JPH0330979Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a switch structure for setting the output logic, etc. of a photoelectric switch.

Prior Art A photoelectric switch is used in a factory to detect the presence or absence of a person or object based on whether or not light projected from a light emitting element is incident on a light receiving element, and to control various equipment based on the detection output. It is often used for the purpose of saving labor.

However, the point detected by the photoelectric switch is often far away from the equipment to be controlled, and furthermore, the detection point has a limited installation area and is often in a poor environment, such as being easily exposed to rain or dust. many.

For this reason, as one type of photoelectric switch, as shown in FIG. 6, a main body part 2 containing, for example, a light emitting/receiving element and its driving circuit is housed in a small sealed case 1, and power supply lines, output lines, etc. are enclosed. A system has been developed and used in which the shielded wire 3 is drawn out from the case 1 and can be connected to equipment controlled by a photoelectric switch.

By the way, it is necessary to set the output logic of the photoelectric switch 4 according to the connected control equipment. Note that the output logic setting means whether there is an output when receiving light, or
No output when light is blocked, or no output when light is received.
This specifies whether to output when light is blocked.

Conventional output logic settings include a signal line 5 for output logic switching inside the shielded wire 3 drawn out from case 1.
This is done by setting the signal line 5 to an "H" level potential or an "L" level potential on the control equipment side.

Considering the actual usage condition of the photoelectric switch 4, for example, the distance between the detection point and the control device is
The shield wire 3 is often long, with a distance of 10 m, in some cases up to 50 m to 100 m.
In this case, electromagnetic waves generated by the peripheral electrical equipment tend to generate induced voltage at a relatively high voltage level in the signal line 5 for switching output logic, and the potential of the signal line 5 is changed to set the output on the control equipment side. There were cases in which the output was output using an output logic different from the logic, causing the control equipment to malfunction.

As a means to avoid such unstable operation, for example, as shown in FIG. 7, a mechanical switch 6 such as a toggle switch or a slide switch is provided in the case 1 of the photoelectric switch, and a signal line 5 for switching the output logic is provided. Alternatively, as shown in Fig. 8, a short dedicated line 7 for logic switching can be drawn out from the case 1 separately from the shielded wire 3 for output, and a dedicated switch 8 can be installed near the installation point of the photoelectric switch. in,
It is possible to perform logical settings.

However, the former method of providing the mechanical switch 6 is not suitable for practical use, as photoelectric switches themselves are becoming smaller and it is difficult to secure mounting space and the sealing performance is impaired. In addition, the latter method of providing a short dedicated line 7 slightly degrades the function of the photoelectric switch 4, which is useful due to its compact size and ease of installation, and is also inappropriate for practical use. It is.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a switch structure capable of switching the output logic of a photoelectric switch without the above-mentioned problem of inductive interference and without the disadvantages of providing a mechanical switch 6 or a dedicated line 7.

Means for Solving the Problems The present invention provides a photoelectric switch housed in a closed case, including an operating means movably held on the outer surface of the case and having a reflective surface formed on the surface facing the case, and a A light transmitting window provided at a passing position of the reflective surface, a light emitter/receiver for setting provided in the case so as to face the reflective surface through the window, and a projector and receiver provided in the case for setting the above. This photoelectric switch is characterized by comprising a setting state determination circuit that determines the setting state depending on whether or not a light receiver detects a reflective surface.

Effect: According to the above means of the present invention, the setting state determination circuit using the light emitter/receiver as the detection means and the operating means having a reflective surface are separated into the inside and outside of the sealed case via the transparent window of the case. It is possible to set the output logic, etc. without impairing the airtightness of the sealed case, and there is no need to use a signal line for switching the output logic. Furthermore, the size and shape of the means described above are smaller than that of a mechanical switch, and they are also superior in functionality.

Embodiment A photoelectric switch 9 which is an embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, 10 is a light projecting lens 1 on the front.
1 and a closed case 15 in which a light receiving lens 12 is fitted and fixed, and a cylindrical embossment 14 for leading out an output shield wire 13 is formed protrudingly on the rear surface;
is housed in a sealed case 10, and the light emitting element 1
6, a printed circuit board on which photoelectric switch circuit parts such as the light receiving element 17 and its drive circuit (not shown) are assembled; 18, an operating means for output logic switching rotatably fitted on the cylindrical embossing 14; A soft resin ring body 19 is a bushing fitted and fixed to the end of the cylindrical embossing 14 in order to draw out the shield wire 13 while maintaining waterproofness and to prevent the ring body 18 from coming off. A reflective surface 21 is formed by attaching and fixing a reflective plate to a part of the ring body 18, and a reflective surface 21 is formed on a part of the back surface of the closed case 10, corresponding to the passing position of the reflective surface 2 of the rotating ring body. A light-transmissive window 22 made of transparent resin or the like is assembled on the printed circuit board 15 inside the case so as to face the reflective surface through the window 21, and as shown in FIG. 23 is a printed light emitting/receiving device for setting that detects whether or not the light emitted from the optical element 22a is facing the reflective surface 20 based on whether or not the light emitted from the optical element 22a is reflected and returns to the light receiving element 22b such as a phototransistor. Board 1
This is a setting state determination circuit that drives the setting light projector/receiver 22 assembled on the reflective surface 5 and determines the output logic depending on whether or not it faces the reflective surface 20.

