JP4066529B2 - Flexible tube end holder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flexible tube terminal holder that enables a flexible tube to be firmly connected to a connection partner component without a tool. This holder is particularly suitable for applications in which the end of a jacket (a jacket made of a flexible tube) such as an optical fiber cord or a coaxial cord is connected to a connector or the like.
[0002]
[Prior art]
For example, when an optical fiber cord is connected to an optical connector, a gripping bracket is provided in the connector housing, and the optical fiber cord drawn into the connector housing by caulking the bracket or tightening with a screw is used with the gripping bracket. The method of holding is often adopted,
(1) It is necessary to incorporate a holding bracket into the housing, which deteriorates connector productivity.
(2) A caulking tool or a screw tightening tool is required for connection.
(3) Depending on whether the bracket is tightened or not, there is a concern that the optical fiber in the cord may be disconnected.
(4) Since the cord is simply held from the outside of the jacket with metal fittings, the reliability of fixing the jacket is insufficient.
There is a problem.
[0003]
On the other hand, there is a known pipe joint shown in FIG. This pipe joint is disclosed in Japanese Patent Laid-Open No. 10-110870, and an inner cylinder 22 provided in a main body 21 is inserted into a pipe 23 to be connected, and a cap nut (cover) 24 is connected to the main body 21. Then, the cap sleeve 24 is contracted by the cap nut 24, and the protrusion 26 on the inner surface of the sleeve is bitten into the outer periphery of the tube 23 to fix the tube 23 on the inner cylinder 22.
[0004]
This pipe joint can be used for connecting an optical fiber cord. The inner tube 22 is extended to a position just below the retaining sleeve 25 to pass the optical fiber in the cord through the hole of the inner tube 22, and an optical fiber cord jacket is further interposed between the extended inner tube 22 and the retaining sleeve 25. When sandwiched, the optical fiber cord can be connected to the main body 21 without applying a holding force to the optical fiber.
[0005]
[Problems to be solved by the invention]
The pipe joint of FIG. 7 has an advantage that an optical fiber cord, a coaxial cord, or the like can be connected to the main body 21 without applying any tightening force to a core wire such as an optical fiber. But on the other hand,
(1) There are many parts and the assembly is complicated.
(2) Many parts that require cutting work are included, and the manufacturing cost is high.
(3) Since it is a screw fitting structure, it is possible to forget to attach the pin 27 for preventing the loosening (the possibility is not low). There are concerns about disassembly.
(4) If the cap nut is manually tightened, a large pulling strength cannot be obtained. Therefore, an operation tool (wrench, spanner, etc.) is required, and an easy connection cannot be made.
Have the disadvantages.
[0006]
Therefore, the present invention is composed of two parts with a simple structure that can be mass-produced by plastic injection molding, etc., and can be assembled without tools, and the optical fiber cord jacket and the like can be fixed to the connection partner parts with reliability. An object is to realize and provide a tube terminal holder.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention comprises a connecting member for a flexible tube having an inner cylinder projecting to the outside, and a stopper having a tube receiving hole. A concave portion is formed in the convex portion and the longitudinal middle portion, and a convex portion is formed on the inner cylinder receiving hole inner surface of the stopper in a state where the stopper is mounted, and is placed on the outer side of the inner cylinder. Provided is a flexible tube terminal holder in which a connecting end side of a tube is fitted and the stopper is fitted on the outer side so that the tube is sandwiched between an inner cylinder and the stopper.
[0008]
Such a holder becomes more preferable when the following configurations (a) to (e) are added.
[0009]
(A) The outer diameter of the tube fitting portion (the portion into which the tube is fitted) of the inner cylinder is made equal to or smaller than the inner diameter of the flexible tube, and the inner diameter of the tube receiving hole of the stopper is set to the outer diameter of the tube. And the same diameter or larger.
(B) The inner cylinder is formed integrally with the connection partner component, and further, a protrusion is provided on one of the mutual butting surfaces of the stopper and the connection partner component, and a recess is provided on the other to fit the protrusion.
(C) The outer diameter on the proximal end side of the inner cylinder is made the same as or larger than the outer diameter of the flexible tube, and the inner cylinder is divided into two vertically in the inner cylinder at the front side of the large diameter portion. A slit is provided.
