JPH02131738A - Flexible tube for endoscope and its manufacture - Google Patents

Abstract

PURPOSE:To freely vary the flexibility of a desired part by forming an outer layer of a flexible tube for an endoscope with a mixture of plural resins of different hardness, and varying arbitrarily its mixing ratio. CONSTITUTION:A flexible tube 4 is constituted of a flex (spiral tube) 9 formed by winding spirally an elastic band-like plate, a braid (net tube) 8 braided by a metallic fine wire for covering this flex 9, and a skin 7 consisting of elastomer allowed to adhere extending over the whole periphery of the outside surface of the blade 8. The skin 7 which covers the outside peripheral surface of the braid 8 is formed by mixing soft elastomer 11 and hard elastomer 12. Its mixing ratio is formed so that a ratio of the hard elastomer 12 becomes higher gradually toward an operating part body side 14. That is, as for a tip constituting part side 13, the soft elastomer 11 and the hard elastomer 12 are mixed by a large quantity and a small quantity, respectively since the flexibility is necessary.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flexible tube for an endoscope and a method for manufacturing the same, in particular, a flexible tube for an endoscope in which the outer skin is formed by coating and molding a resin. Regarding.

[Prior Art] As is well known, the flexible tube that constitutes the main body of the long insertion section of the endoscope that is inserted into the test subject is a flexible tube made of elastic band-shaped plates wound in a spiral shape from the inside. A spiral tube called a helical tube, and a mesh tube called a braid made of thin metal wires coated on the spiral tube or braided with thin metal wires and synthetic fibers, etc.
It is formed by covering this mesh pipe with a synthetic resin covering. That is, a flexible helical tube and a reticular tube that is tightly attached to the outer surface of the helical tube and covered in order to prevent the helical tube from stretching form a helical tube member, and the outer surface of the helical tube member is The flexible tube is coated with a synthetic resin outer skin that smooths the surface and prevents liquids such as body fluids from entering the flexible tube.

In addition, the flexible tube configured in this manner has a degree of flexibility consisting of a hard part and a soft part so that it can be easily inserted into the curved cavity of the limb examination part. , the means for changing the flexibility of this flexible tube has conventionally been disclosed in Japanese Utility Model Publication No. 63-3.
As disclosed in Japanese Patent No. 4641, (i) Several types of synthetic resin tubes having different hardnesses are connected by adhesion, heat welding, chemical melting, etc., and are covered as an outer skin over the reticular tube.

(i) Applying a synthetic resin to the reticular tube and varying the coating thickness of the synthetic resin.

(iii) Changing the wall thickness or helical pitch of the helical tube.

(1) Change the flexibility of appropriate items stored in the flexible tube, such as the coiled guide tube of the bending operation wire.

The flexible tube is configured so that the hardness of the flexible tube changes along the longitudinal force direction between the distal end side and the proximal side of the operating section main body.

In particular, flexible tubes of endoscopes used for medical purposes are said to have good operability if they have a soft tip and become more rigid toward the proximal end. This flexibility is a necessary condition for devices in which the tip is inserted deep into the body.

FIG. 13 is an enlarged view of a main part of a conventional flexible tube for an endoscope, which is an example of this hardness-curing means. This flexible tube 4A has a soft body layer 7A and a hard body layer 7B.
It is made of two layers, and is made hard from any position on the distal side to the proximal side, making the tip flexible, and the operating part side part relatively hard, improving ease of insertion into body cavities. It is something that

[Problems to be Solved by the Invention] However, as mentioned above, when the outer skin is formed of two layers, a soft layer and a hard layer, there is a drawback that the layers tend to peel off easily, and furthermore, where the hardness changes suddenly, Since the R shape was different between the two, insertability was poor and resistance against twisting etc. was also poor. In addition, if either the blade or the flex is formed into a two-stage structure with a rough and fine structure, and the flexibility of the tip side and the operating part side is changed, it will be easier to insert the blade or the flex into the body cavity and during diagnosis inside the body cavity. , it curves sharply, making it difficult to operate. That is, since the flexibility is not exhibited as expected, there is a drawback that not only is time and effort was wasted, but accurate diagnosis cannot be obtained.

Therefore, the above-mentioned conventional means for changing the flexibility of flexible tubes have the disadvantage that they are difficult and time-consuming to manufacture and increase costs.

