JP2008083669A - Sleeve and optical receptacle using the same - Google Patents

Abstract

The conventional split sleeve has a problem in that since the polishing marks are formed in a complicated direction on the inner peripheral surface, the contact area with the ferrule varies and the holding force is not stable. Also, since the polishing marks on the inner peripheral surface are formed parallel to the axial direction of the sleeve, the frictional resistance on the sliding surface between the outer peripheral surface of the ferrule and the inner peripheral surface of the sleeve is reduced, and the holding power of the ferrule is reduced. Could be reduced. Provided is a ferrule having a stable holding force that improves the holding power of the ferrule of the sleeve and is hardly affected by the external environment such as temperature and humidity.
A sleeve having a polishing mark formed on an inner peripheral surface 1b of a cylinder 1 into which a ferrule is inserted. The polishing mark is formed in a direction substantially perpendicular to the axial direction of the cylinder 1. .
[Selection] Figure 1

Description

  The present invention relates to a sleeve used for an optical connector for connecting ferrules through which an optical fiber is inserted, and an optical receptacle including the sleeve.

  2. Description of the Related Art In recent years, optical communication using an optical fiber 10 is used with an increase in the amount of information in information communication. In this optical communication, a cylindrical ferrule 20 that holds the optical fiber 10 with an inner hole is used to connect the optical fibers 10 to each other.

  Further, in such an optical connector for connecting the optical fibers 10 held by the ferrule 20, a split sleeve 30 having a slit in the longitudinal direction is used. As shown in FIG. 7, the split sleeve 30 is formed by inserting and abutting the ferrules 20 holding the optical fibers 10 from both ends of the split sleeve 30 so that the optical fibers held by the ferrules 20 are aligned. The optical connection is realized. Since such a split sleeve 30 connects the optical fibers 10 so as to reduce optical connection loss, it is necessary to process the through hole of the split sleeve 30 into which the ferrule 20 is inserted with high accuracy.

  As a method for processing the through hole of the split sleeve 30, as shown in FIG. 8A, for example, the tip is formed in a tapered shape in the through hole 31a of the cylindrical body 31 made of ceramics fixed to the fixture 40. The pin 41 coated with diamond abrasive mixed with the oily slurry is inserted, the pin 41 is rotated while the tapered surface of the pin 41 is in contact with the through hole 31a, and the cylindrical body 31 is moved up and down gradually. The inner peripheral surface 31b of the cylindrical body 31 is processed by moving in the direction.

Therefore, in this processing method, when the cylindrical body 31 is moved upward, a spiral polishing mark 32 is formed in the rotational direction of the pin 41 from the upper side of the cylindrical body 31, while the cylindrical body 31 is moved downward. Sometimes a polishing mark 32 is formed in the rotational direction of the pin 41 from the lower side of the cylindrical body. As a result, the split sleeve 30 is formed at an angle at which the polishing marks 32 formed on the inner peripheral surface of the cylindrical body 31 are inclined with respect to the axial direction A of the split sleeve 30 as shown in FIG. (For example, refer to Patent Document 1).

Further, the split sleeve 30 ′ in another example is roughened in the through hole 31 a of the cylindrical body 31 by honing or the like, and diamond powder or CBN powder is injected from the nozzle toward the through hole 31 a, so that FIG. As shown in the figure, there is a case where a polishing mark 32 is formed so as to be parallel to the axial direction A of the through hole 31a of the cylindrical body 31 (see, for example, Patent Document 2).
JP-A-2-231545 Japanese Patent Laid-Open No. 2005-10698

  However, in the split sleeve 30, since the polishing marks 32 are formed in a complicated direction on the inner peripheral surface 31b, the contact area between the outer peripheral surface of the ferrule 20 and the inner peripheral surface 31b of the split sleeve 30 varies, and the ferrule There was a problem that the holding power of the was not stable.

  Further, in the split sleeve 30 ′, the polishing marks 32 are formed in parallel to the axial direction A of the split sleeve 30 ′ on the inner peripheral surface 31b, so that the formation direction of the polishing marks 32 and the insertion direction of the ferrule 20 are different. Are the same. As a result, in this split sleeve 30 ′, the insertion direction of the ferrule 20 and the formation direction of the polishing marks 32 are the same, and therefore, on the sliding surface between the outer peripheral surface of the ferrule 20 and the inner peripheral surface 31b of the split sleeve 30 ′. There was a possibility that the frictional resistance was reduced and the holding power of the ferrule was lowered.