(D) A plurality of spiral cam grooves having one end opened at the outlet of the tube receiving hole on the inner surface of the portion of the tube receiving hole that receives the inner cylindrical large diameter portion, are provided at a constant pitch in the circumferential direction. A cam follower that slidably fits in each cam groove is provided on the outer periphery on the tip side of the end, and furthermore, on the mutual abutting surface of the stopper and the connecting part, the positions are aligned at the end point where the inner cylinder is inserted into the stopper, and they are fitted together. Two pairs of matching protrusions and recesses are provided symmetrically.
(E) The surface on the inner cylinder tip side of the convex portion on the outer periphery of the inner cylinder is a forward and downward inclined surface, and the surface on the receiving hole inlet side of the convex portion on the inner surface of the tube receiving hole is a slope inclined in the direction opposite to the inclined surface.
Further, when the inner cylinder hole is penetrated to the inside of the connection partner part and a linear body such as an optical fiber covered and protected by the flexible tube can be drawn into the connection counterpart part from the hole of the inner cylinder, It can be used to connect optical fiber cords with core wires inside. The holder used for connecting the optical fiber cord is a curved surface that removes the edge of the hole and expands the hole diameter toward the inlet at the inlet of the hole of the inner cylinder and the inlet of the tube receiving hole of the stopper. Is preferably provided.
[0010]
[Action]
The holder according to the present invention has a simple structure of two components, which are constituent elements, and the two components can be formed by injection molding of plastic or the like that is excellent in mass productivity, thereby reducing costs.
[0011]
In addition, after the inner cylinder is inserted into the tube, assembly is completed when a stopper that is preliminarily fitted onto the tube is press-fitted to the outside of the inner cylinder, so that the work can be performed without a tool and the work efficiency is improved.
[0012]
Further, by providing the convex portion and the concave portion on the inner cylinder and the convex portion on the inner surface of the tube receiving hole, the tube meanders and is sandwiched, so that sufficient holding force is exhibited even in assembly by human power.
[0013]
In the case where the configuration (a) is added, the convex portion of the inner surface of the tube receiving hole engages with the convex portion of the inner cylinder so that the stopper is surely prevented from coming off and the holder is inadvertently disassembled. There is nothing.
[0014]
Further, if the stopper and the connection partner part are provided with a protrusion and a recess, the stopper is prevented from rotating, and the effect of preventing disassembly is further enhanced.
[0015]
Further, when the tip of the inner cylinder is divided into two, the inner cylinder is reduced in diameter when the stopper is press-fitted, and the effect of facilitating the press-fitting can be obtained. Even if the convex part on the outer periphery of the inner cylinder and the convex part on the inner surface of the tube receiving hole are provided with a slope, the convex part on the stopper side can be easily guided by the slope when the stopper is attached and removed. It is possible to get over and it becomes easy to attach and remove the stopper.
[0016]
In addition, when a spiral cam groove is provided on the inner surface of the tube receiving hole and the cam follower on the inner cylinder is engaged with the cam groove, the stopper is operated by the cam groove and the cam follower when the stopper is engaged while rotating. Propulsive force for press-fitting is generated, and the stopper can be easily attached by human power.
[0017]
In addition, if a curved surface that increases the hole diameter toward the inlet is provided at the inlet portion of the inner cylinder and the inlet portion of the tube receiving hole, the linear member such as an optical fiber passing through the inner cylinder is swayed to the edge of the hole. Even if it hits, a tight bending force is not applied to a contact point, and it becomes difficult to cause the breakage of the filament at the lead-out portion from the hole.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the holder of the present invention. The holder shown in the figure is an example in which the optical fiber cord A is connected to the optical connector 2.
In the optical fiber cord A, as shown in FIG. 2, the optical fiber a (core wire) is wrapped with a reinforcing fiber b made of a tensile strength fiber made of an aromatic resin and the outside is covered with a jacket c made of a vinyl tube or the like. It has a structure.
[0019]
1 includes an optical connector 2 having an inner tube 1 and a stopper 4 having a tube receiving hole 3. A convex portion 5 (in the figure, an annular convex portion) is provided on the outer peripheral portion of the inner cylinder 1, and a concave portion 6 (in the figure, an annular groove) is provided in the longitudinal intermediate portion of the inner cylinder 1.
[0020]
Further, the inner surface of the tube receiving hole 3 is provided with a convex portion 7 that comes directly above the concave portion 6 when the stopper 4 is mounted. When the tube receiving hole 3 and the inner cylinder 1 are concentric, the radial gap g generated between the convex portions 5 and 7 is set smaller than the thickness of the jacket c. Further, the outer diameter d of the tube fitting portion of the inner cylinder 1 is made equal to or smaller than the inner diameter of the jacket c, and the inner diameter d ₁ of the tube receiving hole 3 is made equal to or larger than the outer diameter of the jacket c. It is enlarged.
