JPH0722570B2 - Method for forming flexible portion for endoscope - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for forming a flexible part used as an insertion part into an observation target part, a universal cord or the like in medical and industrial endoscopes. Is.

[Prior Art] In an endoscope, an operation section main body is connected to an insertion section into an observation target section and a universal cord connected to a light source device, and the universal cord reaches the insertion section via the operation section main body. In the meantime, an optical fiber bundle for transmitting the illumination light from the light source device and other built-in components such as an air / water supply pipe are inserted as necessary. In addition to the above-mentioned components, the insertion portion is also provided with a treatment tool insertion channel for inserting a treatment tool such as an optical fiber bundle that transmits an image of the observation target portion and forceps.

Thus, the above-mentioned insertion part and universal cord are provided with a flexible part structure that forms an insertion passage for inserting each built-in object, and when the insertion part is inserted into the observation target part, The flexible part has a flexible hollow cylindrical structure to allow bending along the insertion path and to improve the operability of the main body of the operation part of the universal cord. is doing. Such a soft part has a predetermined number of taps, such as a spiral tube made of a spiral metal strip or a node ring tube formed by pivotally connecting a number of ring members with a metal wire such as a stainless wire. A knitted protective net is applied to form a flexible part structure in which an insertion passage for an internal component is formed, and the outer periphery of this soft part structure is made of urethane resin or the like and has a high degree of flexibility and strength. It is formed by coating with a resin.

Here, it is conventionally known that the above-mentioned coating layer is formed by supplying synthetic resin melted by a molding means such as extrusion molding to the outer peripheral surface of the flexible part structure. When the coating layer is formed in this manner, the coating layer has a good biting property with respect to the protective net and both are integrated, so that the surface is smooth and the durability is excellent.

[Problems to be Solved by the Invention] By the way, in the molding means such as the extrusion molding described above, it is difficult to align the axis of the flexible part structure with the center of the die due to its structure. However, the soft part has a large requirement for flexibility due to its nature, and therefore the thickness of the coating layer needs to be thin, but there is a slight deviation in the axis of the soft part structure from the die during molding. Therefore, it is not possible to form a coating layer having a uniform thickness, which is not preferable in appearance, and there is a disadvantage that the coating layer peels off during use. Further, when the deviation of the above-mentioned axis becomes large, there is a possibility that the resin is not supplied to a part at the time of forming the coating layer and the protective net remains exposed.

The present invention has been made in view of the above points, and an object thereof is to make the thickness of the coating layer formed on the outer periphery of the flexible part structure as uniform as possible by using a molding means. To be able to.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention comprises a spiral tube or a node ring tube covered with a protective net, and an internal component such as an optical fiber bundle is inserted therein. A method for forming a flexible portion for an endoscope by forming a synthetic resin coating layer on the outer periphery of a protective net that constitutes a flexible portion structure having an insertion passage that allows the outer surface of the protective net to be formed, After coating a soft resin tape formed of a synthetic resin material that is the same as or compatible with the coating layer in a spiral shape with a space, and forming the coating layer on the outer periphery by a molding means, The characteristic is that the resin tape is made to function as a spacer for keeping a predetermined distance from the protective net when the coating layer is formed.

[Operation] By winding the resin tape around the flexible portion structure in advance as described above, the resin tape functions as a spacer for separating the outer surface of the flexible portion structure from the inner surface of the die, The axis of the soft part structure can be aligned with the center of the die as much as possible, and the thickness of the coating layer can be made uniform.

[Embodiment] In order to explain an embodiment of the present invention, first, FIG. 1 shows an overall structure of a flexible portion.

In the figure, reference numeral 1 denotes a flexible portion structure, and the flexible portion structure 1 is formed by knitting a spiral tube 2 made of a spiral metal strip and a metal wire with a predetermined number of holdings and a certain number of strokes. And a protective net 3 made of a net body formed by the spiral tube 2, and the spiral tube 2 is one wound in one direction and the other wound in the opposite direction. A protective net 3 is attached to the outer circumference of the spiral tube 2 formed in this way. Then, when the same number of soft strands and hard strands are combined with the respective possessions in the protective net 3, when the strands are fed from the reel and knitted, the change in tension in each strand is changed. Even if there is, it can be knitted smoothly without causing slack. At both ends of the flexible part structure 1 thus formed, annular recesses 4a, 5 are formed on the outer peripheral surface.
The bases 4 and 5 with a are attached.

Further, a coating layer 6 made of a synthetic resin that is smooth and flexible, such as urethane resin, is formed on the outer periphery of the flexible portion structure 1. Before the coating layer 6 is formed, the flexible portion structure 1 is formed on the flexible portion structure 1. The resin tape 7 is wound around. The resin tape 7 is soft, and is made of urethane resin, which is similar to the coating layer 6, or a resin material that is well compatible with the resin forming the coating layer 6. The resin tape 7 has a large pitch interval on the end side where the base 5 is mounted,
It is wound in a spiral shape with intervals so that the pitch interval on the end side where the base 4 is mounted becomes small.

