JPH0221837A - Flexible tube for endoscope - Google Patents

Abstract

PURPOSE:To partially change the flexibility of a flexible tube by changing the braiding angle of element wires in the axial direction of a network tube at the time of sequentially stacking a network tube formed by braiding plural elements wires on the outer periphery of a spiral tube and an outer cover having flexibility. CONSTITUTION:A flexible tube 4 is formed by sequentially stacking a braid (network tube) 10 formed by braiding plural element wires 10a and an outer cover 11 having flexibility on the outer periphery of a flex (spiral tube) 9. The network tube 10 is braided at an angle theta1 of of about 65 deg. with respect to the shaft center (axis of tube) of the flexible tube 4 at the forward end side portion of the flexible tube 4, for example, in the vicinity of a connecting portion with a bent portion 5. The end portion in band (operation part 1) of the flexible tube 4, for example, in the vicinity of the end portion of a folding member 1a, it is braided at an angle 4 of about 45 deg. with respect to the shaft center (axis of tube) of the flexible tube 4. The angle is gradually changed from theta1 to theta2 as it goes from the forward end side of the flexible tube 4 to the side in hand, so that the flexible tube 4 is let have softness at the forward end side of the flexible tube 4 and hardness at the side in hand by a difference of the braiding angle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flexible tube for an endoscope that constitutes an endoscope insertion section.

[Conventional technology] In endoscopes, flexible tubes are used in the insertion section.

This flexible tube uses a structure in which the outer periphery of a flex (helical tube), a braided braid of multiple strands (reticular tube), and a flexible outer skin are sequentially laminated, and the tip side is flexible. It is said that those with a relatively hard hand side (operation part side) are easier to insert into body cavities.

Therefore, in order to achieve this,
As disclosed in Japanese Utility Model Publication No. 05 and Japanese Utility Model Publication No. 60-38961, the outer skin of the elastomer that forms the outermost layer of the flexible tube is multilayered, and a soft elastomer and a hard elastomer are combined to create a flexible tube. I was trying to change my gender.

However, such a multi-layered outer skin inevitably increases the wall thickness of the flexible tube, resulting in a thicker outer diameter, which may be disadvantageous in terms of ease of insertion into a body cavity. Moreover, since elastomers are sensitive to heat, they are heated and softened within the body cavity, making it impossible to obtain a sufficient altitude.

Therefore, in order to solve this problem,
By changing the thickness of the flex of a flexible tube and the number of overlapping layers at at least one location on its axis (tube axis) as in Publication No. 26, sufficient flexibility can be achieved even when heated in a body cavity. A method has been proposed that allows for changes in the following.

[Problems to be Solved by the Invention] However, even with such a structure, an increase in the partial wall thickness of the flexible tube, that is, an increase in the outer diameter cannot be avoided. Moreover,
New problems arise, such as difficulty in assembly.

This invention was made in view of these circumstances, and aims to provide a flexible tube for an endoscope that can change the flexibility in the axial direction without increasing the outer diameter. purpose.

[Means for Solving the Problems] In order to achieve the above object, a mesh tube is configured by changing the braiding angle of the strands in the axial direction of the mesh tube.

[Operation] As the flexible tube bends, a force acts on the reticular tube that tends to float inward of the bend. Here, this floating force changes depending on the braiding angle of the strands with respect to the axial direction of the flexible tube. In other words, the flexibility of the flexible tube is partially changed by utilizing the degree of pressure applied to the outer skin of the reticular tube.

[Example] This invention will be described below with reference to 1. A description will be given based on the first embodiment shown in FIG. FIG. 4 shows the external appearance of the endoscope, with reference numeral 1 an operating section to which a universal cord is connected, and 3 an insertion section formed by sequentially connecting a curved section 5 and a distal end component 6 to a flexible tube 4. The proximal end of the insertion section 3 is connected to the operation section 1. Note that 7 is an angle knob for remotely controlling the curved section 5 provided on the operation section 1, and 8 is an eyepiece section. Further, reference numeral 1a denotes a bending member that is connected to the operating section and covers the outer periphery of the proximal end of the flexible tube 4.

The structure of the flexible tube 4 is shown in FIG. The flexible tube 4 has a braid (reticular tube) 10 formed by braiding a plurality of wires 10a around the outer periphery of a flex (helical tube) 9.
It is constructed by sequentially laminating flexible outer skins 11. This braid 10 is made by changing the braiding angle of the strands 10a with respect to the axial direction of the flexible tube 4.

That is, as shown in FIG. 1, the blade 10 is attached to the distal end of the flexible tube 4, for example, near the connecting portion with the curved portion 5, with respect to the axis (tube axis) of the flexible tube 4. approximately 65°
It is braided at an angle of θ1. Also, at the end of the flexible tube 4 on the hand side (operation part 1), for example, near the end of the snapping member 1a, the angle is approximately 45° with respect to the axis (tube axis) of the flexible tube 4.
It is braided at an angle of θ2. As the angle increases from the distal end of the flexible tube 4 toward the proximal side, θ
1 to θ2, and due to the difference in the braiding angle, the tip side of the flexible tube 4 is made soft and the proximal side is made hard.