[0021]
In this holder, the inner cylinder 1 is inserted inside the jacket c, the stopper 4 is press-fitted into the outer side, and the reinforcing fiber b and the jacket c are sandwiched between the inner cylinder 1 and the stopper 4. If it carries out like this, the reinforcement fiber b and the jacket c will be hooked on the convex parts 5 and 7, and cannot be pulled out easily. In particular, the provision of the concave portion 6 and the convex portion 7 causes the jacket c to meander in a complicated manner between the inner tube and the stopper 4, and the pullout strength is enhanced to achieve stable retention.
[0022]
The optical fiber a is drawn into the housing of the connector 2 through the inside of the inner cylinder 1. Therefore, it is not affected at all by the stress that holds the optical fiber cord A.
[0023]
In addition, while this holder has a strong pulling strength, when the stopper 4 is fitted, the convex portion 7 gets over the convex portion 5 while compressing the jacket c, so that the press-fitting stress of the stopper is high. In some cases, press-fitting by human power becomes difficult. Therefore, in such a case, structures and elements as shown in FIGS. 3 to 5 are added. The additional elements are listed below.
[0024]
(1) The front surface 5a of the convex portion 5 in the direction of inserting the inner cylinder is formed into a forward and descending slope that can easily get over the convex portion 7.
(2) A slit 8 that divides the inner cylinder vertically into two is provided at the tube fitting portion of the inner cylinder 1 so that the diameter of the inner cylinder 1 is reduced when the convex part 7 gets over the convex part 5.
(3) A large-diameter portion 1a having the same diameter as or larger than the outer diameter of the jacket c (FIG. 1) is provided on the proximal end side of the inner cylinder 1, and the inner surface of the large-diameter portion receiving portion 3a of the tube receiving hole 3 is spiraled. Cam groove 9 (FIGS. 3 and 6 show the groove expanded). In addition, a cam follower 10 that is slidably fitted in the cam groove 9 is provided on the outer periphery of the distal end of the large-diameter portion 1a.
In this way, the stopper 4 is fitted while being rotated, and an axial thrust force serving as a pressure input is generated in the engaging portion between the cam groove 9 and the cam follower 10. When a plurality of cam grooves 9 and cam followers 10 are provided at a constant pitch in the circumferential direction, axial thrust can be generated in a balanced manner.
By applying the above-described devices, easy assembly by human power becomes possible.
[0025]
Next, particularly when the configuration (3) is adopted, the stopper 4 may be loosened naturally. Therefore, as shown in FIGS. 3 to 5, the recess 11 is provided symmetrically on the end surface of the connector 2 with respect to the inner cylinder 1, and the stopper 4 is located at a position corresponding to the recess 11 at the insertion end point of the inner cylinder 1. Protrusions 12 are provided that come into and fit into the recesses 11. The engagement between the recess 11 and the protrusion 12 prevents the stopper 4 from rotating due to an unexpected stress, and the reliability of preventing the holder from being disassembled is increased.
[0026]
1, 3, 4, and 6, if the surface 7 a on the receiving hole entrance side of the convex portion 7 is inclined to the opposite direction to the inclined surface 5 a, even when the stopper 4 is removed. The convex portion 7 can easily get over the convex portion 5.
[0027]
Further, as shown in FIG. 6, when the core wire such as the optical fiber a is passed through the inside of the inner cylinder 1 and is drawn into the connector or the like, as shown in FIG. If the curved surface 1b, 3b is provided at the inlet portion of the receiving hole 3 to remove the edge of the hole and expand the hole diameter toward the inlet side, even if the core wire passing through the inner cylinder 1 swings in the direction perpendicular to the axis, A local bending stress is not applied to the edge of the hole, and disconnection of the core wire at the lead-out portion from the hole due to the local bending and damage to the jacket can be avoided.
[0028]
【The invention's effect】
As described above, in the tube terminal holder of the present invention, the inner cylinder having the convex portion on the outer periphery is provided in the connection partner part, the inner cylinder is inserted into the tube end, and the outer portion is prevented from being detached by the convex portion. Since the tube end is press-fitted and the tube end is fastened and the tube end is fastened, the component parts are simple, mass production by injection molding or the like is possible, and the cost can be reduced.
