JPS5835328B2 - 2-wire non-contact micro switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-contact microswitch, and more particularly to a photoelectric two-wire non-contact microswitch that produces a non-contact switching output based on the transmission and reception of light.

Photoelectric non-contact microswitches also come in various shapes and sizes depending on their uses, for example, from ordinary ones to ultra-small ones.

Therefore, the circuit parts that generate non-contact switching outputs based on external operations also need to be manufactured with different shapes and sizes.

However, sharing parts is extremely effective in reducing costs, and it is desirable to share this circuit section with non-contact microswitches of various shapes and sizes.

Further, the photoelectric 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 the load to turn it on and off.

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.

This invention allows circuit parts to be shared even if they have different shapes and sizes depending on various uses, simplifies assembly work and reduces manufacturing costs, and is a two-wire system. It is an object of the present invention to provide a two-wire type non-contact microswitch which eliminates the drawbacks of the three-wire type described above.

Below, this invention is applied to a transmission type photoelectric non-contact microswitch (one that obtains a non-contact switching output by controlling the transmission and reception of light between a light emitting element and a light receiving element using a light shielding plate).
An example will be explained.

In FIGS. 1A and 1H, the case 2 is molded with resin as described later, and plate-shaped terminal pieces 12 and 13 protrude from the bottom surface of the case 2.

Further, on the upper surface thereof, locking pieces 15, 16 and leads 14 are provided.
1. 142 (see FIG. 3) protrudes and is further provided with a protrusion 21 having a stopper 22.

Furthermore, a claw portion 23 is provided on the side surface of the case 2.

This case 2 is easily resin molded.

That is, as shown in FIG.
, punch out the locking pieces 15, 16 and the frame 11.

Initially, these parts are connected by a frame 11 so that they cannot be separated.

Then, these punched out terminal pieces 12, 13 and leads 14
The case 2 including the 1° 142 and the locking pieces 15 and 16 is molded with resin.

Thereafter, the frame 11 is cut and the locking pieces 15, 16 are bent (see FIG. 3).

Note that the terminal pieces 12 and 13 are punched out integrally with the IJ-cords 141 and 142, respectively.

Further, in FIGS. 1A and 1B, a circuit unit 3 is attached to the upper surface of the case 2.

This unit 3 includes resin members 3a, 3b and leads 33.
~36 (see Figure 3).

The resin members 3a and 3b include pellets 31 containing light emitting elements,
Pellets 32 each containing a light receiving element are provided in an opposing arrangement.

The manufacturing process of this circuit unit 3 is almost the same as that of case 2 described above.

That is, the leads 33 to 36 are punched out from a single conductive plate without being separated, and then pellets 31. A pellet 32 containing a light receiving element is fixed at a predetermined location and connected to leads 33 to 36.

Then, the resin members 3a and 3b are resin molded including the leads 33 to 36 and the aforementioned pellets 31 to 32, and then the leads 35 and 36 are bent.

The aforementioned pellets 31 and 32 constitute a circuit section 30 as shown in FIG. 5, for example.

In FIG. 5, the circuit section 30 includes a photoelectric detection circuit 310, a constant voltage circuit 321, which includes a smoothing circuit. 5CR322 shown as an example of a switching element, a constant voltage diode 323,
It is composed of a backflow prevention diode 324, a current limiting resistor 325, and a rectifying bridge 326.

The photoelectric detection circuit 310 includes a light emitting element 31 as shown in FIG.
1. It is composed of a light receiving element 312, an amplifier circuit 313, and a level detection circuit 314.

Specifically, as shown in FIG. 3, the circuit unit 3 is attached to the case 2 by respectively connecting the leads 33 and 34 to the glue leads 14L142 on the upper surface of the case 2 (see FIG. 4).

This connection is made, for example, by welding or spot.

Further, in FIGS. 1A and 1B, a coil spring 6 and a light shielding plate 7 are locked to the locking pieces 15 and 16.

That is, 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 (see FIG. 4).

