JP3151199U - Protective structure of detection end in fiber unit of optical fiber sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a strong protection structure for a detection end of a fiber unit of an optical fiber sensor. SOLUTION: The structure of a detection end portion 3 of an optical fiber unit 1 is configured such that a metal distal end side shaft portion 4 in which an optical fiber is fixed in a coaxial center position and a proximal end portion side of the shaft portion are fixed. The tip end side shaft portion is covered with a fiber protection pipe 4a that covers the optical fiber in a fixed state and protects the fiber, and covers the outer periphery of the fiber protection pipe. A double pipe protection structure with a reinforcing pipe 4b for reinforcing the fiber protection pipe was adopted. [Selection] Figure 1

Description

  The present invention relates to a fiber unit in an optical fiber sensor in which a detection end on one end is directed to an object to be detected and the other end is connected to an amplifier unit, and relates to a protection structure for the detection end of the fiber unit.

  For example, a transmissive optical fiber sensor is used to detect the presence or absence of a very small electronic component such as a chip. As shown in FIG. 5, the transmission type optical fiber sensor has one end side (detection end portion 20a) of the single-line optical fiber 20 on the light-projecting side and one end side of the single-line optical fiber 30 on the light-receiving side ( The detection end portion 30a) is arranged opposite to the position of the object S to be detected, and the other end side (connection end portion 20b) of the single optical fiber on the light projecting side and the other end side of the single optical fiber on the light receiving side. (Connecting end 30b) is connected to the amplifier unit 40, and the light projected from the detecting end 20a on the light projecting side toward the position of the detected object is received by the detecting end 30a on the light receiving side to be detected. The presence or absence of an object can be detected.

  As shown in FIG. 5, the conventional fiber unit in this transmission type optical fiber sensor has a detection end portion fixed and arranged toward the position of the object to be detected. Since the layer is composed of a single protective pipe 21 and a base part 22 that fixes the base end side of the pipe, the thin layer has a structure in which the thin fiber end is protected only by the single protective pipe 21. Particularly, the protective structure for the tip portion of the thin fiber is weak in strength.

  As described above, the detection end portion of the conventional optical fiber unit is weak in strength as the protection structure of the fiber tip portion, so that the fiber tip portion is easily damaged, and the fiber tip endures even by a relatively small impact. There was an adverse effect of deforming the shape of the part.

  In view of such circumstances, the present invention aims to provide a strong protection structure for the detection end of the optical fiber unit, thereby making it difficult to damage the tip of the fiber and causing the tip of the fiber even by impact. The object is to make the shape of the part difficult to be deformed.

  In order to achieve the above-mentioned object, the present invention is directed to an optical device in which a detection end on one end side of a single-wire optical fiber is directed to an object to be detected, and a connection end on the other end side of the optical fiber is connected to an amplifier unit. An optical fiber unit in a fiber sensor, wherein the detection end portion of the optical fiber unit is made of a metal (stainless steel) distal end side shaft portion in which the optical fiber is fixed in a straight coaxial center position and the shaft A metal (stainless steel) base shaft portion attached in a fixed state on the base end side of the portion, and the tip side shaft portion covers the optical fiber in a fixed state to protect the fiber A double pipe protection structure with a fiber protection pipe made of (made of stainless steel) and a metal (stainless steel) reinforcement pipe that covers the outer periphery of the fiber protection pipe in a fixed state and reinforces the fiber protection pipe Providing protective structure for detecting end of the fiber unit of the optical fiber sensor according to claim.

  The reinforcing pipe is fixed to the outer periphery on the base side of the fiber protection pipe excluding the length range of the front end of the fiber protection pipe shifted from the front end of the fiber protection pipe by a predetermined length toward the base end. Provided is a protection structure for a detection end portion of a fiber unit of an optical fiber sensor which is configured to cover and reinforce the fiber protection pipe.

  According to the present invention, the structure of the tip side shaft portion of the detection end portion of the optical fiber unit is made of a metal (stainless steel) fiber protection pipe that covers the optical fiber in a fixed state to protect the fiber, and the fiber protection. A double pipe protection structure with a metal (stainless steel) reinforcement pipe that covers the outer periphery of the pipe in a fixed state and reinforces the fiber protection pipe, thus increasing the strength of the pipe protection structure that protects the tip of the optical fiber. It is possible to effectively protect the tip of the small-diameter optical fiber. Therefore, the tip portion of the fiber can be made difficult to be damaged, and the shape of the tip portion of the fiber can be made difficult to be deformed by an impact.

It is a partially longitudinal front view of the fiber unit of the present invention. FIG. 2 is an enlarged longitudinal sectional view taken along line AA in FIG. 1. It is an enlarged vertical sectional view by the BB arrow line of FIG. It is a schematic front view which shows explanatoryly the attachment state of the detection end part of this invention. It is a front view which shows the outline of the conventional transmission type optical fiber sensor explanatory.

  An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a detection end 3 on one end side of a single optical fiber 2 (shown by a broken line) is directed to an object to be detected (not shown), and a connection end 10 on the other end side of the optical fiber 2 is an amplifier. 1 shows an optical fiber unit 1 in a transmissive optical fiber sensor connected to a unit (not shown).

