JP2023077581A - gas detector - Google Patents

Abstract

To suppress a change in a position of a conveying body relative to a detection unit regardless of a mode of conveyance of the conveying body in a gas detector.SOLUTION: A gas detector 1 includes: a detector body 2; a gas sensor 3 that is detachably mounted to the detector body 2 and detects gas to be detected; a sensor cover 4 that is detachably mounted to the detector body 2 and covers the gas sensor 3; a filter 5 provided in a gas inlet 42 of the sensor cover 4; and a filter holding part 6 that is detachably mounted to the sensor cover 4 and holds the filter 5 in the gas inlet 42 in a state of being mounted to the sensor cover 4. The filter 5 is disposed inside the sensor cover 4. The filter holding part 6 holds the filter 5 inside the sensor cover 4.SELECTED DRAWING: Figure 1

Description

The present invention relates to gas detectors.

Patent Literature 1 discloses a gas detector that detects a gas to be detected (for example, combustible gas). In the gas detector of Patent Document 1, a gas sensor for detecting a gas to be detected is provided in a detector body (case body) and covered with a sensor cover (chamber unit). A filter (rod-shaped filter) for removing foreign matter is press-fitted into the gas inlet of the sensor cover. The filter press-fitted into the gas inlet is attached with one end protruding outside the sensor cover so that it can be taken out by picking it up with fingers.

Japanese Patent No. 3776037

In the gas detector of Patent Literature 1, since the filter is press-fitted into the gas inlet of the sensor cover, replacement of the filter is troublesome. Further, the gas detector of Patent Document 1 is configured such that the filter can be put in and taken out from the outside of the sensor cover when the filter is replaced. Therefore, there is a possibility that the filter may be accidentally detached from the sensor cover.
The gas detector of Patent Document 1 has another cover (nozzle body base) that covers one end of the filter projecting outside the sensor cover. However, another cover is attached to the sensor cover from the outside of the sensor cover by engaging the female threads of the other cover with the male threads of the sensor cover. As a result, there is a high possibility that another cover will be accidentally removed from the sensor cover.

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and an object of the present invention is to provide a gas detector in which the filter can be easily replaced and in which the filter can be prevented from coming off unexpectedly. do.

One aspect of the present invention includes a detector body, a gas sensor detachably attached to the detector body for detecting a gas to be detected, and the gas sensor detachably attached to the detector body. a sensor cover for covering; a filter provided at a gas inlet of the sensor cover; a holding part, wherein the filter is arranged inside the sensor cover, and the filter holding part is a gas detector holding the filter inside the sensor cover.

ADVANTAGE OF THE INVENTION According to this invention, it is a gas detector. WHEREIN: A filter can be easily exchanged and it can suppress that a filter comes off unexpectedly.

It is a sectional view showing the important section of the gas detector concerning one embodiment. 2 is a cross-sectional view showing a state in which the sensor cover, the filter, and the filter holder are integrally removed from the detector main body in the gas detector of FIG. 1; FIG. FIG. 3 is a cross-sectional view showing a state after the filter holding portion is removed from the sensor cover in the state shown in FIG. 2; 4 is an enlarged view of region IV in FIG. 3; FIG. FIG. 4 is a cross-sectional view showing a state after the filter is removed from the sensor cover in the state shown in FIG. 3; 3 is a cross-sectional view showing a state after removing the gas sensor from the detector body in the state shown in FIG. 2; FIG.

An embodiment of the present invention will be described below with reference to FIGS.
As shown in FIG. 1 , the gas detector 1 of this embodiment includes a detector body 2 , a gas sensor 3 , a sensor cover 4 , a filter 5 and a filter holding portion 6 .

The gas sensor 3 detects a specific gas (detection target gas) as a detection target. The gas to be detected may be hydrogen gas, for example. The gas sensor 3 is detachably attached to the detector body 2 .

