JP2008167778A - Flexible tube of endoscope and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible tube of an endoscope with a desired excellent flexibility in which a flexible tube skeleton made of a plurality of joint pieces connected rotatingly is covered with a netted tube, and also to provide a method for producing the same. <P>SOLUTION: A core rod 20 is inserted into the flexible tube skeleton 7. All axial rattling tabs of the flexible tube skeleton 7 are extended longitudinally and both ends of the flexible tube skeleton 7 are engaged with the core rod 20. The circumference of the flexible tube skeleton 7 is then covered closely with the netted tube 8. By doing so, the netted tube 8 is adhered to and covers the circumference of the flexible tube skeleton 7 in such a state that all axial rattling tabs of the flexible tube skeleton 7 are extended in the longitudinal direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an endoscope flexible tube and a method of manufacturing the same.

  In general, a flexible tube of an endoscope is generally configured such that a mesh tube is tightly coated on a metal spiral tube and a flexible sheath is further coated on the outside thereof, and the mesh tube is attached to the metal spiral tube in the manufacturing process. In the work of close-contact coating, a metal core is passed through a metal spiral tube, and then a mesh tube covered with the metal spiral tube is squeezed into close contact with the metal spiral tube (for example, Patent Document 1).

  However, if the flexible tube of an endoscope using such a metal spiral tube is subjected to high-temperature and high-pressure steam sterilization (autoclave) after using the endoscope, the metal spiral tube may shrink in the axial direction. In some cases, the flexibility may change drastically.

Therefore, in order to obtain durability that does not easily shrink due to high-temperature and high-pressure steam sterilization (autoclave), instead of a metal spiral tube, a plurality of rigid short joint pieces are arranged in series on a coaxial line to form a rivet There is one that uses a flexible tubular frame structure that is rotatably connected by a connecting shaft (for example, Patent Document 2).
Patent No. 3791882 JP-A-9-24020

  However, the flexible tube frame structure in which a plurality of joint pieces are rotatably connected by a connecting shaft has a backlash mainly due to a slight gap in a fitting portion between the connecting shaft and the connecting hole. Yes, if the mesh tube is tightly covered with the axial backlash being compressed and contracted and the state is fixed, the bending motion between adjacent joint pieces becomes heavy and the bending angle becomes small. In some cases, desired flexibility cannot be obtained.

  The present invention relates to a flexible tube of an endoscope having a structure in which a mesh tube is coated on a flexible tube frame formed by rotatably connecting a plurality of joint pieces. It is an object of the present invention to provide an endoscope flexible tube and a method for manufacturing the same.

  In order to achieve the above object, the flexible tube of the endoscope of the present invention can be bent as a whole by pivotally connecting a plurality of short cylindrical joint pieces arranged in series on a coaxial line. A flexible tube frame is formed, a mesh tube formed by braiding a metal wire is covered with a flexible tube frame, and an outermost layer is covered with a flexible skin. In the flexible tube, a net-like tube is tightly coated on the outer periphery of the flexible tube frame in a state where all the axial backlash existing in the flexible tube frame is stretched in the longitudinal direction.

  In the endoscope flexible tube manufacturing method of the present invention, the core tube is passed through the flexible tube frame, and the axial backlash existing in the flexible tube frame can be extended in the longitudinal direction. A mesh tube is tightly coated on the outer periphery of the flexible tube frame with both ends of the flexible tube frame being locked to the core, and both ends of the flexible tube frame are attached to the core. It is preferable that a length adjusting mechanism between the locking portions for adjusting the length between the first and second locking portions that are each detachably locked is provided.

  According to the present invention, in a flexible tube of an endoscope having a configuration in which a flexible tube frame formed by rotatably connecting a plurality of joint pieces is covered with a mesh tube, a flexible tube frame is provided. Since the net-like tube is tightly coated on the outer periphery of the flexible tube frame in a state where the total backlash in the axial direction existing in the tube is stretched in the longitudinal direction, the flexible tube can obtain a desired good flexibility. Can do.

  A plurality of short cylindrical joint pieces arranged in series on a coaxial line are rotatably connected to form a flexible tube frame that can be bent as a whole, and a mesh tube formed by braiding a metal wire. In the flexible tube of an endoscope having a configuration in which a flexible tube frame is covered and a flexible skin is covered on the outermost layer, the total amount of backlash in the axial direction existing in the flexible tube frame is reduced. In a state of being stretched in the longitudinal direction, a mesh tube is tightly coated on the outer periphery of the flexible tube frame. In order to manufacture a flexible tube of such an endoscope, a cored bar is passed through the flexible tube frame, and the axial backlash existing in the flexible tube frame is stretched in the longitudinal direction. A net-like tube is tightly coated on the outer periphery of the flexible tube frame in a state where both ends of the tube frame are locked to the cored bar.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 6 shows the appearance of an endoscope, and the flexible tube portion 1 constituting the insertion portion inserted into the body has flexibility that can be bent to an arbitrary state by an external force, and an optical fiber. And various built-in objects such as signal cables and tubes are inserted in the interior.

