JPH0440170Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is an optical fiber sensor device that detects the existence of objects, detects counting, or recognizes colors.
Alternatively, the present invention relates to an optical fiber terminal structure that can be used in an optical communication device using an optical fiber as a transmission path.

[Conventional technology]

2. Description of the Related Art Conventionally, a sensor head portion, that is, a terminal portion of an optical fiber sensor device, as shown in FIGS. 15 and 16, for example, has been put into practical use. That is, after partially removing the covering material from the tip of the optical fiber, it is fitted into a threaded cap, fixed with adhesive, and the tip is polished as necessary.
On the other hand, prepare a fixing angle as shown in Fig. 16, fit the above-mentioned cap into its through hole, and secure it by tightening it from both sides with two sets of nuts and washers. The angle is fixed at the location where it should be detected.

However, when fixing the terminal part in this way, the optical fiber and the cap must be fixed with adhesive, which increases the number of manufacturing steps and time, which increases costs. Contamination of the optical fiber was a concern. In addition, since the cap is screwed to a fixed angle, it takes a lot of effort to install it, and there is also the problem that it is not possible to mount a large number of them closely together.

[Problem that the invention attempts to solve]

In view of the above conventional problems, the present invention aims to provide an optical fiber terminal structure that can hold optical fibers without using adhesives, can be fixed with simple operations, and is compatible with various installation methods. It is something.

[Means for solving problems]

In other words, the gist of the present invention is that in an optical fiber terminal structure in which a core holder is fitted to the terminal portion of the optical fiber and a base holder is further fitted, the core holder is located at a rear position from the head. The cylindrical body is extended, a hole is provided along its axis into which the optical fiber is inserted, and the circumferential surface of the cylindrical body is cut in the axial direction so that the free end faces the rear position of the head. and at least one elastic engagement piece having an engagement protrusion on the outside and a fitting portion on the outside,
The base holder includes a hole into which the core holder is inserted, and an engaging portion that engages in a complementary manner with the engaging portion of the elastic engaging piece, and the base holder is provided with a fixing attachment means. The optical fiber terminal structure is characterized by:

〔Example〕

The present invention will be described below with reference to drawings of embodiments. First, an example of a so-called reflective sensor head using two optical fibers will be described with reference to FIGS. 1 to 10.

Fig. 1 shows the terminal structure of the present invention before assembly, and Fig. 2 shows the assembled state. In the figure, 1 indicates a two-core optical fiber cable,
2 is a core holder, and 3 is a base holder.
Of these, the optical fiber cable 1 is made by peeling off a part of the coating material 11 at the tip, and using the optical fiber cable 10.
Leave it exposed.

The core holder 2 is made of a synthetic resin material, etc., and has a cylinder 22 extending from the head 20 to a rear position, and has a hole 21 along its axis into which an optical fiber is inserted. A pair of elastic engagement pieces 23 are provided on the circumferential surface of the cylinder, cut in the axial direction so that the free end faces the rear position of the head, and having an engagement protrusion 23A on the inside and an engagement part 23B on the outside. ing. In this example, the cross-sectional shape of the hole 21 is oval in order to fit two optical fibers therein. Further, in the figure, 24 is a stopper, and 25 is a fitting guide protrusion.

Further, the base holder 3 is also made of a synthetic resin material, and has a hole 30 into which the core holder 2 is inserted, and a pair of engagement members that complementarily engage with the engagement portions 23B of the elastic engagement pieces. A section 31 is provided. The height of the protruding part of the engaging part 31 at this time is determined based on the fact that the engaging protrusion 23A of the elastic engaging piece 23 slightly digs into the covering material 11 of the optical fiber cable 1, as will be described later. Note that 32 in the figure
33 is a step corresponding to the stopper 24, and 33 is a guide groove corresponding to the fitting guide protrusion 25.
Reference numeral 34 denotes attachment holes provided in the vertical and horizontal directions.

Next, the state of assembly will be explained based on FIGS. 5 and 6. First, the optical fiber cable 1 in the state shown in FIG. 1 is fitted into the core holder 2 as shown in FIG. In this state, the engagement protrusions 23A of the pair of elastic engagement pieces 23 do not bite into the sheathing material 11 of the optical fiber cable 1, but their tips are tightly fitted into the holes 21. At this time, the tip of the optical fiber 10 may be polished if necessary. Next, as shown in Figure 6, the base holder 3
When fitted, these fittings are secure and cannot be easily removed. That is, the engaging portion 31 of the base holder 3 and the engaging portion 2 of the elastic engaging piece 23
3B, so that the elastic engagement piece 23
The engaging protrusion 23A is pressed inward and slightly bites into the coating material 11 of the optical fiber cable, so that the optical fiber cable 1 and the core holder 2 are firmly fixed. At the same time, the engaging portions 23B and 31 of the core holder 2 and the base holder 3 are engaged with each other, and these are also firmly fitted, ultimately ensuring the fixation of the three.