  The present invention has been made in view of the above problems, and is a sleeve in which polishing marks are formed on the inner peripheral surface of a cylindrical body into which a ferrule is inserted, and the polishing marks are in the axial direction of the cylindrical body. On the other hand, it is characterized by being formed in a substantially vertical direction.

  In the present invention, the polishing mark is characterized in that a larger number of central portions of the cylindrical body are formed than an end portion of the cylindrical body.

  Furthermore, in this invention, the said grinding | polishing trace is formed outside the area | region of 0.1-0.3L from the end surface of the said cylinder, when the full length of the said cylinder is set to L. It is characterized by the above-mentioned.

  Furthermore, in the present invention, the polishing mark is characterized in that a central portion of the cylindrical body is formed deeper than an end portion of the cylindrical body.

  In the present invention, the cylindrical body is characterized in that the thickness of the central portion is larger than the thickness of both end portions.

  Furthermore, in the present invention, the cylindrical body has a first region having a substantially uniform thickness at a central portion, and a second region having a thickness decreasing from the first region toward the end portion. .

  The optical receptacle of the present invention includes a sleeve of the present invention, a ferrule having one end inserted into the through-hole and held on the inner peripheral surface of the sleeve where the polishing mark is formed, and the other end of the ferrule And a holder that holds

  In the optical receptacle according to the present invention, a polishing mark is formed on the outer peripheral surface of the ferrule inserted into the through hole in a direction substantially perpendicular to the axial direction of the ferrule.

  According to the sleeve of the present invention, since the polishing mark provided on the inner peripheral surface of the cylinder into which the ferrule is inserted is formed in a direction substantially perpendicular to the axial direction of the cylinder, the direction of the polishing mark and The insertion direction of the ferrule is substantially perpendicular. Therefore, in this invention, the frictional force of the inner peripheral surface of a cylinder and the outer peripheral surface of a ferrule becomes large. As a result, in the present invention, since the force (holding force) for holding the ferrule inserted into the cylindrical body can be improved, the inserted ferrule can be firmly fixed, and for example, temperature, humidity, etc. Changes in holding power due to changes in the external environment can be reduced.

  In the present invention, if more polishing marks are formed in the central part of the cylinder than the end of the cylinder, the ferrule can be firmly fixed and the ferrule insertion part, that is, the cylinder Since the frictional force at the end can be reduced, the ferrule can be easily inserted. In particular, if such a polishing mark is formed in the central portion outside the region of 0.1 to 0.3 L from the end surface of the cylinder, assuming that the total length of the cylinder is L, the ferrule can be inserted efficiently. The holding power of the ferrule can also be improved.

  Further, if the polishing mark at the center of the cylinder is formed deeper than the polishing mark formed at the end of the cylinder, the frictional force at the center of the cylinder can be increased. As a result, in this embodiment, when the tips of the ferrules inserted from the openings at both ends of the cylinder are brought into contact with each other at the center of the cylinder, the relative positional deviation between the tips of the ferrules can be suppressed. Therefore, the light coupling efficiency can be improved.

  In the present invention, if the thickness of the central portion of the cylinder is set larger than the thickness of both ends, the holding force of the ferrule is maximized at the central portion of the cylindrical body and the ferrule is held at the end of the cylindrical body. Since the force can be reduced as compared with the central portion, the insertion property of the ferrule into the cylinder can be improved, and the ferrule can be firmly held in the central portion of the cylinder.

  In particular, in the present invention, if the cylindrical body is provided with a first region having a substantially uniform thickness at the central portion, and a second region having a gradually decreasing thickness from the first region toward the end portion, The holding force of the ferrule in the first region can be made substantially uniform, and from the end of the cylinder toward the first region between the end of the cylinder and the first region (second region). The holding power of the ferrule can be gradually increased. As a result, in this embodiment, when the tips of the ferrules inserted from the openings at both ends of the cylinder are brought into contact with each other at the center of the cylinder, the holding force of the ferrule in the vicinity of the tip of the ferrule can be stabilized. In addition, since the structure is such that the once inserted ferrule is difficult to be removed, the relative displacement between the ferrule tips can be significantly reduced.