As shown in FIGS. 2 and 6, the gas sensor 3 has a sensor body 31 that detects a detection target gas and a sensor cap 32 that covers and protects the sensor body 31 . The sensor main body 31 has a detection surface 36 for detecting the gas to be detected. Further, the sensor main body 31 has an electrode 33 for electrically connecting the sensor main body 31 to the detector main body 2 which will be described later. The sensor cap 32 is formed in a cylindrical shape with a bottom that covers the sensor main body 31 . The sensor cap 32 is formed with an opening 34 that exposes the sensing surface 36 of the sensor main body 31 to the outside of the sensor cap 32 .

The detector main body 2 has a case 21 and a mount 22 provided on the case 21 . The mount 22 has a socket 23 into which the electrode 33 of the gas sensor 3 is inserted. The gas sensor 3 is detachable from the detector main body 2 by inserting and removing the electrode 33 from the socket 23 . Although not shown, the case 21 includes a power supply unit for supplying power to the gas sensor 3, a control circuit for controlling the operation of the gas detector 1 including the gas sensor 3, and the like. .

As shown in FIGS. 1 and 2, the sensor cover 4 is detachably attached to the detector body 2 . A sensor cover 4 covers the gas sensor 3 attached to the detector body 2 . The sensor cover 4 is formed in a bottomed cylindrical shape having one insertion opening 41 . The gas sensor 3 is inserted inside the sensor cover 4 through the insertion port 41 of the sensor cover 4 . Further, in this embodiment, the mounting base 22 of the detector main body 2 is also inserted inside the sensor cover 4 through the insertion opening 41 . That is, the sensor cover 4 covers the mounting base 22 and the gas sensor 3 mounted thereon.

The sensor cover 4 has a gas introduction port 42 . The gas introduction port 42 is an opening of the sensor cover 4 for introducing a gas (especially a gas to be detected) into the inside of the sensor cover 4 while the sensor cover 4 covers the gas sensor 3 . In this embodiment, the gas introduction port 42 is located at the end of the sensor cover 4 opposite to the insertion port 41 .

The sensor cover 4 has a first accommodation portion 43A, a second accommodation portion 43B, a third accommodation portion 44 and a fourth accommodation portion 45 formed inside the sensor cover 4 . Filters 5, which will be described later, are accommodated in the first and second accommodation portions 43A and 43B. In the following description, the first and second accommodation portions 43A and 43B may be called the filter accommodation portion 43. As shown in FIG. The first and second housing portions 43A and 43B (filter housing portion 43) constitute a gas introduction port 42 of the sensor cover 4. As shown in FIG. The third accommodation portion 44 accommodates the filter holding portion 6 and the gas sensor 3, which will be described later. The mounting base 22 of the detector main body 2 is mainly accommodated in the fourth accommodation portion 45 . These first, second, third, and fourth housing portions 43A, 43B, 44, and 45 are arranged in order from the gas introduction port 42 of the sensor cover 4 toward the insertion port 41. As shown in FIG.

The sensor cover 4 has a first thread 47 formed inside it. In this embodiment, the first screw 47 is a female screw formed on the inner periphery of the third housing portion 44 .

The sensor cover 4 is detachably fixed to the detector main body 2 by screws while covering the gas sensor 3 . Specifically, the sensor cover 4 has a flange 48 positioned at the end on the insertion port 41 side. The flange 48 is arranged to overlap the outer surface of the case 21 of the detector main body 2 while the sensor cover 4 covers the gas sensor 3 . The fixing screw 7 (male screw) is passed through the flange 48 and engaged with the female screw hole 24 formed in the case 21 , thereby fixing the sensor cover 4 to the detector main body 2 .

As shown in FIG. 1, in a state where the gas sensor 3 and the sensor cover 4 are attached to the detector main body 2, the internal space of the sensor cover 4 where at least the detection surface 36 of the gas sensor 3 is exposed passes through the gas introduction port 42 to the sensor. It suffices if it continues to the outside of the cover 4 . In this embodiment, the detection surface 36 of the gas sensor 3 faces the gas introduction port 42 of the sensor cover 4 .

