JPS5835326B2 - 2-wire non-contact micro switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-contact microswitch that controls the transmission and reception of light between a light projecting section and a light receiving section that are arranged opposite each other using a light shielding plate or the like, and particularly relates to a two-wire non-contact microswitch.

Conventionally, in this type of non-contact microswitch, a light-emitting element, a light-receiving element, etc. have been packaged as individual items.

This packaged product is large in size, which poses a problem in reducing the size of the device.

In addition, there are many wiring steps for each element and connections to external circuits (circuits that amplify the output of the light-receiving element, current-limiting resistors for the light-emitting element), etc., which increases the cost.
It was also complicated.

Further, this type of photoelectric type non-contact microswitch has conventionally been configured as a three-wire type.

This should be at least 2 for power and at least 1 for signal.
A device with a total of three terminals, in which a power supply is connected to the two power supply terminals, and a load is connected between one signal terminal and one of the two power supply terminals. The idea is to connect this load and give a signal to this load to control the on/off of this load.

However, in the case of a 3-wire system, the signal cable has 3 connections, which not only complicates the connection work, but also increases the possibility of mixing up the connection points, and furthermore, in the event of a failure, there are 3 connections in the signal cable. It is also troublesome in terms of maintenance, as each wire must be inspected to see if it is broken.

The present invention provides a 2-wire non-contact microswitch that is easy to downsize and assemble, thereby reducing manufacturing costs, and that eliminates the drawbacks of the 3-wire type described above by configuring it as a 2-wire type. The purpose is to provide.

An embodiment of the present invention will be described below.

First, its configuration will be explained along the manufacturing process.

First, as shown in FIG. 1, one metal plate is punched out to form the terminal pieces 11 to 14, the locking piece 1516, and the frame 10.

Each of the terminal pieces 11 to 14 and the locking pieces 15, 16 are punched out so as to be connected to the frame 10, so that they cannot be separated.

Further, the locking piece 15 is provided with a hole 151, and the locking piece 16 is provided with a hole 151.
A groove 161 and a notch 162 are provided in the groove 161 .

Next, as shown in FIG. 2, pellets 3 and 4 are fixed to the locking piece 15 and the terminal piece 13, respectively.

The pellet 3 is a light receiving element 30 (see Figures 5 and 8).
This is an IC pellet for configuring a light receiving section including.

The terminals of this IC pellet 3 are connected to the terminal piece 11 (via the locking piece 16) and the terminal pieces 12 to 14.

Pellet 4 is a light emitting element pellet, and its terminal is connected to terminal piece 1.
Connect to 3 and 14.

Next, transparent resin members 21 and 22 containing the IC pellet 3 and the light emitting element pellet 4 are molded under low pressure, and as shown in FIG.
, an opaque resin case 2 including the terminal pieces 11 to 14 and the locking pieces 15 and 16 is molded.

Then, the frame 10 is cut to separate the case 2 from the frame 10.

Further, as shown in FIG. 4, the terminal pieces 13°14
and bend the locking pieces 15 and 16.

Note that there are claws 2 on both side walls of the case 2 for locking the cover 5.
5 (one of which is hidden in the figure) is provided respectively.

Further, the convex portion 23 of the case 2 is provided with a stopper 24, which will be described later.

Next, the coil 6 and the light shielding plate 7 are attached to the case 2.

As shown in FIGS. 5 and 6, while the spring hook 62 of the coil spring 6 is locked in the hole 71 of the light shielding plate 7, the other spring hook 61 is locked in the hole 151 of the locking piece 15.

Then, one end of the light shielding plate 7 is engaged with the groove 161 of the locking piece 16.

At this time, the light shielding plate 7 receives a counterclockwise torque (FIG. 6) from the coil spring 6, and is stopped by the stopper 24.

After this, cover 5 is placed over case 2.

The cover 5 is prevented from coming off by claws 25 and the like.

A push button 8 is attached to the hole 51 of the cover 5.

The pellets 3 and 4 constitute a circuit section.

For example, as shown in FIG. 7, this circuit section 31 includes a photoelectric detection circuit 32, a constant voltage circuit 33 including a smoothing circuit, a 5CR34 which is an example of a switching element, and a constant voltage diode 35.
, a reverse current prevention diode 36, a current limiting resistor 37, and a rectifying bridge 38.

The photoelectric detection circuit 32 includes a light emitting element (pellet) 4, a light receiving element 30, an amplifier circuit 321, and a level detection circuit 322.

Next, the operation of the non-contact microswitch constructed in this way will be explained.

5 and 6, when the push button 8 is pressed, the push button 8 is retracted and the coil spring 6 is deflected.

In addition, since the locking piece 16 is provided with a notch 162,
The spring 6 can be sufficiently bent.

Initially, when the deflection is small, the light shielding plate 7 is still subjected to counterclockwise torque by the spring 6, and is positioned upward while being stopped by the stopper 24.

At this time, the light shielding plate 7 blocks a portion of the light rays from the light emitting element pellet 4 and prevents the light rays from entering the light receiving element 30.

Therefore, in FIG. 7, the output of the photoelectric detection circuit 32 becomes "L" (the circuit is configured in such a way).
CR34 is off.

As a result, the connection between the terminal pieces 11 and 12 is turned off.

(Strictly speaking, as described below, the current supplied to the photoelectric detection circuit 52 flows as a leakage current.

However, this is extremely small and can be considered off).