  According to the optical receptacle of the present invention, the sleeve of the present invention, a ferrule having one end portion inserted into the through-hole of the cylindrical body and held on the inner peripheral surface of the sleeve where the polishing mark is formed, By providing the holder that holds the other end of the ferrule, it is possible to improve the holding power of the ferrule, so that the ferrule can be firmly fixed.

  Further, in the optical receptacle of the present invention, if a polishing mark is formed on the outer peripheral surface of the ferrule inserted into the through hole of the sleeve in a direction substantially perpendicular to the axial direction of the ferrule, Since the forming direction of the sleeve and the forming direction of the polishing mark of the sleeve match, the area where the outer peripheral surface of the ferrule and the inner peripheral surface of the sleeve are in line contact can be increased, and the ferrule can be fixed more firmly. It becomes.

  A first embodiment of the sleeve of the present invention will be described below with reference to FIG. Fig.1 (a) is a front view of sleeve X1 which concerns on 1st Embodiment of this invention, FIG.1 (b) is a schematic diagram which shows the aspect of the grinding | polishing trace formed in the inner peripheral surface of sleeve X1.

  As shown in FIGS. 1A and 1B, the sleeve X1 according to the first embodiment of the present invention is configured by a cylindrical cylindrical body 1 having a through hole 1a into which a ferrule is inserted. Yes. The cylindrical body 1 is formed with a processing mark 2 on the inner peripheral surface 1b of the cylindrical body 1 exposed to the through hole 1a side, and a slit 1c in the longitudinal direction of the cylindrical body 1, and the through hole 1a into which the ferrule is inserted. The opening edge 1d is formed in a curved surface shape.

  The tubular body 1 has a function of holding a ferrule (not shown) having an optical fiber inserted from the opening of the through hole 1a, and the ferrules inserted from the openings at both ends of the through hole 1a are inserted into the through holes. The optical fibers of the ferrule are optically coupled by abutting within 1a.

  The shape of the cylindrical body 1 is not particularly limited as long as it has a through hole 1a capable of holding a ferrule. For example, the cylindrical body may be a cylindrical body or a rectangular column (triangular prism) having a through hole 1a. , Square pillars, etc.).

The cylindrical body 1 may be made of, for example, a metal such as phosphor bronze, beryllium copper, brass or stainless steel, a plastic such as an epoxy resin or a liquid crystal polymer, or a ceramic such as alumina or zirconia. In such a material, it is preferable to form the cylinder 3 with zirconia ceramics. Specifically, partially stabilized zirconia containing ZrO ₂ as a main component, Y ₂ O ₃ , CaO, MgO, CeO ₂ , and Dy ₂ O ₃ as stabilizers and mainly containing tetragonal crystals. Ceramics. Such partially stabilized zirconia ceramics have excellent wear resistance and moderately elastically deform, so that even if the ferrule is inserted and removed many times, it is not easily damaged.

  When the slit 1c is formed along the longitudinal direction of the cylinder 1, the through-hole 1a of the cylinder 1 is formed slightly smaller than the outer diameter of the ferrule to be inserted. Therefore, when the ferrule is inserted into the through hole 1a of the cylindrical body 1, the outer peripheral surface of the ferrule and the inner peripheral surface 1b of the cylindrical body 1 slide, whereby the inner diameter of the cylindrical body 1 (the diameter of the through hole 1a). Is enlarged. Specifically, the cylindrical body 1 is elastically deformed so that the width of the slit 1c is widened by using a portion facing the slit 1c (hereinafter referred to as a slit facing portion 1e) across the through hole 1a as a fulcrum. The inner diameter of the body 1 is enlarged. The cylindrical body 1 whose inner diameter is enlarged by elastic deformation firmly holds the ferrule by the force of returning to the original shape. Therefore, when extracting the ferrule held by the cylinder 1, it is necessary to apply a force larger than the force of the cylinder 1 to return to the original shape. At this time, the necessary force is called a ferrule holding force of the sleeve. Since the holding force of the ferrule can be regarded as the same as the force of returning the cylindrical body 1 to the original shape, it is proportional to the amount of expanding the inner diameter of the cylindrical body 1.