The filter 5 has a function of removing foreign substances such as dust and a function of removing miscellaneous gases so that only the gas to be detected reaches the gas sensor 3 . Miscellaneous gases are gases other than the gas to be detected (for example, hydrogen sulfide, carbon monoxide, carbon dioxide, methane, ozone, etc.). The filter 5 also has a function of removing the influence of the wind on the gas sensor 3 and the like.

As shown in FIGS. 1 to 4, the filter 5 is provided at the gas introduction port 42 of the sensor cover 4. As shown in FIG. Also, the filter 5 is arranged inside the sensor cover 4 . In the present embodiment, the filter 5 is housed in a filter housing portion 43 (first and second housing portions 43A, 43B) inside the sensor cover 4 and forming part of the gas introduction port 42 .
A part of the filter 5 housed in the filter housing portion 43 of the sensor cover 4 (specifically, one end of a third filter element 51C described later and one end of a fourth filter element 52 described later) It abuts on the abutment surface 46 of the filter accommodating portion 43 forming the inner surface. Since the filter 5 abuts against the abutment surface 46 , the filter 5 does not slip out of the sensor cover 4 from the gas introduction port 42 .
The filter 5 of this embodiment will be further described below.

As shown in FIGS. 3-5, the filter 5 of this embodiment has multiple filter elements 51 . The filter elements 51 of this embodiment include a first filter element 51A, a second filter element 51B, and a third filter element 51C. The first filter element 51A and the second filter element 51B are elements that adsorb miscellaneous gases contained in the gas entering the inside of the sensor cover 4 through the gas introduction port 42, respectively. The first and second filter elements 51A, 51B may be made of activated carbon, for example. Since the first and second filter elements 51A, 51B of the filter 5 have the same function, the filter 5 may have, for example, only one of the first and second filter elements 51A, 51B. The third filter element 51</b>C is an element that suppresses or prevents wind (gas flow) outside the sensor cover 4 from reaching the gas sensor 3 and affecting the gas sensor 3 . The third filter element 51C may be made of sintered metal, for example.

These first to third filter elements 51A to 51C are housed inside the sensor cover 4 (filter housing portion 43) while being arranged in order in the direction from the gas introduction port 42 of the sensor cover 4 toward the insertion port 41. be.

As shown in FIGS. 4 and 5, the filter 5 of this embodiment further has a pair of fourth filter elements 52, 52 sandwiching the first and second filter elements 51A, 51B in the direction in which they are arranged. The pair of fourth filter elements 52, 52 are elements that adsorb dust that enters inside the sensor cover 4 through the gas introduction port 42 together with the gas. Also, the pair of fourth filter elements 52, 52 support the first and second filter elements 51A, 51B from both sides in the direction in which they overlap so as to stabilize the shapes of the first and second filter elements 51A, 51B. do. The fourth filter element 52 may be made of, for example, a nonwoven fabric, a porous sheet, a wire mesh, or the like.

The first and second filter elements 51A and 51B and the pair of fourth filter elements 52 and 52 sandwiching them are housed in the first housing portion 43A of the filter housing portion 43. As shown in FIG. Among the plurality of filter elements 51A, 51B, 52, 52 housed in the first housing portion 43A, one fourth filter element 52 exposed to the outside of the sensor cover 4 through the gas introduction port 42 of the sensor cover 4 is the filter housing. 46 A of 1st contact surfaces of 43 A of 1st accommodating parts which comprise a part of contact surface 46 of the part 43 are contact|abutted. This prevents the first and second filter elements 51A and 51B and the pair of fourth filter elements 52 and 52 from slipping out of the sensor cover 4 through the gas inlet 42 .

The third filter element 51C is accommodated in the second accommodation portion 43B of the filter accommodation portion 43 . The third filter element 51C abuts on the second contact surface 46B of the second housing portion 43B forming part of the contact surface 46 of the filter housing portion 43 . This prevents the third filter element 51C from slipping out of the sensor cover 4 from the second accommodation portion 43B through the first accommodation portion 43A.

