JPH1058U - Flame detector protective cover - Google Patents

Abstract

(57) [Summary] [Purpose] Even when a flame detector is installed in a bad environment such as outdoors, a predetermined detection shop is monitored to prevent deterioration in sensitivity. The present invention is characterized in that a cylindrical side wall, a mounting portion to the sensor ground plane provided at one end of the side wall, and an out-of-field irradiation prevention plate extending toward the mounting portion are provided at the other end of the side wall.

Description

[Detailed description of the invention]

[0001]

[Industrial applications]

 The present invention relates to a protective cover when a flame detector is installed outdoors.

[0002]

[Prior art]

 If the sensor is installed outdoors, it must be possible to detect fire even under adverse conditions such as dust, dirt, rain or high humidity. In order to protect the sensor from such adverse conditions, the sensor is installed in a cylindrical protective cover with side walls so that the sensor is housed.

[0003] First, a smoke detector is installed so as to be housed in a protective cover, and a side wall provided with a heater covers up to an upper end portion of a smoke introduction port. (June 60, 153686). It is also conceivable to extend the side wall of the protective cover to the lower end of the smoke inlet of the smoke detector, and to provide some openings on the side wall for the introduction of smoke.

[0004] However, in the former, although drip-proof and moisture-proof effects can be ensured, since the side wall is not covered up to the smoke inlet, dust or dirt may clog the smoke inlet and deteriorate the sensitivity of the sensor. There is. In the latter case, even if the detector is covered with the side wall up to the smoke inlet, dust, dust, water droplets, etc. may also enter from the opening provided in the side wall. In the latter case, if there is no opening in the side wall, smoke from immediately below the detector can be detected quickly, but if the fire occurrence point is shifted from the detector, the smoke will flow into the smoke inlet of the detector. There is a problem that it is difficult to penetrate, and as a result, the monitoring range of the sensor is reduced.

[0005] Furthermore, in addition to the smoke detector, a constant-temperature sensor that detects a fire by a change in the surrounding temperature using a semiconductor such as a thermistor, or a differential sensor that closes contacts by air expansion of a detection unit using a diaphragm. The sensor is not suitable for outdoor installation where the temperature changes greatly.

[0006]

[Problems to be solved by the invention]

 With flame detectors, if external light from outside the detection field of view of the detector tube reflects on the inner wall of the protective cover and malfunctions, or if dust, dirt, water droplets, etc. adhere to the detector tube, it will not be detected. Degree may be deteriorated.

[0007]

[Means for Solving the Problems]

 The present invention is a protection cover of a flame detector having an ultraviolet detector tube for detecting ultraviolet rays from a flame, and when installed, is higher than the above ultraviolet detector tube and does not obstruct the detection field of view of the ultraviolet detector tube. A cylindrical side wall having a height, a mounting portion to the sensor ground plane at one end of the side wall, and a transparent or translucent out-of-field irradiation prevention plate provided at the other end in the direction of the mounting portion. It is intended to solve the problem.

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a protective cover in a state where a flame detector is installed, FIG. 2 is a perspective view of the protective cover, and FIG. 3 is a perspective view of a protective cover of another embodiment.

In FIG. 1, reference numeral 11 denotes a head of a flame detector, which is provided with an ultraviolet detector tube (not shown) having a detection field of view a, and is detachably connected to a base 12 to form a flame detector main body 10. doing. The base 12 is provided with screw holes for screwing to the sensor ground plane 13 and wiring holes through which signal lines extending from the head 11 pass. 1 is a protective cover, which is installed so as to surround the main body 10. Reference numeral 6 denotes an out-of-field irradiation prevention plate for preventing ultraviolet rays from outside the detection field of view a from reflecting inside the protective cover 1 and entering the ultraviolet detection tube.

In FIG. 2, the protective cover has a cylindrical shape with one end opened, 1 is a protective cover main body, and a mounting portion 5 sandwiched between a base 12 and a sensor ground plane 13; A side wall 2 extending in the sensor direction is provided on the periphery of the portion 5, and a conical out-of-view irradiation plate 6 is detachably provided at a lower end portion of the side wall 2. The mounting portion 5 has a screw hole and a wiring hole of the base 12, a screw hole 4 and a wiring hole 3 communicating with each other.

In order to install the flame detector and the protection cover configured as described above, first, the screw holes 4 provided in the mounting portion 5 of the protection cover 1 and the screw holes of the base 12 and the wiring provided in each of them are provided. The holes are connected, screwed to the sensor ground plane 13 and connected to the base 12 by rotating the head 11.

When the base 12 and the head 11 are attached and detached, the attachment or detachment is performed by hand or using a sensor attaching / detaching device. However, if the distance between the inner peripheral surface of the side wall 2 and the outer peripheral surface of the base 12 is too short. Since the attachment / detachment becomes difficult, the attachment portion 5 is formed slightly wider than the outer peripheral surface of the base 12, and a distance from the outer peripheral surface of the base 12 to the inner peripheral surface of the side wall 2 is secured such that a finger can easily enter. You.

When the head 11 is connected to the base 12, the out-of-field irradiation prevention plate 6 is connected to the lower end of the side wall 2. The out-of-field irradiation prevention plate 6 is formed in a conical shape, and prevents ultraviolet rays from outside the detection field of view a from reflecting on the inner peripheral surface of the side wall 2 and entering the ultraviolet detection tube. Further, if the out-of-field irradiation prevention plate 6 is opaque, the operation indicator (not shown) attached to the flame detector cannot be seen, so it must be transparent or translucent.

The height of the cylindrical side wall 2 formed on the periphery of the mounting portion 5 is set so as not to block the detection field of view a of the ultraviolet detector tube. It is determined by the height up to the detector tube and the detection angle of the ultraviolet detector tube.

Further, as shown in FIG. 3, the protective cover 1 has a configuration in which the mounting portion 5 is spread outward and the screw hole 4 is provided outside the side wall 2 so that the wiring hole 3 needs to be provided. Instead, the flame detector main body 10 and the protective cover 1 can be separately mounted. In this case, it is not necessary to make the out-of-field irradiation prevention plate 6 detachable as shown in FIG. 2, and mounting is possible even if it is fixed from the beginning.

[0016]

[Effect of the invention]

 Since the present invention is configured as described above, it is possible to prevent dust, dirt, water droplets, etc. from adhering to the ultraviolet detector tube without narrowing the detection visual field and preventing the influence of ultraviolet rays from outside the visual field. This has the effect that the flame can be detected reliably even outdoors.

[Brief description of the drawings]

FIG. 1 is a sectional view of a protective cover in a state where a flame detector is installed.

FIG. 2 is a perspective view of a protective cover.

FIG. 3 is a perspective view of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protective cover 2 Side wall 3 Wiring hole 4 Screw hole 5 Mounting part 6 Out-of-field irradiation prevention plate 10 Flame detector main body 11 Head 12 Base 13 Sensor ground plane a Detection field of ultraviolet detector tube

Claims (1)

[Utility model registration claims] 1. A protection cover for a flame detector having an ultraviolet detector tube for detecting ultraviolet light from a flame, the cover being higher than the ultraviolet detector tube when installed and not blocking the detection field of view of the ultraviolet detector tube. A side wall having a cylindrical shape, a mounting portion to the sensor ground plane at one end of the side wall, and a transparent or translucent out-of-field irradiation prevention plate provided at the other end in the direction of the mounting portion. Flame detector protective cover.