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

At this time, the light shielding plate I receives a torque in the counterclockwise direction (in FIG. 1B) from the coil spring 6, and is stopped by the stopper 22.

Further, the light shielding plate 7 is located between the resin members 3 a and 3 b.

Further, a cover 5 is fitted onto the case 2.

This fitting is prevented from coming off by the claws 23.

Further, a hole 51 is provided in the cover 5, and this hole 51
A push button 4 is supported so as to be freely retractable.

Next, the operation will be explained.

In FIG. 1B, when the push button 4 is pressed, the push button 4 is retracted and the coil spring 6 is deflected.

Note that since the engagement piece 16 is provided with a notch 162 (see FIG. 10), 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 22.

At this time, this light shielding plate γ is the pellet 31 (light emitting element 31
1) without blocking the light beam from the pellet 32 (light receiving element 31
2) A ray of light is incident.

Therefore, in FIG. 5, the output of the photoelectric detection circuit 310 becomes rLJ, and the 5CR 322 is turned off.

As a result, the terminal strips 12 and 13 are turned off (strictly speaking, as described below, the current supplied to the photoelectric detection circuit 310 flows as a leakage current).

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

On the circuit section 30 side, a voltage as shown in FIG. 7A is generated at point A.

This voltage is dropped by the resistor 325, and a voltage as shown in FIG. 7B is generated at point B.

Therefore, sufficient current for operation can be supplied to the photoelectric detection circuit 310.

In FIG. 1B, when the push button 4 is retracted and the spring 6 is bent to a certain extent, the light shielding plate 7 is now subjected to a clockwise torque and is positioned downward by a snap action.

Then, the light beam from the pellet 31 (light emitting element 311) is blocked, and the pellet 32 (light receiving element 312) no longer receives light.

Therefore, in FIG. 5, the output of the photoelectric detection circuit 310 becomes rHJ, and the 5CFt 322 is turned on.

As a result, the terminal pieces 12 and 13 are turned on, and power is supplied to the load.

On the other hand, on the circuit section 30 side, a voltage as shown in FIG. 8C is generated at point C.

This voltage is dropped by the forward drop voltage valve by diode 324, creating a voltage at point B as shown in FIG. 8B.

Therefore, in this case as well, sufficient current is supplied to the photoelectric detection circuit 310 for operation.

Therefore, the photoelectric detection circuit 310 is connected to the 5CR32
2, it receives power supply and outputs a detection signal for driving the 5CR 322 in both on and off states.

Further, in FIG. 1B, when the push button 4 is released from being pressed, the coil spring 6 returns to an undeflected state by its own elastic force, and pushes the push button 4 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 terminals 12 and 13 is turned off.

Note that the present invention is not limited to the above-mentioned actual case, but can also be applied to a reflective photoelectric type non-contact microswitch, as shown in FIGS. 9A and 9H, for example.

That is, in FIG. 9 AtB, the circuit unit 8 consists of a resin member 8a and leads 83, 84 (see FIG. 10), and a pellet 81 containing a light emitting element and a pellet 82 containing a light receiving element are attached to the resin member 8a. and are located on substantially the same plane.

The projection and reception of light between the C and Pellets 81 and 82 is controlled by the reflecting plate 1a.

Further, this circuit unit 8 is attached by connecting its leads 83 and 84 to the leads 141 and 142 on the top surface of the case 2 by welding, spotting, etc. (first
(See Figures 0 and 11).

In addition, FIG. 9A. B1 In FIGS. 10 and 11, parts corresponding to those in FIGS. 1A, B, 2, and 3 are designated by corresponding numbers, and their explanations will be omitted.

Furthermore, in the above embodiment, a so-called voltage division type two-wire switching circuit is adopted as the circuit configuration as shown in FIG. 5, but a phase division type two-wire switching circuit is used as shown in FIG. May be adopted.

That is, instead of the constant voltage diode 323 in FIG. 5, a 5CR327, a constant voltage diode 328, and a resistor 3 are used.
29 is provided.