The object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to enable the hardness of the outer skin formed by covering molding of a synthetic resin to be arbitrarily changed in the longitudinal direction of a flexible tube, and to automatically obtain a desired hardness. An object of the present invention is to provide a flexible tube for an endoscope and a method for manufacturing the same.

[Means and effects for solving the problem] In order to achieve the above object, the present invention provides an endoscope comprising a flex (helical tube), a blade (mesh tube), and an outer skin, which are laminated in this order. No. 11 flexible tube, characterized in that the outer skin is formed by mixing a soft elastomer and a hard elastomer, and the flexibility of the flexible tube is changed by changing the mixing ratio. This method of manufacturing a flexible tube involves inserting a flexible tube member for forming a flexible tube into a synthetic resin molding machine, moving it in the axial direction within the molding machine, and introducing a plurality of resins with different hardness into the molding machine. The mixed resin is mixed at a mixing ratio corresponding to the insertion amount of the flexible tube member, and the mixed resin is applied to the moving flexible tube member to form a covering outer skin of the flexible tube.

[Examples] The present invention will be described below based on illustrated examples. Third
The figure is a schematic diagram showing the overall configuration of an endoscope into which the flexible tube for an endoscope of the present invention is incorporated. The body cavity insertion section 3 includes, in order from the operation section main body 2 side, a flexible tube 4, a curved tube 5.
It is connected to the tip component 6.

FIG. 1 shows a flexible tube 4 for an endoscope showing a first embodiment of the present invention.
FIG.

This flexible tube 4 includes a flex (helical tube) 9 made of an elastic band-shaped band wound spirally, a braid (mesh tube) 8 braided with thin metal wires covering the flex 9, and the entire outer surface of the blade 8. It consists of an outer skin 7 made of elastomer that is applied over the entire length.

The configuration of the blade 8 is knitted with thin metal wires. The outer skin 7 that covers the outer peripheral surface of the blade 8 is formed by mixing a soft elastomer 11 and a hard elastomer 12. As shown in FIG. 1, the mixing ratio is such that the ratio of the hard elastomer 12 gradually increases toward the operating section main body side 14. That is,
Since the tip component side 13 requires flexibility, a large amount of the soft elastomer 11 and a small amount of the hard elastomer 12 are mixed. In other words, more of the hard elastomer 12 is gradually mixed toward the operation part main body 14 side, and the soft elastomer 11
It is formed by mixing a small amount of

When the outer skin 7 of the flexible tube 4 is constructed in this way, the inner surface 1'j
When operating l, the tip side 13 becomes a soft part, and it gradually becomes hard as it goes to the operating part main body side 14.
There is no sudden change in the R shape, and the operation when inserting the body cavity insertion part 3 into the body cavity can be carried out very smoothly.

In addition, in order to make the outer skin gradually harder as it goes from the tip side 13 to the operation part main body side 14, the mixing ratio of the hard and soft elastomers 11 and 12 was gradually changed, but the mixing ratio of both elastomers was changed in stages. You may change it to

FIG. 2 shows a flexible tube 4 for an endoscope showing a second embodiment of the present invention.
Flexible tube 4 when the flexibility of the outer skin 7 is changed stepwise
FIG. That is, the mixing ratio of the soft elastomer 11 and the hard elastomer 12 is changed in stages from the tip end side 13 toward the operating section main body side 14. For example, the mixing ratio of the hard elastomer 12 is increased stepwise as regions A-B-C-D such that the mixing ratio is A<B<C<D.

In this case, it goes without saying that the number of partitioned areas and the mixture ratio of hardness and softness can be arbitrarily designed depending on the endoscope's intended use (eg, large intestine, stomach, bronchus, etc.).

Next, a manufacturing method according to the present invention for manufacturing the outer skin 7 of the flexible tube formed as described above will be described.

First, as shown in FIG. 4.5, an example of the manufacturing apparatus for carrying out the above-mentioned method is as follows. A conveyance path forming member 17 for forming a conveyance path 16 for conveying along the axial direction of the longitudinal direction, and a resin supply path 19a, 19 that rotatably supports this conveyance path forming member 17.
b. Molding die 1 that constitutes the mixing section 20 and the application section 21
8 and the supply path 19a of this molding die 18. A plurality of resin feeders 22 and 23 each having discharge ports 22a and 23a connected to the supply passages 19b and supplying resins of different hardness to the supply passages 19a and 19b, respectively;
The mixing section 20 mixes the resins having different hardnesses supplied into the respective sections 19b, and the resin mixed in the mixing section 20 is applied to the entire circumference of the outer surface of the flexible tube member 15 conveyed through the conveyance path 16. The coating section 21 is covered, the detection means is arranged to expose the position of the flexible pipe member 15 in the conveyance path 16, and the resin is removed from each resin supply section 22, 23 based on the detection force of the detection means. The main part thereof is composed of a control section 24 that controls the amount of resin discharged.

