KR100376940B1 - A limit switch for monitoring valve open/close status, which has on/off display lamps and operated by internal DC battery or external AC power - Google Patents

Abstract

The present invention, unlike the existing limit switch, built-in DC battery and ON / OFF lamp for monitoring the opening and closing of the limit switch to limit the external power (AC) and internal power (DC battery) can be selectively used according to the environment As a switch, it is a new type of limit switch that can be operated by the built-in DC battery without the external power supply and power cable as well as the existing wiring work using the AC power supply (control panel ↔ limit switch installation site). It is possible to easily monitor the operation status of the valve through the operation of the lamps installed in the system.In particular, the limit switch can reduce the number of errors and monitor the correct operation status through on-site access and ease of installation, especially in places where electric power reception is difficult. In providing.

Description

Lamp-operated valve open and close limit switch {A limit switch for monitoring valve open / close status, which has on / off display lamps and operated by internal DC battery or external AC power}

The present invention enables the use of AC (AC → DC converted power supply, hereinafter AC) and DC battery (hereafter DC) and can easily detect the operation status through ON / OFF operation lamp. The detection system can minimize the loss caused by errors by easily detecting operation errors by ON / OFF operation lamp.

It is easy and accurate to detect the opening and closing state of a similar valve (hereinafter referred to as a valve) where the valve stem protrudes to the outside such as a gate or a globe valve and moves up and down by rotation. It is easy and quick to detect problems that may occur due to expected valve malfunction or operator's mistake, and can prevent various problems in advance. In particular, since it is detachable from the outside of the valve, the sensor (or limit switch) is installed inside the valve or inside the pipe to detect the difference. Unlike the existing limit switch, the DC battery is different from the limit switch. It is a new type of limit switch with excellent site accessibility that can be used by the built-in power supply without installing external power and power cable, and the user can change the device such as valve or piping by considering the structure and size of the valve. The present invention provides an ON / OFF lamp-operated valve opening and closing monitoring device that can be simply attached to the outside of a valve without using it.

According to the present invention, the power supplied to the limit switch can be selectively used for DC and AC, so that it can be easily applied even in a field where electric power reception is difficult. Wiring work was essential as a form of DC power supply (power supply 12V or 24V), and there were some difficulties and hassles in faucet and field accessibility.

The present invention has been made in consideration of the above problems, and its primary object is that AC or DC can be used depending on the installation conditions of the power supply of the limit switch. It is excellent, and the operation of the lamp installed in the limit switch makes it easy to monitor the opening and closing state of the valve from a long distance.

1 is a principle of operation of a general limit switch

2 is a block diagram and operation principle of the limit switch of the present invention

3 and 4 are examples of application of this limit switch.

5 and 6 are electrical circuit diagrams of an embodiment of the present limit switch.

<Description of the symbols for the main parts of the drawings>

(1): Switch lever (2): Contact lever

(3): spring (4): contact lever

(5): Battery (6): OFF lamp

(7): ON lamp (8): Common terminal

(9): External power input terminal (10): Internal contact terminal

(11): Lamp holder (12): Battery holder (13): Control panel side off lamp (14): Control panel side on lamp

The present invention is a general limit switch operation method [converting the limit switch through a DC power supply (12V DC or 24V DC) after converting AC 110V or 220V to DC (Fig. 1), a power cable is essential. Unlike the AC-to-DC conversion process, the circuit is configured so that DC can be used directly by the built-in battery, and if necessary, a 2-Way circuit system (Fig. 2) is constructed to use AC power. DC or AC power can be selected according to the situation of the site. When using DC power, the working time and working method can be simplified compared to the conventional limit switch, which required wiring work. There is an advantage that can be greatly reduced. In addition, in the monitoring of valve opening and closing, it is possible to easily install and use the relative operation part that can be in contact with the limit switch in the upper part or the center of the stem outside the valve. Can be.

The built-in DC battery is a typical 3V cadmium (lithium or 6V alkaline) battery that can be replaced easily according to the life of the battery, and the lamp used is also removable and easy to replace. The battery and lamp can be selected from 3-6V within rated capacity to meet each other. When the DC battery or AC power is activated, the lamp is operated and the red (ON / OFF) or green (ON / OFF) lamp is operated according to the sensor contact point of the switch, and this lamp can be easily monitored from a long distance.

