JP2005287575A - Insertion section of endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a curving operability of an angle portion by continuously changing the thickness of a coating layer in the axial direction and to control the curving characteristics of the angle part not to vary according to a product. <P>SOLUTION: A coating layer 15 of the angle portion 2b has the thickness changing toward its axial direction, however, at a position of its connecting part to a soft portion 2a, constantly has the same wall thickness to prevent the change in the curving operation characteristics of the angle portion 2b. An annular projection 16 is formed on its outer circumferential face to be a criterion of the position for cutting it after mounting the coating layer 15, the projection 16 is a limit position when performing a yarn winding 17 at the end part of the coating layer 15 and, when adhesive 18 is applied on the yarn wind 17, is functioned as a dam retaining to prevent the sticking-out of the adhesive 18. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an insertion portion of an endoscope used for medical purposes, and particularly relates to a coating layer in an angle portion constituting the insertion portion.

  The insertion portion of the endoscope is provided in connection with the main body operation portion, and is inserted into a body cavity or the like and used for purposes such as examination and diagnosis. Most of the insertion portion is a soft portion from the side connected to the main body operation portion, and an angle portion and a hard tip portion are sequentially connected to the soft portion. An illumination unit and an observation unit constituting the endoscope observation means are attached to the distal end hard part, and the angle unit is an angle operation device provided in the main body operation unit to direct the distal end hard part in a desired direction. Thus, the bending operation can be performed in two directions up and down or four directions up and down and left and right by remote control.

  Therefore, the structure of the angle part is provided by attaching a metal net to the outer periphery of the structure of the angle part which is a node ring structure constituted by pivotally attaching a plurality of angle rings. A coating layer is attached to the outer periphery. The covering layer is made of a tube-shaped member that can be expanded and contracted, and both ends thereof are fixed to the connecting portion to the soft portion and the connecting portion to the distal end hard portion.

  Here, the angle portion needs to be bent even in a narrow body cavity. For this reason, when the angle portion is bent by 90 °, the rising height of the distal end portion of the distal end hard portion with respect to the axis of the soft portion is suppressed low. There must be. In other words, it is desirable that the angle portion bend gently over the entire length thereof, thereby suppressing the rising height of the hard tip portion and increasing the radius of curvature, thereby providing a treatment instrument insertion channel provided in the insertion portion. There is an advantage that the operability of insertion of the treatment instrument inserted through the device is improved. However, since the hard tip portion connected to the tip side of the angle portion is in a free state, when the bending operation is performed, the tip side portion is hardly bent, and the connection side from the intermediate position to the soft portion is the most. As a result of sudden bending, the radius of curvature at the time of 90 ° bending decreases, and the rising height of the distal end hard portion also increases.

From the above, when bending the angle part, in order to bend gently from the connection part to the soft part, by making the connection side of the angle part to the soft part somewhat difficult to bend, Conventionally, various proposals have been made to equalize bending stress. Then, in order to increase the curvature of the angle portion and bend gently over almost the whole, pay attention to the covering layer of the angle portion, and connect to the base end side of the covering layer, that is, the soft portion. For example, Patent Document 1 discloses a configuration in which the partial side is made thick and the thickness is continuously reduced toward the distal end side, that is, the connecting portion side to the distal end hard portion.
Japanese Utility Model Publication No. 53-20953

  When the bending operation is performed by changing the thickness of the coating layer of the angle portion as in the prior art described above, the resistance to bending on the proximal end side of the angle portion increases, and the distal end side is not bent. Since the resistance decreases, the entire angle portion is gently curved. Moreover, since the thickness of the coating layer is continuously changed, the resistance to bending continuously changes from the proximal end side to the distal end side of the angle portion, so that the entire angle portion is gently curved. This is the most advantageous.

  By the way, the covering layer in the angle portion is formed in a tube shape in which a material such as rubber having elasticity is formed into a cylindrical shape, but is formed so as to have an extra length in advance. In general, it is attached to a net constituting the structure of the angle portion and assembled so as to cut off and remove the excess length. In this case, if the thickness of the coating layer is uniform, there is no particular problem regardless of where the cutting position is cut, but if the cross section is tapered, the thickness of the coating layer depends on the cutting position. May change. As a result, the operability is affected, for example, the operating force required for the bending operation at the angle portion changes.

  As described above, in the configuration of Patent Document 1, since it is difficult to manage the thickness of the coating layer, some endoscopes have a thick coating layer, and a thin coating layer is formed. Variations may occur in the coating layer, as if there are things. As a result, the bending operation characteristics of the angle portion are greatly different depending on the endoscope, and it is impossible to avoid problems such as affecting the operability of the bending operation of the angle portion.

  The present invention has been made in view of the above points. The purpose of the present invention is to continuously change the thickness of the coating layer in the axial direction in order to improve the bending operability of the angle portion. None, and it is possible to control the bending characteristic of the angle portion so as not to vary depending on the product by an endoscope.