In this case as well, 5C
Turn R322 on and off to control the power supply to the load (
wealth) can.

On the circuit section 30a side, when 5CR322 is off, the first
Voltages as shown in FIG. 3 are generated at points A and B, and current is supplied to the photoelectric detection circuit 32.

On the other hand, when 5CR322 is on, voltages as shown in FIG. 14 are generated at points B and C.

5 from the time when the anode potential of 5CR327 becomes zero
This is because the gate current does not flow and the 5CR 327 is not triggered until the CR 327 is turned off and the anode potential exceeds the Zener potential Vz of the voltage regulator diode 328.

Therefore, in this case as well, sufficient current can be supplied to the photoelectric detection circuit 310.

As described above with reference to actual cases, according to the present invention, the case and the circuit unit are configured separately, and the leads protruding from each are connected to each other to mechanically fix the case and to electrically connect the case and the circuit unit. The same circuit unit can be used regardless of the shape or size of the case.

In this way, the circuit unit can be shared by various non-contact microswitches, and manufacturing costs can be reduced.

Furthermore, since the case and circuit unit are separated, they can be manufactured on separate production lines and later assembled into one, streamlining the manufacturing process and simplifying the manufacturing process. This can also contribute to cost reduction.

Furthermore, since the circuit unit employs a two-wire switching circuit, the number of external terminals can be reduced and the device can be made smaller, and the wiring work for external loads and power sources connected to the terminals is also simplified.

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

[Brief explanation of drawings]

Figures 1A and 1B show one embodiment of the present invention.
Figure A is a plan view, Figure 1B is a side view, Figure 2 is Figure 1A,
3 and 4 are perspective views, FIG. 5 is a block diagram, and FIG. 6 is a block diagram showing the photoelectric detection circuit 310 of FIG. 5, and FIGS. Fig. 8 is a waveform diagram showing waveforms at each point in Fig. 5, Fig. 9 A and B show modified examples, Fig. 9 A is a plan view, Fig. 9 B is a side view, Fig. 10 11 is a perspective view for explaining FIG. 9, FIG. 12 is a block diagram showing another modification, and FIG.
The figure and FIG. 14 are waveform diagrams showing waveforms at each point in FIG. 12. 11... Frame, 12, 13... Terminal piece, 141.142... Case lead, 1
5, 16... Locking piece, 2... Case,
3, 8...Circuit unit, 3a, 3b, 8b.
...Resin member, 30°30a...Circuit part, 31, 32...Pellet, 4...Push button, 5...Cover, 6... Coil spring, 7... Light shielding plate, 7a... Reflection plate.

Claims (1)

[Claims] 1. Two terminals for connecting a power source and a load in series protrude outward, and two leads and a locking part that extend integrally from the two terminals protrude inward. A case unit that is molded with resin and includes these parts, and two leads that are molded as a whole and that protrude to the outside are mechanically fixed to the case unit by being connected to the two leads of the case unit. It has a switching element connected to the two leads to switch between them, and a switching element connected to the two leads in parallel with this switching element. A circuit unit including a photoelectric detection circuit having a light emitting element and a light receiving element connected to each other and receiving power supply and outputting a detection signal for driving the switching element when the switching element is turned on or off. an operating section that is supported by the locking section and controls transmission and reception of light between the light emitting element and the light receiving element; and a cover that is fitted into the case unit so as to cover the operating section and the circuit unit. A two-wire non-contact microswitch, comprising: a push button attached to the cover for operating the operating section. 2. A light-emitting element and a light-receiving element provided in the circuit unit are arranged to face each other, and the operating section is a movable shielding member that transmits and blocks light rays projected from the light-emitting element to the light-receiving element. Range of 2 described in item 1
Wire type non-contact micro switch. 3. The light emitting element and the light receiving element provided in the circuit unit are arranged on substantially the same plane, and the operation section is a movable member having a reflecting mirror that reflects the light beam projected from the light emitting element and making it enter the light receiving element. A two-wire non-contact microswitch according to claim 1, characterized in that: