JPH0346712A - Switch with failure previewing function - Google Patents

Abstract

PURPOSE:To secure the switch output by comprising two optical sensors, and obtaining the operating output with one optical sensor to be operated first and the reset output with one optical sensor to be reset first. CONSTITUTION:In the process that an actuating piece 15 moves from the free position to the operating position, resisting a spring 19, under the condition that the actuating piece 15 shades the light from projecting elements of optical sensors 23a, 23b, the light of the sensor 23a reaches elements 26 through a first transmission window 27 to output the operating output. When the actuating piece 15 moves furthermore, the light from the sensor 23b reaches the elements 26 through a transmission window 28 to output the signal, and both the sensors 23a, 23b are operated together. At this stage, in the case that overtravel is short, a judgement that the actuating piece 15 does not move sufficiently is judged to perform the failure preview output. Next, when a movement of the actuating piece 15 to the free position is completed, the actuating piece 15 shades the light from the sensor 23a to reset. The switch output to the outside can be secured even if any one of sensors gets out of order by obtaining the operating output with one optical sensor to be operated first and the reset output with one optical sensor to be reset first.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch whose failure state can be known in advance.

[Prior art and its problems]

Conventionally, there are plunger-type limit switches that have a snap-action switch built into a housing and an operating plunger that protrudes from the housing, and roller-lever-type limit switches that convert rotational motion of a roller lever into linear motion.

However, in these switches, cutting oil adheres between the operating plunger and the head, or between the rotary shaft that supports the low 2 lever and the head, and this may solidify or become contaminated due to the adhesion of chips. The operation plunger, roller lever, and other movable parts may not return properly, overtravel (that is, lack of movement after operation), or for roller lever types, roller wear may cause malfunction (or incorrect settings). be.

On the other hand, if a built-in switch has a bad contact or breakage of the movable contact plate due to odor, welding of the contacts, or dust adhering to the contacts, this may cause product defects in mechanical devices that use such switches. , the production line may have to be stopped to repair the switch.

[Purpose of the invention]

In view of these conventional problems, this invention improves the various drawbacks of built-in switches, especially snap-action switches, and also eliminates problems such as improper setting of operating elements such as switch operating plungers and levers, and poor return of movable parts of switches. The purpose is to know in advance.

[Summary of the invention]

In order to achieve the object, the present invention changes the switch built into the housing into a snap action switch and uses an optical sensor. Of these two sets of optical sensors, the one that operates first obtains the operating output, the one that returns first obtains the return output, and the operating state of both optical sensors is used to determine the operation output. It predicts failure of the movable part to return by predicting a setting failure or by measuring the difference in the recovery time of both optical sensors, and even if either one of the optical sensors fails, the switch output will not change. Signal is secured.

〔Example〕

An embodiment of the present invention will be explained below with reference to the drawings.

That is, in FIGS. 1 and 2, a head 3 is detachably attached to one end, that is, the head, of the housing l along its axis.

A rotating shaft 4 is disposed in this head so as to extend in a direction intersecting the axis of the housing l. An operator 5, ie, one end of a lever, is connected to one end of this rotating shaft 4, that is, a portion protruding from the head 3, and a roller 6 is rotatably supported at the free end of this lever. A cam portion 7 having a flat surface is formed in a portion of the rotating shaft 4 located inside the head 3, and a cup plunger 8 is in contact with one surface of the cam portion by a spring 9. One end of the internal plunger 11 abuts on the other surface, and the other end extends into the nouji puffer fish 1. This internal plunger converts the rotational movement of the operating element 5, ie, the rotating shaft 40, into a linear movement along the axis of the housing l. A diaphragm seal 12 is provided between the housing l and the head 3 to provide a seal between them, and an internal plunger 11 passes through the center of this seal in an airtight manner. Further, a built-in switch 13 is housed within the housing l. This switch is connected to the case 14 as shown in Figure 3.
The actuator 15 is disposed along the axis of the case. This actuator is formed into an elongated plate shape from a non-transparent material, and has a first position along the axis of the case 14, that is, a free position before movement, and a second position, that is, an operating position after movement. It is supported so that it can reciprocate between the two. A plunger 17 is connected to one end of the actuator, and this plunger projects outside the case 14. A cap-shaped sealing member 18 is provided between the plunger and the case 14 to provide a seal between the two. Further, a spring 1 is connected between the other end of the actuator 15 and the case 14.
9 is provided, and this spring always urges the work element 15 toward the first position, that is, the free position.

Also, one end of the actuating lever 21 is attached to a pin 2 in the housing l.
2, its free end abuts the plunger 17, and its middle abuts the other end of the inner plunger 11.

This causes the actuator 15 to move in conjunction with the movement of the operator 5.

Inside the case 14 are two optical sensors 23, namely 23a.
, 23b are accommodated. This optical sensor is composed of a light emitting element 25 and a light receiving element 26 that optically face each other, and a predetermined interval is provided between the pixel elements. Furthermore, both optical sensors 23a and 23b maintain a predetermined distance from each other in the moving direction of the actuator 15 so that the actuator 15 optically separates the respective light emitting element 25 and light receiving element 26. It is arranged like this.

On the other hand, the actuator 15 has a pair of transparent windows 27 and 28 that selectively guide light to the light emitting element 25 or the light receiving element 26 of each of the original sensors 23a and 23b in the moving direction, that is, the axis of the case 14. These double-speed light windows and both light sensors 23a are provided spaced apart from each other in the direction of the edge.
, 23b have a positional relationship such that when the actuator 15 moves, the operating point of one optical sensor 23a and the operating point of the other optical sensor 23b are different from each other.

In FIG. 4, the case 14 is covered by a cup (-29), and an electronic circuit board 30 forming an electronic circuit is attached to this cup (-29).

Further, the opening of the housing is covered by a cup (-31).

When the above-mentioned odor control operator 5, that is, the lever rotates once around the rotating shaft 4 from the free state, the amount of rotation is changed to a tightening sound of the internal plunger 11. Pressed. When this actuator is in the free position, both optical sensors 23a are activated as shown in FIG. 5(a).

The light emitted from the light projecting element 25 of 23b is transmitted to the actuator 15.
Since the light is blocked by the light, it does not reach the light receiving element 26.

Next, when the actuator 15 moves against the spring 19 from the free position to the operating position and reaches the position shown in FIG. 1
The light emitted from the light emitting element 25 of the optical sensor 23a reaches the light receiving element 26 thereof. At this time, the operation output is output from the first optical sensor 23a as shown at time t in FIG. The light emitted from the light emitting element 25 of the first and second optical sensor 23b reaches the light receiving element 26 through the second transparent window 28 and reaches the light receiving element 26.
The second optical sensor 23b emits a signal as shown in FIG.

In this state, both optical sensors 23a and 23b are operating.

At this time, if there is insufficient overtravel, that is, if the actuator 15 starts returning after the first optical sensor 23a operates but before the second optical sensor 23b operates, the setting of the operator 5 is defective, that is, the actuator 15 is It is assumed that the setting has not been sufficiently moved to the operating position, and a failure prediction is output indicating that the setting is defective. This detection is carried out at time t, as shown in FIG. 2 optical sensor 23
This is done when b is not working.

Next, with the operating element 5 in a sufficiently operating position, that is, with the operating element 15 in the second position, an external force is applied to the operating element 5 (
The operator then begins to return to its original position by the spring 9 and cup granger 8. At the same time, the actuator 15 is
As shown in Figure (b), the urging force of the sedge ring 19 causes it to start moving from the second position, that is, the operating position, toward the first position, that is, the free position. As a result, the actuator 16 blocks the light from the light emitting element 25 to the light receiving element 26 of the second photosensor 23b at time t in FIG. 6, contrary to the previous case. That is, the second optical sensor 23b returns to normal, and at the same time, the output signal as a switch is turned off. At this point, a timer counter (not shown) for recovery failure starts counting.

Then, when the operator 5 completely returns to its original position and the operator 15 returns to the first position, that is, the free position, the operator 15 moves to the first optical sensor 23a at time t in FIG.
The light emitting element 25 also blocks the light reaching the light receiving element 26,
bring it back. When this timer counter stops counting and the count number of the timer counter exceeds a preset initial value, it outputs a failure prediction signal. Conversely, if the counted number is smaller than the initial setting value, the timer counter is initialized.

Control of the output signals of these switches and failure prediction control can be performed using a computer, such as a microcomputer.

In other words, the output signal of the switch is the operation output of the two optical sensors that operates first, and the return output of the one that returns first, that is, at time 1 in Figure 6.
．． The operation output is obtained at the same time point type, and the return output is obtained at °C.
Therefore, even if one of the optical sensors fails, the switch output to the outside will be ensured.

In addition, if the setting of the operator 5 is incorrect, the number of counts from the output of the original sensor that first operated is the two optical sensors 23a.
, 23b.

Furthermore, an operator 5, that is, a lever, a rotating shaft 4, a cup plunger 8. Internal plunger 11° operating lever 21
Alternatively, failure of the movable part such as the actuator 15 to return is detected based on the count from the time when the optical sensor returns first.

Note that the above-mentioned optical sensor 23 is the optical sensor 23a so that the second optical sensor 23b operates first.

The relative positional relationship between 23b and the light-transmitting windows 27 and 28 can be set, and the effect in this case is substantially the same as in the embodiment described above.

Further, although a roller lever type operator 5 is shown, a normal lever type can be used as a lever, and a plunger type can be used as an external plunger.

The block diagram shown in FIG. 7 uses a well-known computer to predict switch failures, and the CPU 34 has all the functions of a normal CPU, including an arithmetic section, a control section, a memory, and a timer counter. This CPU has a driver circuit 35 that drives the light projecting elements 25 and 25.
．． 35 and light receiving circuits 36 and 36 that convert optical signals from light receiving elements 26 and 26 into electrical signals are connected, respectively.

Further, the CPLJ 34 includes a constant voltage circuit 37, a control output driver circuit 38. Control output display circuit 39, output transistor diagnosis circuit 40. Failure prediction output driver circuit 41,
A failure prediction display circuit 42 is connected to the control output display circuit 39, and an indicator light 43 is connected to the failure prediction display circuit 4.
2 has an indicator light 44 and a control output driver circuit 3.
A transistor 45 is connected to the circuit 8, and a transistor 46 is connected to the failure prediction output driver circuit 4.

Note that a power source 47 is connected between terminal a and earth 0, a load 48 is connected between terminals a and b, and a load 49 is connected between terminals a and c.

〔Effect of the invention〕

As described above, this invention uses an optical contact, that is, an optical switching element, instead of a mechanical contact as an internal switch, so unlike a snap action switch, there are no problems such as welding of the contacts, breakage of the movable contact plate, or dust, etc. There is no risk of poor contact due to adhesion to the contacts.

In addition, this invention has two optical sensors and two transparent windows,
The light sensor is arranged in a positional relationship in which the operation start point of one optical sensor and the operation start point of the other optical sensor are different from each other, and the optical sensor that operates first obtains an operational output, and the optical sensor that operates first obtains an operational output, and the light that returns first. Since the recovery output is obtained by the sensor, the switch output can be ensured even if any of the optical sensors fails.

In addition, by detecting the operating status of both optical sensors, it is possible to know if the setting of the operator is incorrect, so if the setting position shifts due to loosening of a screw or the like while the switch is in use, the switch output can be used to detect this. (You can know it before it happens.)

In addition, failure of the movable part to return is detected by measuring the difference in the return times of both sensors, so if the movement of the movable part begins to move slower than the set value, that is, before it reaches a complete return failure. You can know its status.

[Brief explanation of drawings]

Fig. 1 is a front view of the switch according to the invention with the cover removed, Fig. 2 is a side sectional view, Fig. 3 is an enlarged front view of the built-in switch, Fig. 4 is an exploded perspective view of the built-in switch, and Fig. 5 6 is a front view showing the operating state of the built-in switch, FIG. 6 is a waveform diagram showing the output state of the built-in switch, and FIG. 7 is a block circuit diagram. DESCRIPTION OF SYMBOLS 1...Housing, 3...Head, 4...Rotating shaft, 5...Operator, 6...Roller 7...Cam part, 8...Cup plunger 9...Spring ,
11... Internal plunger 12... Diaphragm seal, 13... Built-in switch, 14... Case,
15... Actuator, 17... Plunger 18...
・Seal member, 19... Spring, 21... Operating lever 22... Bottle, 23... Light sensor 25.
...Light emitting element, 26...; Light receiving element, 27... Translucent window, 28... Translucent window, 29... Cover, 30... Electronic circuit board, 31... Cover 34. ...CPU. 35... Driver circuit, 36... Light receiving circuit, 37
... Constant voltage circuit, 38 ... Control output driver circuit, 39 ... Control output display circuit, 40 ... Output transistor control circuit, 41 ... Failure prediction output driver circuit, 42 ... Failure Prediction display circuit, 43... indicator light,
44... Indicator light, 45... Transistor, 46...
・Transistor, 47...Power supply, 48...Load%4
9...Load.

Claims (4)

[Claims] (1) An operator (5) driven by an external force is supported so as to move relative to the housing (1), and the housing (1) is formed of a non-transparent material; and an actuator (15) that interlocks with the operator (5).
) is supported so as to be able to reciprocate between a first position and a second position, and within the housing (1) there are light projecting elements ( A light sensor (23) composed of a light receiving element (25) and a light receiving element (26).
), and these optical sensors are arranged so that the light emitting element and the light receiving element are optically separated by the actuator (15), and the actuator (15)
are arranged at a predetermined interval from each other in the direction of movement, and the actuator (15) further includes a pair of light-transmitting windows that selectively guide light from each of the light emitting elements to each of the light receiving elements. (27) and (28) are provided spaced apart from each other in the direction of movement, and both of these light-transmitting windows and the above-mentioned both optical sensors (23) are connected at the time when one of the optical sensors starts operating when the actuator (15) moves. The optical sensor has a positional relationship that is different from the operation start point of the optical sensor and the optical sensor that operates first in the process in which the actuator (15) moves from the first position to the second position. In addition to obtaining the operating output of the switch, the operating state of the operating element (5) is obtained from the operating state of both optical sensors (23) when the operating element (15) moves from the first position to the second position. A switch with a failure prediction function that detects a defect in the operating position. (2) supporting an operator (5) driven by an external force so as to move relative to the housing (1), and forming a non-translucent material in the housing (1); and an actuator (15) that interlocks with the operator (5).
) is supported so as to be able to reciprocate between a first position and a second position, and within the housing (1) there are light projecting elements ( A light sensor (23) composed of a light receiving element (25) and a light receiving element (26).
), and these optical sensors are arranged so that the light emitting element and the light receiving element are optically separated by the actuator (15), and the actuator (15)
are arranged at a predetermined interval from each other in the direction of movement, and the actuator (15) further includes a pair of light-transmitting windows that selectively guide light from each of the light emitting elements to each of the light receiving elements. (27) and (28) are provided spaced apart from each other in the direction of movement, and both of these light-transmitting windows and the above-mentioned both optical sensors (23) are connected at the time when one of the optical sensors starts operating when the actuator (15) moves. The optical sensor has a positional relationship that is different from the operation start point of the optical sensor and the optical sensor that operates first in the process in which the actuator (15) moves from the first position to the second position. to obtain the operating output of the switch, and in the process of the actuator (15) moving from the second position to the first position, the optical sensor that returns first obtains the return output of the switch, and the actuator ( 15) A switch with a failure prediction function, characterized in that failure of the movable part to return is detected by measuring the return time difference between the two optical sensors (23) when the optical sensor (23) returns from the second position to the first position. . (3) supporting an operator (5) driven by an external force so as to move relative to the housing (1), and forming a non-translucent material in the housing (1); and an actuator (15) that interlocks with the operator (5).
) is supported so as to be able to reciprocate between a first position and a second position, and within the housing (1) there are light projecting elements ( A light sensor (23) composed of a light receiving element (25) and a light receiving element (26).
), and these optical sensors are arranged so that the light emitting element and the light receiving element are optically separated by the actuator (15), and the actuator (15)
are arranged at a predetermined interval from each other in the direction of movement, and the actuator (15) further includes a pair of light-transmitting windows that selectively guide light from each of the light emitting elements to each of the light receiving elements. (27) and (28) are provided spaced apart from each other in the direction of movement, and both of these light-transmitting windows and the above-mentioned both optical sensors (23) are connected at the time when one of the optical sensors starts operating when the actuator (15) moves. The optical sensor has a positional relationship that is different from the operation start point of the optical sensor and the optical sensor that operates first in the process in which the actuator (15) moves from the first position to the second position. to obtain the operating output of the switch, and in the process of the actuator (15) moving from the second position to the first position, the optical sensor that returns first obtains the return output of the switch, and the actuator ( Detects a malfunction in the operating position of the operator (5) from the operating states of both the optical sensors (23) when the operator (15) moves from the first position to the second position; 15) A switch with a failure prediction function, characterized in that failure of the movable part to return is detected by measuring the return time difference between the two optical sensors (23) when the optical sensor (23) returns from the second position to the first position. . (4) Both the optical sensors (23) are connected to the housing (1).
), and the actuator (15) is supported by the case (14). Switch with predictive function.