JP3837867B2 - Endoscope flexible tube and manufacturing method thereof - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a flexible tube used as a flexible tube portion of an insertion portion or a light guide soft portion in an endoscope.
[0002]
[Prior art]
As shown in FIG. 5, an endoscope used for medical use, industrial use or the like has a main body operation unit 2 connected to a proximal end portion of an insertion unit 1 inserted into a body cavity or the like, and a main body operation unit. 2 is connected to a light guide soft part 3 detachably connected to a light source device (not shown). The insertion portion 1 is composed of a flexible tube portion 1a from the side connected to the main body operation portion 2, and the flexible tube portion 1a is configured to bend in an arbitrary direction along the insertion path. ing. In addition, an angle portion 1b is connected to the tip of the flexible tube portion 1a, and a hard tip portion 1c is connected to the angle portion 1b. The distal end hard portion 1c is provided with an endoscope observation mechanism or the like, and the angle portion 1b can be bent by remote operation by the main body operation portion 2 in order to direct its visual field in a desired direction. .
[0003]
Although not shown from the flexible tube portion 1a constituting the insertion portion 1 through the angle portion 1b to the distal end hard portion 1c, light constituting a light guide or an image guide (in the case of an optical endoscope) is omitted. When a solid-state image sensor such as a CCD is provided on the fiber or the hard end 1c, a signal cable (in the case of an electronic endoscope) connected to the solid-state image sensor and a treatment tool such as a forceps are derived. A treatment instrument insertion channel, a tube including an air / water supply pipe, and other long insertion members are inserted. On the other hand, a light guide is inserted into the light guide soft part 3, and an air / water pipe is also inserted. Further, in the case of an electronic endoscope, the light guide soft part 3 is connected not only to the light source device but also to the processor. For this reason, the signal cable is also inserted into the light guide soft part 3. . As described above, all the insertion members inside the endoscope have a soft structure.
[0004]
As described above, the flexible tube portion 1a, the angle portion 1b, and the light guide soft portion 3 have various insertion members inserted therein, and these insertion members are soft members in nature. For this reason, the conditions that the flexible tube portion 1a, the angle portion 1b, and the light guide soft portion 3 must have are to protect the members that are flexible in the bending direction and that are inserted through the inside. In order to achieve this, it must have shape retention, that is, crush resistance. For this, they are formed of flexible tubes. The angle portion 1b can be bent by remote operation, but the flexible tube portion 1a and the light guide soft portion 3 may be bent when an external force is applied.
[0005]
FIG. 6 shows the configuration of a flexible tube used as the flexible tube portion 1 a and the light guide soft portion 3. Here, the flexible tube portion 1a and the light guide flexible portion 3 have basically the same configuration although there are some differences in structure due to the relationship between the parts where they are used and the members to be connected. Yes.
[0006]
In the figure, reference numeral 4 denotes a flexible tube. The flexible tube 4 has a spiral tube 5 as a structure, and the spiral tube 5 includes outer and inner spiral bodies 5a and 5b. The spiral bodies 5a and 5b are formed by spirally winding a metal band such as stainless steel, thereby ensuring the insertion paths of various insertion members. Further, in order to give flexibility in the bending direction, the spiral bodies 5a and 5b are wound with a predetermined pitch interval, and the winding directions are opposite to each other. A cylindrical mesh body 6 braided with a metal wire is provided on the outer periphery of the spiral tube 5, and an outer skin layer 7 is further laminated on the cylindrical mesh body 6. Here, the outer skin layer 7 is formed of a soft resin material having good sliding property, for example, a urethane resin or the like in order to hold the inside of the flexible tube 4 in a hermetically sealed state and smoothly perform insertion into a body cavity or the like. Yes. If the outer skin layer 7 is directly formed on the spiral tube 5, it may be peeled off and damaged, so that the cylindrical mesh body 6 functions as the base of the outer skin layer 7. In general, an adhesive is applied to the cylindrical mesh body 6 in advance in order to integrate the outer skin layer 7 with the outer skin layer 7.