  The holding force of the ferrule depends on the elastic force obtained from the elastic modulus and thickness of the cylindrical body 1, but is also affected by the frictional force between the outer peripheral surface of the ferrule and the inner peripheral surface of the cylindrical body 1. The That is, if the frictional force between the outer peripheral surface of the ferrule and the inner peripheral surface of the cylindrical body 1 increases, the force required to remove the ferrule from the cylindrical body 1 increases. improves.

  In the present invention, the polishing marks 2 provided on the inner peripheral surface 1 b of the cylinder 1 are formed in a direction substantially perpendicular to the axial direction A of the cylinder 1. In other words, the polishing mark 2 is formed so as to be orthogonal to the ferrule insertion direction. The polishing mark 2 is formed when the through-hole 1a into which the ferrule is inserted is processed with high accuracy. For example, the width is 0.01 to 0.5 μm and the depth is 0.01 to 0.5 μm. It is a minute groove. As described above, in the present invention, the polishing marks 2 are formed in a direction substantially perpendicular to the axial direction A of the cylindrical body 1, so that the minute marks perpendicular to the ferrule insertion direction are adjacent between the adjacent polishing marks 2. Protrusions are formed. Therefore, in the present invention, the frictional resistance between the inner peripheral surface 1b of the cylindrical body 1 and the outer peripheral surface of the ferrule is increased so that the insertion of the ferrule is prevented, so that the force for holding the ferrule inserted into the cylindrical body 1 is maintained. (Holding power) can be improved. As a result, in the present invention, it is possible to firmly fix the inserted ferrule, and to reduce changes in holding force due to changes in the external environment such as temperature and humidity.

  Further, the polishing mark 2 need not be completely orthogonal to the axial direction A of the cylindrical body 1, but is preferably within an angle range of ± 5 ° from the direction orthogonal to the axial direction A. Furthermore, if the polishing marks 2 are 90% or more of the polishing marks 2 with respect to the total number of the polishing marks 2, the ferrule holding force can be improved efficiently if the polishing marks 2 are perpendicular to the axial direction of the cylindrical body 1. it can. In particular, if a polishing mark is formed on the outer peripheral surface of the ferrule inserted into the cylinder 1 in the same direction as the polishing mark 2 of the cylinder 1 (direction perpendicular to the longitudinal direction of the ferrule), Since the frictional force between the outer peripheral surface and the inner peripheral surface of the cylinder 1 is increased, the ferrule holding force can be further improved.

  As shown in FIG. 1B, the polishing mark 2 is not limited to a circular shape that is connected to the circumferential direction of the cylindrical body 1, but with respect to the axial direction A. If it is formed in a substantially vertical direction, the length may be short.

  In addition, as a method for measuring the angle of the polishing mark 2, for example, the sleeve X1 is cut in a longitudinal direction with a surface grinder and processed into a half-cut state, and the angle of the polishing mark 2 projected using a projector or a metal microscope is used. It becomes possible by measuring.

  Further, it is desirable that the polishing mark 2 is formed deeper in the central portion 1g of the cylindrical body 1 than in the end portion 1f of the cylindrical body 1. According to such a form, the said frictional force in the center part of a cylinder can be enlarged. As a result, in this embodiment, when the tips of the ferrules inserted from the openings at both ends of the cylinder are brought into contact with each other at the center of the cylinder, the relative positional deviation between the tips of the ferrules can be suppressed. Therefore, the light coupling efficiency can be improved. Thus, if the polishing mark 2 is deepened in the portion where the holding power is most desired to be increased, the decrease in the frictional force on the inner peripheral surface of the ferrule caused by the humidity of the external environment can be reduced.

  The depth of the polishing mark 2 is preferably 0.02 to 0.2 μm at the end 1 f of the cylinder 1 and 0.3 to 1.0 μm at the center 1 g. If the depth of the end portion 1f is less than 0.02 μm, the possibility that the holding force fluctuates due to the influence of the external environment (in a humid environment) increases, and if it exceeds 0.2 μm, the contact area with the ferrule decreases. In some cases, the desired ferrule holding power cannot be obtained. Further, when the depth of the polishing mark 2 in the central portion 1g is less than 0.3 μm or exceeds 1.0 μm, it is difficult to improve the ferrule holding force in the central portion 1g. In addition, the center part 1g of the cylinder 1 shows the area | region outside the area | region of 0.1-0.3L from the end surface of the cylinder 1, if the full length of the cylinder 1 is set to L.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic view showing an aspect of polishing marks formed on the inner peripheral surface of the sleeve X2 according to the second embodiment of the present invention.