On the circuit section 31 side, a voltage as shown in FIG. 9A is generated at point A.

This voltage is dropped by the resistor 37, and a voltage as shown in FIG. 9B is generated at point B.

Therefore, sufficient current can be supplied to the photoelectric detection circuit 32 for operation.

5 and 6, when the push button 8 is retracted and the spring 6 is bent to a certain extent, the light shielding plate T is now subjected to a clockwise torque and is positioned downward by a snap action.

In this case, a portion of the light beam that has been blocked until now will be incident on the light receiving element 30.

Therefore, in FIG. 7, the output of the photoelectric detection circuit 32 becomes "H" and the 5CFt34 is turned on.

As a result, the terminal strips 11 and 12 are turned on, and power is supplied to the load.

On the other hand, on the circuit section 31 side, a voltage as shown in FIG. 10C is generated at point C.

This voltage is dropped by the forward drop voltage valve by the diode 36, and a voltage as shown in FIG. 10B is generated at point B.

Therefore, in this case as well, sufficient current is supplied to the photoelectric detection circuit 32 for operation.

In this way, the photoelectric detection circuit 32 operates by receiving power supply whether the 5CR34 is on or off.
This is to output a detection signal to be captured on the gate of 5CR34.

When the push button 8 is released, the coil spring 6 returns to its undeformed state due to its own elastic force, and pushes the push button 8 back up to its original position.

Accordingly, the light shielding plate 7 also comes to be positioned upward by a snap action, and as a result, the connection between the terminal pieces 11 and 12 is turned off.

Note that the present invention is not limited to the above-mentioned one embodiment.

For example, in the above embodiment, as shown in FIG. 7, a so-called voltage division type two-wire switching circuit is adopted as the circuit configuration, but as shown in FIG.
A wire switching circuit may also be used.

That is, instead of the constant voltage diode 35 in FIG.
5CR40, a constant voltage diode 39, and a resistor 41 are provided.

In this case, 5CFt is also determined according to the output of the photoelectric detection circuit 32.
34 can be turned on and off to control the power supply to the load.

On the circuit section 31a side, when the 5CR34 is off, voltages shown in FIG. 12 are generated at points A and B, and current is supplied to the photoelectric detection circuit 32.

On the other hand, when 5CR34 is on, voltages as shown in FIG. 13 are generated at points B1 and C.

5C from the time when the anode potential of 5CR40 becomes zero
This is because the gate current does not flow and the 5CR40 is not triggered until R40 is turned off and the anode potential exceeds the Zener potential V2 of the voltage regulator diode 39.

Therefore, even in this case, sufficient current can be supplied to the photoelectric detection circuit 32.

, As described above with reference to actual cases, according to the present invention, the circuit section including the light-receiving element and the light-receiving circuit is integrated into an IC, and the IC pellet is embedded in the case, thereby achieving miniaturization. be able to.

Further, since the terminal pieces are made of plate-shaped members arranged on the same plane, they can be easily formed by punching or the like.

Furthermore, since the IC pellet can be wired by fixing it to the terminal piece, the fixing and wiring work is extremely easy.

In this way, assembly work becomes extremely simple and manufacturing costs can be reduced.

In addition, since the circuit section is composed of a photoelectric detection type two-wire switching circuit, it is possible to reduce the number of external terminal pieces and achieve a smaller size. It also becomes easier.

Furthermore, since there are two external terminal pieces and two external wires, even if a cable breaks, it is easy to confirm the failure and improve reliability.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining each process according to an embodiment of the present invention, FIG. 5 is a partially sectional plan view of this embodiment, and FIG. 6 is a side view of the same. 7 is a block diagram showing the circuit configuration, FIG. 8 is a block diagram showing the photoelectric detection circuit 32 of FIG. 7, FIGS. 9 and 10 are waveform diagrams showing waveforms at each point in FIG. 7, and FIG. The figure is a block diagram showing a modified example.
2 and 13 are waveform diagrams showing waveforms at each point in FIG. 11. 10... Frame, 11-14... Terminal piece, 15.16... Locking piece, 2...
Case, 21゜22...Transparent resin member, 3...
...IC pellet, 31.31a...Circuit part, 4...Light emitting element pellet, 5...
Cover 6... Coil bar: *,?・・・・・・
Light blocking plate.

Claims (1)

[Claims] 1. Two plate-shaped terminal pieces arranged on the same plane and to which a power source and a load are to be connected in series, and a terminal piece connected to the two terminal pieces and connected between these terminal pieces. It has a switching element that performs switching, and is further connected to the two terminal pieces in parallel with the switching element, and receives power supply to drive the switching element when the switching element is turned on or off. An IC pellet having a light-receiving element and a light-receiving circuit that outputs a detection signal, a transparent resin member molded including the IC pellet, and a mold-molded opaque synthetic resin including the transparent resin member and the terminal piece. a case that is fixed to another terminal piece protruding from this case, is arranged opposite to the light receiving element, and is electrically connected to the two terminal pieces in the same manner as the light receiving element and the light receiving circuit, and is connected to the switching terminal. a light-emitting element that emits light upon receiving power when the element is turned on or off; an operating unit that is attached to the case and controls transmission and reception of light between the light-emitting element and the light-receiving element; A two-wire contactless micro, comprising: a cover fitted into the case to cover the light-emitting element, the light-receiving element, and the operating section; and a push button attached to the cover to operate the operating section. switch.