  A bending portion 2 that is bent by a force acting by remote operation is provided at the distal end portion of the flexible tube portion 1, and a distal end portion body 3 on which an observation window or the like is arranged is connected to the distal end of the bending portion 2. The bending portion 2 is operated in a desired direction as exemplified by a two-dot chain line by selectively rotating the bending operation knobs 5 and 6 in the operation portion 4 connected to the proximal end of the flexible tube portion 1. Can be bent at a desired angle.

  A connector portion 12 that is detachably connected to a light source device (also serves as a video processor) (not shown) is attached to the distal end of a flexible connecting flexible tube 11 that extends rearward from the operation portion 4. .

  FIG. 7 shows a configuration of the flexible tube portion 1. In the flexible tube portion 1 of the present invention, a plurality of short cylindrical joint pieces 70 arranged in series on a coaxial line are rotatably connected. A flexible tube frame 7 that is flexible as a whole is formed, and a net-like tube 8 braided with an ultrafine wire made of, for example, a stainless steel fine wire is closely adhered to the outer peripheral surface thereof, and the outermost layer portion that is the outer periphery In addition, a flexible outer skin 9 made of a synthetic resin material or an elastomer is coated. In addition, illustration of built-in things, such as an optical fiber bundle, is abbreviate | omitted.

  As shown in FIG. 8 which is a perspective view of a single piece, the joint piece 70 includes both front and rear ends of a short cylindrical short tube portion 71 made of a metal material such as austenitic stainless steel material. A pair of tongue pieces 72, 72 and 73, 73 are formed so as to project at 180 ° symmetrical positions in the circumferential direction.

  Each pair of tongue pieces 72, 72 and 73, 73 has a short pair of tongue pieces 72, 72 at one of the front and rear ends so that the tongue pieces 72, 73 of adjacent joint pieces 70 overlap each other. A pair of tongue pieces 73, 73 at the other end are formed without a step difference from the short cylinder portion 71.

  And it is inserted from the other tongue piece 73 side into the connection hole 74 formed in one tongue piece (in this embodiment, the tongue piece formed in a recess) 72 of the overlapping tongue pieces 72 and 73. The adjacent joint pieces 70 are connected to each other by the connecting shaft 75 so as to be rotatable.

  The joint piece 70 of this embodiment is integrally formed with the tongue pieces 72 and 73 and the connecting shaft 75 by a manufacturing method such as metal injection, for example, and the connecting shaft 75 extends from the outside to the inside with respect to the connecting hole 74. It is formed so as to protrude inward in a short cylindrical shape so as to be inserted and rotated and fitted. As shown in FIG. 9, which is a front view of the joint piece 70, the connection hole 74 and the connection shaft 75 are provided in directions different by 90 ° around the axis of the joint piece 70.

  Returning to FIG. 7, the connecting hole 74 is sized to be loosely fitted to the connecting shaft 75 to some extent, so there is a backlash due to a slight gap in the fitting portion, and the mesh tube 8 Is tightly coated on the outer periphery of the flexible tube frame 7 in a state where all the axial backlash existing in the flexible tube frame 7 is stretched in the longitudinal direction. Therefore, as shown in FIG. 7, the connecting shafts 75 are moved to one side in the connecting holes 74, and the total length of the flexible tubular frame 7 is in the longest length.

  FIGS. 1 to 5 show a reticulated tube 8 in a state in which all the backlash in the axial direction existing in the flexible tube frame 7 is extended in the longitudinal direction in the process for manufacturing the flexible tube as described above. The process of the part which touches and coats the outer periphery of the flexible tube frame 7 is shown.

  FIG. 2 shows a cored bar 20 that is passed through the flexible tube frame 7 prior to coating the flexible tube frame 7 with the mesh tube 8 and is loosely inscribed in the flexible tube frame 7. A fixed end block 22 for locking the joint piece 70 located on one end side of the flexible tube frame 7 is formed on one end side of the straight insertion rod portion 21 that is passed through the state. A pair of screw holes 23 (first locking portions) are formed in the fixed end block 22 in accordance with the position of the connecting hole 74 formed in the joint piece 70.

  On the other end side of the insertion rod portion 21, a movable end block 24 for locking the joint piece 70 located on the other end side of the flexible tube frame 7 is positioned in the axial direction with respect to the insertion rod portion 21. It is provided so that can be adjusted.

  Specifically, a guide rod 25 that protrudes from the insertion rod portion 21 to the axial position is inserted into a through hole 26 that is formed at the axial position of the movable end block 24 so as to freely advance and retract in the axial direction. By screwing the fixing screw 28 into the screw hole 27 formed in the movable end block 24, the movable end block 24 can be fixed to the guide rod 25 at an arbitrary position. Is formed.