  In order to achieve the above-described object, the present invention provides a stretchable coating layer on the outermost peripheral part of the angle part among the insertion part of the endoscope composed of a flexible part, an angle part, and a distal end hard part. The covering layer has a thickness that is the thickest on the connection side to the soft part, and a thickness that is the thinnest on the connection side to the hard tip part, and the thickness continuously changes in the axial direction. In addition, among the thickness changing portions, a feature is that a convex portion is formed on the outer peripheral surface at a position where a predetermined thickness is obtained.

  Here, the convex part formed in the outer peripheral surface of the coating layer serves as a standard for confirming the position to be attached to the net attached to the outer periphery of the structure made of the angle ring constituting the angle part. Therefore, it is desirable to provide in the vicinity of the connecting part to the soft part side or the distal end hard part side. Since the thickness of the coating layer is thick on the side connected to the soft portion, it is more desirable to form a convex portion that serves as a guideline for the cutting line of the coating layer in the vicinity of the connection portion to the soft portion.

  Both ends of the coating layer are fixed by winding a thread and applying an adhesive. Therefore, the convex part can be formed from the connecting part to the soft part at the limit position of this thread winding and adhesive application. In this case, if the convex part is formed in an annular shape, it functions as a stopper when performing the thread winding. It will also function as a dam when applying adhesive. Therefore, the protruding end of the convex portion in this case is preferably set to a height position not exceeding the adhesive application surface.

  By configuring as described above, when the bending operation of the angle portion is performed, the angle portion is gently bent from the connection side to the soft portion. In addition, since the curved portion smoothly curves over the entire length of the angle portion, the radius of curvature is increased, the insertion of the treatment instrument is improved, and the protruding height of the distal end hard portion can be suppressed low.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows the overall configuration of the endoscope. In the figure, 1 is a main body operation unit, 2 is an insertion unit, and 3 is a universal cord. The insertion part 2 is a soft part 2a for most of the length from the side connected to the main body operation part 1, and an angle part 2b and a hard tip part 2c are connected to the soft part 2a. . As is well known, the distal end hard portion 2c is provided with an endoscope observation means and the like, and the angle portion 2b is operated vertically or vertically and horizontally by operating the angle operation means 4 provided in the main body operation portion 1. Can be bent. Therefore, by operating the angle operation means 4 in the body cavity, the endoscope observation means provided on the distal end hard portion 2c can be directed in a desired direction.

  Next, FIG. 2 shows a cross section of the angle portion 2b. In FIG. 2, various members inserted into the angle portion 2b are not shown. The angle portion 2b is composed of a predetermined number of angle rings 11 as the structure 10, and has a node ring structure in which the adjacent angle rings 11 are pivotally attached by pivot pins 12 in the vertical and horizontal directions. The angle ring 11a at the distal end is coupled to the distal end hard portion 2c, and the angle ring 11b at the proximal end is coupled to a coupling ring 13 for coupling to the soft portion 2a. Furthermore, a net 14 made of a braided metal wire is attached to the outer periphery of the structure 10, and this net 14 is covered with a coating layer 15.

  The angle portion 2b is bent up and down and left and right by an angle operation means 4 provided in the main body operation portion 1 by remote operation. For this purpose, four operation wires 5 are inserted from the angle operation means 4 into the insertion portion 2. The distal end portion of each operation wire 5 is fixed to the angle ring 11a at the distal end portion constituting the angle portion 2b. And in the angle part 2b, the relationship which makes 90 degrees mutually in the circumferential direction is hold | maintained through the insertion hole provided in the pivot pin 12, for example. On the other hand, inside the soft part 2 a, the adhesive coil is inserted to extend to the main body operation part 1. The operation wire 5 is composed of an upper and lower pair and a left and right pair. When one of the upper and lower operation wires 5 is pulled into the main body operation unit 1 and operated so as to extend the other, the angle portion 2b bends in the vertical direction. . Further, when one of the left and right operation wires 5 is pulled into the main body operation unit 1 and operated so as to extend the other, the angle portion 2b is bent in the left-right direction. Note that the operation wires 5 do not necessarily have to be provided in a pair on the top and bottom and on the left and right. For example, a configuration in which a pair of operation wires 5 is provided on the top and bottom can be employed.

  As described above, the angle portion 2b is bent by remote operation. The bending operation of the angle portion 2b is also performed in a narrow body cavity. Therefore, in order to be able to bend the angle portion 2b in a compact manner, the side of the angle portion 2b that is connected to the flexible portion 2a is most difficult to bend, and is easily bent continuously toward the distal end hard portion 2c. For this reason, the thickness of the coating layer 15 which comprises the angle part 2b is changed continuously. In other words, the connecting side to the soft part 2a is the thickest and has a taper shape in which the thickness continuously decreases toward the hard end part 2c. Moreover, the change in thickness occurs on the outer surface side, and in the natural state, the inner diameter of the coating layer 15 is uniform over the entire length.