7 and 8 show an example of installing the terminal structure assembled as described above, in which the plate member 4
FIG. 8 shows an example in which three parts are stacked and fixed with long bolts 5 using the through-holes 34 for attachment.

Furthermore, FIGS. 9 and 10 show another embodiment in which attachment and detachment are facilitated. The engaging portion 31' of the base holder 3 is made into an elastic piece shape, and a piece of the shape shown in FIG. There is no difference from the above embodiment except that the hole 35 is provided. The fitting procedure and operation are the same, but when disconnecting, the engaging part 31' is inserted through the hole 35.
This can be easily done by expanding the

Figs. 11 and 12 show examples of terminal structures in which one optical fiber cable 1 is fitted. Fig. 11 is used as a sensor head of a transmission type sensor device, and Fig. 12 is used as a kind of optical connector. suitable for That is, the case shown in FIG. 11 is substantially the same as the embodiment shown in FIG. 1 above, except for the single optical fiber cable 1. The case shown in FIG. 12 is substantially the same as the example shown in FIG. 11, except that the base holder 3 is made large enough to accommodate the photoelectric conversion element 6 and can even accommodate the entire core holder 2. .

13 and 14 show other examples of the base holder 3, with FIG. 13 having a stepped shape and FIG. 14 having a screw provided on the outer periphery. In addition, the elastic engagement piece 2 of the core holder 2
3, it is sufficient if there is at least one on the circumferential surface.

[Effects of the invention] Since the present invention has the above-described structure, the optical fiber and the core holder, as well as the core holder and the base holder, can be fitted together by the action of the elastic engagement piece of the core holder. This has the advantage that the fitting operation can be performed firmly and reliably, and that the fitting operation can be easily performed.

[Brief explanation of the drawing]

Figures 1 to 10 show an embodiment using two optical fibers, where Figure 1 is a perspective view before assembly, Figure 2 is a perspective view of the assembled state, and Figure 3 is a perspective view of the assembled state.
Figure 4 is an enlarged cross-sectional plan view of the base holder and core holder, Figure 5 is an enlarged cross-sectional plan view of the optical fiber cable fitted into the core holder, and Figure 6 is an enlarged cross-sectional plan view of the optical fiber cable fitted to the core holder. FIGS. 7 and 8 are perspective views showing installation examples of the present invention; FIGS. 9 and 10 are enlarged sectional plan views and perspective views showing another embodiment; FIGS. 12 and 12 are enlarged sectional plan views showing an embodiment using one optical fiber cable, FIGS. 13 and 14 are perspective views showing another embodiment of the base holder, and FIGS. 15 and 16.
The figures are an enlarged sectional view and a perspective view showing a conventional example. 1... Optical fiber cable, 10... Optical fiber, 11... Covering material, 2... Core holder,
20... Head, 21... Hole, 22... Cylindrical body, 23
...Elastic engagement piece, 23A...Engagement protrusion, 23B...
...Engagement part, 3...Base holder, 30...Hole,
31...Engagement part.

Claims (1)

[Claims for Utility Model Registration] 1. In an optical fiber terminal structure in which a core holder is fitted to the terminal part of the optical fiber and a base holder is further fitted, the core holder has a tube extending from the head to the rear position. The cylindrical body is extended, and a hole is provided along its axis into which an optical fiber is inserted, and the circumferential surface of the cylindrical body is cut and raised in the axial direction so that the free end is located at the rear of the head, and a hole is provided on the inside for engagement. The base holder is provided with a mating protrusion and at least one elastic engagement piece having an engagement portion on the outside, and the base holder has a hole into which the core holder is inserted, and the base holder is complementary to the engagement portion of the elastic engagement piece. An optical fiber terminal structure comprising an engaging portion that engages with the base holder, and a base holder provided with attachment means for fixing the base holder. 2. The optical fiber terminal structure according to claim 1, which is a registered utility model, wherein the engaging portion of the base holder is made of an elastic piece and the core holder can be attached and detached.