  In the sleeve X2 according to the second embodiment of the present invention, as shown in FIG. 2A, the polishing mark 2 is formed more in the central portion of the cylindrical body 1 than in the end portion of the cylindrical body 1. The configuration is the same as that of the first embodiment except for the difference.

  In the sleeve X2 according to the second embodiment of the present invention, since there are few polishing marks 2 at the end of the cylinder 1 that is in the vicinity of the opening of the through hole 1a into which the ferrule is inserted, the cylinder 1 The frictional force between the outer peripheral surface of the ferrule and the inner peripheral surface 1b of the cylindrical body 1 at the end portion 1f can be reduced. Therefore, the ferrule can be easily inserted in the sleeve X2. Furthermore, since many polishing marks 2 are formed in the center part of the cylinder 1, the said frictional force in the center part of the cylinder 1 can be enlarged. Thereby, in the sleeve X2, since the holding force of the ferrule in the center part of the cylinder 1 can be improved, it is possible to firmly hold the contact part between the ferrules located in the center part of the cylinder 1. The connection loss between the optical fibers held by the ferrule due to the positional deviation of the ferrule can be reduced. Further, the polishing marks 2 may be formed on the inner peripheral surface 1b of the cylinder 1 so as to gradually increase from the end 1f of the cylinder 1 toward the center.

  Further, the formation position of the polishing mark 2 is, as shown in FIG. 2 (b), when the total length of the cylinder 1 is L, the center portion outside the region of 0.1 to 0.3L from the end surface of the cylinder 1 If only the ferrule is formed, the ferrule can be easily inserted, and the ferrule holding force at the contact portion of the ferrule can be efficiently improved.

Next, a third embodiment of the present invention will be described with reference to FIG. Fig.3 (a) is a schematic diagram which shows the aspect of the sleeve X3 which concerns on 3rd Embodiment of this invention. In the sleeve X3 according to the third embodiment of the present invention, as shown in FIG. 3A, the thickness of the central portion 1g of the cylindrical body 1 is larger than the thickness of both end portions 1f. Except for the difference, the configuration is the same as that of the first embodiment. That is, in the sleeve X3, the ferrule holding force can be maximized at the central portion 1g of the cylindrical body 1, and the ferrule holding force at the end portion 1f of the cylindrical body 1 can be reduced compared to the central portion 1g. The insertability of the ferrule into the cylinder 1 can be improved, and the ferrule can be firmly held in the central portion 1g of the cylinder 1. In addition, a sleeve X3 ′, which is a modified example of the sleeve X3 according to the third embodiment of the present invention shown in FIG. 3B, has a cylindrical body 1 having a thickness from the end portion 1f toward the center of the central portion 1g. It is formed so as to become thicker gradually. In this sleeve X3 ′, since the holding force of the ferrule can be gradually increased from the end 1f of the cylindrical body 1 toward the central portion 1g, the inserted ferrule has a structure that is difficult to be removed. It is possible to remarkably reduce the relative positional deviation between each other.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic view showing an aspect of a sleeve X4 according to the fourth embodiment of the present invention.

  As shown in FIG. 4, in the sleeve X4 according to the fourth embodiment of the present invention, the cylindrical body 1 has a first region 1h having a substantially uniform thickness at the central portion 1g, and ends from the first region 1h. It differs from 1st Embodiment of this invention by having the 2nd area | region 1i where thickness becomes small toward the part 1f. In the first region 1h, the thickness of the cylindrical body 1 is uniform, and the second region 1i has a truncated cone shape. In the sleeve X4, when the tips of the ferrules inserted from the openings of the both end portions 1f of the cylindrical body 1 are brought into contact with each other at the central portion 1g of the cylindrical body 1, the holding power of the ferrule in the vicinity of the leading end portion of the ferrule is stabilized. In addition, since the structure is such that the once inserted ferrule is difficult to remove, the relative displacement between the ferrule tips can be significantly reduced. In addition, it is preferable that the width | variety in the longitudinal direction of the cylinder 1 of this 1st area | region 1h and the 2nd area | region 1i which continues to the both ends is substantially the same.

    Next, a method for manufacturing the sleeve X1 according to the first embodiment of the present invention will be described with reference to FIG.