The conveyance path forming member 17 is formed of a rotating nozzle shaft made of a thick-walled vibrator, and is rotatably suspended horizontally in the center of the molding die 18, and its center hole forms the conveyance path of the serpentine tube member 15. It is 16. This conveyance path forming member 17 has an outer circumferential surface at its center part that is connected to the U stand 1 of the molding die 18.
It is rotatably arranged in an inner cylinder 25 fixed to 8a, and one side, that is, the feeding side (right side in the figure) of the flexible tube member 15, is rotatably supported by bearing members 27a and 27b. The fixed pulley 28 is rotated by a driving force transmitted from a motor M (not shown) (see FIG. 5) via a belt 29. A conical nozzle portion is formed on the other side, that is, the delivery side (left side in the figure) of the flexible tube member 15, and a forming die 30 is fixed to the base 18a so as to cover this nozzle portion. The mixing section 20 and application section 21 are configured by the above.

One of the feeding passages 19a and 19b, one of which is the feeding passage 19b, is connected to the outer periphery of the inner cylinder 25 and the inner periphery of the outer cylinder 26, which is fixed to the base 18a and arranged around the inner cylinder 25. The other supply path 19a is formed by a gap formed between the outer cylinder 26 and the base 18a, and both supply paths 19a and 19b are It is formed so as to send the resin toward the mixing section 20. The one supply path 19b has a discharge port 22.
A is connected to the discharge port 22a, and a hard resin (hard elastomer) for the outer skin is co-supplied from one of the resin feeders 22 through the discharge device 22b of the pump':5. ing. Further, a discharge port 23a is connected to the other supply path 19a, and a discharge device 23 such as a pump is connected to the discharge port 23a from the other resin feeder 23.
Low hardness resin (soft elastomer) for outer skin through b
is being supplied. The dispensing devices 22b and 23b are each controlled by an output J signal from the control section 24, as will be described later. Further, the resin feeding machines 22 and 23 are composed of twin extruders.

In addition, the inner cylinder 25 and the outer cylinder 26 are formed such that the left end thereof, which forms the delivery side of the resin supply path, is sloped so as to be continuous with the conical circumferential surface of the nozzle part, and the left end of the inner cylinder 25 and the outer cylinder 26 are formed into a slope that is continuous with the conical peripheral surface of the nozzle part. A transport path 19c is formed between the inner surface of the die 30 and the resin for the outer skin to be supplied to the mixing section 20.

The mixing part 20 consisting of the conical nozzle part has a spiral protrusion 3 on its cone-shaped peripheral surface as shown in FIG. 6(^).
1 is integrally formed, and when the conveyance path forming member 17 rotates, the resins of different hardness that have been extruded through the supply paths 19a, 19b and the transport path 19c are transferred to the spiral protrusion 31. The mixed resin is mixed by the action of the screw, and the mixed resin is coated on the outer periphery of the flexible tube member 15 being conveyed within the conveyance path 16 by the coating section 21.

Further, the spiral protrusion 31 forming the mixing part 20 is
As shown in FIG. 6 (13), a large number of wart-like protrusions 32
Alternatively, as shown in FIG. 6(C), a plurality of protrusions 33 protruding along the axial direction and formed at equal angles on a conical surface may be used.

Further, the means for detecting the position of the flexible tube member 15 within the conveyance path 16 is constituted by a photoreflector 35 that detects a control mark 34 attached to the outer peripheral surface of the flexible tube member 15. controls the ejection amount of the ejection devices 22b and 23b based on the mark position signal from the photoreflector 35 that has read the control mark 34.

Furthermore, the conical nozzle part forming the mixing part 20 is
As shown in FIG. 7, a distal tip portion 36 is detachably attached to the distal end thereof, and this distal tip portion 36 can be replaced for each flexible tube member 15 having a different outer diameter. The optimum coating pressure is applied uniformly to the flexible tube member 15.