[0007]
The flexible tube 4 is formed as described above. When this flexible tube 4 is configured as the flexible tube portion 1a of the insertion portion 1, it must be bent over its entire length. The flexible tube portion 4 bends along an insertion path such as in a body cavity. Therefore, in the body cavity, when an external force is applied, the flexible tube portion 4 must bend flexibly to some extent. However, if the flexibility of the flexible tube portion 1a in the bending direction is made too high, for example, if the resistance when inserting into the insertion path is large, such as a colonoscope or the like, there is a risk of hindering the insertion operation. is there. Therefore, depending on the insertion path, the flexible tube portion 1a must be hardened to some extent in the bending direction, that is, the rigidity in the bending direction must be increased. Further, since the resistance increases as the insertion portion 1 is inserted into the body, the flexibility in the bending direction of the flexible tube portion 1a does not have to be uniform over the entire length, but rather the distal end side is flexible in the bending direction. It is preferable to give the characteristic that the rigidity increases as it goes toward the base end side. Further, an angle portion 1b is connected to the flexible tube portion 1a. The angle portion 1b is for directing the distal end hard portion 1c in a desired direction. In some cases, the bending operation can be performed up to 180 ° or more. Made. For this reason, when bending at the maximum bending angle or an angle close thereto, in order to prevent stress from being concentrated on the connecting portion between the angle portion 1b and the flexible tube portion 1a, the flexible tube portion 1a The vicinity of the connecting portion with the angle portion 1b needs to be more flexible.
[0008]
In view of the above requirements, the bending characteristic of the flexible tube 4 configured as the flexible tube portion 1a of the insertion portion 1 is particularly flexibly bent at the distal end side and continuously to at least a predetermined position toward the proximal end side. It is preferable to change so that it may become hard. Thus, various devices have been made to change the hardness of the bending direction in the axial direction of the flexible tube 4. Since the flexible tube portion 4 is composed of the spiral bodies 5a and 5b, the cylindrical mesh tube 6 and the outer skin layer 7, the flexibility in the bending direction is changed based on any of these members. As for the spiral bodies 5a and 5b constituting the spiral tube 5, there are known ones in which the width and thickness are continuously changed or the surface is plated and the thickness of the plating is changed. Further, regarding the cylindrical net tube 6, there is one in which the knitting method, the wire diameter and the like are changed in the axial direction. It is also known to change the amount of adhesive supplied to the cylindrical mesh tube 6. Further, regarding the outer skin layer 7, since the outer skin layer 7 is usually formed by extrusion molding, two kinds of resins having different hardnesses are supplied from the extruder to change the mixing ratio in the axial direction. There is also. Furthermore, after forming the flexible tube 4, a configuration in which a change in flexibility is provided in the axial direction of the flexible tube portion 4 is also proposed by forming a resin coat layer inside. .
[0009]
[Problems to be solved by the invention]
As described above, various attempts have been made to change the characteristics relating to the flexibility in the bending direction in the axial direction of the flexible tube, but the spiral tube has essentially a crushed resistance in the flexible tube portion. It is intended to bend, and bends almost without resistance in the bending direction. Therefore, depending on the structure of the spiral tube, it is not possible to give a very significant difference in hardness. Further, the cylindrical mesh body is extendable, and it is not easy to configure the cylindrical mesh body to have a substantial difference in hardness. Furthermore, the adhesive cannot have stable characteristics over time because it deteriorates over a long period of time.
[0010]
It is the skin layer that has the greatest influence on the flexibility in the bending direction of the flexible tube. When the flexible tube bends, the outer skin layer contracts at the inner portion in the bending direction and extends at the outer portion. Although the outer skin layer is formed of a soft resin, it is not necessarily stretchable, so that its resistance to expansion and contraction is extremely large. Therefore, the resistance to bending of the flexible tube is the greatest factor against the expansion and contraction of the outer skin layer. In this sense, changing the hardness of the outer skin layer is extremely advantageous in changing the flexibility of the flexible tube in the bending direction. However, in order to extrude using two types of resins with different properties, a large-scale device is required, and not only the control of adjusting the extrusion pressure of the two types of resins is extremely complicated, but also depending on the product. However, the problem is that there are large molding problems such as variations in hardness.
[0011]
The present invention has been made in view of the above points, and an object of the present invention is to make it possible to change the flexibility in the bending direction of the flexible tube in the axial direction by simple processing. There is.
[0012]
[Means for Solving the Problems]
In order to achieve the above-described object, the flexible tube of the endoscope according to the present invention includes an inner skin layer made of a soft resin on a flexible cylinder in which an insertion passage of an insertion member is formed. In the flexible tube of the endoscope , one or a plurality of thinned portions are formed in the circumferential direction in the outer skin layer, and the thinned portion is widest at one end side of the outer skin layer and wide. The present invention is characterized in that the thickness is continuously increased to the middle position in the axial direction or the other end position, and the width is narrowed .
