to simultaneously close a plurality of gas introduction openings related to a plurality of gas sensors in a gas detector,
At least one of the plurality of functional portions that block the individual gas introduction openings is a specific functional portion having a filter characteristic different from that of the other functional portions ;
A sheet main body formed by joining two filter sheets to each other at least at the periphery, and an interference gas removal layer held between the two filter sheets of the sheet main body, the interference gas removal layer being held The specific function portion is formed by the formed portion, and the interference gas removal layer viewing hole is formed at a position corresponding to the specific function portion of one of the two filter sheets. To do.

  The gas detector of the present invention comprises the above-described filter complex.

  In the gas detector according to the present invention, the filter complex is formed with an engagement hole at a position corresponding to the holding projection for holding the filter complex formed in the gas detector body. It is preferable that the filter complex is held by the gas detector body by engaging the holding protrusion.

  In the gas detector of the present invention, it is preferable that the filter complex is formed with an arrangement deformation portion for arranging the filter complex in a predetermined posture with respect to the gas detector main body.

  According to the filter composite of the present invention, all of the gas introduction openings related to a plurality of gas sensors including those having sensitivity to interference gas are simultaneously closed by simply disposing this in the arrangement area of the gas detector. Therefore, it is possible to realize a state in which a required filter action can be obtained for all the gas sensors by a simple operation.

  Further, in the filter composite of the present invention, according to the configuration in which the interference gas removal layer viewing hole is formed in the filter sheet, the degree of contamination of the interference gas removal layer can be easily achieved by visually recognizing the interference gas removal layer. Can be confirmed.

  According to the gas detector of the present invention, the filter complex is disposed at a required position with respect to the gas detector main body by engaging the engagement hole with the holding protrusion formed in the gas detector main body. In addition, according to the configuration in which the arrangement deforming portion is formed in the filter composite, it is prohibited to arrange in an incorrect posture, so that an appropriate arrangement state can always be obtained. .

  Hereinafter, a gas detector filter composite of the present invention and a gas detector including the same will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory view showing the appearance of an example of the configuration of the gas detector of the present invention, where (A) shows a front view and (B) shows a rear view. 2 is a cross-sectional view taken along the line AA in FIG. 1B, and FIG. 3 is an explanatory cross-sectional view schematically showing the arrangement relationship of the filter holder, the filter cover, and the filter complex. ) Is a diagram illustrating a disassembled state, and (b) is a diagram illustrating a state in which a filter complex and a filter cover are attached to the filter holder. FIG. 4 is a partially enlarged view of the DD line portion of FIG. 1B with the filter cover of the gas detector body removed.

  This gas detector is provided with a plurality of different types of gas sensors including gas sensors that are sensitive to interference gas components other than the detection target gas component. The filter complex 20 is mounted to remove the interference gas component in the gas to be detected with respect to the gas sensor.

In this gas detector, as a gas sensor, a button-type gas sensor, specifically, an oxygen gas detection gas sensor SA made of a galvanic gas sensor, a hydrogen sulfide gas detection gas sensor SB made of a constant potential electrolysis gas sensor, and a constant potential electrolysis. There are arranged four gas sensors SA to SD, which are a carbon monoxide gas detection gas sensor SC made up of a gas sensor and a hydrocarbon gas detection gas sensor SD made up of a catalytic combustion type gas sensor.
Of these four gas sensors SA to SD, the carbon monoxide gas detection gas sensor SC is a gas sensor having sensitivity to hydrogen sulfide gas and hydrocarbon gas, and the hydrocarbon gas detection gas sensor SD is hydrogen sulfide gas. It is also a gas sensor having sensitivity.

  These gas sensors SA to SD are arranged in a state in which two sets are arranged side by side in the vertical direction along the plane parallel to the back surface of the gas detector in the upper region inside the gas detector. Corresponding to each of the gas sensors, gas introduction openings 30A to 30D into which a test gas is introduced are provided. Specifically, the gas introduction openings 30 </ b> A to 30 </ b> D are formed so as to penetrate through the filter holder 30, which will be described later, in a state of being located at each vertex position of the quadrilateral.

  The gas sensors SA to SD are removably held by a filter holder 30 which is detachable from the gas detector main body 10, and a filter placement portion 34 in which gas introduction openings 30 </ b> A to 30 </ b> D are located on the back surface of the filter holder 30. Is formed as a slight recess.