  As shown in FIG. 3 which is a single perspective view of the movable end block 24, a circumferential groove 29 (second locking portion) is formed. The circumferential groove 29 is for engaging the connecting shaft 75 of the joint piece 70, and a guide groove 29 a that opens at the end face of the movable end block 24 to guide the connecting shaft 75 into the circumferential groove 29. Are formed at 180 ° symmetrical positions.

  FIG. 4 shows a state where such a mandrel 20 is passed through the flexible tube frame 7, and one end side of the flexible tube frame 7 is locked through the connection hole 74 of the joint piece 70. The screw 30 is locked to the cored bar 20 by screwing it into the screw hole 23 of the fixed end block 22.

  The other end side of the flexible tube frame 7 engages the connecting shaft 75 of the joint piece 70 with the circumferential groove 29, and then the total backlash in the axial direction existing in the flexible tube frame 7 is set. The movable end block 24 is moved to the maximum rightward in FIG. 4 so as to be stretched in the longitudinal direction, and the fixed screw 28 is tightened tightly to be locked to the core metal 20.

  In this manner, after the axial backlash existing in the flexible tube frame 7 is stretched in the longitudinal direction, both ends of the flexible tube frame 7 are locked to the core bar 20, 1, the reticulated tube 8 is coated on the outer periphery of the flexible tube frame 7, and is squeezed well to adhere to the outer surface of the flexible tube frame 7.

  Finally, the fixing screw 28 and the locking screw 30 are loosened, and the cored bar 20 is removed from the flexible tubular frame 7 as shown in FIG. By doing in this way, the net-like tube 8 is tightly coated on the outer periphery of the flexible tube frame 7 in a state where the axial backlash existing in the flexible tube frame 7 is stretched in the longitudinal direction. .

  The present invention is not limited to the above-described embodiments. For example, the connecting shaft 75 is integrally formed on the overlapping inner tongue piece 72, or adjacent joint pieces 70 are rotated by rivets. The present invention can be applied to flexible tubes of endoscopes having various structures such as those that are freely connected.

It is side surface sectional drawing of the process by which a reticular tube is coat | covered with a flexible tube frame in the manufacturing method of the flexible tube of the endoscope of the Example of this invention. It is side surface sectional drawing of the core metal used at the process by which a flexible tube | skeleton frame | skeleton is coat | covered with a mesh tube in the manufacturing method of the flexible tube of the endoscope of the Example of this invention. It is a single-piece | unit perspective view of the movable end block of the metal core used in the manufacturing method of the flexible tube of the endoscope of the Example of this invention. It is side surface sectional drawing of the process just before a mesh tube is coat | covered with a flexible tube frame in the manufacturing method of the flexible tube of the endoscope of the Example of this invention. It is side surface sectional drawing of the state by which the mesh tube was coat | covered in the flexible tube frame in the manufacturing method of the flexible tube of the endoscope of the Example of this invention. 1 is an external view of an example of an endoscope to which the present invention is applied. It is a partial side sectional view of a flexible tube part of an endoscope of an example of the present invention. It is a perspective view of the single piece of the joint piece of the Example of this invention. It is a front view which shows a part of single piece of the joint piece of the Example of this invention in a cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flexible tube part 7 Flexible tube frame 8 Reticulated tube 9 Flexible outer shell 20 Core metal 21 Insertion bar part 22 Fixed end block 23 Screw hole (1st latching | locking part)
24 Movable end block (length adjustment mechanism between locking parts)
28 Fixing screw (length adjustment mechanism between locking parts)
29 Circumferential groove (second locking part)
30 Locking screw 70 Joint piece 72 Tongue piece 73 Tongue piece 74 Connection hole 75 Connection shaft

Claims (3)

A plurality of short cylindrical joint pieces arranged in series on a coaxial line are rotatably connected to form a flexible tube frame that can be bent as a whole, and a mesh tube formed by braiding a metal wire. In a flexible tube of an endoscope having a configuration in which the flexible tube frame is covered and a flexible outer skin is coated on the outermost layer.
The reticulated tube is tightly coated on the outer periphery of the flexible tube frame in a state where all the axial backlash existing in the flexible tube frame is stretched in the longitudinal direction. Endoscope flexible tube. A plurality of short cylindrical joint pieces arranged in series on a coaxial line are rotatably connected to form a flexible tube frame that can be bent as a whole, and a mesh tube formed by braiding a metal wire. In the method of manufacturing a flexible tube of an endoscope having a configuration in which the flexible tube frame is covered and the outermost layer is covered with a flexible skin,
A cored bar is passed through the flexible tube frame, and the axial backlash existing in the flexible tube frame is extended in the longitudinal direction to lock both ends of the flexible tube frame to the cored bar. A method for manufacturing a flexible tube for an endoscope, wherein the mesh tube is tightly coated on the outer periphery of the flexible tube frame.   A length adjusting mechanism between the locking portions for adjusting the length between the first locking portion and the second locking portion in which both ends of the flexible tube frame are detachably locked to the metal core. The method for manufacturing a flexible tube for an endoscope according to claim 2, wherein:

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