JP4579136B2 - Explosion-proof gas detector - Google Patents

Description

  The present invention relates to an explosion-proof gas detector.

  Gas detectors used in environments where ignition or explosion may occur due to the presence of an explosive atmosphere containing flammable gas or steam are required to have an explosion-proof structure with high explosion-proof properties. Various types of explosion-proof gas detectors having such an explosion-proof structure have been known so far.

  And, in such an explosion-proof gas detector, in order to have a configuration that satisfies a predetermined explosion-proof standard, it is generally easy to become large-sized, which hinders the target work at the work site or the like. Therefore, it is desired to configure it as a small one.

  The present invention has been made based on the above circumstances, and is a novel device capable of easily manufacturing and maintaining the entire gas detector while ensuring sufficient explosion-proof properties. An object of the present invention is to provide a small explosion-proof gas detector having a structure.

An explosion-proof gas detector according to the present invention includes an explosion-proof container including a cylindrical main body portion having a bottom wall portion and a lid portion screwed onto the main body portion, and a bottom of the main body portion of the explosion-proof container. A plurality of strut members extending in the axial direction of the main body portion from the wall portion, and disposed along the inner surface of the bottom wall portion at a position close to the bottom wall portion of the main body portion of the explosion-proof container; A power supply terminal board fixed to the front end side position of the support member, and a liquid crystal display board and an operation board assembly in which the main board is integrally combined,
The operation substrate assembly is characterized in that a liquid crystal display substrate and a main substrate having a gas detection output signal processing circuit are connected in a stacked state separated from each other in the axial direction of the explosion-proof container.

  In the explosion-proof gas detector of the present invention, it is preferable that the power terminal board has a noise filter circuit.

  In the explosion-proof gas detector according to the present invention, the operation substrate assembly includes a support plate connected in a stacked state to the liquid crystal display substrate and spaced apart from each other in the axial direction. It can be set as the structure fixed to.

  Furthermore, in the explosion-proof gas detector of the present invention, the body portion of the explosion-proof container is made of metal, and the lid portion is pivoted from a circular end wall portion having an opening in the center and an outer peripheral edge position of the end wall portion. Formed of a sheet-like glass member mounted to cover the opening of the end wall portion of the lid member and a metal lid member made of a sleeve-like peripheral wall portion that protrudes and extends in the direction. The liquid crystal display substrate can be viewed from the outside of the explosion-proof container through the transparent region.

According to the explosion-proof gas detector of the present invention, the necessary circuit configuration substrate is divided into the power supply terminal substrate, the liquid crystal display substrate, and the main substrate, so that each substrate has a small area. In addition, since they are stacked and supported by a common support member, the entire explosion-proof container can be made small, and the gas detector can be made small. Can be configured.
In addition, the liquid crystal display substrate and the main substrate constitute an integrated operation substrate assembly, which is supported by the support member, so that in the explosion-proof container, from the opening of the main body portion before the lid portion is mounted. Since the operation board assembly can be easily assembled, the gas detector can be easily manufactured and the maintenance work of the main board performed as necessary is easy. In addition, since the lid portion is configured to be attached to the main body portion by screwing, the explosion-proof container can be mounted while the main body portion and the lid portion are detachably mounted. It can be configured as having sufficient explosion-proof properties.

FIG. 1 is a plan view showing the configuration of an example of the explosion-proof gas detector of the present invention, and FIG. 2 is a cross-sectional view taken along the line CC of the explosion-proof gas detector shown in FIG.
The explosion-proof gas detector 10 includes an explosion-proof container 20 including a cylindrical main body portion 21 having a bottom wall portion 22 and a lid portion 30, and a plurality of required explosion-proof containers 20 are provided in the explosion-proof container 20. A circuit configuration substrate, specifically, a liquid crystal display substrate 41, a main substrate 44, and a power supply terminal substrate 52 are accommodated. In FIG. 1, 11 is an output side cable connection part, 12 is a power cable connection part, 15 is an explosion-proof gas sensor, and for example, a diffusion infrared gas sensor having an explosion-proof case attached to a sensor unit is used. .