  As shown in FIGS. 1 to 3, the detection end portion 3 includes a stainless-steel tip side shaft portion 4 in which the optical fiber 2 having a circular cross section is fixed to a linear coaxial center position and the shaft portion. 4 is composed of a stainless steel base shaft portion 5 fixedly attached in the axial length direction on the same axis on the same axis, and the distal end side shaft portion 4 fixes the optical fiber 2 having a circular cross section. A stainless steel tube-shaped fiber protection pipe 4a that covers the state and protects the fiber, and a stainless steel tube-shaped tube that covers the outer periphery of the fiber protection pipe 4a in a fixed state and reinforces the fiber protection pipe 4a. A double pipe protection structure is provided by the reinforcing pipe 4b. Thus, the strength of the distal end side shaft portion 4 is greatly improved by employing the double pipe protection structure of the fiber protection pipe 4a and the reinforcing pipe 4b.

  As shown in FIGS. 1 and 3, the inner diameter of the substantially cylindrical base shaft portion 5 is larger than the outer diameter of the distal end side shaft portion 4 (that is, the outer diameter of the reinforcing pipe 4 b). The proximal end side of the distal end side shaft portion 4 (fiber protection pipe 4a, reinforcing pipe 4b) is fixedly attached to the axial center position in the shaft portion on the distal end side of the portion 5 via a stainless steel tubular spacer 6. It is.

  In the embodiment of the detection end 3 shown in FIG. 1, the reinforcing pipe 4b is fixedly put on the outer periphery of the base of the fiber protection pipe 4a except for the outer periphery of the fiber protection pipe 4a. The fiber protection pipe is reinforced. That is, the reinforcing pipe 4b has an outer periphery on the base side of the fiber protection pipe 4a excluding the length range of the tip of the fiber protection pipe 4a shifted from the tip of the fiber protection pipe 4a by a predetermined length toward the base end. The fiber protection pipe is reinforced in a fixed state. In this way, the outer diameter of the range covered only by the fiber protection pipe 4a is made smaller than the outer diameter of the range covered by the fiber protection pipe 4a and the reinforcing pipe 4b in a doubled manner, so that FIG. The detection end 3 can be accurately attached to the attachment support structure 15 of the detection end shown in FIG. The fiber protection pipe 4a (the outer diameter of the fiber protection pipe 4a on the distal end side not covering the reinforcing pipe 4b) is fitted outside the narrow attachment hole 15a on the detection side of the attachment support structure 15 shown in FIG. It is formed in the diameter. As shown in FIG. 4, the base shaft portion 5 of the detection end 3 is fixed in a thick mounting hole 15 b of the mounting support structure 15 by screwing means such as a tightening bolt (not shown). In FIG. 4, the lower side shows the detection end portion 3 on the light emitting side, the upper side shows the detection end portion 3 on the light receiving side, and a chip that moves between the two detection end portions 3 and 3 that are arranged to face each other in the direction of the arrow. The presence or absence of the detected object S can be detected.

  The optical fiber portion from the base shaft portion 5 to the connection end portion 10 is covered with a flexible covering tube 8 as in the conventional case. In FIG. 1, reference numeral 2a denotes an end portion on the detection side of the optical fiber 2, and 2b denotes an end portion on the connection side of the optical fiber 2 connected to the amplifier unit.

  In the embodiment shown in FIG. 1, the outer diameter of the first fiber protection pipe 4a constituting the distal end side shaft portion 4 is about 0.2 mm, the inner diameter is about 0.12 mm, and the outer side of the double reinforcing pipe 4b. The diameter is about 0.4 mm. The ultrafine optical fiber 2 is passed through a fixed state in the circular tube of the first fiber protection pipe 4a. Further, the axial length of the fiber protection pipe 4a (the axial length from the tip to the base shaft portion 5) covering the entire length of the fiber tip is about 20 mm, and the reinforcing pipe 4b is the tip of the fiber protection pipe 4a. Is fixedly placed on the outer periphery of the fiber protection pipe 4a having a length range shifted backward by about 5 mm. Further, in the same figure, the outer diameter of the base shaft portion 5 is about 1.5 mm. Of course, the structure of the detection end of the present invention is not limited to these values.

DESCRIPTION OF SYMBOLS 1 Optical fiber unit 2 Optical fiber 3 Detection end part 4 Front end side shaft part 4a Fiber protection pipe 4b Reinforcement pipe 5 Base shaft part 6 Tubular spacer 8 Covered tube 10 Connection end part

Claims (2)

  This optical fiber unit is an optical fiber unit in an optical fiber sensor in which a detection end portion on one end side of a single optical fiber is directed to an object to be detected and a connection end portion on the other end side of the optical fiber is connected to an amplifier unit. A metal base shaft portion in which the detection end portion of the unit is attached in a fixed state to a metal distal end side shaft portion in which the optical fiber is fixed in a coaxial position and a base end side of the shaft portion is fixed. The tip side shaft is coated with the optical fiber in a fixed state to protect the fiber, and the fiber protective pipe is covered with the outer periphery of the fiber protective pipe in a fixed state. 2. A protection structure for a detection end portion of a fiber unit of an optical fiber sensor, characterized in that a double pipe protection structure is provided by a reinforcing metal pipe.   The reinforcing pipe is fixedly placed on the outer periphery of the base side of the fiber protection pipe excluding the length range of the front end of the fiber protection pipe shifted from the front end of the fiber protection pipe by a predetermined length toward the base end. The protection structure of the detection end part in the fiber unit of the optical fiber sensor of Claim 1 made into the structure which reinforces this fiber protection pipe.

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