  First, a cylindrical body 1 having a predetermined shape is obtained by extrusion molding or press molding using a material such as a metal such as stainless steel or phosphor bronze, a plastic such as epoxy or liquid crystal polymer, or a ceramic such as alumina or zirconia.

  In the case where the cylindrical body 1 is formed of ceramics, it is also possible to bake and harden in the firing step, or to perform cutting, or to form the molded body integrally by ceramic injection molding and then fire it under predetermined conditions. Obtainable.

  Next, as shown in FIG. 5, a plurality of magnetic pole portions 51 and 52 having permanent magnets are installed outside the obtained cylindrical body 1, and the magnetic abrasive grains 53 put into the through holes 1 a of the cylindrical body 1 are arranged. On the other hand, at the same time as applying the polishing pressure by the magnetic field, the magnetic abrasive grains are rotated by rotating the magnetic pole portions 51 and 52 connected to the arm 50 in the circumferential direction of the cylindrical body 1. The magnetic abrasive grains 53 are subjected to a relative movement to impart centrifugal force to the inner peripheral surface 1b of the cylinder 1 so that the abrasive grains 53 advance in a direction perpendicular to the axial direction A of the cylinder 1. To do. According to such a polishing process, the inner peripheral surface 1b of the cylindrical body 1 can be processed with high accuracy, and the inner peripheral surface 1b of the cylindrical body 1 is polished in a direction substantially perpendicular to the axial direction A. The scar 2 can be formed.

  Such a magnetic abrasive grain is not particularly limited as long as it is a magnetic body having such a hardness that the polishing mark 2 can be formed on the inner peripheral surface 1b of the cylindrical body 1. For example, the grain size is 3 to 500 μm. Steel balls can be used. Further, from the viewpoint of improving the polishing power of the steel ball and shortening the processing time, it is preferable to use a material in which diamond abrasive grains of 0.2 to 2 μm are dispersed and bonded to the surface of the steel ball by electrodeposition.

  Finally, the slit 1c is processed using a grinding wheel in which diamond abrasive grains are applied to the cylinder 1 to form the sleeve X1 of the present invention. When the depth of the polishing mark 2 is made different between the central portion 1g and the end portion 1f, for example, as a method of forming the central portion 1g deeply, the magnetic abrasive grains 53 shown in FIG. By rotating for a longer time than if, it can be formed easily.

    Next, an embodiment of an optical receptacle using the sleeve of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of the optical receptacle Y according to the first embodiment of the present invention.

  The optical receptacle Y includes a sleeve X1 of the present invention, a ferrule 4 having one end portion inserted into the through hole 1a of the sleeve X1 and held by the inner peripheral surface 1b of the sleeve X1, and a ferrule. 3 is provided with a holder 5 holding the other end of 3 and a shell 6 for protecting the sleeve X1.

  The optical fiber 3 has a function of propagating light, and for example, a quartz optical fiber, a plastic optical fiber, a multicomponent glass optical fiber, or the like can be used.

  The ferrule 4 is a member for protecting the optical fiber 3 and cooperating with the sleeve X1 so that the central axis of the optical fiber 3 coincides with the central axis of the optical fiber protected by the plug ferrule (not shown). For example, it has a cylindrical shape.

Examples of the material constituting the ferrule 4 include zirconium oxide (zirconia), aluminum oxide (alumina), mullite, silicon nitride, silicon carbide, aluminum nitride and the like, ceramics containing these as main components, and glass such as crystallized glass. Examples include ceramics, phosphor bronze, beryllium copper, brass, stainless steel, and plastics such as epoxy and liquid crystal polymer. Among them, zirconia-based ceramics (ceramics mainly composed of zirconia) are excellent in weather resistance and toughness. Is preferred. Among zirconia-based ceramics, in particular, at least one selected from the group consisting of zirconium oxide (ZrO ₂ ) as a main component and Y ₂ O ₃ , CaO, MgO, CeO ₂ , Dy ₂ O _{3 and the} like is used as a stabilizer. Partially stabilized zirconia ceramics (mainly tetragonal crystals) are included as a more preferable material from the viewpoints of wear resistance and elastic deformation.

  Since the holder 5 and the shell 6 are often welded to a case for storing an optical element or the like as an optical module, materials that can be welded such as stainless steel, copper, iron, nickel, etc. are used. In consideration of weldability, stainless steel is preferably used.