[0013]
As described above, the resistance when the flexible tube is bent and the outer skin layer expands and contracts has a significant effect on the bending characteristics, but the resistance during expansion and contraction can be changed depending on the thickness of the outer skin layer. Therefore, when the thickness of the outer skin layer is changed, the bending characteristics can be changed in the axial direction. Therefore, the thinned portion is formed by cutting and flattening a part of the outer skin layer, and forming at least one place in the circumferential direction, and forming a plurality of places as necessary. The side is the thinnest, and the thickness is continuously increased from one end side to the other end or halfway, and the width is continuously changed . In the case where the insertion tube is configured as a flexible tube portion, the end portion on the thinnest side of the thinned portion is a connection portion to the angle portion of the insertion portion. In this case, it is possible to make the angle portion thinner than other portions because the curved side in the vertical direction of the angle portion is bent greatly.
[0014]
On the other hand, as a method for manufacturing a flexible tube of an endoscope of the present invention, an outer skin layer made of a soft resin is formed on an outer peripheral surface of a flexible cylinder having an insertion passage for an insertion member formed therein by an extruder. A flexible tube is formed by laminating, and then a blade is brought into contact with the outer skin layer of the flexible tube on the outlet side of the extruder, the outer skin layer is scraped to a predetermined depth, and the extrusion of the flexible tube is performed. By displacing the blade in a direction away from the flexible tube in accordance with the feed from the molding machine, the depth of scraping off the outer skin layer is continuously reduced, and the thickness of the outer skin layer is continuously increased in the axial direction. It is characterized by forming a thinned portion in which changes.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Also in the present invention, since the overall configuration of the endoscope is not substantially different from that shown in FIG. 5, the same reference numerals are used for members that are the same as or equivalent to those shown in this drawing.
[0016]
1 and 2 show the overall configuration of the flexible tube. In the figure, reference numeral 10 denotes a flexible tube, and the flexible tube 10 has an insertion passage for inserting a flexible insertion member such as an optical fiber, a cable, and tubes. The structure of the insertion passage is composed of a spiral tube, preferably a double spiral tube wound at a predetermined pitch interval in opposite directions, and this spiral tube is inserted into a cylindrical mesh body. Further, an outer skin layer 11 is laminated on the outer periphery of the cylindrical net. Although the internal structure is not shown in FIGS. 1 and 2, the laminated structure itself is not substantially different from the configuration of FIG. 6 described above. And this flexible tube 10 is used as what comprises the flexible tube part 1a which bends in arbitrary directions along an insertion path | route in the insertion part 1, for example. In this case, a base 12 for connecting to the angle portion 1b is connected to one end portion, and a screw ring 13 to be screwed to the main body operation portion 2 is connected to the other end portion. .
[0017]
Here, the outer skin layer 11 in the flexible tube 10 does not have a uniform thickness over its entire length, and the thinned portion 11a is formed by cutting and flattening the portion indicated by the phantom line in FIG. Has been. The thinned portion 11a includes a screw ring 13 connected to the distal end side, that is, the end portion on the side where the base 12 connected to the angle portion 1b is mounted is deepest and wide, and connected to the base end side, that is, the main body operating portion 2. The provided side is thin and narrow and has a substantially triangular shape. Here, when the flexible tube 10 is bent, the outer skin layer 11 made of a soft resin contracts on the inner side in the bending direction and extends outward. However, if the thickness of the outer skin layer 11 is increased, the resistance to bending increases. When the thickness is reduced, the resistance to bending is also reduced. Accordingly, the distal end side of the flexible tube 10 can be easily bent by the thinned portion, and the depth and width of the thinned portion 11a are continuously reduced toward the proximal end side. The distal end side of the tube 10 can be bent most easily, and the tube 10 can be continuously hardened in the bending direction toward the proximal end side. Further, when the thickness of the outer skin layer 11 is changed, desired bending characteristics can be given depending on the degree of the change. However, when the thinned portion 11b is formed, it becomes weaker than other portions. However, for example, if the minimum thickness is suppressed to about half of the normal thickness, sufficient strength is maintained, and there is no possibility of causing damage or the like. . If the thickness is halved, it is possible to give a very large difference in flexibility in the bending direction from other parts.
[0018]
By configuring as described above, for example, when configured as the flexible tube portion 1a in the insertion portion 1 of the colonoscope, the resistance increases as the insertion depth of the insertion portion 1 into the body increases. Since the flexible tube portion 1a constituting most of the length of the insertion portion 1 is hardened in the bending direction as it is deeply inserted into the body, a pushing thrust force into the body can be surely applied. In addition, since the distal end side bends flexibly, when the angle portion 1b connected to the flexible tube portion 1a is bent to bend the angle portion 1b, the connection to the flexible tube portion 1a is performed. Since sudden bending from the installed portion can be prevented and stress can be dispersed, the durability of the insertion portion 1 is improved and there is no fear that an excessive force is applied to the internal insertion member.
[0019]
On the other hand, the light guide flexible portion 3 has one end connected to the main body operation portion 2 and the other end provided with a connector for detachably connecting to the light source device or the like. It has a structure. For this reason, it is necessary to give rigidity to the connecting portion to the hard structure and to change the bending characteristics in the axial direction so that the intermediate portion bends without resistance. In this case, it is preferable that the thinned portion of the outer skin layer is formed in the middle portion of the flexible tube, and both end portions are made thickest.
[0020]
Here, the outer skin layer 11 is formed by molding means using an extrusion molding machine. Therefore, the thinned portion 11a can be formed in the outer skin layer 11 when performing extrusion molding. Therefore, a method for forming the thinned portion 11a in the outer skin layer 11 together with the extrusion will be described with reference to FIG. Note that the thinned portion 11a is not necessarily formed at the time of molding. For example, after the outer skin layer 11 is formed, it can be scraped off with a cutter or the like as necessary.
[0021]
Thus, FIG. 3 shows an example of the configuration of an extruder for laminating the outer skin layer 11 on the outer periphery of the flexible tube 10. In the stage before the outer skin layer 11 of the flexible tube 10 is laminated, the flexible tube structure 16 is formed by attaching the cylindrical mesh body 15 to the spiral tube 14 (preferably a double spiral tube). . Thus, in the figure, reference numeral 20 denotes a molding machine. The molding machine 20 includes a well-known extruding portion 21 composed of a hopper, a screw and the like, and a synthetic resin in a molten state extruded by the extruding portion 21, such as a urethane resin. Is generally constituted by a head portion 22 for covering the outer peripheral surface of the flexible tube constituting body 16.
[0022]
The head unit 22 is configured as a head unit called an in-die head, an in-die cross head, or a solid cross head. The head portion 22 is attached to a head support 23 that supports the head portion 22 in a fixed manner. The head support 23 includes a gate 23 a serving as a passage for supplying the molten synthetic resin 24 extruded from the extrusion unit 21 to the head unit 22. The head portion 22 includes a nipple 26 and a die 27 that form a manifold 25 so that the molten resin 24 fed from the gate 23 a can be supplied to the outer peripheral surface of the flexible tube structure 16. It has a structure. The nipple 26 is provided with a conical recess 26 a for guiding the insertion of the flexible tube structure 16. In addition, a conical convex portion 26 b that forms the manifold 25 in cooperation with the conical concave portion 27 a on the left end side of the die 27 is formed on the right end side of the nipple 26 in the drawing.
[0023]
In the molding machine 20 formed in this way, the thickness of the outer skin layer 11 formed on the outer periphery of the flexible tube structure 16 is determined at the right side in the drawing from the outlet of the manifold 25 in the die 27. It has a peripheral wall 27b. In the figure, reference numeral 28 denotes a tightening portion for preventing the nipple 26 and the die 27 from coming off, and the die 27 is screwed onto the head support 23 and a protrusion 23b formed on the head support 23. A lock nut 29 is screwed into the nipple 26 so that the molding machine 20 is held in an assembled state. Yes.
[0024]
Although the molding machine 20 is configured as described above, the outer layer 11 is formed by allowing the flexible tube structure 16 to pass through the head portion 22 by being pushed in the axial direction by pushing means (not shown). . A blade 30 for forming the thinned portion 11a is provided on the outlet side of the molding machine 20. The blade 30 is provided obliquely so that the cutting edge faces the molding machine 20 side, and is movable in a direction perpendicular to the direction in which the flexible tube 10 as a molded product flows, that is, in the vertical direction.
[0025]
By configuring in this way, the flexible tube constituting body 16 is inserted into the molding machine 20 from the side where the base 12 is connected, and the blade 30 is brought to the lowest lowered position immediately after the base part 12 passes through the position of the blade 30. To lower. Thereby, a part of the outer skin layer 11 is cut and removed. Here, since the resin constituting the outer skin layer 11 is in a state before being cured, the blade 30 can easily bite into the outer skin layer 11. The position where the blade 30 contacts the outer skin layer 11 is cut deepest. When the blade 30 is pulled up according to the feed of the flexible tube 10, the cut depth and width of the outer skin layer 11 continuously decrease, and the blade 30 is separated from the outer skin layer 11. Thus, the thinned portion 11a is formed. Therefore, the thinned portion 11a having a desired depth and width can be formed by a simple operation that only controls the lifting and lowering operation of the blade 30, and the desired flexibility in the bending direction in the axial direction of the flexible tube 10 is desired. It is possible to have the characteristics.
[0026]
If only one blade 30 is provided, directionality is generated in the flexibility in the bending direction. For example, if the blade 30 is provided at two or more, preferably about four, at substantially the same angle, the blade 30 is substantially provided. Therefore, it is possible to form a flexible tube having substantially the same flexibility in any direction. The blade tip of the blade 30 may be linear, but may be formed in an arc shape having a larger radius of curvature than the outer diameter of the flexible tube 10.
[0027]
The thinned portion can be provided over the entire length of the flexible tube as shown in FIGS. 1 and 2, but, for example, on the distal end side of the outer skin layer 41 like the flexible tube 40 shown in FIG. The thinned portion 41a can be formed from the side where the base 42 is provided to the middle position. And you may make it provide many thin parts 41a not only in one place but in the circumferential direction. When the flexible tube 40 configured as described above is used as the flexible tube portion 1a of the insertion portion 1 by connecting the base 42 to the angle portion 1b, the flexible tube portion 1a has a base end side, that is, The connection side to the main body operation unit 2 is provided with sufficient rigidity in the bending direction in order to improve the insertion operability, and the tip side portion has no flexible structure, and follows the bending of the angle portion 1b. Will bend easily. As a result, the operability of the angle operation is improved and the stress when bent at a large bending angle such as 180 ° or more can be suppressed from being concentrated on the transition portion from the flexible tube portion 1a to the angle portion 1b. Thus, the durability of the insertion portion 1 is improved.
[0028]
Further, when the angle portion 1b is operated at an angle, the flexible tube is configured to have a difference in the bending angle in the bending direction so that the bending degree in the vertical direction is larger than the bending degree in the left-right direction. It is also possible to further reduce the thickness of the thinned portion in the direction of bending at the distal end side of the portion 1a.
[0029]
【The invention's effect】
As described above, according to the present invention, since the thinned portion is formed in a part of the outer skin layer, flexibility in the bending direction in the axial direction of the flexible tube can be achieved by a simple process of cutting the outer skin layer. The desired characteristics can be given, and this characteristic can be maintained very stably, and the hardness changes depending on the thickness of the outer skin layer, so the characteristics change over time. There is an effect such as no fear.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a flexible tube showing an embodiment of the present invention.
FIG. 2 is a front view of FIG. 1;
FIG. 3 is a cross-sectional view of an outer layer extrusion molding machine shown together with a means for forming a thinned portion.
FIG. 4 is a front view of a flexible tube showing another embodiment of the present invention.
FIG. 5 is an external view showing a general configuration of an endoscope.
FIG. 6 is a diagram illustrating the configuration of a flexible tube according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insertion part 1a Flexible pipe part 1b Angle part 1c Hard tip part 2 Main body operation part 3 Light guide soft part 10,40 Flexible pipe 11,41 Outer skin layer 11a, 41a Thinning part 12,42 Base 13 Screw ring 14 Spiral Tube 15 Cylindrical network 16 Flexible tube structure 20 Molding machine 21 Extruding unit 22 Head unit 30 Blade

Claims (4)

In a flexible tube of an endoscope in which an outer skin layer made of a soft resin is provided on a flexible cylindrical body in which an insertion passage of an insertion member is formed,
The outer skin layer is formed with one or more thinned portions in the circumferential direction,
The thinned portion is configured such that one end side of the outer skin layer is the thinnest and wide, the thickness continuously increases to the middle position or the other end position in the axial direction, and the width is narrowed. An endoscope flexible tube characterized by the above. The thinned portion is configured to continuously change a depth and a width in an axial direction of the outer skin layer by cutting and flattening a part of the outer skin layer. The endoscope flexible tube as described. The flexible tube is used as a flexible tube portion that constitutes an insertion portion of the endoscope, and is a connecting portion to an angle portion of the flexible tube portion. The flexible tube of an endoscope according to claim 1 , wherein the thinned portion is formed on a side .   A flexible tube is formed by laminating an outer skin layer made of a soft resin with an extruder on the outer peripheral surface of a flexible cylindrical body in which an insertion passage of an insertion member is formed, and then the outlet side of the extruder The blade is brought into contact with the outer skin layer of the flexible tube, the outer skin layer is scraped to a predetermined depth, and the blade is separated from the flexible tube in accordance with the feeding of the flexible tube from the extruder. An endoscope characterized by continuously reducing the depth at which the outer skin layer is scraped by displacing the outer skin layer, and forming a thinned portion whose thickness continuously changes in the axial direction in the outer skin layer. The manufacturing method of the flexible tube.

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