Depending on the installation, ① Check the opening and closing state of the valve through the lamp by connecting it to the control panel or the required position using the AC power cable (see Fig. 5), ② When using DC power, the limit switch is required without the cable. (See Fig. 6), ③ It can be installed at the control panel and two sites at the same time as necessary to monitor the two places at the same time. The structure is removable.

Example

The DC (built-in battery) circuit of FIG. 2 operates as follows.

As the switch lever 1, the contact lever 2 is operated by ON / OFF operation up and down by the relative operating portion of the valve.

The contact lever 2 moves up and down by the leaf spring 3, and the contact lever 4 is interlocked by the up and down movement to generate an ON / OFF contact to operate the lamp. When the valve is completely closed, the OFF lamp 6 is operated. When the valve starts to open and is fully opened, the ON lamp 7 is operated by the contact of the internal contact terminal 10. In the AC circuit, the operation from the switch lever 1 to the leaf spring 3 is the same, and when power is supplied to the lower contact of the external power input terminal 9 and the common terminal 8 when the valve is closed, As in the case of DC operation, the OFF lamp 6 and the ON lamp 7 in the field are operated, and the OFF lamp 13 and the ON lamp 14 of the control panel (not shown) are the lamps 7 and ( 6) will work in the same way.

The lamp of the limit switch can be easily detached by installing a lamp holder 11, and the battery 5 can also be easily replaced according to the life by installing the battery holder 12.

3 and 4 show an application example of the limit switch. A support plate (bracket) was attached to the side of the limit switch, and the support plate was attached to the stem or valve body of the valve to stabilize it.

In the case of Figure 3 is an example applied to a large valve, by attaching a limit switch on the upper stem of the valve, the vertical movement by the valve stem, the contact is formed by the circular limit guide on the valve handle, The lamp is operated by the contact, and FIG. 4 is an example applied to a small valve. Since the vertical movement section of the valve stem is short, a relative switch lever is formed in the middle of the stem to make contact with the limit switch. This switch lever is moved by movement, and the lever makes contact with the limit switch so that the lamp is operated.

Conventional limit switches used in the prior art is used by switching from AC to DC, but the present invention can selectively use AC and DC to suit the situation or use of the site, and the error according to the detection by the built-in ON / OFF operation lamp This is a new type of limit switch that can reduce the number of valves.

The basic principle of operation is to apply the existing limit switch, but for the purpose of limit switch, the built-in battery can be used considering the maximum accessibility of the site so that it can be used without wires and the ON / OFF operation lamp can reduce the detection error. It is noteworthy to insert.

The present invention can be immediately introduced into the detection of chemical plants, critical systems of the production process and valves, and the method can reduce the operator's operation errors, and thus has a wide range of applications and a simple structure with almost no malfunction of the limit switch itself. In terms of price, the application can be broadly applied industrially, and considering the high price of the electric valve currently produced, it will be very advantageous in terms of simplicity and economics of configuration and field installation.

Claims (4)

delete In the limit switch, A contact lever 2 that moves up and down by the force of the leaf spring 3 connected to the switch lever 1, an increasingly lever 4 interlocked with the contact lever 2 to operate a lamp, and the increasingly lever 4 To the internal contact terminal 10 for DC operated by), the common terminal 8 for AC operated by the contact lever 4 and the external power input terminal 9, and the internal contact terminal 10. A lamp-operated valve open / close monitoring limit switch, characterized by a limit switch composed of lamps (7) (6) for ON / OFF indication that are lighted crosswise by means of a lamp. The method of claim 2, The limit switch is a lamp-operated valve open and close monitoring limit switch, characterized in that installed on the outside of the valve to be ON / OFF operation by the relative operation of the valve. The method of claim 2, The external power supply (AC) input terminal (9) is a lamp operated valve opening and closing limit switch, characterized in that connected to the ON / OFF indicator lamps (14, 13) of the control panel installed on the outside.