JPH029465Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to a power supply circuit for an internal unit with a plug, and is particularly applicable when the plug attached to the internal unit and the socket attached to the case are in contact for a certain length or more. This invention relates to a power supply circuit for an internal unit with a plug connected to a power supply contact via a limit switch that is closed.

Conventional technology In controllers, control panels, etc., an internal unit with a printed wiring board and a surface frame is removably inserted into a fixed case with a terminal board on the back to form one unit, and multiple units are combined. A system is used. In this type of unit, for purposes such as checking circuit connections, it is necessary to open and close only the power supply circuit for each unit while the unit is connected to the system.

Conventionally, a power switch for this purpose was provided on the front frame. However, there is a risk that a worker's body, clothing, or belongings may accidentally come into contact with the power switch on the front frame, causing the power circuit to open or close unintentionally, resulting in serious damage to the system, and the risk of erroneous operation. There are drawbacks.

Purpose of the invention Therefore, the purpose of the present invention is to solve the above-mentioned drawbacks of the power switch provided on the surface frame of the plug-equipped internal device of the prior art by providing a power supply circuit for the plug-equipped internal device with a simple structure. There is something to do.

Structure of the Invention In order to achieve the above object, the power supply circuit of the internal unit with a plug according to the present invention has a multi-contact socket connected to a power terminal via one limit switch, and a multi-contact plug that fits into the socket. an internal device, and an operating rod held in the internal device facing the limit switch, and the operating rod is provided at a portion that closes the limit switch when the multi-contact plug and the multi-contact socket are in contact for a certain length or more. A configuration is used in which the limit switch is used as a power switch by holding the rod.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 showing a schematic sectional view of an embodiment, FIGS. 2 to 4 showing a plan view thereof in different operating positions, and FIG. 5 showing an electrical circuit,
The inner device 1 has a surface frame 2 and a printed wiring board 3. A multi-contact plug 5 having a signal contact 4 and a power contact 4p is formed at one end of the printed wiring board 3. The case 6 into which the internal device 1 is inserted has a terminal board 7 on its back, and an external circuit is connected to an external cable 9.
It is connected to this terminal board 7 by. The multi-contact socket 8 that fits into the multi-contact plug 5 of the internal device 1 is
It is connected to the terminal board 7 through a connection socket 10 and is disposed within the case 1.

In the present invention, the power terminal 7p of the terminal board 7 and the power terminal 4p of the multi-contact plug 5 are connected via a limit switch 11. An operating rod 12 is attached to the internal device 1 so as to face the limit switch 11. Limit switch 11 has a movable arm 13 that comes into contact with operating rod 12 when it is in the operating position.

To explain the operation, the internal device 1 is
As shown in the figure, when electrically isolated from the case 6, the multi-contact plug 5 of the printed wiring board 3 is separated from the multi-contact socket 8 of the case 6. When the inner device 1 is inserted into the ground 6 and the tip of the plug 5 reaches position p1 in FIG. 3 (see FIG. 5), the signal contact 4 and power contact 4p of the multi-contact plug 5 are It makes contact with a corresponding contact (not shown) in the multi-contact socket 8. At this time, the signal contact 4 of the multi-contact plug 5 is connected to an external circuit via the terminal board 7, but the power contact 4p thereof is not connected to the external circuit, especially the power source, because it is a limit switch 11. Therefore, connection inspection and other inspections and tests of printed wiring board 3 can be performed with the power turned off.

The inner device 1 is further inserted into the case 6, and the tip of the multi-contact plug 5 of the printed wiring board 3 is further inserted into the case 6 by a distance S from the position p1, as shown in FIGS. 1 and 4. Position p2 towards the back
(See Fig. 5), that is, when the multi-contact plug 5 and the multi-contact socket 8 are in contact for a certain length or more, which is less than the distance S, the tip of the operating rod 12 attached to the internal unit 1 The movable arm 13 of the limit switch 11 is contacted and driven to close the limit switch 11. Therefore, at this time, the internal device 1 enters a normal operating state.

When it is desired to cut off only the power supply circuit of the internal unit 1 which is in a normal operating state, the tip of the multi-contact plug 5 may be moved from position p2 to position p1 in FIGS. 4 and 5.

6 and 7 show an embodiment in which a spring is inserted between the operating rod 12 and the internal device 1. FIG. That is, internal device 1
A bracket 14 is fixed to the bracket 14, and the operating rod 12 is loosely fitted into the bracket 14. One end of the spring 15 is locked to the bracket 14 and the other end is locked to the operating rod 12. After the tip of the multi-contact plug 5 of the printed wiring board 3 reaches the position p1 as shown in FIG.
Further, when pushed in the direction of the limit switch 11, if there is a resistance from the movable arm 13 of the limit switch, the spring 15 is compressed. By pushing the printed wiring board 3 in the direction, the spring 15 is further compressed,
When the elastic reaction force of the spring 15 increases beyond the above-mentioned resistance force, the movable arm 13 moves and the limit switch 11
is closed.

Even if the printed wiring board 3 is accidentally pushed further in the above direction after the limit switch 11 is closed,
Only the spring 15 is compressed and no harmful mechanical forces are applied to the limit switch 11. Therefore, the embodiments of FIGS. 6 and 7 have the feature of preventing damage to the limit switch 11.

Effects of the Invention As explained above, the power supply circuit of the internal unit with a plug according to the present invention uses a limit switch that is closed after the multi-contact plug and the multi-contact socket have been in contact for a certain length or more. It has the following effects.

(a) Compared to the case where the power switch is attached to the front frame, the power supply circuit can be maintained in the open or closed state more reliably.

(b) It is possible to prevent erroneous operations related to opening and closing of the power supply circuit.

(c) By using a single limit switch, the internal unit with a plug can be connected to and removed from the socket in the case without applying any voltage, so there is no risk of generating sparks during connection or disconnection or damaging the printed wiring board due to the sparks. The power switch can be omitted from the surface of the internal unit.

(d) Since no power switch is provided on the front frame, the function of the front frame can be enhanced by using the portion corresponding to the power switch for other purposes such as display and adjustment.

(e) The simple structure of attaching the operating rod to the internal unit via a spring makes it easy to prevent damage to the limit switch.

[Brief explanation of the drawing]

1 is a schematic sectional view of an embodiment of the present invention; FIGS. 2, 3 and 4 are plan views thereof in different operating positions; FIG. 5 is an explanatory diagram of the electric circuit;
7 and 7 are explanatory diagrams of main parts of another embodiment. 1... Internal unit, 2... Surface frame, 3... Printed wiring board, 4... Signal contact, 4p... Power contact, 5
...Multi-contact plug, 6...Case, 7...Terminal board, 8...Multi-contact socket, 9...External cable, 10...Connection cable, 11...Limit switch, 12...Operation rod, 13... Movable arms, 14
...Bracket, 15...Spring.

Claims (1)

[Claims for Utility Model Registration] (1) A multi-contact socket connected to a power supply terminal via one limit switch, an internal device having a multi-contact plug that fits into the socket, and the The limit switch is provided with an operating rod held in an internal device, and the limit switch is operated as a power switch by holding the operating rod in a position that closes the limit switch when the multi-contact plug and the multi-contact socket are in contact for a certain length or more. Power supply circuit for internal unit with plug. (2) Utility Model Registration Claim 1: The power supply circuit for an inner unit with a plug, in which a spring is interposed between the inner unit and the operating rod.