  As shown in FIG. 3, a filter cover 35 is provided to cover the surface of the filter holder 30 on which the filter placement portion 34 is formed. The filter cover 35 allows the filter complex 20 placed in the filter placement portion 34 to be formed. It is assumed that it is pinched. Reference numeral 36 denotes a recess having a shape that matches the shape of the protrusion of the holding protrusion 33 of the filter holder 30.

  A holding projection 33 is formed at the center of the quadrilateral of the four gas introduction openings 30 </ b> A to 30 </ b> D in the filter placement portion 34 of the filter holder 30.

  And the state which block | closes all the four gas introduction openings 30A-30D of the said filter holder 30 by the filter composite body 20 arrange | positioned by the filter arrangement | positioning part 34 of the filter holder 30 is achieved.

  5 is an explanatory view showing the surface of an example of the configuration of the filter composite of the present invention, FIG. 6 is an explanatory view showing the back surface of the filter composite of FIG. 5, and FIG. 7 is a gas sensor for detecting carbon monoxide gas. 6 is an enlarged cross-sectional view taken along line BB in FIG. 6 showing a specific functional part according to FIG. 6, and FIG. 8 is an enlarged cross-sectional view taken along line CC in FIG. 6 showing specific functional parts relating to a gas sensor for detecting hydrocarbon gas. .

  The filter complex 20 has an outer contour corresponding to the filter arrangement portion 34. Specifically, the entire filter complex 20 having an engagement hole 26 penetrating in the thickness direction in the central region thereof has a substantially rectangular shape. Yes. Reference numeral 29 denotes a notch for avoiding the threaded portion 37. However, the notch 29 is formed on three sides of the quadrilateral filter composite 20, so that it is the same as the deformation portion 24 to be described later. There is also a function of arranging the filter complex 20 in a predetermined posture with respect to the gas detector main body 10.

  The engagement hole 26 of the filter complex 20 has a circular shape, and the inner diameter thereof is the same as or slightly smaller than the outer diameter of the holding projection 33 of the filter holder 30. In one example, the engagement hole 26 has an inner diameter of 12 mm, and the holding projection 33 has an outer diameter of 12 mm.

  The engagement hole 26 is formed with an arrangement deformation portion 24. Specifically, the arrangement deformation portion 24 is formed as a wedge-shaped notch protruding upward at an upper portion of the engagement hole 26. Is formed.

  In the filter composite 20, the front side filter sheet 21 and the back side filter sheet 22 having a shape covering the front surface of the filter arrangement portion 34 are pressure-bonded to each other at the outer peripheral edge portion and the inner peripheral edge portion related to the engagement hole 26. In addition, the interference gas removal layers 28C and 28D are sandwiched and integrated between the front surface side filter sheet 21 and the rear surface side filter sheet 22.

  The interference gas removal layers 28C and 28D are provided at locations corresponding to the gas introduction openings 30C and 30D related to the specific gas sensors SC and SD in a portion that is not joined in a properly arranged state. The locations are specific function portions 23C and 23D of the filter complex 20. The parts other than the specific function parts 23C and 23D in the parts that are not joined are in a state in which the two filter sheets 21 and 22 are in contact with each other, and are related to the normal gas sensors SA and SB in a properly arranged state. The portions corresponding to the gas introduction openings 30A and 30B are normal functional portions 23A and 23B.

  The interference gas removal layers 28C and 28D have a function of removing interference gas components from the gas sensors SC and SD. That is, the interference gas removal layer 28D related to the hydrocarbon gas detection gas sensor SD is formed by stacking two layers of the hydrogen sulfide removal film 31 for removing the hydrogen sulfide gas, and for detecting the carbon monoxide gas. In the interference gas removal layer 28C according to the gas sensor SC, two layers of hydrogen sulfide gas removal films 31 for removing hydrogen sulfide gas are stacked, and two layers of activated carbon-containing films 32 for removing hydrocarbon gas are stacked. These are composed of a total of four layers arranged downstream of the hydrogen sulfide gas removal film 31 in the flow direction of the test gas.

The hydrogen sulfide gas removal film 31 is constituted by, for example, a silica gel-mixed paper containing silica gel impregnated with silver perchlorate, p-toluenesulfonic acid, glycerin and methyl alcohol, and a gas sensor SC related to carbon monoxide gas. In addition, hydrogen sulfide gas having sensitivity to the gas sensor SD related to hydrocarbon gas is adsorbed and removed by the action of silica gel.
The activated carbon-containing film 32 is made of, for example, a felt containing activated carbon, and adsorbs and removes hydrocarbon gas having sensitivity to the gas sensor SC related to carbon monoxide gas by the action of activated carbon.