The ring body 18 needs to be articulated so as to clearly distinguish between the state in which the reflecting surface 20 and the light emitter/receiver 22 for setting are facing each other and the state in which they are not facing each other, and to prevent the position from shifting after setting. On the outer circumferential surface of the cylindrical embossing 14, two protrusions 14a, 14a are formed protrudingly at a positional relationship of ¹⁸⁰⁰ as shown in FIG. 3, and on the inner circumferential surface of the ring body 18, as shown in FIG. As shown ^, four depressions 18a, 18a, . Also, in order to display the setting position, the ring body 18 has a mark 18b such as an arrow.
On a part of the back surface of the case 10, there are output logic displays 10a, 1 such as "H" level output when light is received or "L" level output when light is received in order to align the mark 18b.
Add 0a...

Next, the output logic switching operation of the photoelectric switch 9 will be explained.

The photoelectric switch 9 is attached to the detection point, and the output shield wire 13 is led out from the rear end.
When connecting to a control device, know the output logic required by the control device. Then, the ring body 18 is rotated so as to match the output logic, and the setting mark 18b attached to the ring body 19 is aligned with one of the output logic displays 10a, 10a, . . . on the case.
The light receiving element 22b receives light only when the reflective surface 20 of the ring body 18 faces the light projector/receiver 22. Then, the setting state determination circuit 23 generates an output logic determination signal O of "H" level or "L" level depending on whether or not light is being received. The drive circuit on the printed circuit board 15 outputs an output logic according to this output O to the control equipment through the output signal line in the shielded wire 13.

Furthermore, although the above embodiment shows an example in which the switch structure of the present invention is used only for switching the output logic, it can also be used to set other operating information of the photoelectric switch, such as switching the operating mode of the internal drive circuit. can.

Furthermore, when increasing the amount of operation information, it is sufficient to provide a plurality of sets of light emitters/receivers for setting and setting state discriminating circuits.
For example, as shown in FIG. 5, a plurality of setting light emitting/receiving devices 21, 21, etc., which are appropriately arranged in correspondence with the passing positions of the reflecting surface 20, and the same number of setting state determination circuits 23, 23,... If they are provided in combination, information for the number of sets can be set.

Further, in the above embodiment, the ring body 1 is used as the operating means.
8 was used, but its shape is arbitrary. In short, it is sufficient that it has a reflective surface and is slidably held at an arbitrary position on the outside of the case 10 by a guide means, and may be one that slides in a linear direction. However, since a photoelectric switch usually has a protruding cylindrical emboss for leading out the output shield wire, the ring body 1 using this
If No. 8 is adopted, the structure can be simplified and manufacturing can be facilitated, and it is also preferable in terms of appearance and operability.

The closed case 10 used in the present invention may be provided with a light-transmitting window at least at the front position of the light emitter/receiver provided in the case corresponding to the passage position of the reflective surface. , its material is arbitrary. For example, either metal or resin can be used.

Effects of the invention The present invention has an operating means having a reflective surface slidably held along the outer surface of a closed case of a photoelectric switch, and a light-transmitting window provided in a part of the closed case. Since the output logic, etc. is set using the setting emitter/receiver facing the reflective surface of the operating means, signal lines for output logic switching can be eliminated.
Even if the photoelectric switch is installed at a long distance from the control equipment, malfunctions due to induction interference can be eliminated, and since no mechanical switch is used, the photoelectric switch can be made smaller without compromising the airtightness of the closed case.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a photoelectric switch showing an embodiment of the present invention, Fig. 2 is a view showing the state in which the emitter/receiver for setting in Fig. 1 corresponds to the reflecting surface, and Fig. 3 is a closed type switch. FIG. 4 is a rear view of the case, FIG. 4 is a plan view of the ring body of the photoelectric switch shown in FIG. 1, and FIG. 5 is a diagram showing the relationship between the arrangement of a plurality of light emitters and receivers and the reflecting surface. Figures 6 to 8 show conventional examples, Figure 6 is a sectional view showing a photoelectric switch in which a signal line for switching output logic is arranged in parallel within a shielded wire for output, and Figure 7 is a cross-sectional view of a photoelectric switch for switching output logic. FIG. 8 is a side view of a photoelectric switch using a mechanical switch. FIG. 8 is a side view of a photoelectric switch using a dedicated line for output logic switching. 9...Photoelectric switch, 10...Sealed case,
13... Shield wire, 14... Cylindrical embossing,
18... Operating means [ring body], 20... Reflective surface,
21...Light-transmitting window, 22...Light emitter/receiver for setting.

Claims (1)

[Scope of utility model registration request] In a photoelectric switch housed in a sealed case, there is an operating means that is movably held on the outer surface of the case and has a reflective surface formed on the surface facing the case, and a light transmitting means provided at a position where the reflective surface of the case passes. a window, a light emitter/receiver for setting provided in the case so as to face the reflective surface through the window, and whether or not the light emitter/receiver for setting provided in the case detects the reflective surface. What is claimed is: 1. A photoelectric switch comprising: a setting state determination circuit that determines a setting state based on the setting state of the photoelectric switch.