Further, in the embodiment of the manufacturing apparatus described above, a protrusion 31, a protrusion 32, or a protrusion 33 is provided around the M6 portion 20, which is a conical nozzle part, so that a screw action can be performed. However, as shown in FIG. 8, the inner surface of the molding die 30 has a protrusion 31a, a protrusion 32a, or a protrusion 3 on the inner surface of the mixing part 20.
3a may be provided, and these protrusions 31 may be provided on both the peripheral surface of the mixing section 20 and the inner surface of the forming die 30.
, 31a, or protrusion 32.32a or protrusion 33
, 33a are provided and combined, the resin mixing performance is further improved.

Next, a manufacturing method of the present invention will be described in which the outer surface of the flexible tube member 15 is coated with an outer skin that changes the flexibility of the flexible tube using the manufacturing apparatus configured as described above.

FIG. 9 is a diagram for explaining one embodiment of the manufacturing method according to the present invention, in which a position-based control means is adopted, and in this case, the position of the From the tip side of the flexible tube member 15, for example, 30 cm, 60 cm,
The control mark 34 is attached at a location lm.

Erroneous reading can be prevented by forming this mark 34 with a different color mark or a mark with a different number of lines.

Then, the flexible pipe member 15 bearing the mark 34 is drawn into the conveyance path 16 of the conveyance path forming member 17 which is rotationally driven by the motor M, and is taken through the conveyance path l6 at a constant speed.

Here, the resin supplied from the resin feeder 22 has a high hardness, that is, a hard resin X, and the resin co-supplied from the resin feeder 23 has a low hardness, that is, a soft resin Y. At first, resin X:resin Y is discharged at a ratio of about 1=9. Therefore, the resin mixed in this ratio is applied and coated as a skin. When the 30 cm mark 34 passes through the detection section 35 of the photoreflector, its position is detected and sent to the control section 24 as a mark position signal. Then, the control unit 24 controls each discharge device 22b, 23b of the supply device 22.23 based on this position signal, and changes the ratio of their discharge amounts to a ratio of resin X:resin Y - 3:7. Then, the flexible pipe member 15 is coated with the resin having this mixing ratio as an outer skin.

Next, when the 60 cm mark 34 passes through the detection unit 35, it is detected that it is the second mark.
The control unit 24 controls the discharge amount so that the mixture ratio of resin X:resin Y-5 is 5:5. Therefore, coating is performed at this mixing ratio to form an outer skin. When the 1 m mark section 34 passes the detection section 35, it is detected that it is the third mark, and the control section 24 changes the discharge amount to a ratio of resin X:Y=9:1. T for a certain period of time depending on the mixing ratio of the resin. coated. And this fixed time T. After the lapse of time, the resin X:Y discharged melon returns to its initial state, and the above-mentioned coating operation is repeated again.

The flexible tube manufactured by the above-mentioned outer shell manufacturing method has a change in hardness as shown in the graph in FIG. 9. That is, 4
It becomes a flexible tube with a hardness corrosion of steps.

Furthermore, the timing at which the discharge amount changes (inclination Z in the graph of Fig. 9) can be arbitrarily changed using a start timing device (not shown), which allows for sudden changes in the hardness of the flexible tube. , it can be made more gradual. Further, the number of marks may be added depending on the number of stages at which the hardness of the flexible tube is desired to be changed.

10 to 12 show other embodiments of the manufacturing method according to the present invention. In the manufacturing method of this embodiment, a time-based control means is employed. In this case, as shown in FIG. 10, a control mark 34A is attached to one location on the flexible tube member 15. And this mark 3
4A is detected by the detection unit 35, the discharge amount of resins having different hardnesses is changed, and this is coated and molded. In this embodiment as well, the resin supplied from the resin supply machine 22 is a hard resin X1, and the resin supplied from the resin supply machine 23 is a soft resin Y. When the flexible tube member 15 with the control mark 34A is drawn through the conveyance path 16 at a constant speed, the resin is initially discharged at a ratio of X:Y=1:9, and the resin is mixed at that ratio. It is coated as shown in FIG. 11(^).

Next, when the control mark 34A passes the position of the detection unit 35, the timing is detected, and the control unit 24 that receives the control signal controls the discharge amount to a ratio of resin X:Y-3:7. As shown in FIG. 11 (13), coating is carried out at this mixing ratio for a time T1. Then, after this time T1 has elapsed, the controller 24 controls the resin X:
The discharge amount is changed to a ratio of Y-5:5, and the mixing ratio is maintained for a time T2 as shown in FIG. 11(C). After this time T2 has elapsed, the control unit 24 changes the mixing ratio to resin XzY■9:1, and changes this to the ratio shown in FIG.
), the coating is carried out for a time T3, and the skin forming operation is completed. Moreover, after this operation is completed, it returns to the initial state. As described above, the method of the above embodiment controls the time, and thereby a flexible tube having four stages of hardness corrosion is manufactured.