  The thickness of the hydrogen sulfide gas removal film 31 is, for example, 0.27 mm. Moreover, the thickness of the activated carbon containing film | membrane 32 is 0.5 mm, for example. Furthermore, the thickness of the filter sheets 21 and 22 is 0.5 mm, for example.

  The surface side filter sheet 21 is formed with interference gas removal layer visual recognition holes 25C, 25D made of through holes in portions corresponding to the specific function portions 23C, 23D (the upper right position and the lower left position in FIG. 5). reference).

  The front surface side filter sheet 21 is deformed so as to protrude outward depending on the thickness of the interference gas removal layers 28C and 28D, and the protruding portions 27C and 27D are formed, but the back surface side filter sheet 22 is deformed. It is not flat. The protrusions 27C and 27D are sized to be received inside the corresponding gas introduction openings 30C and 30D.

  The functional portions 23A to 23D in the filter complex 20 have a circular shape, and the size thereof is set to, for example, a diameter of 9.6 mm so as to block the gas introduction openings 30A to 30D. .

In such a filter complex 20, the protrusions 27C and 27D are received in the gas introduction openings 30C and 30D corresponding to the holding protrusions 33 of the gas detector main body 10, respectively. Engagement is performed by press-fitting the engagement hole 26 into the holding projection 33 so that the placement deformation portion 24 of the composite 20 is positioned upward (upward in FIG. 1). At this time, the inner peripheral edge of the engagement hole 26 is slightly deformed by being press-fitted into the holding protrusion 33.
Furthermore, the filter complex 20 is fixed to the filter placement portion 34 by the recess 36 of the filter cover 35 being fitted into the holding projection 33 of the filter holder 30.

  Gas introduction holes 18A to 18D communicating with the gas introduction openings 30A to 30D are formed on the back surface of the gas detector. Specifically, in the gas detector main body 10, each of the filter covers 35 is provided with the gas introduction holes 18A to 18D. Corresponding to the gas sensors SA to SD, the filter cover 35 is formed to penetrate in the thickness direction.

Note that the types and arrangement positions of the functional members such as the signal processing circuit board constituting the gas detector can be appropriately set.
For example, in the figure, 13 is a display unit for displaying the type and concentration of the detected gas, 19 is an operation button, 40 is an alarm sound generating unit for generating an alarm sound, and 43 is emitting alarm light. A light emitting unit for alarm, 47 is a driving power source, and 49 is a ring-shaped hanging member.

  The operation of the above gas detector will be described. The test gas in the environmental atmosphere passes through the filter complex 20 and reaches each of the gas sensors SA to SD, and the concentration of the target gas is detected. When the concentration of the detection target gas detected by the gas sensors SA to SD exceeds the alarm reference value set for the gas, an alarm operation signal is generated, and the alarm light emitting unit 43 emits light and alarms. In the sound generation unit 40, an alarm sound is generated and notified.

  According to the filter complex 20 of the present invention as described above, all the gases related to the plurality of gas sensors SA to SD including those having sensitivity also to the interference gas by simply disposing it in the gas detector. Since the introduction openings 30A to 30D can be closed at the same time, a small filter having a function necessary for each of the plurality of gas sensors SA to SD is disposed at a position corresponding to each gas sensor SA to SD. A state in which a required filter action can be obtained for each of all the gas sensors SA to SD can be realized by a simple operation without repeating the operation.

  That is, in this gas detector, the filter complex 20 is replaced by removing the filter cover 35 and removing the filter complex after use in the filter arrangement portion 34 by removing it, and mounting it on the gas detector before use. By engaging the engaging hole 26 with the holding projection 33 of the filter holder 30 and attaching the filter cover 35 again so that the disposing filter 24 is positioned above the gas detector. Easy to do.

  In addition, since the interference gas removal layer viewing holes 25C and 25D are formed in the surface side filter sheet 21, the degree of contamination of the interference gas removal layers 28C and 28D can be determined by visually checking the interference gas removal layers 28C and 28D. It can be easily confirmed.