Next, FIG. 2 shows molding means for forming the coating layer 6. Although the drawing shows that the coating layer 6 is formed by extrusion molding, a molding method other than this can also be used.
Needless to say, even in the case of extrusion molding, the molding machine may employ other configurations.

In the figure, 10 indicates a molding machine, which comprises a known extruding part 11 including a hopper, a screw, etc., and a synthetic resin in a molten state extruded by the extruding part 11 in the flexible part structure 1. Head portion 12 for forming a coating on the outer peripheral surface
It is composed of and.

The head unit 12 is configured as a head unit called an in-die head, an in-die crosshead, or a solid crosshead. The head portion 12 is attached to a head support 13 that fixedly supports the head portion 12. The head support 13 includes a gate 13a that serves as a passage for supplying the molten synthetic resin 20 extruded from the extruding portion 11 to the head portion 12. The head part 12 is provided with a nipple 15 and a die for forming a manifold 14 so that the molten resin 20 fed from the gate 13a can supply the coating layer 6 to the outer peripheral surface of the flexible part structure 1. The structure has 16 and. The nipple 15 is provided with a conical recess 15b for guiding the insertion of the flexible structure 1. Further, on the right end side of the nipple 15 in the drawing, a conical convex portion 15c which forms the manifold 14 in cooperation with the conical concave portion 16a on the left end side of the die 16 is formed. On the right side of the outlet of the manifold 14 in the molding machine 10 thus formed, there is an inner peripheral wall 16b that determines the wall thickness of the coating layer 6 formed on the outer periphery of the flexible portion structure 1. In FIG. 2, 17 denotes a tightening bolt for preventing the nipple 15 and the die 16 from coming off, and the die 16 is a protrusion 13b formed on the head support 13 and screwed to the head support 13. The ridge 17a formed on the nipple 17 is engaged with the lock nut 18, and the lock nut 18 is screwed into the nipple 15, whereby the molding machine 10 is held in the assembled state. ing.

The coating layer 6 is formed on the outer periphery of the flexible portion structure 1 by using the above-described molding machine 10. Regarding the method of forming the coating layer 6,
A description will be given with reference to FIGS. 3 to 5.

First, as shown in FIG. 3, a protective net 3 is attached to the spiral tube 2.
The flexible portion structure 1 is formed by covering the protective portion 3 with the protective net 3 by previously immersing the flexible portion structure 1 in an adhesive layer.
In this state, as shown in FIG. 4, the resin tape 7 is wound around the outer circumference of the flexible portion structure 1 from the side of the cap 4 toward the side of the base 5 with a longer pitch interval. As a result, the winding area of the resin tape 7 is large on the side of the base 4 and the area of the base 5 is large.
There will be fewer sides.

After the resin tape 7 is wound as described above, the covering layer 6 is formed by supplying the synthetic resin 20 to the outer periphery of the flexible part structure 1 using the molding machine 10. That is, the tip of the flexible part structure 1 is inserted from the side of the conical recess 15b of the die 15, and the resin 20 is extruded from the extruding part 11 to the manifold 14 through the gate 13a of the head support 13 at a predetermined pressure. The synthetic resin 20 supplied in this way is applied to the outer periphery of the flexible part structure 1 while passing through the die 16 to form the coating layer 6.

Here, in the coating layer 6, the axis of the flexible part structure 1 is a die 16
When it is pulled out in a state of being accurately positioned on the center of the inner peripheral wall 16b, its thickness becomes uniform, but if the axis of the flexible part structure 1 is misaligned, the coating layer 6 in the circumferential direction becomes The wall thickness becomes uneven. However, since the resin tape 7 is wound around the outer peripheral surface of the flexible portion structure 1, the resin tape 7 serves as a spacer, and at least between the outer periphery of the flexible portion structure 1 and the inner peripheral wall 16b of the die 16. Since a gap corresponding to the thickness of the resin tape 7 is formed in the core, the deviation of the axis of the flexible portion structure 1 described above is suppressed, and the difference in the wall thickness of the coating layer 6 in the circumferential direction is reduced. As a result, the wall thickness becomes uniform. Here, since the resin tape 7 and the coating layer 6 are made of the same member or made of a synthetic resin having a property of being well compatible with each other, as shown in FIG. The synthetic resin 20 thus formed forms a layer integrated with the resin tape 7.