And in the optical receptacle Y which is 1st Embodiment of this invention, the ferrule 4 is hold | maintained by the internal peripheral surface 1b of the sleeve X1 in which the grinding | polishing trace 2 is formed. Therefore, in the optical receptacle Y, the frictional force on the sliding surface between the inner peripheral surface 1b of the sleeve X1 and the outer peripheral surface of the ferrule 4 increases. As a result, since the optical receptacle Y can improve the holding power of the ferrule, it is possible to firmly fix the ferrule. In the optical receptacle Y, the ferrule inserted into the through hole 1a of the sleeve X1. 4 is formed on the outer peripheral surface of the ferrule 4 in a direction substantially perpendicular to the axial direction of the ferrule 4, the direction of formation of the polishing mark of the ferrule 4 and the direction of formation of the polishing mark 2 of the sleeve X1 are the same. The portion where the outer peripheral surface of the sleeve and the inner peripheral surface of the sleeve are in line contact can be increased, and the ferrule can be more firmly fixed.

BRIEF DESCRIPTION OF THE DRAWINGS The sleeve which concerns on the 1st Embodiment of this invention is shown, (a) is a front view, (b) is a schematic diagram which shows the aspect of the grinding | polishing trace formed in the internal peripheral surface of a sleeve. (A), (b) is a schematic diagram which shows the aspect of the grinding | polishing trace formed in the internal peripheral surface of the sleeve which concerns on the 2nd Embodiment of this invention. (A), (b) is a schematic diagram which shows the aspect of the grinding | polishing trace formed in the internal peripheral surface of the sleeve which concerns on the 3rd Embodiment of this invention. It is a schematic diagram which shows the aspect of the grinding | polishing trace formed in the internal peripheral surface of the sleeve which concerns on the 4th Embodiment of this invention. It is the schematic which shows the manufacturing method of the sleeve which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the optical receptacle which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure of a common optical connector. The conventional sleeve is shown, (a) is the schematic which shows the processing method of the conventional sleeve, (b) is a schematic diagram which shows the aspect of the grinding | polishing trace formed in the internal peripheral surface of the conventional sleeve. It is. It is a schematic diagram which shows the aspect of the grinding | polishing trace formed in the internal peripheral surface of the conventional sleeve.

Explanation of symbols

X1, X2, 30, 30 ': Sleeve Y: Optical receptacle 1, 31: Tube 1a, 31a: Through hole 1b, 31b: Inner peripheral surface 1c: Slit 1d: Edge 1e: Slit facing portion 1f: End 1g : Central part 1h: 1st area | region 1i: 2nd area | region 2, 32: Polishing trace 3, 10: Optical fiber 4, 20: Ferrule 4: Receptacle 5: Holder 6: Shell 40: Fixing tool 41: Pin 50: Work pieces 51, 52: Magnetic pole part 53: Magnetic abrasive grains

Claims (8)

A sleeve in which a polishing mark is formed on the inner peripheral surface of a cylindrical body into which a ferrule is inserted,
The sleeve, wherein the polishing mark is formed in a direction substantially perpendicular to the axial direction of the cylindrical body. 2. The sleeve according to claim 1, wherein the polishing mark is formed more in a central portion of the cylindrical body than in an end portion of the cylindrical body. 3. The sleeve according to claim 2, wherein the polishing mark is formed outside an area of 0.1 to 0.3 L from an end surface of the cylindrical body, where L is a total length of the cylindrical body. The sleeve according to any one of claims 1 to 3, wherein the polishing mark is formed so that a central portion of the cylindrical body is deeper than an end portion of the cylindrical body. The sleeve according to any one of claims 1 to 4, wherein a thickness of a central portion of the cylindrical body is larger than thicknesses of both end portions. 6. The cylindrical body includes a first region having a substantially uniform thickness at a central portion, and a second region having a thickness gradually decreasing from the first region toward an end portion. The sleeve as described in. A sleeve according to any one of claims 1 to 6;
One end is inserted into the through-hole of the cylindrical body, and a ferrule held on the inner peripheral surface of the sleeve in which the polishing mark is formed,
And a holder that holds the other end of the ferrule. The optical receptacle according to claim 7, wherein a polishing mark is formed on an outer peripheral surface of the ferrule inserted into the through hole in a direction substantially perpendicular to an axial direction of the ferrule.

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