  Here, as shown in FIG. 3, the covering layer 15 is generally formed into a tube shape by means of injection molding or extrusion molding using a rubber material such as fluorine rubber, urethane rubber, EPDM, etc. It is incorporated so as to be deposited on the net 14. By making the molding a little longer than the actual size at the time of molding, the work of attaching to the net 14 can be easily performed. Therefore, after being actually incorporated in the angle portion 2b, the extra length indicated by the phantom line in FIG. 3 is cut and removed. Since the coating layer 15 has a constant inner diameter, uniform adhesion to the net 14 can be obtained when the coating layer 15 is attached to the outer periphery of the net 14.

  Since the thickness of the coating layer 15 changes in the axial direction, there is a difference in the thickness of the coating layer 15 in the mounted state depending on the position where the coating layer 15 is cut and removed. Then, depending on the product, the operability when the angle portion 2b is bent varies. Therefore, in the covering layer 15 attached to the angle portion 2b, the bending operation characteristics of the angle portion 2b vary depending on the product by always having the same thickness at the position of the connecting portion to the soft portion 2a. I am trying not to.

  Therefore, as is apparent from FIG. 3, an annular convex portion 16 is formed on the outer peripheral surface of the covering layer 15 so as to be a guide for a position where the covering layer 15 is cut after the covering layer 15 is mounted. . Here, the position of the convex portion 16 formed on the outer peripheral surface of the coating layer 15 does not directly indicate a cutting line, and a predetermined interval from the position where the convex portion 16 is provided to the base end side, for example, several mm to It is set so as to cut a position separated by a few dozen mm. The convex portion 16 can be formed integrally when the coating layer 15 is extruded.

  As described above, the convex portion 16 is not provided at the position of the cutting line, but by cutting the position displaced from the position of the convex portion 16 to the base end side by a predetermined length, the convex portion 16 is covered with the coating layer. This is for facilitating the work of fixing the end portion of the coating layer 15 after mounting 15. As shown in FIG. 4, the end portion of the covering layer 15 extends to the connection ring 13 to form the spool 17, and then is fixed by applying an adhesive 18 on the spool 17. It will be. In this case, the convex portion 16 serves as a reference to which position the thread winding 17 is applied when the bobbin 17 is first applied, that is, indicates a limit position of the bobbin 17. To the position of the rising wall. Accordingly, the bobbin 17 can be accurately formed without a gap, and the end portion of the bobbin 17 can be processed smoothly.

  Then, after the thread winding 17 is applied, this portion is fixed by the adhesive 18, and the dam function for preventing the protrusion at the time of application of the adhesive 18 is exhibited. Therefore, even if a little excess adhesive 18 is supplied, it does not protrude onto the coating layer 15. As a result, the fixing process of the end portion of the coating layer 15 can be performed smoothly and with high accuracy. Accordingly, the height of the convex portion 16 is set to be approximately the same height as the surface of the adhesive 18 when the adhesive 18 is applied. And since the site | part in which the convex part 16 is formed originally bulges from an outer surface to some extent by thread winding and adhesion | attachment, even if the convex part 16 is formed in the coating layer 15, what kind of appearance is There is no sense of incongruity.

  And although the coating layer 15 is a thin thing and is changing thickness continuously, the thickness is about 0.3-0.5 mm in the thinnest part normally, and is 0 in the thickest part. .About 6-0.8 mm. Therefore, it is difficult to reliably determine the difference in thickness in terms of appearance, and there is a possibility that it is erroneously attached in the reverse direction. When the convex portion 16 is formed on the thick side of the covering layer 15, the convex portion 16 also functions as an index for identifying the direction of the covering layer 15. Therefore, by confirming the position of the convex portion 16, it is possible to reliably prevent the reverse assembly of the covering layer 15.

It is a whole lineblock diagram showing an example of an endoscope provided with an insertion part of the present invention. It is sectional drawing of the angle part which comprises the insertion part of FIG. It is a half sectional view of a coating layer. It is sectional drawing which shows the edge part adhering part of a coating layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body operation part 2 Insertion part 2a Soft part 2b Angle part 2c Hard tip part 10 Structure 11 Angle ring 13 Connection ring 14 Net 15 Covering layer 16 Convex part 17 Thread winding 18 Adhesive

Claims (3)

Among endoscope insertion parts composed of a soft part, an angle part, and a distal end hard part, those provided with a stretchable coating layer on the outermost peripheral part of the angle part,
The coating layer has a thickest connection side to the soft part, a thinnest connection side to the tip hard part, and the thickness continuously changes in the axial direction.
An insertion portion of an endoscope, characterized in that a convex portion is formed on an outer peripheral surface at a position where the thickness is changed among the thickness changing portions. The end portion on the soft part side of the covering layer is fixed by winding with a thread winding and an adhesive, and the convex part is circled from the connecting part to the soft part to the limit position of this thread winding and adhesive application. 2. The endoscope insertion portion according to claim 1, wherein the insertion portion is formed in an annular shape. The insertion portion of the endoscope according to claim 2, wherein the protruding end of the convex portion is configured to be at a height position not exceeding the adhesive application surface.

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