阅读说明：本技术 内窥镜用管及内窥镜 (Tube for endoscope and endoscope ) 是由 上田佳弘 于 2019-09-13 设计创作，主要内容包括：本发明提供一种内窥镜用管,其即使通过大径化也具有可承受软性内窥镜中的使用的灵活性,且容易检测形成内周面的氟树脂层的损伤。内窥镜用管(100)具备：气密性的内层管部件(101),由氟树脂形成；通气性的外层部件(102),硬度比内层管部件(101)低,且覆盖内层管部件(101)的外周面；及线圈状加强部件(103),卷绕在形成于外层部件(102)的外周面上的螺旋状槽部(104)。内窥镜(2)在插入部(10)具备由内窥镜用管(100)形成的处置器具插通通道(23)。(The invention provides a tube for an endoscope, which has flexibility for bearing the use of a flexible endoscope even through the diameter is increased, and is easy to detect the damage of a fluorine resin layer forming the inner circumferential surface. An endoscope tube (100) is provided with: an airtight inner-layer pipe member (101) formed of a fluororesin; an air-permeable outer layer member (102) which has a lower hardness than the inner layer tube member (101) and covers the outer peripheral surface of the inner layer tube member (101); and a coiled reinforcing member (103) wound around a spiral groove (104) formed on the outer peripheral surface of the outer layer member (102). The endoscope (2) is provided with a treatment instrument insertion channel (23) formed by an endoscope tube (100) in an insertion section (10).)

1. An endoscope tube for an endoscope, comprising:

an airtight inner pipe member formed of a fluororesin;

an air-permeable outer layer member having a hardness lower than that of the inner layer tube member and covering the outer peripheral surface of the inner layer tube member; and

and a coil-shaped reinforcing member wound around a spiral groove portion formed on an outer peripheral surface of the outer layer member.

2. The endoscope tube according to claim 1,

the outer layer member is formed in a band shape and is spirally wound around an outer peripheral surface of the inner layer member.

3. The tube for an endoscope according to claim 1 or 2,

the spiral groove portion and the coil-shaped reinforcing member are bonded by an adhesive filled only in the spiral groove portion.

4. The endoscope tube according to claim 3,

the adhesive is formed by melting and re-solidifying a thermoplastic resin applied to the surface of the coiled reinforcing member in advance.

5. The tube for an endoscope according to any one of claims 1 to 4,

the thickness of the outer layer member is greater than one-half of the thickness of the inner layer tube member.

6. The tube for an endoscope according to any one of claims 1 to 4,

the thickness of the outer layer member is greater than the thickness of the inner layer tube member,

the ratio of the hardness of the inner pipe member to the hardness of the outer pipe member has a value greater than the ratio of the thickness of the outer pipe member to the thickness of the inner pipe member.

7. The tube for an endoscope according to any one of claims 1 to 6,

the inner diameter of the inner pipe member is D mm, the outer diameter of the inner pipe member is D mm, and the inner diameter is 30 < D⁴-d⁴＜180。

8. The tube for an endoscope according to any one of claims 1 to 7,

the outer layer member contains a porous fluororesin.

9. An endoscope comprising a treatment instrument insertion channel formed of the endoscope tube according to any one of claims 1 to 8 in an insertion portion.

10. The endoscope of claim 9, wherein,

the treatment instrument insertion channel has an inner diameter of 5mm to 8 mm.

11. The endoscope of claim 10,

the distance between the central axis of the treatment instrument insertion channel in the curved portion of the insertion portion and the central axis of the insertion portion is smaller than the distance between the center of the opening of the treatment instrument insertion channel in the distal end surface of the insertion portion and the center of the distal end surface.

Technical Field

The present invention relates to an endoscope tube and an endoscope.

Background

The insertion portion of the flexible endoscope incorporates a plurality of tubes, for example, tubes forming a treatment instrument insertion channel. A flexible endoscope including an insertion portion that flexibly deforms according to the shape of a human body lumen can reduce intrusion into a subject, and an endoscope tube incorporated in the insertion portion is required to be flexible in bending. The endoscope tube is required to maintain a constant cross-sectional shape with respect to the bending so as not to interfere with insertion of the treatment instrument and flow of the fluid. Further, the inner peripheral surface of the tube forming the treatment instrument insertion channel is preferably low in friction and high in hardness because it is in sliding contact with the treatment instrument. Further, since the flexible endoscope is repeatedly used by cleaning, sterilizing, and disinfecting, the tube for the endoscope is also required to have airtightness and chemical resistance. As a material of the endoscope tube satisfying these conditions, a fluororesin such as PTFE (polytetrafluoroethylene) is generally used.

For example, an endoscope tube described in patent document 1 includes an inner layer made of a fluororesin and an outer layer made of a composite material of a fluororesin and a polyimide-based resin, and a spiral groove is formed in an outer peripheral surface of the outer layer, and a metal spiral material is wound around the spiral groove. The endoscope tube is reinforced by a metal spiral material wound around a spiral groove, and maintains a constant cross-sectional shape with respect to bending. The endoscope tube described in patent document 2 also has a spiral groove formed in the outer peripheral surface of a tube main body made of a fluororesin, and a coil member is wound around the spiral groove. In the endoscope tube described in patent document 2, the outer peripheral surface of the tube body around which the coil member is wound is covered with a urethane resin.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2002-204778

Patent document 2: japanese patent laid-open publication No. 2013-255577

Disclosure of Invention

Technical problem to be solved by the invention

The treatment using a flexible endoscope has been increasing year by year, and a treatment instrument that can cope with a higher level of treatment has been required in the clinical field of flexible endoscopes. In order to meet this demand, it is conceivable to enlarge the diameter of the treatment instrument insertion channel and to insert a plurality of treatment instruments. However, as the diameter of the treatment instrument insertion channel increases, the bending rigidity of the endoscope tube forming the treatment instrument insertion channel increases. When the bending rigidity of the endoscope tube is increased, the operability when bending the insertion portion is lowered, and there is a possibility that a disadvantage that the life of the lead wire for driving the bending mechanism is shortened may occur.

In order to suppress an increase in bending rigidity of the pipe accompanying the increase in diameter, it is effective to reduce the thickness of the fluororesin layer having relatively high hardness. However, in the endoscope tube described in patent document 1, a spiral groove is formed in the outer peripheral surface of the outer layer containing the fluororesin, and a metal spiral material is wound around the spiral groove to reinforce the tube. Similarly to the endoscope tube described in patent document 2, a spiral groove is formed in the outer peripheral surface of a tube main body made of a fluororesin, and a coil member is wound around the spiral groove to reinforce the tube. In order to form the spiral groove, the outer layer or the tube body needs to have a thickness of a certain level or more, which is an obstacle to suppressing an increase in bending rigidity of the tube.

Further, the fluororesin layer typically forms the inner circumferential surface of the pipe, and when the thickness of the fluororesin layer is reduced, the durability against abrasion and perforation is reduced. Further, in the endoscope tube described in patent document 1, an inner layer as a fluororesin layer forming the inner peripheral surface is covered with an outer layer formed of a composite material of a fluororesin and a polyimide-based resin, and in the endoscope tube described in patent document 2, a tube body as a fluororesin layer forming the inner peripheral surface is covered with a polyurethane resin. In these cases, even if the fluororesin layer forming the inner peripheral surface is perforated, airtightness is maintained in the entire tube, and there is a possibility that the perforated fluororesin layer may be overlooked.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a tube for an endoscope which has flexibility to withstand use in a flexible endoscope even when the diameter thereof is increased, and which can easily detect damage of a fluororesin layer forming an inner peripheral surface.

Means for solving the technical problem

An endoscope tube according to an aspect of the present invention includes: an airtight inner pipe member formed of a fluororesin; an air-permeable outer layer member having a lower hardness than the inner layer tube member and covering an outer peripheral surface of the inner layer tube member; and a coil-shaped reinforcing member wound around a spiral groove portion formed on an outer peripheral surface of the outer layer member.

An endoscope according to an aspect of the present invention includes a treatment instrument insertion channel formed by the endoscope tube in an insertion portion.

Effects of the invention

According to the present invention, it is possible to provide a tube for an endoscope which has flexibility to withstand use in a flexible endoscope even when the diameter thereof is increased, and which can easily detect damage to a fluororesin layer forming an inner peripheral surface.

Drawings

Fig. 1 is a perspective view for explaining an example of an endoscope according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of an example of an endoscope system including the endoscope of fig. 1.

Fig. 3 is a partial cross-sectional view for explaining an example of the endoscope tube according to the embodiment of the present invention.

Fig. 4 is a schematic view of an inspection method of inspecting damage of the inner layer pipe member of fig. 3.

Fig. 5 is an enlarged cross-sectional view showing a damaged portion of the inner-layer tube member of fig. 3.

Fig. 6 is a partial cross-sectional view of a modification of the endoscope tube of fig. 3.

Fig. 7 is a partial cross-sectional view of another modification of the endoscope tube of fig. 3.

Fig. 8 is a schematic view of an endoscope including a treatment instrument insertion channel formed by the endoscope tube of fig. 3 in an insertion portion.

Detailed Description

Fig. 1 shows an example of an endoscope for explaining the embodiment of the present invention, and fig. 2 shows an example of an endoscope system including the endoscope of fig. 1.

The endoscope system 1 includes an endoscope 2, a light source device 3, a processor unit 4, and a suction pump 5. The endoscope 2 is a flexible scope, and includes: an insertion unit 10 inserted into a subject; an operation part 11 connected to the insertion part 10; and a universal cord 12 extending from the operation unit 11, and a connector 13 connected to the light source device 3 is provided at a distal end of the universal cord 12.

The insertion section 10 is composed of a distal end portion 14, a bending portion 15 connected to the distal end portion 14, and a soft portion 16 connecting the bending portion 15 and the operation section 11. An imaging unit 17 including an imaging element such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor is mounted on the distal end portion 14. The bending portion 15 is configured to be bendable, and the bending of the bending portion 15 is operated by the operation portion 11. The flexible portion 16 is configured to be flexible to such an extent that it can be deformed in conformity with the shape of the insertion path in the subject.

The operation unit 11 is provided with an operation button 18A for operating suction using the suction pump 5, an operation knob 18B for operating bending of the bending portion 15, an operation button 18C for operating imaging using the imaging unit 17, and the like. The operation unit 11 is provided with an inlet portion 24 of a treatment instrument insertion channel 23 through which a treatment instrument is inserted.

The light guide 20 and the cable 21 are provided inside the insertion portion 10, the operation portion 11, and the universal cord 12. The light guide 20 guides the illumination light generated by the light source device 3 to the tip end portion 14. The cable 21 transmits the operating power, control signal, and image pickup signal of the image pickup unit 17 between the image pickup unit 17 and the processor unit 4. The processor unit 4 generates photographic image data from the input photographic image signal, displays the generated photographic image data on the monitor 6, and records the generated photographic image data.

A plurality of manipulation wires 22 and treatment instrument insertion channels 23 are provided inside the insertion portion 10 and the manipulation portion 11. The operation wire 22 reaches the distal end portion 14 of the insertion portion 10 from the operation portion 11, and is pushed toward the distal end portion 14 or pulled toward the operation portion 11 by the operation of the operation knob 18B of the operation portion 11. The bending portion 15 of the insertion portion 10 bends in accordance with the push and pull of the operation wire 22. The treatment instrument insertion channel 23 extends from an inlet portion 24 provided in the operation portion 11 to the distal end portion 14 of the insertion portion 10, and an outlet portion 25 of the treatment instrument insertion channel 23 opens at the distal end surface of the distal end portion 14. The treatment instrument inserted into the treatment instrument insertion channel 23 through the opening of the inlet portion 24 is guided to the distal end portion 14 of the insertion portion 10 by the treatment instrument insertion channel 23, and protrudes from the distal end portion 14 through the opening of the outlet portion 25.

The treatment instrument insertion channel 23 merges with the suction tube 26 in the operation portion 11. The suction pipe 26 extends to the connector 13 through a valve 27 opened and closed by the operation button 18A, and is connected to the suction pump 5 through a connection pipe 29 provided in the connector 13 and connected to a pipe head 28. By the valve 27 being opened, the fluid such as blood is sucked from the opening of the outlet portion 25 of the treatment instrument insertion passage 23 into the suction pump 5 through the suction tube 26. Further, a forceps plug 30 is attached to the inlet portion 24 via an opening/closing valve, and when suction is performed, the opening of the inlet portion 24 is closed by the forceps plug 30, so that the internal pressure of the treatment instrument insertion channel 23 becomes negative pressure.

The endoscope 2 may have a channel other than the treatment instrument insertion channel 23. As another channel, an air/water supply channel for supplying a gas (for example, air) and a liquid (for example, water) to the distal end portion 14 for cleaning the observation window of the imaging unit 17 can be exemplified. The air/water supply channel is provided inside the insertion portion 10, the operation portion 11, and the universal cord 12, and is connected to a water supply tank (not shown) via a connector 13.

Fig. 3 shows an example of an endoscope tube for explaining the embodiment of the present invention.

The endoscope tube 100 shown in fig. 3 is used for the treatment instrument insertion channel 23 of the endoscope 2, for example, but may be used for channels (air-feeding and water-feeding channels, etc.) other than the treatment instrument insertion channel 23. The pipe 100 includes an inner pipe member 101, an outer pipe member 102, and a coiled reinforcing member 103.

The inner tube member 101 forms the inner circumferential surface of the tube 100, and when the tube 100 is used for the treatment instrument insertion channel 23, the inner tube member 101 is in sliding contact with the treatment instrument inserted through the treatment instrument insertion channel 23. The inner pipe member 101 is formed of a fluororesin having low friction and high hardness, and has airtightness. Examples of the fluororesin include non-expanded PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), and FEP (perfluoroethylene propylene copolymer).

The outer layer member 102 is formed in a tubular shape covering the entire outer periphery of the inner layer pipe member 101. A spiral groove portion 104 is formed on the outer peripheral surface of the outer layer member 102. The outer layer member 102 has air permeability, and the hardness of the outer layer member 102 is smaller than that of the inner layer pipe member 101. The hardness of the inner-layer pipe member 101 and the outer-layer member 102 is set to a hardness obtained by a micro vickers hardness test or a hardness test by a nanoindentation method. The material of the outer layer member 102 is, for example, porous fluororesin such as expanded PTFE.

The outer layer member 102 can be formed by extrusion molding, for example. Specifically, the material of the outer layer member 102 heated and melted is extruded from the die, and the inner layer pipe member 101 moving through the die is continuously covered with the material extruded from the die. Then, the material covering the inner pipe member 101 is solidified to form the outer layer member 102. As a method of forming the outer layer member 102, in addition to the method of forming only the outer layer member 102 in advance, there is a method of forming the outer layer member 102, and then coating the outer layer member with the inner layer pipe member 101, and heating the inner layer member while fastening the outer layer member and the inner layer pipe member, thereby joining the outer layer member and the inner layer pipe member. The spiral groove portion 104 can be formed by, for example, laser processing, pressing of a metal wire in a heated state, or the like.

The coiled reinforcing member 103 is a member formed by molding a metal wire such as a stainless steel wire into a coil shape, and is strong against deformation of a cross-sectional shape flattened flat and flexible against bending, for example. The coil-shaped reinforcing member 103 is wound around the spiral groove portion 104 of the outer layer member 102. In a cross section perpendicular to the central axis of the wire rod forming the coil-shaped reinforcing member 103, the entire coil-shaped reinforcing member 103 may be accommodated in the spiral groove portion 104, and a part of the coil-shaped reinforcing member 103 may protrude outside the spiral groove portion 104.

When comparing the pipe 100 with a pipe having the same inner diameter and the same outer diameter as those of the pipe 100 and made of the same fluororesin as that of the inner pipe member 101 as a whole in thickness, the pipe 100 including the outer layer member 102 having a lower hardness than that of the inner pipe member 101 has a relatively small bending rigidity, and is advantageous for increasing the diameter.

When the pipe 100 is bent, the bent portions of the inner pipe member 101 and the outer pipe member 102 are bent, and the cross-sectional shapes of the inner pipe member 101 and the outer pipe member 102 are flattened, but the flattening is restricted by the coiled reinforcing member 103 wound around the outer peripheral surface of the outer pipe member 102. The coil-shaped reinforcing member 103 is wound around the spiral groove portion 104 of the outer layer member 102, and the relative movement of the coil-shaped reinforcing member 103 and the outer layer member 102 in the axial direction is restricted. Therefore, even when the pipe 100 is bent, the coiled reinforcing member 103 is held at the bent portions of the inner pipe member 101 and the outer pipe member 102. Thus, the cross-sectional shapes of the inner-layer tube member 101 and the outer-layer member 102 are maintained constant with respect to the bending of the tube 100, and insertion of a treatment instrument or flow of fluid is ensured.

Further, the bending rigidity of the pipe 100 is reduced as the thickness of each of the inner pipe member 101 and the outer pipe member 102 is reduced, but a thickness sufficient to integrate the inner pipe member 101 and the outer pipe member 102 and to maintain the sectional shape by itself is required, and the thickness is appropriately set according to the diameter of the pipe 100, for example. Further, as described above, since the inner pipe member 101 is made of a fluororesin having a relatively high hardness, the inner pipe member is thin to suppress bending rigidity, and is bent even with a relatively large bending radius. Therefore, the outer layer member 102 has low hardness, and is preferably thicker than the inner layer pipe member 101 in order to prevent bending of the inner layer pipe member 101. From the above, from the viewpoint of reducing the bending rigidity of the pipe 100, in the thickness sufficient to integrate the inner pipe member 101 and the outer pipe member 102 and maintain the sectional shape by itself, the thickness of the outer pipe member 102 is preferably larger than half of the thickness of the inner pipe member 101, more preferably the thickness of the outer pipe member 102 is larger than the thickness of the inner pipe member 101, and the value H1/H2 of the ratio of the hardness H1 of the inner pipe member 101 to the hardness H2 of the outer pipe member 102 is larger than the value T2/T1 of the ratio of the thickness T2 of the outer pipe member 102 to the thickness T1 of the inner pipe member 101. The hardness here is, for example, a hardness obtained by a micro vickers hardness tester or a hardness test by a nanoindentation method. The hardness H1 of the inner tube member 101 and the hardness H2 of the outer tube member 102, the wall thickness T1 of the inner tube member 101, and the wall thickness T2 of the outer tube member 102 obtained by these measurement methods preferably have the following relationships. For example, if the wall thickness of the inner pipe member 101 is 0.1mm and the wall thickness of the outer pipe member 102 is 0.4mm, T2/T1 is 4. At this time, when the hardness H1 of the inner layer tube member 101 is 80MPa, the hardness H2 of the outer layer member 102 is preferably less than 20MPa, and thus H1/H2 becomes larger than T2/T1.

The bending rigidity of the pipe 100 is affected by the second moment of area of the pipe 100, particularly the second moment of area of the inner pipe member 101 having relatively high hardness. Assuming that the thickness of the inner-layer pipe member 101 is constant in the circumferential direction, the inner diameter of the inner-layer pipe member 101 is d [ mm ]]The outer diameter is set to D [ mm ]]In the case of (2), the second moment of area of the inner pipe member 101 is π/64 × (D)⁴-d⁴) Preferably 30 < D⁴-d⁴< 180. Wherein mm represents mm.

Fig. 4 and 5 show an example of an inspection method for inspecting the presence or absence of damage to the inner-layer pipe member 101. Further, it is assumed that the tube 100 is also used for the treatment instrument insertion channel 23 of the endoscope 2.

As shown in fig. 4, in a state where the endoscope 2 is immersed in the liquid, gas such as air is supplied to the inside of the insertion portion 10 and outside the treatment instrument insertion channel 23. For example, as shown by the broken-line arrows in fig. 4, the gas is introduced from the connector 13, passes through the universal cord 12 and the inside of the operation portion 11, and is supplied to the inside of the insertion portion 10 and the outside of the treatment instrument insertion passage 23.

When the inner tube member 101 is damaged and the airtightness of the inner tube member 101 is lost, the gas supplied to the inside of the insertion portion 10 and outside the treatment instrument insertion channel 23 passes through the damaged portion of the inner tube member 101 and leaks to the inside of the treatment instrument insertion channel 23 as the gas pressure increases. The gas leaked to the inside of the treatment instrument insertion channel 23 is released into the liquid as bubbles from, for example, an opening of the outlet portion 25 of the treatment instrument insertion channel 23. This detects damage to the inner pipe member 101.

Fig. 5 shows an enlarged view of a damaged portion of the inner pipe member 101, and the inner pipe member 101 is provided with a hole H. The hole H is covered with the outer layer member 102, but the outer layer member 102 has air permeability, and the outer peripheral surface of the outer layer member 102 is exposed except for the spiral groove portion 104 around which the coil-shaped reinforcing member 103 is wound. The gas supplied to the inside of the insertion portion 10 and outside the treatment instrument insertion channel 23 flows into the hole H from the exposed outer peripheral surface of the outer layer member 102, and leaks into the inside of the treatment instrument insertion channel 23 through the hole H.

On the other hand, when the outer layer member 102 is formed of a polyimide resin as in the endoscope tube described in patent document 1, and when the outer peripheral surface of the outer layer member 102 around which the coiled reinforcing member 103 is wound is covered with a urethane resin as in the endoscope tube described in patent document 2, the outermost peripheral surface of the tube 100 becomes airtight, and even if the hole H is opened in the inner layer tube member 101, the airtightness is maintained in the entire tube 100. As a result, the gas supplied to the inside of the insertion portion 10 and outside the treatment instrument insertion channel 23 does not leak to the inside of the treatment instrument insertion channel 23, and the presence of the hole H is ignored.

Fig. 6 shows a modification of the tube 100.

In the example shown in fig. 6, the coil-shaped reinforcing member 103 and the spiral groove portion 104 are bonded by an adhesive 105 filled only in the spiral groove portion 104. According to this example, when the pipe 100 is bent, the coiled reinforcing member 103 is reliably held by the bent portions of the inner-layer pipe member 101 and the outer-layer member 102. Thus, the cross-sectional shapes of the inner-layer tube member 101 and the outer-layer member 102 are maintained constant with respect to the bending of the tube 100, and insertion of a treatment instrument or flow of fluid is ensured.

The adhesive 105 is filled only in the spiral groove portion 104, and the outer peripheral surface of the outer layer member 102 is exposed except for the spiral groove portion 104. Therefore, even if the adhesive 105 has airtightness, damage to the inner-layer pipe member 101 can be detected by the inspection method shown in fig. 4 and 5.

The adhesive 105 filled only in the spiral groove portion 104 may be formed of a thermoplastic resin previously applied to the surface of the coil-shaped reinforcing member 103. At this time, the coil-shaped reinforcing member 103 is heated in a state where the coil-shaped reinforcing member 103 is wound around the spiral groove portion 104, and the thermoplastic resin applied in advance on the surface of the coil-shaped reinforcing member 103 is temporarily melted. Then, the molten thermoplastic resin is re-solidified inside the spiral groove portion 104, whereby the thermoplastic resin is filled only in the spiral groove portion 104. The thermoplastic resin filled in the spiral groove portion 104 becomes an adhesive 105, and the coil-shaped reinforcing member 103 is bonded to the spiral groove portion 104. Of course, the adhesive 105 may be applied to the spiral groove portion 104.

Fig. 7 shows another modification of the tube 100.

In the example shown in fig. 7, the outer layer member 102 is formed in a band shape and spirally wound around the outer peripheral surface of the inner layer pipe member 101. The belt-like outer layer member 102 spirally wound around the outer peripheral surface of the inner pipe member 101 is flexible to bending, like the coiled reinforcing member 103. According to this example, the bending rigidity of the tube 100 can be further reduced. Further, since the outer peripheral surface of the outer-layer member 102 is exposed, damage to the inner-layer member 101 can also be detected by the inspection method shown in fig. 4 and 5.

According to the pipe 100 and the modification thereof, the bending rigidity can be reduced, which is advantageous for increasing the diameter. The treatment instrument insertion channel 23 has an inner diameter of usually 4mm or less, but by using the tube 100, a treatment instrument insertion channel 23 having a large diameter of 5mm to 8mm can be realized, which has flexibility to withstand use in a flexible endoscope.

Fig. 8 shows an example of the arrangement of the treatment instrument insertion channel 23 having a large diameter in the insertion portion 10.

The treatment instrument insertion channel 23 is formed by the tube 100, and the inner diameter of the treatment instrument insertion channel 23 is 5mm to 8 mm. The outer diameter of the insertion portion 10 provided with the treatment instrument insertion channel 23 having the large diameter is, for example, about 13 mm.

The distance D1 between the central axis C1 of the treatment instrument insertion channel 23 in the bending portion 15 of the insertion portion 10 and the central axis C2 of the insertion portion 10 is smaller than the distance D2 between the center O1 of the opening of the treatment instrument insertion channel 23 in the distal end portion 10A of the insertion portion 10 and the center O2 of the distal end portion 10A. In other words, the treatment instrument insertion channel 23 is disposed on the central axis C2 of the insertion section 10 in the bending section 15 and is disposed on the distal end portion 14 so as to be offset from the central axis C2 of the insertion section 10.

In the bending portion 15, other built-in components such as the light guide 20 (see fig. 2), the cable 21 (see fig. 2), the plurality of operation wires 22 (see fig. 2), and the air/water feeding channel are arranged along the outer periphery of the treatment instrument insertion channel 23 and appropriately dispersed in the circumferential direction, and the treatment instrument insertion channel 23 is surrounded by these other built-in components. Thus, the treatment instrument insertion channel 23 is held on the central axis C2 of the insertion portion 10 in the bending portion 15.

On the other hand, the distal end portion 14 has a columnar distal end rigid portion 40, the distal end rigid portion 40 holds an internal component of the distal end portion 14 mounted on the imaging unit 17 (see fig. 2) and the like, and the distal end rigid portion 40 is formed with a through hole 42 having a circular cross section and penetrating the distal end rigid portion 40 in the axial direction. The tube 100 forming the treatment instrument insertion passage 23 is joined to the distal end rigid portion 40 so as to communicate with the through hole 42. The through-hole 42 forms an opening of the treatment instrument insertion channel 23 at the distal end portion 10A.

The center axis of the through-hole 42 is offset from the center axis of the distal end rigid portion 40 that coincides with the center axis C2 of the insertion portion 10, and the tube 100 joined to the distal end rigid portion 40 so as to communicate with the through-hole 42 is appropriately bent between the distal end rigid portion 40 and the bending portion 15. Thus, the treatment instrument insertion channel 23 is held at the distal end portion 14 so as to be offset from the central axis C2 of the insertion portion 10.

The curved portion 15 is a portion repeatedly curved with a minimum radius of curvature in the insertion portion 10. The treatment instrument insertion path 23 is held by the central axis C2 of the insertion portion 10 at the bending portion 15, so that the bending angle of the treatment instrument insertion path 23 can be equally reduced regardless of the bending direction of the bending portion 15, and the displacement of the treatment instrument insertion path 23 in the axial direction due to bending and bending back can be suppressed. This can improve the operability when bending the bending portion 15.

An example of manufacturing the endoscope tube will be described below.

The tube of production example 1 has the same configuration as the tube 100 shown in fig. 3, and the entire outer periphery of the airtight inner tube member 101 made of fluororesin is covered with the air-permeable outer layer member 102 having lower hardness than the inner tube member 101, and the coil-shaped reinforcing member 103 is wound around the spiral groove portion 104 formed on the outer peripheral surface of the outer layer member 102. The pipes of production examples 2 and 3 have the same configuration as the modification of the pipe 100 shown in fig. 4, and the coil-shaped reinforcing member 103 and the spiral groove portion 104 are bonded by the adhesive 105 filled only in the spiral groove portion 104. The pipe of production example 4 has the same structure as the pipe 100 shown in fig. 3, except that the outer layer member 102 is made of urethane resin and has airtightness. The pipe of production example 5 has the same configuration as the pipe 100 shown in fig. 3, except that the coil-shaped reinforcing member 103 is omitted.

The inner diameter D and the outer diameter D of the inner tube member 101 in each production example are shown in table 1. The results of the evaluation of the bending rigidity and the bending resistance and the possibility of detecting damage to the inner pipe member 101 are shown in table 1 for the pipes of the respective production examples. The flexural rigidity was evaluated by the reaction force measured in the 3-point bending test, and a case where the fulcrum distance was 60mm and the reaction force was 5N or less when the deflection amount was 3mm was evaluated as a, and a case where the reaction force exceeded 5N was evaluated as B. The evaluation of the bending resistance was carried out depending on whether or not the pipe was bent when the pipe was bent at a curvature radius of 20mm, and the case where the pipe was not bent was evaluated as a and the case where the pipe was bent was evaluated as B. It is assumed that the damage of the inner pipe member 101 is detected by the inspection method shown in fig. 4 and 5.

[ Table 1]

As shown in table 1, even when the pipes of production examples 1 to 3 had a large diameter d of not less than 5mm and not more than 8mm, the flexural rigidity and the bending resistance were both evaluated as a, and damage to the inner pipe member 101 could be detected. On the other hand, the tube of production example 4 in which the outer layer member 102 was formed of urethane resin could not detect damage to the inner layer tube member 101. The pipe of production example 5, in which the coiled reinforcing member 103 was omitted, was evaluated as B in terms of bending resistance.

Will be filled withAs is clear from comparison of production example 2 and production example 5 in which the inner diameter and the outer diameter of the layered tube member 101 are the same, the coiled reinforcing member 103 can suppress bending of the tube with respect to bending without increasing the bending rigidity. And, when looking at D related to the second moment of area of the inner pipe member 101⁴-d⁴When the value (D) is (1), production examples 1 to 3 all satisfy 30 < D⁴-d⁴< 180, the flexural rigidity of production example 4 was evaluated as B, D⁴-d⁴The value of (d) is 602. As is clear from the results, 30 < D is preferable⁴-d⁴＜180。

As described above, the endoscope tube disclosed in the present specification includes: an airtight inner pipe member formed of a fluororesin; an air-permeable outer layer member having a lower hardness than the inner layer tube member and covering an outer peripheral surface of the inner layer tube member; and a coil-shaped reinforcing member wound around a spiral groove portion formed on an outer peripheral surface of the outer layer member.

In the endoscope tube disclosed in the present specification, the outer-layer member is formed in a band shape and is spirally wound around the outer peripheral surface of the inner-layer member.

In the endoscope tube disclosed in the present specification, the spiral groove portion and the coil-shaped reinforcing member are bonded to each other with an adhesive agent filled only in the spiral groove portion.

In the endoscope tube disclosed in the present specification, the adhesive is formed by melting and resolidifying a thermoplastic resin applied in advance to the surface of the coiled reinforcing member.

In the endoscope tube disclosed in the present specification, the thickness of the outer layer member is larger than half of the thickness of the inner layer tube member.

In the endoscope tube disclosed in the present specification, the thickness of the outer layer member is larger than the thickness of the inner layer tube member, and the value of the ratio of the hardness of the inner layer tube member to the hardness of the outer layer member is larger than the value of the ratio of the thickness of the outer layer member to the thickness of the inner layer tube member.

Further, the endoscope disclosed in the present specificationIn the tube, the inner diameter of the inner tube member is D mm, the outer diameter of the inner tube member is D mm, and the inner diameter is 30 < D⁴-d⁴＜180。

In the endoscope tube disclosed in the present specification, the outer layer member contains a porous fluororesin.

The endoscope disclosed in the present specification includes a treatment instrument insertion channel formed of an endoscope tube in an insertion portion.

In the endoscope disclosed in the present specification, the treatment instrument insertion channel has an inner diameter of 5mm to 8 mm.

In the endoscope disclosed in the present specification, a distance between a central axis of the treatment instrument insertion channel and a central axis of the insertion portion in the bending portion of the insertion portion is smaller than a distance between a center of an opening of the treatment instrument insertion channel and a center of the distal end surface on the distal end surface of the insertion portion.

Description of the symbols

1-endoscopic system, 2-endoscope, 3-light source device, 4-processor unit, 5-suction pump, 6-monitor, 10-insertion portion, 10A-front end face of insertion portion, 11-operation portion, 12-universal cord, 13-connector, 14-front end portion, 15-bending portion, 16-soft portion, 17-image pickup portion, 18A, 18C-operation button, 18B-operation knob, 20-light guide, 21-cable, 22-operation wire, 23-treatment instrument insertion passage, 24-inlet portion, 25-outlet portion, 26-suction tube, 27-valve, 28-tube head, 29-connection tube, 30-forceps plug, 40-front end hard portion, 42-through hole, 100-endoscope tube, 101-inner tube member, 102-outer layer member, 103-coiled reinforcing member, 104-helical groove portion, 105-adhesive, C1-central axis of treatment instrument insertion channel, C2-central axis of insertion portion, D1, D2-distance, H-hole opened in inner tube member, O1-center of opening of treatment instrument insertion channel, O2-center of tip face of insertion portion.