JPH0451492Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field This invention relates to an explosion-proof indicator light used in explosion-proof electric mechanical equipment installed in locations where there is a risk of explosion.

(b) Prior art and its drawbacks Industrial Safety and Health Regulations (Ministry of Labor Ordinance No. 32 of 1972) No.
Article 280, Paragraph 1 stipulates that the structure of electrical machinery and equipment must be explosion-proof. However, in conventional flameproof explosion-proof indicator lights and safety-increased explosion-proof indicator lights, a guard is attached around the glass lens that covers the lamp to protect against external damage. For this reason, conventional lamps have had the disadvantage that there are places where it is difficult to see the light from the lamp because it is blocked by the guard, resulting in a narrow field of view. In addition, when replacing the lamp, the guard has a locking structure, so it must be removed using a tool, which not only makes the work cumbersome, but also requires the lighting circuit installed inside the explosion-proof container. Since it had a normal structure, it also had the disadvantage that it could not be worked on until the power was turned off.

(c) Purpose of the invention This invention was created in view of the above circumstances. By using LED lamps instead of incandescent lamps and making the lighting circuit intrinsically safe, it eliminates the need for guards. With electricity on
The purpose of this invention is to provide an explosion-proof indicator light that allows the replacement of LED lamps.

(d) Configuration and effect of the device The explosion-proof indicator of this device is an integral unit of an LED lamp and an LED lamp lighting circuit connected to a power source. The LED lamp lighting circuit is an intrinsically safe explosion-proof circuit that is equipped with a resistor that limits the current flowing into the LED lamp and a Zener diode that limits the voltage applied to the LED lamp. This integral unit is:
It is characterized by being able to be installed inside an explosion-proof container.

Intrinsically safe explosion-proof construction refers to a structure in which it has been confirmed through ignition tests that there is no risk of sparks, arcs, or heat generated by the parts that make up the electrical equipment to ignite gas or steam. (Electrical machinery and equipment explosion-proof construction standards [Ministry of Labor Notification No. 1962]
(Enacted No. 16, amended Ministry of Labor Notification No. 80 in 1972)) When this idea is configured as above, the LED lamp is lit by an intrinsically safe explosion-proof LED lamp lighting circuit, so no guard is required to protect against external injuries. becomes. This prevents the light from the LED lamp from being blocked and narrowing the field of view, and
This makes it extremely easy to replace LED lamps. Furthermore, by using an intrinsically safe explosion-proof LED lamp lighting circuit, the current is limited by a resistor and the voltage is limited by a Zener diode, so there is no risk of danger even if the LED lamp is damaged. There is no need to turn off the power when replacing the lamp. Furthermore, since no guard is required, it can also be used as an illuminated structure for push button switches and the like. In addition,
Since the LED lamp and lighting circuit are integrally formed, it can be installed as is in a container with a conventional flameproof explosion-proof structure or an increased safety explosion-proof structure instead of an indicator light with a guard.

(e) Embodiment FIG. 1 is a longitudinal cross-sectional view of an explosion-proof indicator light which is an embodiment of this invention, and FIG. 2 is a longitudinal cross-sectional view of a container to which the explosion-proof indicator light is attached.

The explosion-proof indicator lamp of this example includes LED lamp 1,
It is composed of an LED lamp lighting circuit 2 and a molded resin case 3. The LED lamp 1 is an incandescent bulb-shaped lamp in which a large number of light emitting diodes are embedded in a display portion and a cap-type terminal is formed at the rear.
LED lamp lighting circuit 2 consists of power supply and LED lamp 1
This is a safety circuit connected between the power supply circuit and the current flowing to the LED lamp 1 by a resistor connected in series with the power supply circuit, and a Zener diode connected in parallel to the power supply circuit to limit the current flowing to the LED lamp 1.
By limiting the voltage applied to the device, it is made intrinsically safe and explosion-proof. The molded resin case 3 is located at the front.
Socket part 4 for attaching LED lamp 1
This case has an LED lamp lighting circuit 2 fixed to the rear end, and connects the output terminal of the LED lamp lighting circuit 2 and the socket part 4 with a connecting rod 5,
5 makes it conductive. The LED lamp 1 is attached to the socket part 4 of this molded resin case 3 and has an LED lamp lighting circuit 2 fixed to the rear end.
is formed integrally with. Note that the lens 6 may be made of plastic, which has low pressure resistance, instead of glass. Of course, it is also possible to eliminate it if it is acceptable in terms of appearance.

This explosion-proof indicator light configured as above is
As shown in FIG. 2, it is used by being installed in a container 8 having a pressure-resistant explosion-proof structure or an increased safety explosion-proof structure.
Even if there is a general electrical circuit other than an intrinsically safe circuit inside this container 8, there will be no problem with explosion-proof performance because the wiring for the LED lamp lighting circuit is built-in. 7
You can also use them side by side.

As explained above, the explosion-proof indicator lamp of this embodiment does not require a guard to cover the display part of the LED lamp 1, so the light is not blocked and the field of view is not narrowed, and the locking structure is improved. Since this eliminates the need for the LED lamp 1, the replacement work of the LED lamp 1 becomes extremely easy as it is only necessary to replace the LED lamp 1 attached to the socket portion 4 without any special tools. Furthermore, this LED lamp 1 is lit by an intrinsically safe explosion-proof LED lamp lighting circuit 2 that limits the current and voltage, so there is no danger in the event of damage, and the power supply is required when replacing. No need to cut. Moreover, since the LED lamp 1 and the LED lamp lighting circuit 2 are integrally formed, the container 8 has a conventional pressure-resistant explosion-proof structure and an increased safety explosion-proof structure.
It can be installed as is instead of an indicator light with a guard inside. In addition, since a guard is not required, the cost can be reduced compared to the conventional explosion-proof indicator lamp using an incandescent bulb, even if the installation of a new LED lamp lighting circuit 2 is taken into account. Furthermore, it is now possible to replace the conventionally required glass lenses with plastic lenses, and in this respect as well, costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an explosion-proof indicator lamp according to an embodiment of this invention, and FIG. 2 is a longitudinal cross-sectional view of a container to which the explosion-proof indicator lamp is attached. 1...LED lamp, 2...LED lamp lighting circuit, 8...container.

Claims (1)

[Claim for Utility Model Registration] An LED lamp and an LED lamp lighting circuit connected to a power source are integrally formed, and the LED lamp lighting circuit includes a resistor that limits the current flowing into the LED lamp and a voltage applied to the LED lamp. This integrally formed circuit is equipped with a Zener diode that limits the
An explosion-proof indicator light that can be installed inside an explosion-proof container.