The lid portion 30 of the explosion-proof container 20 includes, for example, a circular end wall portion 26 having a circular opening 26A in the center, and a sleeve-like peripheral wall portion 27 extending in the axial direction from the outer peripheral edge position of the end wall portion 26. The metallic lid member 25 and a plate-like glass member 28 mounted so as to close the opening 26 </ b> A of the lid member 25, and the transparent region T is formed by the plate-like glass member 28. Here, as the plate-like glass member 28, one having a thickness of, for example, 10 mm is used.
A screw groove is formed on the inner peripheral surface of the distal end side portion of the peripheral wall portion 27 of the lid member 25 over the entire circumference in the circumferential direction. The peripheral wall portion 27 is formed on the outer peripheral surface of the opening side portion of the main body portion 21. The lid portion 30 is detachably attached to the main body portion 21 by being screwed into the thread groove.
In FIG. 2, reference numeral 24 denotes a seal member made of, for example, an O-ring, interposed between the outer peripheral surface of the main body portion 21 and the inner peripheral surface of the peripheral wall portion 27 in the lid portion 30.

  An example of the configuration of the screw fitting portion 35 in the explosion-proof container 20 shows a fitting length of 10 mm or more, for example 14 mm, and a number of fitting mountains of 5 or more, for example, 7 mountains. By setting it as such a structure, the explosion-proof container 20 can be comprised as what has sufficient explosion-proof property.

  The bottom wall portion 22 of the main body portion 21 of the explosion-proof container 20 is located at a position spaced radially outward from the outer edge of the region facing the transparent region T of the lid portion 30. The column member mounting portions 23 are formed at, for example, two positions on the concentric circle as the center. In this embodiment, the column member mounting portion 23 is configured by forming a column member insertion hole 23A extending in the thickness direction at the center of the upper surface of the frustum-shaped base projecting upward in the axial direction of the main body portion 21. It is located at a diagonal position with the central axis of the main body portion 21 as the center.

In the explosion-proof container 20, two strut members 50 are disposed via a bearing member 55 attached to a power supply terminal substrate 52 arranged in a state of extending along the inner surface of the bottom wall portion 22 of the main body portion. Mounted on the mounting portion 23 and provided so as to protrude from the bottom wall portion 22 of the main body portion 21 in the axial direction.
Specifically, the bearing member 55 includes a sleeve member 56 and a bush 57 having a cylindrical portion fitted into the opening of the sleeve member 56, and the cylindrical portion of the bush 57 is connected to the power supply terminal substrate 52. The formed positioning hole is fitted from one surface side of the power supply terminal board 52, and a sleeve member 56 is fitted to a cylindrical portion protruding from the other face of the power supply terminal board 52 and attached to the power supply terminal board 52. ing. The strut member 50 is fitted to the bush 57 with the base end portion protruding from the other surface (the lower surface in FIG. 2) of the sleeve member 56, and the base end portion is the strut member in the strut member mounting portion 23. It is fitted in the insertion hole 23A.

  The power terminal board 52 preferably has a noise filter circuit. Thereby, a signal can be output in a state in which noise caused by a connection cable or the like is removed.

  In this explosion-proof gas detector, the operation substrate assembly 40 configured as a single structure by integrally combining the liquid crystal display substrate 41 and the main substrate 44 is supported at the front end side position of the column member 50. .