  Further, according to the gas detector as described above, the filter complex 20 is connected to the gas detector main body by engaging the engaging hole 26 with the holding projection 33 formed in the gas detector main body 10. In addition, since the placement deforming portion 24 is formed in the filter complex 20, it is prohibited to place the filter composite 20 in a wrong posture, and it is always appropriate. An arrangement state can be obtained.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various change can be added.

  For example, the holding protrusion 33 of the filter holder 30 and the engagement hole 26 of the filter complex 20 are formed in these shapes if the purpose of engaging the engagement hole 26 with the holding protrusion 33 is achieved. The positions to be formed can be designed as appropriate.

  Further, for example, the shape and type of the arrangement deforming portion 24 of the filter complex 20 are not limited as long as the purpose of indicating the arrangement direction of the filter complex 20 is achieved.

Further, for example, the interference gas removal layer 28C is not limited to a structure having a total of four layers in which two layers of the hydrogen sulfide gas removal film 31 and the activated carbon-containing film 32 are laminated, and is sufficient for the gas sensor SC. The thickness, the number of stacked layers, and other configurations are not particularly limited as long as a sufficient amount of the test gas can be introduced and the interference gas component can be sufficiently removed.
If the interference gas removal layer 28D is also configured to introduce a sufficient amount of the test gas to the gas sensor SD and obtain a sufficient removal effect of the interference gas component, the hydrogen sulfide gas removal is performed. The thickness, the number of layers, and other configurations of the film 31 are not particularly limited.

It is explanatory drawing which shows the external appearance in an example of a structure of the gas detector of this invention, Comprising: (a) is a front view, (b) shows a rear view. It is an expanded sectional view of the AA line cross section in FIG. It is sectional drawing for description which shows typically the arrangement | positioning relationship of a filter holder, a filter cover, and a filter composite, Comprising: (a) is a figure which shows the state decomposed | disassembled, (b) is a filter composite and a filter cover in a filter holder It is a figure which shows the state with which was mounted | worn. It is the elements on larger scale shown in the state which removed the filter cover of the gas detector main body about the DD line | wire part of FIG. It is explanatory drawing which shows the surface of an example of a structure of the filter composite_body | complex of this invention. It is explanatory drawing which shows the back surface of the filter composite body of FIG. It is the BB line expanded sectional view in Drawing 6 showing the specific functional part concerning the gas sensor for carbon monoxide gas detection. FIG. 7 is an enlarged cross-sectional view taken along line CC in FIG. 6, showing a specific functional part related to a gas sensor for detecting hydrocarbon gas.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Gas detector main body 13 Display part 18A-18D Gas introduction hole 19 Operation button SA Gas sensor SB for oxygen gas detection Gas sensor SB for hydrogen sulfide gas detection Gas sensor SD for carbon monoxide gas detection Gas sensor for hydrocarbon gas detection 20 Filter Composite 21 Front Side Filter Sheet 22 Back Side Filter Sheets 23A-23D Functional Part 24 Displacement Deformation Parts 25C, 25D Interference Gas Removal Layer Viewing Holes 26 Engagement Holes 27C, 27D Protrusions 28C, 28D Interference Gas Removal Layers 29 Notch 30 Filter holder 30A-30D Gas introduction opening 31 Hydrogen sulfide gas removal film 32 Activated carbon-containing film 33 Holding protrusion 34 Filter arrangement part 35 Filter cover 36 Recess 37 Screw part 40 Alarm sound generation part 43 Light emission for alarm Portion 47 Driving power source 49 Hanging member

Claims (4)

A filter complex arranged to simultaneously close a plurality of gas introduction openings related to a plurality of gas sensors in a gas detector,
At least one of the plurality of functional portions that block the individual gas introduction openings is a specific functional portion having a filter characteristic different from that of the other functional portions ;
A sheet main body formed by joining two filter sheets to each other at least at the periphery, and an interference gas removal layer held between the two filter sheets of the sheet main body, the interference gas removal layer being held The specific function portion is formed by the formed portion, and the interference gas removal layer viewing hole is formed at a position corresponding to the specific function portion of one of the two filter sheets. Filter complex. A gas detector comprising the filter composite according to claim 1. In the filter complex, an engagement hole is formed at a position corresponding to the holding protrusion for holding the filter complex formed in the gas detector body, and the engagement hole is engaged with the holding protrusion. The gas detector according to claim 2, wherein the filter composite is held by the gas detector main body. The gas detector according to claim 3, wherein the filter complex is formed with an arrangement deformation portion for arranging the filter complex in a predetermined posture with respect to the gas detector main body.