As shown in FIGS. 2 and 3, the filter holder 6 is detachably attached to the sensor cover 4 . The filter holding portion 6 of this embodiment has a second screw 61 . The second screw 61 is a screw that meshes with the first screw 47 of the sensor cover 4 . By engaging the second screw 61 with the first screw 47 , the filter holding portion 6 is detachably attached to the sensor cover 4 . In this embodiment, the second screw 61 is a male screw formed on the outer circumference of the filter holding portion 6 .
The filter holder 6 attached to the sensor cover 4 is arranged inside the sensor cover 4 . Specifically, the filter holding portion 6 is housed in the third housing portion 44 of the sensor cover 4 . The second screw 61 of the filter holding portion 6 meshes with the first screw 47 of the sensor cover 4 , so that the filter holding portion 6 is held in the third housing portion 44 of the sensor cover 4 .

As shown in FIGS. 1 and 2 , the filter holding portion 6 holds the filter 5 in the gas introduction port 42 (filter housing portion 43 ) inside the sensor cover 4 while attached to the sensor cover 4 . Specifically, between the filter holding portion 6 arranged in the third housing portion 44 of the sensor cover 4 and the contact surface 46 (first contact surface 46A, second contact surface 46B) of the filter housing portion 43 The filter 5 is held in the gas introduction port 42 by sandwiching the filter 5 between the .

Here, the plurality of filter elements 51 and 52 (the first to third filter elements 51A to 51C and the fourth filter element 52) constituting the filter 5 are arranged so that the filter 5 is attached to the contact surface 46 (sensor cover) of the filter housing portion 43. 4) and the filter holding portion 6 in a sandwiched direction. That is, the plurality of filter elements 51 and 52 are sandwiched between the filter holding portion 6 and the contact surface 46 of the filter accommodating portion 43 in the direction in which they are arranged.

As described above, the filter 5 is held inside the sensor cover 4 by the filter holding portion 6 . Thereby, as shown in FIGS. 1 and 2, the filter 5 and the filter holding portion 6 attached to the sensor cover 4 can be detachably attached to the detector body 2 together with the sensor cover 4 .

The filter holding portion 6 of this embodiment is formed in a tubular shape. The filter holding part 6 is attached to the sensor cover 4 so that the inner side of the filter holding part 6 is connected to the gas introduction port 42 . As shown in FIG. 1, when the gas sensor 3 and the sensor cover 4 are attached to the detector main body 2, the gas sensor 3 is accommodated inside the filter holder 6 attached to the sensor cover 4. As shown in FIG.

Further, in the gas detector 1 of the present embodiment, when the sensor cover 4 is attached to the detector main body 2 , the filter holding portion 6 attached to the sensor cover 4 is positioned between the inside of the sensor cover 4 and the detector main body 2 . sandwiched between Specifically, the filter holding portion 6 is sandwiched between the filter 5 and the mount 22 of the detector main body 2 .

Next, an example of a method for replacing the gas sensor 3 and the filter 5 in the gas detector 1 of this embodiment will be described.

When replacing the gas sensor 3 in the gas detector 1 shown in FIG. 1, first, the sensor cover 4 is removed from the detector body 2 as shown in FIG. At this time, since the filter 5 is held on the sensor cover 4 by the filter holding portion 6 , the filter 5 is removed from the detector main body 2 while attached to the sensor cover 4 .
Next, as shown in FIG. 6, the electrode 33 of the gas sensor 3 is pulled out from the socket 23 of the mount 22 to remove the gas sensor 3 from the detector body 2 . Thereafter, another gas sensor 3 is attached to the detector main body 2 by inserting the electrode 33 of another gas sensor 3 into the socket 23 of the mounting base 22 . Finally, the replacement of the gas sensor 3 is completed by attaching the sensor cover 4 including the filter 5 and the filter holder 6 to the detector main body 2 as shown in FIG.

When replacing the filter 5 in the gas detector 1 shown in FIG. 1, first, the sensor cover 4 is removed from the detector body 2 as shown in FIG. In this state, the gas sensor 3 is attached to the detector body 2 . Also, the filter 5 is attached to the sensor cover 4 by a filter holding portion 6 .
Next, as shown in FIG. 3, the filter holder 6 is removed from the sensor cover 4. Then, as shown in FIG. Here, the filter holding portion 6 is attached to the sensor cover 4 with a screw structure (first screw 47, second screw 61). Therefore, the filter holding portion 6 can be easily removed from the sensor cover 4 by rotating the filter holding portion 6 with respect to the sensor cover 4 using a general tool such as a screwdriver.

After that, as shown in FIG. 5, the filter 5 is taken out from inside the sensor cover 4 . At this time, the filter 5 can be taken out of the sensor cover 4 from the gas introduction port 42 (filter housing portion 43 ) of the sensor cover 4 through the insertion port 41 . Then, as shown in FIG. 3 , another filter 5 is inserted into the sensor cover 4 through the insertion port 41 and installed in the gas introduction port 42 of the sensor cover 4 . Thereafter, another filter 5 is held in the gas introduction port 42 by attaching the filter holding portion 6 to the sensor cover 4 as shown in FIG. Finally, by attaching the sensor cover 4 including the filter 5 and the filter holder 6 to the detector main body 2 as shown in FIG. 1, the replacement of the filter 5 is completed.
In addition, in the replacement method of the filter 5 described above, the entire filter 5 may be replaced, or only some of the filter elements 51 and 52 constituting the filter 5 may be replaced.

As described above, according to the gas detector 1 of this embodiment, the filter 5 is held inside the sensor cover 4 by the filter holding portion 6 . Moreover, since the filter holding portion 6 is attached to the inside of the sensor cover 4 , it is not exposed to the outside of the sensor cover 4 . Therefore, even if the filter holding portion 6 is not firmly fixed to the sensor cover 4 by press-fitting or the like, it is possible to effectively prevent the filter holding portion 6 from unexpectedly coming off the sensor cover 4 . Therefore, it is possible to effectively prevent the filter 5 from unexpectedly coming off the sensor cover 4 .

In the gas detector 1 of the present embodiment, when removing the filter 5 , the sensor cover 4 is removed from the detector main body 2 , and then the filter holding portion 6 is removed from the sensor cover 4 . When attaching the filter 5 , the sensor cover 4 may be attached to the detector main body 2 after the filter 5 is held on the sensor cover 4 by the filter holding portion 6 . That is, the filter 5 can be easily replaced.

Further, in the gas detector 1 of this embodiment, the filter holding portion 6 has the second screw 61 that meshes with the first screw 47 formed inside the sensor cover 4 . The second screw 61 of the filter holding portion 6 meshes with the first screw 47 of the sensor cover 4 , so that the filter holding portion 6 is attached to the sensor cover 4 . Therefore, the filter holding portion 6 can be easily attached to and detached from the sensor cover 4 simply by rotating the filter holding portion 6 with respect to the sensor cover 4 . Therefore, it becomes possible to replace the filter 5 more easily.

In addition, in the gas detector 1 of the present embodiment, the filter holding portion 6 is formed in a cylindrical shape and attached to the sensor cover 4 so that the inner side of the filter holding portion 6 continues to the gas introduction port 42 . Further, the gas sensor 3 is housed inside the tubular filter holding portion 6 while being covered with the sensor cover 4 . Therefore, the gas sensor 3 can be arranged closer to the gas introduction port 42 of the sensor cover 4 than when the gas sensor 3 is not arranged inside the filter holding portion 6 . This makes it possible to improve the responsiveness of the gas sensor 3 to the detection target gas.

Further, in the gas detector 1 of the present embodiment, the filter holding portion 6 attached to the sensor cover 4 is sandwiched between the inside of the sensor cover 4 attached to the detector main body 2 and the detector main body 2 . Since the filter holding portion 6 is sandwiched between the sensor cover 4 and the detector main body 2 , movement of the filter holding portion 6 inside the sensor cover 4 is restricted. Therefore, it is possible to effectively prevent the filter holding portion 6 from unexpectedly coming off the sensor cover 4 . Therefore, it is possible to more effectively prevent the filter 5 from unexpectedly detaching from the gas introduction port 42 of the sensor cover 4 inside the sensor cover 4 .

Further, in the gas detector 1 of the present embodiment, the plurality of filter elements 51 and 52 forming the filter 5 are arranged in a direction to sandwich the filter 5 between the inner side of the sensor cover 4 and the filter holding portion 6 . Thereby, the plurality of filter elements 51 and 52 can be collectively held inside the sensor cover 4 by the filter holding portion 6 . This effect is particularly useful when the multiple filter elements 51 and 52 have different functions.

Although the present invention has been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

In the present invention, the multiple filter elements 51, 52 may have, for example, the same function.

In the present invention, for example, the first thread 47 formed inside the sensor cover 4 may be a male thread, and the second thread 61 formed on the filter holding portion 6 may be a female thread.

In the present invention, the structure for detachably attaching the filter holding portion 6 to the sensor cover 4 is not limited to the screw structure consisting of the first and second screws 47 and 61. For example, the filter holding portion 6 is attached to the sensor cover 4. It may be a locking structure that is hooked. The locking structure includes a claw formed on one of the filter holding portion 6 and the sensor cover 4, and a locked portion such as a hole or a groove formed on the other of the filter holding portion 6 and the sensor cover 4 to catch the claw. , may be a structure having Further, in the locking structure, for example, when the filter holding portion 6 is arranged at a predetermined position with respect to the sensor cover 4 , the claws are caught by the locked portion, and the filter holding portion 6 is moved from the predetermined position with respect to the sensor cover 4 . It may be a structure in which the hook is released from the latched portion in a state of being rotated by a predetermined angle.

INDUSTRIAL APPLICABILITY The present invention is applicable to various types of gas detectors. INDUSTRIAL APPLICABILITY The present invention is applicable to, for example, a handy type gas detector in which a main body provided with a sensor section, a display, a power supply circuit, a control circuit, etc. is held by hand. Further, the present invention can also be applied to a desk-top type gas detector in which, for example, a body section including a display, a power supply circuit, a control circuit, etc., and a sensor section are separated. In addition, the present invention can also be applied to a multi-type gas detector in which a plurality of sensor units are provided for one main unit in the desktop type described above, for example.
In the gas detector of the aspect described above, the sensor section is a probe section including the gas sensor 3 , the sensor cover 4 , the filter 5 and the filter holding section 6 . The display displays the result of gas detection by the gas sensor 3 and the like.

DESCRIPTION OF SYMBOLS 1... Gas detector, 2... Detector main body, 3... Gas sensor, 4... Sensor cover, 5... Filter, 6... Filter holding part, 42... Gas inlet, 47... First screw, 51, 52... Filter element, 61...Second screw

Claims (5)

the detector body;
a gas sensor that is detachably attached to the detector body and detects a detection target gas;
a sensor cover detachably attached to the detector body and covering the gas sensor;
a filter provided at the gas introduction port of the sensor cover;
a filter holding part that is detachably attached to the sensor cover and holds the filter in the gas introduction port while attached to the sensor cover;
The filter is arranged inside the sensor cover,
The gas detector, wherein the filter holding portion holds the filter inside the sensor cover. The sensor cover has a first thread formed inside the sensor cover,
The gas detector according to claim 1, wherein the filter holding portion has a second screw that engages with the first screw to attach the filter holding portion to the sensor cover. The filter holding part is formed in a cylindrical shape and is attached to the sensor cover so that the inside of the filter holding part is connected to the gas inlet,
3. The gas detector according to claim 1, wherein the gas sensor is housed inside the filter holder. The gas detector according to any one of claims 1 to 3, wherein the filter holding portion is sandwiched between the inside of the sensor cover and the detector main body. The filter has a plurality of filter elements,
The gas detector according to any one of claims 1 to 4, wherein the plurality of filter elements are arranged in a direction sandwiching the filter between the inside of the sensor cover and the filter holder.

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