[0029]
In addition, an operation tool is not required, and a strong holding strength can be obtained by assembly by human power, so that the connection can be simplified and the reliability can be improved.
[0030]
In addition, the inner cylinder is provided with a slit in the vertical direction, the inner cylinder outer peripheral protrusion and the inner surface of the tube receiving hole are inclined, or the tube receiving hole is provided with a spiral cam groove to form an inner cylinder. Assembling the cam follower on the outer periphery in the groove is easier to assemble by human power.
[0031]
Further, in the case where a protrusion and a recess that are fitted to each other at the attachment point of the stopper are provided on the mating surface of the stopper and the component, the stopper is prevented from rotating and the effect of preventing the natural decomposition of the holder is further enhanced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a holder of the present invention in use. FIG. 2 is a perspective view of an optical fiber cord as an example of a connection target. FIG. 3 is a partially broken side view showing an embodiment of a preferred holder. 4 is a partially cutaway plan view of the holder of FIG. 3. FIG. 5 is a perspective view of an inner cylinder of the holder of FIG. 3. FIG. 6 is a cross-sectional view showing a use state of the holder of FIG. Sectional view showing a conventional example of a pipe joint [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Inner cylinder 1a Large diameter part 1b Curved surface 2 Optical connector 3 Tube receiving hole 3a Large diameter part receiving part 3b Curved surface 4 Stopper 5 Convex part 5a Slope 6 Concave part 7 Convex part 7a Slope 8 Slit 9 Cam groove 10 Cam follower 11 Concave part 12 Protrusion A Optical fiber cord a Optical fiber c Jacket

Claims (7)

Consists of a connection partner part of a flexible tube having an inner cylinder projecting to the outside, and a stopper having a tube receiving hole, forming a convex part on the outer periphery of the tip of the inner cylinder, and forming a concave part in the longitudinal intermediate part, Formed on the inner surface of the inner tube receiving hole of the stopper is a convex portion that is placed immediately above the concave portion in a state where the stopper is mounted, and the connection end side of the flexible tube is fitted on the outer side of the inner tube, and further on the outer side A flexible tube terminal holder in which a stopper is fitted and the tube is sandwiched between the inner cylinder and the stopper. The outer diameter of the tube fitting portion of the inner cylinder is equal to or smaller than the inner diameter of the flexible tube, and the inner diameter of the tube receiving hole of the stopper is equal to or larger than the outer diameter of the tube, Furthermore, the terminal holder of the flexible tube of Claim 1 which made the radial clearance between the convex part of an inner cylinder outer periphery and the convex part of an inner cylinder receiving hole inner surface smaller than the thickness of a flexible tube. The said inner cylinder is integrally formed with the said connection partner component, Furthermore, the protrusion was provided in one side of the mutual abutting surface of the said fastener and a connection partner component, and the recessed part which the said protrusion fits in the other was provided. The flexible tube terminal holder. The outer diameter on the base end side of the inner cylinder is made equal to or larger than the outer diameter of the flexible tube, and the inner cylinder is divided into two vertically in the inner cylinder in the front side portion of the large diameter portion. The terminal holder for a flexible tube according to claim 1, 2 or 3, wherein a slit is provided. A plurality of spiral cam grooves, one end of which opens at the outlet of the tube receiving hole, are provided on the inner surface of a portion of the tube receiving hole that receives the large diameter portion of the inner cylinder at a constant pitch in the circumferential direction. A cam follower that slidably fits in each cam groove is provided on the outer periphery on the tip side of the end, and furthermore, on the mutual abutting surface of the stopper and the connecting part, the positions are aligned at the end point where the inner cylinder is inserted into the stopper, and they are fitted together. 5. The flexible tube terminal holder according to claim 4, wherein two sets of matching projections and recesses are provided symmetrically. The surface on the tip side of the inner cylinder of the convex part on the outer periphery of the inner cylinder is a forward and downward slope, and the face on the inlet side of the convex part on the inner surface of the tube receiving hole is a slope inclined in the direction opposite to the slope. The terminal holder of the flexible tube in any one of 5. It is possible to draw an optical fiber or the like, which is covered and protected by a flexible tube, through the inner cylinder hole inside the connection partner part, and into the connection partner part from the inner cylinder hole. 7. An acceptable surface according to claim 1, wherein curved surfaces are provided at the inlet portion of the hole of the tube and the inlet portion of the tube receiving hole of the stopper so as to remove the edge of the hole and increase the diameter of the hole toward the inlet. End holder for flexible tube.

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