When the flexible portion formed in this way is configured as an insertion portion to be inserted into a body cavity such as a human body, further,
In order to make the surface of the coating layer 6 smooth and have solvent resistance, a coating of cross-linked urethane or the like is applied. If both ends of the coating layer 6 are formed even in the annular recesses 4a, 5a of the caps 4, 5, the thickness of both ends of the coating layer 6 in the formation of the annular recesses 4a, 5a will be described. Therefore, there is no possibility that the end portion of the coating layer 6 may be peeled off even if the end portion is not fixed by a means such as winding a thread. Moreover, if the adhesive is applied in advance in the annular recesses 4a, 5a, the fixability of the end portion of the coating layer 6 is further improved.

Thus, even when the resin tape 7 is wound, a part of the flexible portion structure 1 is exposed, and therefore, as shown in FIG. 5, the synthetic resin forming the coating layer 6 is formed. In the non-wound portion of the resin tape 7, 20 penetrates into the inside of the protective net 3 which constitutes the soft part structure 1 and adheres to the adhesive impregnated in the protective net 3, and this portion is By exerting the anchoring action, the coating layer 6 is firmly fixed to the soft part structure 1 and there is no risk of peeling or the like.
Therefore, if the resin tape 7 having a narrow width to some extent is used, it is extremely advantageous to prevent the coating layer 6 from peeling off.

As described above, since the coating layer 6 can be uniformly formed on the outer periphery of the flexible portion structure 1 and the coating layer 6 is prevented from peeling off, the coating layer 6 should be formed thin. As a result, the flexibility of the soft portion can be improved, and the outer diameter of the soft portion can be reduced. Also, resin tape 7
By tightly winding the base 4 side and coarsely winding the base 5 side, it is possible to give a certain amount of strain to the base end side compared to the tip side of the soft part. If the section is used as an insertion section into the observation target section, the insertion operation performed by gripping the base end section is convenient.

As the resin tape 7, the width dimension in the length direction is changed so that the base end side is wide and the tip end side is narrow. Will be able to have. Further, if the adhesive layer is formed on one side surface or both side surfaces of the resin tape 7, the fixing force between the resin tape 7 and the protective net 3 and between the cover layer 6 becomes large.

[Effects of the Invention] As described above in detail, according to the present invention, the coating layer is formed with the resin tape wound around the outer periphery of the protective net in the flexible portion structure. It functions as a spacer between the outer peripheral surface of the flexible portion structure and the inner peripheral surface of the die when the coating layer is formed, and the protective net is not exposed during the formation of the coating layer. As a result, there is no inconvenience such as variation in the thickness of the coating layer, and since the resin tape is formed of the same synthetic resin material as the coating layer or a resin material compatible with it, After the formation, the resin tape substantially forms a part of the coating layer, so that the thin coating layer can be formed to have a substantially uniform thickness. Spiral Since it is wrapped around the cover layer, the cover layer is fixed so as to bite into the protective net at the portion where the resin tape is not interposed, and it surely fits with the resin tape, so that the adherence of the cover layer is substantially There are various effects such as that the quality of the flexible portion is good, and that the yield is improved, such as not being damaged.

[Brief description of drawings]

FIG. 1 shows a structure of a soft part manufactured by the method of the present invention, an upper half of which shows a cross section of the soft part, and a lower half of which shows an external view in a state in which a coating layer is removed. The figure is a cross-sectional view showing an example of a forming means for forming a coating layer,
3 is an external view of the flexible part structure, FIG. 4 is an external view of the flexible part structure showing a state in which a resin tape is wound, and FIG. 5 is an enlarged view of a main part of FIG. 1: flexible part structure, 2: spiral tube, 3: protective net, 6: coating layer,
7: Resin tape, 20: Synthetic resin.

Claims (4)

[Claims] Claim: What is claimed is: 1. A protective net is attached to a spiral pipe or a node ring pipe, and the protective net is formed on the outer periphery of a flexible net structure having an insertion passage through which an internal component such as an optical fiber bundle is inserted. In a method of forming a flexible portion for an endoscope by forming a synthetic resin coating layer, on the outer surface of the protective net, a soft coating formed of a synthetic resin material that is the same as or compatible with the coating layer. A resin tape is wound in a spiral shape with a space, and the coating layer is formed on the outer periphery of the resin tape by molding means.When the coating layer is formed, the resin tape keeps a predetermined distance from the protective net. A method for forming a flexible portion for an endoscope, which is characterized in that it functions as a spacer for putting it on. 2. The resin tape is wound so as to reduce the winding area from one side to the other side in the axial direction of the soft part structure, and the winding is performed. Item 6. A method for forming a flexible portion for an endoscope according to item. 3. The winding area of the resin tape is varied by changing the winding pitch of the resin tape.
A method for forming a flexible portion for an endoscope according to the item. 4. The winding area of the resin tape is made different by changing the width of the resin tape in the lengthwise direction thereof, according to claim (2). A method for forming a flexible portion for an endoscope.