As shown in FIGS. 3 to 5, the operation substrate assembly 40 is configured such that the liquid crystal display substrate 41 and the main substrate 44 are arranged to face each other with the sleeve member 46 interposed therebetween, and the main substrate 44 is sleeved from the other surface side. When the liquid crystal display substrate 41 is fixed to the member 46 by screwing, the fixing pin member 47 is fitted into the fixing hole in the liquid crystal display substrate 41 and the opening of the sleeve member 46 from one side. The sleeve member 46 is fixed to the sleeve member 46.
In this operation substrate assembly 40, a support plate 49 arranged in parallel with the liquid crystal display substrate 41 and the main substrate 44 so as to cover the entire surface of the liquid crystal display substrate 41 on one end surface of the fixing pin member 47 has one surface thereof. The support plate 49, the liquid crystal display substrate 41, and the main substrate 44 are connected to each other in a stacked state spaced apart from each other at a predetermined interval in the axial direction. .
3 to 5, reference numerals 42 and 43 denote a display element and a light emitting element provided in a region facing the transparent region T of the lid portion 30 on one surface of the liquid crystal display substrate 41. It is visible from the outside through the transparent region T of the lid portion 30.

  In the operation substrate assembly 40, the support plate 49 is supported from one side of the support member 49 in a state where the support member 50 is inserted into the support member insertion holes formed in the main substrate 44 and the liquid crystal display substrate 41. The support plate 49 is supported by the column member 50 by being screwed and fixed to the front end surface of the support plate 49, and the plane level of the support plate 49 coincides with the plane level of the upper end opening edge of the main body portion 21. .

  As described above, in this explosion-proof gas detector 10, the three circuit constituent substrates, that is, the power supply terminal substrate 52, the main substrate 44, and the liquid crystal display substrate 41 are stacked in a state where they are separated from each other at a predetermined interval in the axial direction. The power terminal board 52, the main board 44, and the liquid crystal display board 41 are electrically connected by a connector (not shown). Here, the axial distance between the power supply terminal board 52 and the main board 44 is, for example, 30 mm or more because the main board 44 can be reliably prevented from being adversely affected by the power supply terminal board 52. It is preferable.

  The explosion-proof gas detector 10 having the above-described configuration can be manufactured as follows. That is, after the bearing member 55 is attached to the power supply terminal board 52, the two support members 50 are respectively attached to the bearing members 55 attached to the power supply terminal board 52 in a state where the base end portion protrudes downward, In the explosion-proof container 20, after being assembled from the opening of the main body portion 21 before the lid portion 30 is mounted, the base end portion of the column member 50 is fitted into the column member insertion hole 23 </ b> A of the column member mounting portion 23. Then, the operation board assembly 40 prepared in advance is incorporated, and the support plate 49 is fixed to the front end surface of the column member 50 by screwing. Thereafter, the lid portion 30 is attached by being screwed to the main body portion 21, and the explosion-proof gas detector 10 having the above-described configuration can be obtained by connecting the gas sensor 15.

According to the explosion-proof gas detector 10 having the above-described configuration, the necessary circuit configuration substrate is divided into the power source terminal substrate 52, the liquid crystal display substrate 41, and the main substrate 44, so that each substrate has a small area. Further, since they are stacked and supported by the common support member 50, the entire explosion-proof container 20 can be made to have a small diameter, and the gas The detector 10 can be configured as a small one.
In addition, the liquid crystal display substrate 41 and the main substrate 44 constitute an integrated operation substrate assembly 40, and the operation substrate assembly 40 is supported by the support member 50. The liquid crystal display substrate 41 and the main substrate 44 are arranged in a proper posture at predetermined positions only by performing an extremely simple operation of incorporating the operation substrate assembly 40 through the opening of the main body portion 21 before the mounting of the main body 30. Therefore, the predetermined explosion-proof gas detector 10 can be easily manufactured, and maintenance work of the main board 44 that is appropriately performed as necessary can be easily performed at the work site. In addition, since the lid portion 30 is attached to the main body portion 21 by screwing, the explosion-proof container 20 is configured such that the main body portion 21 and the lid portion 30 are detachable, but explosion-proof. The conductive container 20 can be configured to have sufficient explosion-proof properties.

  Furthermore, the explosion-proof gas detector having the above-described configuration is used, for example, by being installed on a vertical wall surface, and the display element 42 and the alarm light-emitting element 43 are disposed through a transparent region formed in the lid portion 30 of the explosion-proof container. Can be visually recognized from the outside, and it is possible to easily grasp the air state of the environmental atmosphere by checking the gas detection result (concentration value) displayed on the display element 42 and the lighting state of the light emitting element 43. can do.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment, A various change can be added.
For example, the specific configuration such as the number and arrangement position of the support members is not particularly limited as long as all necessary substrates can be supported in an appropriate posture.
Further, the positional relationship between the three members, that is, the liquid crystal display substrate, the main substrate, and the power supply terminal substrate, specifically, the distance between the substrates can be appropriately set according to the purpose.
Furthermore, as a gas sensor used in the explosion-proof gas detector of the present invention, any one of a suction type and a diffusion type may be used as long as it has an explosion-proof structure. Also good. In addition, the gas sensor need not be configured to be directly connected to the explosion-proof container, and may be configured to be connected by an appropriate connection cable (remote type), for example.

It is a top view which shows the structure in an example of the explosion-proof type | mold gas detector of this invention. It is CC sectional drawing of the explosion-proof type gas detector shown in FIG. It is a top view which shows the structure of an operation board assembly. FIG. 4 is a right side view of the operation board assembly shown in FIG. 3. It is a front view which shows the action | operation board | substrate assembly shown in FIG. 3 in the state which fractured | ruptured one part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Explosion-proof type gas detector 11 Output side cable connection part 12 Power supply cable connection part 15 Gas sensor 20 Explosion-proof container 21 Main body part 22 Bottom wall part 23 Column member mounting part 23A Column member insertion hole 24 Seal member 25 Cover member 26 End Wall part 26A Opening 27 Peripheral wall part 28 Plate glass member T Transparent region 30 Lid part 35 Screw mounting part 40 Operation board assembly 41 Liquid crystal display board 42 Display element 43 Light emitting element 44 Main board 46 Sleeve member 47 Fixing pin member 49 Support plate 50 Support member 52 Power supply terminal board 55 Bearing member 56 Sleeve member 57 Bush

Claims (4)

An explosion-proof container comprising a cylindrical main body portion having a bottom wall portion and a lid portion screwed onto the main body portion, and an axial direction of the main body portion from the bottom wall portion of the main body portion of the explosion-proof container. A plurality of strut members projecting and extending, a power supply terminal board disposed along the inner surface of the bottom wall portion at a position close to the bottom wall portion of the main body portion of the explosion-proof container, and fixed to the strut member; The liquid crystal display substrate and the main substrate, which are supported at the front end side position of the support member, are combined with the operation substrate assembly,
The operation board assembly comprises an explosion-proof type wherein a liquid crystal display board and a main board having a gas detection output signal processing circuit are connected to each other in a stacked state separated from each other in the axial direction of the explosion-proof container. Gas detector.   The explosion-proof gas detector according to claim 1, wherein the power terminal board has a noise filter circuit.   2. The operation board assembly includes a support plate connected to the liquid crystal display substrate in a stacked state spaced apart from each other in the axial direction, and the support plate is fixed to a tip end of a support member. Alternatively, an explosion-proof gas detector according to claim 2.   The body part of the explosion-proof container is made of metal, and the lid part is a metal comprising a circular end wall part having an opening in the center and a sleeve-like peripheral wall part extending in an axial direction from the outer peripheral edge position of the end wall part. The liquid crystal display substrate is explosion-proof through a transparent region formed by a lid member made of a metal plate and a plate-like glass member mounted so as to close the opening of the end wall portion of the lid member. The explosion-proof gas detector according to any one of claims 1 to 3, wherein the explosion-proof gas detector is visible from the outside of the porous container.