JP5085208B2 - Flexible tube of medical instrument - Google Patents

Description

  The present invention relates to a flexible tube of a medical instrument provided with a cylindrical outer skin having an inner peripheral surface that is coated on an outer peripheral surface of a tubular member.

  At present, endoscopes that are inserted into a body cavity and observe or treat an affected part in the body cavity are widely used. In this type of endoscope, in order to reduce the blind spot observed when inserted into a body cavity, a bending portion is provided near the distal end of the insertion portion, and the bending portion is bent to change the direction of the distal end of the insertion portion. The entire body cavity can be observed. The bending portion of the endoscope needs to be softer than other portions and be able to be bent rapidly.

Therefore, as shown in FIG. 18, the bending portion is composed of a bendable core member 101 and a rubber-like flexible outer tube 102 covering the outer periphery thereof, and the yarn 103 is wound around both ends of the outer tube 102 and tightened. The thread 103 that had been wound by applying the adhesive 104 around the periphery including the thread 103 was hardened.
JP 2002-125916 A

  In the case of the thread winding fixed type as described above, an operation of winding the yarn around the outer periphery of the outer tube in an aligned state and an operation of bonding with an adhesive are necessary. This bobbin work and bonding work are performed manually, and are particularly troublesome and time-consuming when assembling the scope. Also, the finished state appears remarkably in appearance. In this case, the yield of the product was lowered. Although it is possible to avoid this bobbin bonding method and fix the end of the outer tube directly to the curved core material, clean the curved core material when replacing the outer tube when the outer tube is damaged. It is very difficult to peel off the outer tube, and workability at the time of repair is inferior.

  In addition, since the conventional spool fixing structure is a structure in which the adhesive is exposed to the exterior of the outer tube, the durability of the adhesive in the usage environment is low as such. For this reason, it is necessary to study the effects of damage to the adhesive by the various detergents and disinfectants used when cleaning and disinfecting the endoscope. Actions that pay attention to work management to be disinfected are required.

  In view of such circumstances, the present invention provides a flexible tube for a medical device that improves the fixing structure of the outer skin and has high chemical resistance, and also has a structure that allows the outer skin to be fixed and replaced by a simple operation. It is intended to provide a flexible tube for a medical device.

The invention according to claim 1 is a tubular member, a cylindrical outer skin coated on the outer peripheral surface of the tubular member, and a cylindrical inner layer portion integrally formed with the outer skin at an end portion of the outer skin. A cylindrical outer layer portion that is laminated so as to be separable from the inner layer portion, and a member in which the inner layer portion is connected to the tubular member or an end portion of the tubular member by being mounted on the inner layer portion. The outer layer portion is formed on the inner layer portion that is formed on at least one member of the tubular member or the member, and is fixed to the inner layer portion that is pressed against the inner layer portion and the tubular member. A housing portion that enters and locks at least a part of the end portion of the outer layer portion in the stacked state, and divides the end portion of the outer skin into two cylindrical portions located inside and outside. The inner layer portion and the outer layer portion are formed, and the inner layer portion and the outer layer portion are formed. Parts of a flexible tube of the medical device, characterized in that formed integrally with the outer skin.
The invention according to claim 2 is the flexible tube of the medical instrument according to claim 1, wherein the fixing member is a thread-like member wound around the outer peripheral surface of the inner layer portion.
The invention according to claim 3 is the flexible tube of the medical instrument according to claim 1, wherein the fixing member is a sheet-like member wound around the outer peripheral surface of the inner layer portion.
According to a fourth aspect of the present invention, the outer layer portion is made of a thermoplastic resin material, and is welded to the inner layer portion by being heated in a state where the fixing member is stacked on the inner layer portion in which the fixing member is wrapped. A flexible tube of a medical instrument according to any one of claims 1 to 3 , wherein
In the invention according to claim 5 , the outer layer portion is made of a thermoplastic resin, and is heated in a state where the fixing member is overlapped on the inner layer portion in which the fixing member is wrapped, whereby a part of the molten layer is contained in the accommodating portion. The flexible tube of the medical instrument according to any one of claims 1 to 4 , wherein a locking portion that flows into the storage portion and locks to the housing portion is formed.
The invention according to claim 6 is characterized in that the accommodating portion opens toward the outer skin side in the longitudinal direction of the tubular member, and at least a part of the end portion of the outer layer portion can be accommodated. It is a flexible tube of the medical instrument in any one of claim | item 1 thru | or 5 .
The invention according to claim 7 is characterized in that the tubular member or the member has an abutting surface against which an end of the outer layer portion abuts, and an opening of the accommodating portion is formed on the abutting surface. It is a flexible tube of the medical instrument in any one of claim | item 1 thru | or 5 .
According to an eighth aspect of the present invention, at least a part of the end portion of the outer layer portion is accommodated in the accommodating portion so that the end portion of the outer layer portion is attached to the tubular member or the member. The flexible tube of a medical instrument according to any one of claims 1 to 7 , wherein the flexible tube is fixed and prevents an end portion of the outer layer portion from being separated from the inner layer portion.
The invention according to claim 9 is the flexible tube of the medical instrument according to any one of claims 1 to 8 , wherein the medical instrument is an endoscope.

  According to the present invention, the fixing method is improved, the repair property is taken into consideration, the chemical resistance is increased, the tube can be fixed by a simple operation and the tube can be replaced relatively easily.

  An endoscope according to an embodiment of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same configuration are denoted by the same reference numerals.

  FIG. 1 schematically shows the entire endoscope 1. The endoscope 1 here is a fiber type endoscope using an image guide fiber, but may be an electronic type endoscope that picks up an endoscopic image with an imaging element.

  The endoscope 1 includes a large-diameter operation unit 2 and an elongated insertion unit 3. The operation unit 2 is connected to the proximal end (rear end) of the insertion unit 3. A universal cord 4 is connected to the operation unit 2. A light guide connector 5 that can be connected to an endoscope light source device (not shown) is connected to the extended end of the universal cord 4.

  As shown in FIG. 1, the operation unit 2 is provided with operation buttons such as an air supply / water supply operation button and a suction operation button (not shown) in addition to the gripping unit 11 and the angle operation knob 12. An insertion port portion 13 for inserting a treatment tool (not shown) or the like into the insertion channel of the endoscope is provided at a position located on the distal end side (insertion portion side) from the position 11. An eyepiece 14 is provided at the proximal side (base end side) end of the operation unit 2.

  As shown in FIG. 1, the insertion portion 3 is arranged in order from the hand side, that is, the operation portion 2 side, and a flexible portion (soft portion) 21 and a bending portion 22 connected to the tip of the flexible portion 21 , And is constituted by a portion of the distal end portion 23 connected to the distal end of the bending portion 22. The flexible portion 21 is a tubular portion that exhibits flexibility and can be bent by an external force of a predetermined size or more, and the bending portion 22 is forcibly bent by operating the angle operation knob 12. It is the flexible tube part of this invention object. Then, when the bending portion 22 is bent, the tip portion 23 changes its direction according to the bending state. An endoscope using a rigid tube instead of the flexible portion 21 may be used.

  As shown in FIG. 2, the distal end portion 23 of the insertion portion 3 includes a rigid distal end portion main body 25 formed of a metal member. The distal end surface portion of the distal end portion main body 25 has an observation window 31, a channel port 32, an illumination. A window (not shown) and an air / water nozzle (not shown) are provided. You may make it cover the outer surface of the front-end | tip part main body 25 with an electrically insulating resin front-end | tip part cover (not shown), for example. When providing the tip cover, the outer peripheral wall of the tip body 25 is formed by the tip cover. An objective optical system 33 such as an objective lens is installed in the inner part of the observation window 31, and an image in the observation field is formed on the image receiving surface at the tip of the image guide 34 by the objective optical system 33. The image guide 34 is disposed inside the operation unit 2 from the insertion unit 3 and guides the image to the eyepiece unit 14.

  Next, the bending portion 22 will be described. As shown in FIG. 2, the bending portion 22 includes a joint bending mechanism in which a tubular bending core material is constituted by a plurality of bending pieces (joint pieces) 41 and a flexible rubber formed in a tubular shape that covers the joint bending mechanism. A flexible tube that can be bent is constituted by a tube-like outer skin (curved rubber) 42 that exhibits elasticity. Each of the bending pieces 41 is formed of an annular member. The bending pieces 41 are arranged coaxially in a line in the central axis (long axis) L direction of the insertion portion 3. Adjacent bending pieces 41 are close to each other by a rotating shaft portion 43 having an axial center that is orthogonal to the central axis L of the insertion portion 3 and is oriented along the horizontal horizontal direction shown in FIG. It is connected so as to be relatively rotatable in the vertical direction shown in FIG. 1 when viewed from the side. Therefore, any adjacent bending pieces are relatively rotatable in the vertical direction. Therefore, the entire bending portion can be bent in the vertical direction. Further, the rotation shaft portion 43 is configured by a rivet-shaped shaft member that penetrates a portion where tongue-like connecting portions 45 protruding from the end edges of the bending pieces are overlapped with each other.

  As shown in FIG. 2, the bending piece 41 located at the forefront is connected to, for example, the tip end body 25. Further, the bending piece 41 located at the rearmost end is connected to the distal end of the flexible portion 21 via a metal rigid joint pipe 47, for example. The flexible portion 21 is not shown in the figure, but, for example, the outer periphery of a spiral tube formed by forming a strip-shaped plate material is covered with a braided braided blade tube, and the blade tube is covered with a resin outer cover. Composed.

  As shown in FIG. 2, a pair of upper and lower operation wires 51 a and 51 b are arranged in the bending portion 22 along the front-rear direction. The distal end of the operation wire 51a located on the upper side is connected to the upper part of the bending piece 41 (or the member on the distal end portion main body side) located at the most distal end, and the distal end of the operation wire 51b located below is located at the most distal end. It is connected to the lower part of the bending piece 41 (or the member on the tip portion main body side). As a method for connecting the tips of the operation wires 51a and 51b, for example, as shown in FIG. 2, a wall portion corresponding to the connection portion is partially cut and raised inward, and the tip of the operation wire is inserted into the cut and raised piece 52. And fix it by soldering.

  The operation wires 51 a and 51 b are guided by the bending portion 22 through the guide ring 53 protruding from the inner wall surface of the bending piece and guided to the flexible portion 21. The flexible portion 21 is guided through the coiled guide sheath 54 and guided to the operation portion 2. The distal end of the guide sheath 54 is fixed to the inner surface of the joint pipe 47 (see FIG. 2). The proximal ends of the operation wires 51 a and 51 b are connected to a bending operation mechanism (not shown) provided in the operation unit 2. Then, the bending operation mechanism is driven by the angle operation knob 12, whereby the upper and lower operation wires 51a and 51b are alternately pushed and pulled to bend the bending portion 22 in the direction in which the operation wires are pulled.

  The bending portion 22 here is configured to bend only in the vertical direction, but the bending (flexible) type is not limited thereto. For example, when the adjacent bending pieces are connected to each other by the rotation shaft portion so as to rotate in the left-right direction, the bending portion 22 can be bent in the left-right direction. Moreover, if the rotating shaft part that rotates the adjacent bending pieces in the vertical direction and the rotating shaft part that rotates the adjacent bending pieces in the horizontal direction are arranged alternately, for example, the bending part 22 is moved up and down. It can be bent right and left. Moreover, the curved core material of another form may be sufficient. Here, the upper part, the lower part, the left part, and the right part of the bending portion or bending piece can be defined as follows. That is, the right half of the bending piece divided into the right and left sides by a plane passing through both the central axis L of the bending piece and the line perpendicular to the axis of the pivot shaft is the right side portion of the bending piece, and is also divided into the left and right by the plane. The left half of the curved piece is the left part. Further, the upper half of the bending piece divided up and down by a plane passing through both the central axis L of the bending piece and the axis of the rotating shaft portion is defined as the upper portion of the bending piece, and the bending piece divided up and down by the same plane The lower half is the lower part.

  Next, the structure of the bending portion 22 will be specifically described. As shown in FIG. 2, the outer periphery of the rear end portion of the tip end body 25 is formed to be narrower than the tip end portion 55 of the tip end body 25, and this thinly formed portion is the front end portion of the bending piece 41 located at the forefront. It becomes the 1st bending piece attachment part 56 fitted and attached. A step formed by a difference in outer diameter between the first bending piece mounting portion 56 and the tip portion 55 is formed, and a rising wall of the step is a first projection that abuts a tip of an outer skin 42 described later. It is a contact surface 57. Further, the tip of the bending piece 41 positioned at the foremost end abuts at the same position as the first abutting surface 57, and the bending piece 41 positioned at the foremost end is positioned in the axial direction. The bending piece 41 located at the forefront is fixed to the first bending piece mounting portion 56 of the tip end body 25 by fixing means such as soldering, bonding, or screwing.

  The rising height of the first abutting surface 57 is made to substantially coincide with the thickness of the tip portion of the completed outer skin 42. Here, when the front end of the bending piece 41 is positioned against the first abutting surface 57 as shown in FIG. 2, the rising height of the first abutting surface 57 excludes the thickness of the front end portion of the bending piece 41. It becomes the size. And the front-end outer peripheral part of the bending piece 41 becomes the 1st outer skin attaching part 58 which covers and attaches the front-end | tip part of the outer skin 42 mentioned later.

  On the other hand, as shown in FIG. 2, the flange portion 61 is formed in an annular shape so that the flange portion 61 circulates in the middle portion of the outer periphery of the joint pipe 47, and the inner surface of the region portion located on the front end side from the flange portion 61 is located at the rearmost end. The second bending piece mounting portion 62 is fitted and attached to the rear end portion of the bending piece 41 to be fitted. The bending piece 41 located at the rearmost end is fixed to the second bending piece mounting portion 62 by, for example, soldering or bonding. An outer peripheral region portion located on the rear end side of the flange portion 61 in the joint pipe 47 serves as a flexible portion attaching portion 64 that fits and fixes the distal end portion of the outer skin 63 of the flexible portion 21. Further, the outer peripheral portion of the joint pipe 47 located on the front end side with respect to the flange portion 61 is a second outer skin attaching portion 65 to which the rear end portion of the outer skin 42 of the bending portion 22 is fitted and attached. A relatively shallow groove 66 is formed around a part of the outer periphery of the second outer skin attaching portion 65. By engaging the inner surface portion of the thread winding portion of the outer skin 42 into the groove 66, the engaging force of the outer skin 42 with respect to the second outer skin attaching portion 65 is increased.

  As shown in FIG. 2, in the joint pipe 47, a step formed by a difference in outer diameter between the flange portion 61 and the second outer skin attaching portion 65 is formed. The rising wall surface of the step is formed in an annular shape over the entire circumference of the joint pipe 47, thereby forming a second abutting surface 67 that abuts the rear end portion of the outer skin 42. The second abutting surface 67 is a vertical surface perpendicular to the central axis L of the insertion portion 3, and the rising height of the second abutting surface 67 is the height of the outer skin 42 that is fitted to the second outer skin attaching portion 65. It substantially matches the thickness of the base end portion. The configuration and function of the second abutting surface 67 formed on the joint pipe 47 are basically the same except that the first abutting surface 57 formed on the tip body 25 is opposite in direction. It is.

  By the way, the outer skin 42 of the bending portion 22 may be directly covered over the outer periphery of the bending piece 41 as the bending core material of the bending portion 22, but in this embodiment, all the bending pieces 41 are covered. The blade tube 71 as a relatively thin protective tube is covered over the outer periphery, and the outer skin 42 is covered over the outer periphery of the blade tube 71. The blade tube 71 is formed into a tubular shape by knitting or assembling a metal wire such as a metal such as stainless steel or a Kepler (trade name). In addition, the tip side portion of the blade tube 71 may be provided to extend until the tip hits the entire length of the first skin attachment portion 58 of the tip body 25, that is, the position of the first abutting surface 57. Since it is not necessary to expect the protection function by the blade tube 71 at the portion fitted to the main body 25, the tip of the blade tube 71 is stopped at a position before reaching the first abutting surface 57, and the position at that position is the highest. The blade tube 71 is fixed to the outer periphery of the bending piece 41 at the tip. Further, the rear end side portion of the blade pipe 71 is also fitted to the second skin mounting portion 65 of the joint pipe 47 up to a position reaching the second abutting surface 67 or a front position not reaching the second abutting surface 67. Then, it is fixed to the second outer skin attaching portion 65 of the joint pipe 47 by soldering or bonding.

  As shown in FIGS. 2 and 3, the first abutting surface 57 of the distal end portion main body 25 is formed with a first accommodating portion 68 for accommodating at least a part of the distal end portion of the outer skin 42. The first accommodating portion 68 is formed by a hole or a groove formed in the distal end portion main body 25. Here, as shown in FIGS. 2 and 3, the cross-sectional shape is a rectangular groove, and the groove is an annular groove that continuously circulates over the entire circumference. The groove, that is, the opening of the first accommodating portion 68 opens toward the outer skin 42 within the surface of the first abutting surface 57. The depth direction of the first housing portion 68 is substantially parallel to the direction of the central axis L of the bending portion 22. The first accommodating portion 68 may have a shape inclined at an angle inclined with respect to the direction of the central axis L as long as the depth has a direction component in a direction substantially parallel to the direction of the central axis L. For example, when the cross-sectional shape is rectangular, the upper side or the lower side is inclined with respect to the central axis L direction.

  On the other hand, as shown in FIG. 2, a second accommodating portion 69 similar to the first accommodating portion 68 is also formed on the second abutting surface 67 of the joint pipe 47. That is, the second accommodating portion 69 is formed from a hole or a groove. The second accommodating portion 69 accommodates at least a part of the rear end portion of the outer skin 42 located on the second abutting surface 67 of the joint pipe 47. Here, as shown in FIGS. 2 and 7, the cross-sectional shape is formed by a rectangular groove, and the groove is an annular groove that continuously circulates over the entire circumference. The groove, that is, the opening of the second accommodating portion 69 opens toward the outer skin 42 within the surface of the second abutting surface 67. The depth direction of the second housing portion 69 is substantially parallel to the direction of the central axis L of the bending portion 22. The depth direction of the second accommodating portion 69 may be inclined at an angle inclined with respect to the central axis L direction as long as it has a direction component in a direction substantially parallel to the central axis L direction.

  Next, the outer skin 42 of the bending portion 22 will be described. The outer skin 42 is made of a material exhibiting flexible rubber elasticity, for example, a thermoplastic elastomer, and is made of a thermoplastic resin material such as urethane, styrene, or other elastomers such as polyester, polyamide, and silicone. It is integrally formed as a thing.

  The final completed state in which the front end portion of the outer skin 42 is assembled has a form as shown in FIGS. 2 and 6, but the first form is a cylindrical inner layer 75 and a cylindrical outer layer as shown in FIG. It is in a state of being divided into two layers inside and outside with the portion 76, and is laminated so as to be separated from inside and outside. That is, the cylindrical outer layer portion 76 is formed in the same manner as the cylindrical inner layer portion 75 that is separated into the inside and outside by forming a cylindrical cut 77 that coaxially rotates with respect to the distal end portion of the outer skin 42. The distal end sides of the inner layer portion 75 and the outer layer portion 76 remain separated by the notch 77, but the proximal end of the inner layer portion 75 and the proximal end of the outer layer portion 76 are formed integrally with a portion of the other outer skin 42. The The outer skin 42 includes the inner layer portion 75 and the outer layer portion 76 and is integrally formed of the same material.

  As shown in FIGS. 2 and 4, a fixing member is wrapped around the outer peripheral surface of the inner layer portion 75. The fixing member here is a thread 81, and the inner layer part 75 is pressed against and fixed to the first outer skin attaching part 58 by winding the thread 81 around the outer peripheral surface of the inner layer part 75. The yarn 81 is wound in one layer to form a yarn winding portion. As shown in FIG. 4, the thread winding portion here is wound leaving the tip of the inner layer portion 75. The interval at which the yarn 81 is wound may be close, but may be a slight interval or a winding state in which the melted resin or the like can be passed. If the molten resin or the like is wound so that it can pass through, as will be described later, when the inner layer portion 75 or the outer layer portion 76 is heated and melted, a communication path through which the molten resin portion passes to the inner layer portion 75 or the outer layer portion 76 side is formed. Therefore, the inner layer portion 75 and the outer layer portion 76 can be integrally welded and joined in this state with the yarn 81 taken in. That is, a strong bond is obtained. Further, since the yarn 81 does not appear on the appearance, there are no restrictions or requirements on the appearance of the winding operation.

  Further, in the final completed state in which the rear end portion of the outer skin 42 is also assembled, a form as shown in FIGS. 2 and 8 is obtained, but the first form is a cylindrical inner layer part 85 as shown in FIG. It is divided into an inner and outer two layers with a cylindrical outer layer portion 86, and it is in a state of being laminated so as to be able to be separated inside and outside. That is, the cylindrical inner layer part 85 and the cylindrical outer layer part 86 which are separated into the inside and the outside are formed by forming a cylindrical cut 87 which coaxially circulates with respect to the rear end part of the outer skin 42. The distal end sides of the inner layer portion 85 and the outer layer portion 86 remain separated by the notch 87, but the proximal end of the inner layer portion 85 and the proximal end of the outer layer portion 86 are formed integrally with the portion of the other outer skin 42. The That is, the outer skin 42 is integrally formed of the same material including the inner layer portion 85 and the outer layer portion 86.

  As shown in FIGS. 2 and 7, the inner layer portion 85 is pressed against and fixed to the second outer skin attaching portion 65 by winding a thread 81 as a fixing member around the outer peripheral surface of the inner layer portion 85. The thread 81 forms a wound part wound around one layer. The winding interval of the yarn 81 may be close and a slight interval may be provided. A state where a thread 81 is taken into the inner layer 85 and the outer layer 86 since a communication path to the inner layer 85 is formed when the outer layer 86 or the inner layer 85 is heated and melted as will be described later if a slight gap is provided. This is convenient for welding. That is, a strong bond is obtained. Further, since the yarn 81 does not appear on the appearance, there are no restrictions or requirements on the appearance of the winding operation.

  Next, a method for assembling the outer skin 42 of the bending portion 22 will be described. Since the front end portion and the rear end portion of the outer skin 42 are attached in the same manner, the front end portion of the outer skin 42 will be specifically described.

  First, as shown in FIG. 3, the blade tube 71 is fitted over the outer periphery of the bending piece 41, and then the outer skin 42 is covered, and the outer skin 42 is positioned and arranged at a place to be fixed. The tip of the outer skin 42 abuts against the first abutting surface 57. At this time, the rear end of the outer skin 42 abuts against the second abutting surface 67.

  Next, the outer layer portion 76 of the outer skin 42 is turned back as shown in FIG. 4 to expose the inner layer portion 75 to the outside. Then, the thread 81 is wound around the outer periphery of the inner layer portion 75 to be wrapped. For example, the yarn 81 is wound around one layer to form a yarn winding portion. By winding the thread 81, the inner layer portion 75 is tightened and pressed against the first outer skin attaching portion 58. Since the inner layer portion 75 is tightened with the thread 81, the tightened portion is crushed to reduce the thickness in the radial direction. For this reason, even if the yarn 81 as the fixing member is provided, a part of the thickness can be absorbed in the thickness region of the inner layer portion 75. At this time, the thread 81 wound around the inner layer portion 75 may be temporarily fixed with an adhesive.

  After this bobbin winding, the outer layer portion 76 that has been turned is folded back as shown in FIG. 5, and the outer layer portion 76 is put on the outer periphery of the inner layer portion 75 having the bobbin winding portion. Thereby, the inner layer portion 75 and the outer layer portion 76 are arranged in an overlapping state. At this time, the tips of the inner layer portion 75 and the outer layer portion 76 of the outer skin 42 are substantially in contact with the first abutting surface 57.

  Thereafter, at least the range of the outer layer portion 76 covering the inner layer portion 75 is heated to melt the inner and outer two-layer elastomers of the inner layer portion 75 and the outer layer portion 76. If necessary, the outer layer portion 76 is pressed toward the inner layer portion 75 side. Then, the inner layer portion 75 and the outer layer portion 76 are fused and integrated at the melted portion of the inner and outer two layers of the elastomer, and the inner layer portion 75 and the outer layer portion 76 are fixed. Further, the outer layer portion 76 and the inner layer portion 75 are also fused with the winding thread 81 so that the three members are integrated. In particular, if the setting is made so that the melted elastomer can enter between the windings of the yarn 81, such as arranging the winding interval of the yarn 81 or arranging the winding interval of the yarn 81 loosely as described above, the yarn 81 is formed between them. The inner layer part 75 and the outer layer part 76 are directly welded and integrated more firmly through the connecting path. Then, as shown in FIG. 6, the inner layer portion 75 and the outer layer portion 76 are integrated with the fastening thread 81 embedded therein.

  Further, the outer layer portion 76 is pressed toward the inner layer portion 75 or the first accommodating portion 68 in a state where the inner and outer two layers of elastomers of the inner layer portion 75 and the outer layer portion 76 are melted. Then, the melted elastomer flows into the concave groove of the first housing portion 68, and as a result, the groove of the first housing portion 68 is filled with the outer elastomer as shown in FIG. That is, the inner layer portion 75 and the distal end portion of the outer layer portion 76 that have been separated so far are fused and integrated, and a part thereof enters into the groove of the first housing portion 68 and is locked. Since the portion entering the first housing portion 68 engages with the first housing portion 68, peeling of the outer skin tip portion composed of the inner layer portion 75 and the outer layer portion 76 is prevented. In addition, since the tip body 25 and the outer skin 42 are connected by an integral structure having very high adhesion, the structure on the side for fixing the outer skin is excellent in securing watertightness. Moreover, it becomes a structure where the elastomer end part of the outer skin is fitted to the member on the side for fixing the outer skin. For this reason, even if the outer skin receives an external force such as ironing, the outer skin is not easily detached. Further, since the inner layer portion 75 and the outer layer portion 76 are formed as an integrated lump with the fastening thread 81 embedded therein, the end portion of the outer skin 42 has a structure in which deformation is suppressed, that is, the outer skin 42 is hard to peel off from the end portion. Can be obtained. Further, in this fixing structure, the use of an adhesive is basically unnecessary, and high chemical resistance can be expected because the fixing member such as the thread 81 is not exposed to the outer surface of the outer skin.

  Since the rear end portion of the outer skin 42 is attached in the same manner, the inner end portion 85 of the rear end portion of the outer skin 42 and at least the outer layer portion 86 of the outer layer portion 86 are heated and melted at the rear end portion of the outer skin 42 as described above. As shown in FIG. The tip portions of the inner layer portion and the outer layer portion are fused and integrated, and are also integrated with the fastening thread. Similar effects can be obtained (see FIGS. 7 and 8).

  In the above embodiment, the case where the thickness of the inner layer portion of the outer skin 42 and the thickness of the outer layer portion are substantially equal as shown in FIG. 3 has been described. However, as shown in FIG. In comparison, the thickness of the outer layer portion 76 located on the outer side may be reduced. The same applies to the rear end portion of the outer skin 42. By making the thickness of the outer layer portion thinner than the thickness of the inner layer portion, a configuration suitable for reducing the diameter is obtained. Other configurations are the same as those described above.

  In the embodiment shown in FIG. 10, the fixing member that is wrapped around the inner layer portion 75 in order to tighten the inner layer portion 75 is a fixing member 82 such as a stretchable ring, a band, or a heat shrinkable tube instead of the thread 81. is there. According to this, the work of fixing the inner layer portion 75 becomes easier as compared with the case where the inner layer portion 75 is fixed by winding with a thread. In addition, as shown in FIG. 10, it is preferable to form the fixing member 82 as a thin cylindrical member in order to reduce the diameter of the fixing portion that tends to be thick. This can be similarly applied to the rear end portion of the outer skin. Others are the same as those described above.

  Further, in the above-described embodiment, the end portion of the outer skin 42 is divided into two cylindrical portions inside and outside to be divided into an inner layer portion and an outer layer portion. However, as shown in FIG. A cylindrical portion may be extended and this extended portion may be used as the outer layer portion 76. That is, the portion that becomes the outer layer portion 76 is folded from the portion that becomes the inner layer portion 75 so as to cover the outer periphery of the inner layer portion 75. Then, as shown in FIG. 12, at least the outer layer portion 76 of the inner layer portion 75 and the outer layer portion 76 is heated and melted and welded. The tip portions of the inner layer portion and the outer layer portion are fused and integrated, and are also integrated with the fastening thread. Further, a portion following the end portion of the outer skin fixed to the outer skin attaching portion, that is, a boundary portion 83 between the end portion and the central portion of the outer skin is formed thinner than other portions of the outer skin. Bending force is easily absorbed by the boundary portion 83 and is not easily transmitted to the end portion of the outer skin fixed to the outer skin attaching portion. Therefore, the end portion of the outer skin is difficult to peel off from the outer skin attaching portion. This can be similarly applied to the rear end portion of the outer skin. Others are the same as those described above.

  Further, the embodiment shown in FIG. 13 is a case where the outer layer portion 76 is formed as a separate member separated from the outer skin 42, and the outer layer portion 76 is a sheet material 88 formed of a thermoplastic resin material. This can be similarly applied to the rear end portion of the outer skin. According to this, an outer skin edge part can be comprised with a member of a simpler shape. Others are the same as those described above.

  In the embodiment shown in FIG. 14, the outer layer portion 76 is formed as a separate member separated from the outer skin 42. The outer layer portion 76 is a thread material 89 formed of a thermoplastic resin material, and this is used as a fixing member. The part is wrapped around the inner layer part 75. This can be similarly applied to the rear end portion of the outer skin. According to this, an outer skin edge part can be comprised with a member of a simpler shape. Others are the same as those described above.

The embodiment shown in FIG. 15 to FIG. 17 is a modified example of the shape of the accommodating portion that houses at least a part of the end portion of the outer skin.
In the embodiment shown in FIG. 15, at least an inner part of the first abutting surface 57 of the tip end body 25 is inclined, and the first accommodating portion 68 is formed by the inclined surface. The inclination direction of the inclined surface is such that the outer side approaches the outer skin side and the inner side is away from the outer skin. The inner end of the inclined surface reaches the peripheral surface of the first bending piece mounting portion 56 to which the front end portion of the bending piece 41 is fitted and attached, and a groove 92 having a wide back side is formed together with the step 91 at the tip of the bending piece 41. Form. That is, the first accommodating portion 68 forms a huge portion wider than the opening, and this huge portion forms a locking portion in which the tip of the bending piece 41 prevents the movement in the central axis L direction. In addition, since the thickness of the outer skin end portion that enters and locks into the first housing portion 68 becomes thicker than in the case of the above-described embodiment, the locking force that locks into the first housing portion 68 increases, and the above-described As compared with the embodiment, the holding force of the outer skin end portion is increased more firmly.

  In addition, although the said latching | locking part was formed including the level | step difference 91 of the front-end | tip of the bending piece 41, as shown in FIG. You may make it form.

  In the embodiment shown in FIG. 16, the inner surface of the first storage portion 68 is inclined. The inclination direction of the inclined surface is such that the inner side approaches the outer skin side and the outer side is away from the outer skin. This can be similarly applied to the rear end portion of the outer skin. Others are the same as those described above.

  In the embodiment shown in FIG. 17, a plurality of first accommodating portions 68 are formed on the first abutting surface 57 of the distal end portion main body 25. The cross-sectional shape of the first accommodating portion 68 may be a triangle as shown in FIG. 17, but may be other rectangles or semicircles. This can be similarly applied to the rear end portion of the outer skin. Other configurations are the same as those described above.

  Further, the present invention is not limited to the above-described form, and can be applied to other forms. For example, by making the hardness of the outer layer portion located on the outside a material or structure that is harder than the hardness of the inner layer portion located on the inner side, it is possible to make the structure stronger against turning or peeling against an external force. The material of the fixing member for fastening and fixing the inner layer portion is a material that is welded to the inner layer portion and the outer layer portion, particularly the outer layer portion.For example, if the outer layer portion is a urethane elastomer, the fixing member is a polyurethane-based resin, and the outer layer portion is In the case of a styrene-based elastomer, the fixing member is made of the same material as the styrene-based resin. In the case of other elastomeric materials such as polyester, polyamide, and silicone, the same material may be used. When the material is selected so that the outer layer portion and the fixing member are easily welded as described above, the inner layer portion and the outer layer portion can be more firmly integrated, and the fixing end portion of the outer skin is hard to break. In addition, a protrusion is formed at the tip of the outer layer portion, and the protrusion for locking is fitted into a housing portion formed on the shell attachment member such as the tip portion main body to engage the outer layer portion with the skin attachment member. It may be stopped. In the above-described embodiment, the accommodating portion is formed directly on the tip portion main body. However, the accommodating portion may be formed on another member, for example, a tip portion cover that covers the tip portion main body. In the above-described embodiment, the groove portion is continuously formed around the housing portion. However, the hole portion may not be continuous.

1 is a perspective view of an endoscope according to an embodiment of the present invention. The longitudinal cross-sectional view of the insertion part in the said endoscope. Explanatory drawing of the process of mounting | wearing the outer skin of the curved part of the insertion part in the said endoscope. Explanatory drawing of the process of similarly mounting | wearing the outer skin of the curved part of the insertion part in the said endoscope. Explanatory drawing of the process of similarly mounting | wearing the outer skin of the curved part of the insertion part in the said endoscope. Explanatory drawing of the process of similarly mounting | wearing the outer skin of the curved part of the insertion part in the said endoscope. Explanatory drawing of the process of similarly mounting | wearing the outer skin of the curved part of the insertion part in the said endoscope. Explanatory drawing of the process of similarly mounting | wearing the outer skin of the curved part of the insertion part in the said endoscope. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the curved part of the endoscope which concerns on other embodiment of this invention. The longitudinal cross-sectional view of the insertion part in the conventional endoscope.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Endoscope 2 ... Operation part 3 ... Insertion part 21 ... Flexible tube 22 ... Bending part 23 ... Tip part 25 ... Tip part main body 42 ... Outer skin 68 ... Storage part 75 ... Inner layer part 76 ... Outer layer part

Claims (9)

A tubular member;
A cylindrical outer shell coated on the outer peripheral surface of the tubular member;
A cylindrical inner layer portion integrally formed with the outer skin at the end of the outer skin,
A cylindrical outer layer portion that is detachably stacked with respect to the inner layer portion,
A fixing member for fixing the inner layer portion and the tubular member by bringing the inner layer portion into pressure contact with the tubular member or a member connected to an end portion of the tubular member by being mounted on the inner layer portion;
Formed in at least one of the tubular member or the member, and in a state where the outer layer portion is overlapped with the inner layer portion in which the fixing member is wrapped, at least a part of the end portion of the outer layer portion is inserted. An accommodating portion for locking the outer layer portion ;
Equipped with,
The end portion of the outer skin is divided into two cylindrical portions located inside and outside to form the inner layer portion and the outer layer portion, and the inner layer portion and the outer layer portion are formed integrally with the outer skin. A flexible tube of a medical instrument. The flexible tube of a medical instrument according to claim 1, wherein the fixing member is a thread-like member wound around the outer peripheral surface of the inner layer portion. The flexible tube of a medical instrument according to claim 1, wherein the fixing member is a sheet-like member wound around the outer peripheral surface of the inner layer portion. The outer layer portion is made of a thermoplastic resin material, and is welded to the inner layer portion by being heated in a state of being stacked on the inner layer portion in which the fixing member is wrapped. The flexible tube of the medical instrument according to claim 3 . The outer layer portion is made of a thermoplastic resin, and is heated in a state where the fixing member is overlapped on the inner layer portion in which the fixing member is wrapped, whereby a part of the molten layer flows into the housing portion, and is engaged with the housing portion. The flexible tube of the medical instrument according to any one of claims 1 to 4 , wherein a locking portion to be stopped is formed. The said accommodating part opens toward the said outer skin side in the longitudinal direction of the said tubular member, The at least one part of the edge part of the said outer layer part can be accommodated, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. A flexible tube of a medical device according to claim 1. The tubular member or the member has a surface abutment ends of the outer layer portion abuts, in any projecting contact surface of the claims 1 to 5, characterized in that the formation of the opening of the housing part A flexible tube of a medical device according to claim 1. When at least a part of the end portion of the outer layer portion is housed in the housing portion, the end portion of the outer layer portion is fixed to the tubular member or the member by being locked to the housing portion, and from the inner layer portion to the above The flexible tube of a medical instrument according to any one of claims 1 to 7 , wherein an end portion of the outer layer portion is prevented from being separated. The flexible tube of a medical instrument according to any one of claims 1 to 8 , wherein the medical instrument is an endoscope.

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