JPH0224085Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention relates to an optical fiber type reflective photoelectric switch, and more specifically, the invention relates to an optical fiber type reflective photoelectric switch. Regarding reflective photoelectric switches.

(b) Prior art In order to improve the transmission efficiency when assembling this type of optical fiber type reflective photoelectric switch, it is necessary to connect the optical axis of the transmitter/receiver element and the optical axis of the optical fiber so that they are coaxially aligned. However, in the conventional optical coupling method, a dedicated plug is mechanically fixed and attached to the optical fiber, and the plug is inserted into the mating receptacle.

(c) Problems that the invention aims to solve However, since the above method requires a special plug, if the length of the optical fiber is changed depending on the application or installation method, the It was necessary to reattach the plug each time, and the length of the optical fiber could not be freely cut with a knife or the like, resulting in problems of poor practicality and operability.

Furthermore, various structures for holding optical fibers have naturally been proposed, but all of these structures are complex, making the installation process troublesome and having problems with their holding power. However, there were many problems such as increased costs.

This idea allows for connection without the use of a dedicated connection plug.
To provide an optical fiber type reflective photoelectric switch which can easily position and connect the optical axes of a light-receiving element and an optical fiber, has a simple structure, has excellent holding power, and is highly practical and operable.

(d) Means for solving the problem This invention has a through hole with a smaller diameter than the outer diameter of the optical fiber in the front of the light emitting element and the light receiving element, which are built into the switch case. ,
In addition, an expandable and retractable cap having a plurality of slits formed in the peripheral wall of these through holes is arranged, and an optical fiber is press-fitted into each of the through holes, and two of the holding cylinder parts having a diameter smaller than the outer diameter of the cap are pressed. The present invention is characterized in that it is an optical fiber type reflective photoelectric switch in which an integrally formed cap holding tube is press-fitted into the cap.

(E) Function According to the optical fiber type reflective photoelectric switch of this invention, optical fibers are press-fitted into the respective insertion holes of the caps on the front side of the emitter and light-receiving elements, and the two cap holder tubes are inserted into these caps. The optical fiber is attached by press-fitting the presser tube.

(f) Effects of the invention According to this invention, when the optical fiber is press-fitted into the cap, the cap holding tube prevents the cap from expanding in diameter, and the cap tightens and fixes the optical fiber. There is no need for a conventional plug to connect the fiber, and optical coupling can be achieved simply by inserting the optical fiber into the cap. Therefore, there is no need to reattach the plug as described above, and the length of the optical fiber can be freely cut to the optimum length, providing great flexibility.

In addition, by press-fitting the two integrated presser cylinders into the cap, it is possible to optically align the two optical fibers and the emitter/receiver element with a single operation, providing excellent operability and improving the structure. Since it is only equipped with a cap and a cap holding tube, it has the advantage of being simple, and also has the advantage of increasing the holding force of the optical fiber due to the binding force of the cap.

(G) Example of the invention An example of the invention will be described below with reference to drawings.

Figure 1 shows the internal structure of the switch case of a fiber optic reflective photoelectric switch.
A board 2 having an electronic circuit is housed inside the case 1, and connection pins 3 protrude from the case 1.

Further, a light emitting element 4 and a light receiving element 5 are provided side by side at the optical fiber connection side inside the case 1, and a cap 6 is fitted onto the front surface of these elements 4 and 5.

This cap 6 has a sleeve shape as shown in FIG.
A joint cylindrical portion 6b having a smaller diameter than this is integrally introduced, and the tip of this joint cylindrical portion 6b is bent inward into a claw shape, and within the tip of the claw portion 6c,
A through hole 8 having a smaller diameter than the outer diameter of the optical fiber 7
are formed, and a plurality of slits 9 are formed at regular intervals in the circumferential direction at the tip of the joint cylinder including the claw portion 6c.
... is engraved, so that the diameter of the through hole 8 can be expanded or contracted.

Reference numeral 10 denotes a cap holding cylinder, and this cylinder 10 has a holding cylinder part 10 that fits into the joint cylinder part 6b of the cap 6.
The inner hole of the holding cylinder part 10a allows the joint cylinder part 6b to move as the cylinder part 10a is pushed into the cap 6. The taper hole 11 has an inner drawing shape so as to function to reduce the diameter.

It goes without saying that the light projecting element 4 is constituted by a light emitting diode or the like, and the light receiving element 5 is constituted by a phototransistor or the like.

In the above configuration, the cap 6 is connected to the elements 4, 5 by fitting its base cylindrical portion 6a onto the elements 4, 5, and at this time, the through hole 8 is kept coaxial with the elements 4, 5.

In addition, the cap presser tube 10 has its presser tube portion 10
a is externally fitted onto the joint cylindrical portion 6b of the cap 6, but by sliding it to the left in the drawing of FIG.
The degree of external fitting of a and 6b is reduced to allow the joint cylindrical portion 6b to expand in diameter.

Then, the optical fiber 7 is inserted into the cap holding tube 10 and the cap 6 from outside the case.

Since the diameter of the through hole 8 is smaller than that of the optical fiber 7, the diameter is expanded using the aforementioned slit 9 as it is inserted, and then the cap holding tube 10 is pushed to the right in the drawing and press fit. The amount of fitting between the holding cylinder part 10a and the coupling cylinder part 6b increases, the diameter of the fitting cylinder part 6b is reduced by the tapered hole 11 of the holding cylinder part 10a, and the claw part 6c bites into the coating 7a of the optical fiber 7. With this, the optical fiber 7 is connected and fixed to the switch case 1 in a state that resists the pulling force, and the optical fiber 7 and the elements 4 and 5 are positioned and fixed in a coaxial optically coupled state by the tightening force of the claw portion 6c. be done.

[Brief explanation of drawings]

The drawings show one embodiment of this invention, with FIG. 1 being a sectional view of an optical fiber type reflective photoelectric switch, and FIG. 2 being an exploded perspective view of the main parts. 1... Switch case, 4, 5... Emitter/receiver element, 6... Cap, 7... Optical fiber, 8...
Through hole, 9... slit, 10... cap presser tube, 10a... presser tube portion.

Claims (1)

[Scope of Claim for Utility Model Registration] The light emitting element and the light receiving element built into the switch case each have a through hole in the front part thereof with a smaller diameter than the outer diameter of the optical fiber, and Arranging an expandable/contractable cap with a plurality of slits formed in the peripheral wall, press-fitting optical fibers into each of the through holes, and
An optical fiber type reflective photoelectric switch, wherein a cap presser tube, which is formed by integrally forming two presser tube portions having a smaller diameter than the outer diameter of the cap, is press-fitted into the cap.