FIG. 12 is a graph showing the change in the mixing ratio over time in the above example, and as is clear from this graph, the number of stages changes and the changing portion Z of the mixing ratio. The slope 2 of ゛ is exactly the same as that of the embodiment shown in FIG. 9.

[Effects of the Invention] As described above, according to the present invention, the flexible tube for the internal mirror has the following effects:
The resin for forming the outer skin is formed by mixing multiple resins with different hardnesses, and the flexibility of the flexible tube can be changed by arbitrarily changing the mixing ratio, so the flexibility of the desired location can be adjusted. It can be easily changed at will, and therefore the operability of insertion into the test area is extremely good, and the insertion effort and time are greatly reduced. Furthermore, in the case of medical endoscopes, the effects are remarkable, such as alleviating patient pain.

In addition, the manufacturing equipment is configured to simultaneously discharge arbitrary amounts of elastomers of different hardness and materials using multiple resin feeders, mix them at one location, and return them to the flexible pipe member as an outer skin. Since the flexible tube is manufactured by operating the flexible tube using a position control means or a time control means, it is possible to extremely easily manufacture a flexible tube in which the flexibility of any part can be changed.

Therefore, it is possible to provide a flexible tube for an endoscope and a method for manufacturing the same, which eliminates the conventional drawbacks of this type.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of main parts of a flexible tube for an endoscope showing a first embodiment of the present invention, and FIG. 2 is a main part of a flexible tube for an endoscope showing a second embodiment of the present invention. 3 is a perspective view showing the overall structure of the endoscope, and FIG. 4 is an enlarged view of the main parts of a manufacturing apparatus for a flexible tube for an endoscope for carrying out the method of the present invention. The sectional view, FIG. 5, is a schematic diagram showing the drive system in the manufacturing apparatus shown in FIG. 4, and FIG. 6(A). (B) and (C) are protrusions provided around the mixing section in the manufacturing apparatus shown in FIG. 4 above. FIG. 7 is an enlarged sectional view showing the distal tip portion of the mixing section in the manufacturing apparatus shown in FIG. 4 above, and FIG. 8 is a side view showing three examples of the protruding parts. FIG. 9 is an enlarged sectional view showing a modification of the die; FIG. 9 is a diagram for explaining an example of the manufacturing method of the present invention for forming the outer skin of a flexible tube using the manufacturing apparatus shown in FIG. 4; figure. Figure 11 (A). (B). (C)
, (D) and FIG. 12 are diagrams for explaining other examples of the manufacturing method of the present invention for forming the outer skin of a flexible tube using the manufacturing apparatus shown in FIG. FIG. 2 is an enlarged sectional view of a main part of an example of a flexible tube for an endoscope. 1...... Endoscope 2...
・・・・・・・・・・・・・・・・Operation unit body 4...
......Flexible tube 7...
・・・・・・・・・Outer skin 8・・・・・・・・・
・・・・・・・・・Blade 9・・・・・・・・・・・・
・・・・・・Flex 11・・・・・・・・・・・・
・・・・Soft elastomer 12・・・・・・・・・・・・
・・・Hard elastomer 15・・・・・・・・・・・・・・・
・・Serpentine pipe member 16 ・・・・・・・・・・・ Conveyance path 20 ・・・・・Mixing section 21 ・・
・・・・・・・・・・・・Application part 22.23・・・・・・
・Resin supply machine

Claims (2)

[Claims] (1) In a flexible tube for an endoscope, which is constructed by laminating a flex (helical tube), a blade (mesh tube), and an outer skin in this order, the outer skin is formed by mixing a soft elastomer and a hard elastomer. A flexible tube for an endoscope, characterized in that the flexibility of the flexible tube is changed by changing the mixing ratio. (2) Insert the flexible tube member for the flexible tube structure into a synthetic resin molding machine, move it in the axial direction inside the molding machine, and insert multiple resins with different hardness according to the amount of insertion of the flexible tube member into the molding machine. A method for producing a flexible tube for an endoscope, the method comprising: mixing the resin at a mixing ratio, and applying the mixed resin to the moving flexible tube member to form a covering outer skin of the flexible tube.