Specifically, a braiding machine 12 as shown in FIG. 5 is used to manufacture a braid 10 whose braiding angle gradually changes. That is, in the braiding machine 12, a plurality of guide grooves 14 in the shape of an "8" are continuously provided on one side of the braiding machine main body 13 having a donut shape. A support shaft (not shown) of a clique (spooling tool) 15 that moves in a sinusoidal manner using the guide groove 14 as a guide is fitted into the guide groove 14 . Further, the core material 16 is inserted into the hole 13a at the center of the braiding machine body 13.

Note that each clique 15 is wound with a fiber bundle 1-7, which is a bundle of a plurality of strands 10a. The fiber bundles 17 from each clique 15 that move in a sinusoidal manner are wound around the outer peripheral surface of the core material 16 moving in the direction of arrow A, so that the braid 10 is braided. ing. Here, the faster the advancing speed of the core material 16 in the direction of arrow A, the smaller the braiding angle becomes, so start braiding at the angle θ1, gradually increase the advancing speed of the core material 16, and move the flexible tube 4.
The above-mentioned braiding can be achieved by changing the braiding to θ2 within the entire length of the flexible tube 4, or conversely, by starting the braiding at θ2 and gradually slowing down the advancing speed of the core material 16 until it reaches θ1 within the entire length of the flexible tube 4. A flexible tube 4 whose angle changes 17 is produced.

In addition, in this embodiment, the flexible tube 4 and the curved portion 5 are connected without using a large diameter. Specifically, the flexible tube 4 side has a structure as shown in FIG. That is, the portion of the outer skin 11 of the flexible tube 4 adjacent to the connection cap 20 fitted into the blade end is removed (the portion without the outer skin 11 is indicated by reference numeral 21). And this removed outer skin 11
A narrow diameter portion 22 is formed at a portion of the tip.

Then, as shown in FIG. 2, the outer skin 23 of the curved portion 5 is inserted into the connection base 20 until the tip abuts the tip of the outer skin 11 of the flexible tube 4. Then, the binding thread 24 is wound around the tip of the outer skin 23 that has entered the exposed blade portion side and the narrow diameter portion 22 of the outer skin 11, and an adhesive 25 is applied to the wrapped portion to fix it watertight. ing.

That is, since the end portion of the outer skin 23 of the curved portion 11 is arranged and fixed to the portion 21 formed near the connection cap 20 where the outer skin 11 is absent, the connection portion does not become thick.

In addition, 26 is a plurality of adjacent node rings that are rotatably connected to each other and constitutes the curved portion 5, and 27 is a blade (reticular tube) of the curved portion 11.

Therefore, the flexible tube 4 of such an endoscope is flexible on the distal end side and relatively hard on the proximal side.

That is, first, of the 118 g of elements of the blade 10, -
When looking at the book from the side, it has a spiral, substantially sinusoidal wave, as shown by al in FIG. 5 and a2 in FIG. 6.

Now, if we consider bending the flexible tube 4 as shown by the two-dot chain line, the inner circumferential side of the flexible tube 4 will contract and the outer circumferential side will expand at the curved portion. However, due to the structure of the flexible tube 4, the flex tube and the blade 10 are fixed to each other at both ends, so although it freely contracts in the direction of contraction, its movement in the direction of extension is restricted. This can be approximated by the fact that when the flexible tube 4 is bent, the inner circumferential side contracts, the outer circumferential side expands only slightly, and the outer circumferential side does not expand at all.

Based on this premise, when the flexible tube 4 is bent as shown by the two-dot chain line, since there is no elongation on the outer circumferential side, the strands 8a tend to float inward as the tube is bent. At this time, even with the same bending, the smaller the angle of the wire 8a with respect to the axis (tube axis) of the flexible tube 4, the stronger the force that tends to lift it inward. Here, the braid angle shown by 02 in FIG. 6 is smaller than the braid angle shown by θ1 in FIG. This is more than the inward displacement x1 of rat J braided at θ1.
This can be seen from the fact that the inward displacement x2 of the braided "a2" is larger. In other words, braiding at θ2 presses the outer skin 11 with a force stronger than that at θ1, and in order to bend the flexible tube 4 to the same extent, a stronger force must be applied.

Therefore, on one flexible tube 4 whose configuration is not changed, θ
As a characteristic of the flexible tube 4, the part braided in step 1 is more rigid (from the opposite perspective, θ.

is more flexible).

Moreover, as is clear from FIG. 1, the density of the surface of the blade 10 (the area ratio that the fiber bundles 17 occupy with respect to the total surface area of the blade 10) varies from the distal end side of the flexible tube 4 to the proximal side (the operating unit 1 side). ), the outer skin 11 becomes more likely to bite into the blade 10 as it moves toward the hand ().

In other words, the fiber bundles 17 are prevented from moving relative to each other due to the strong anchoring effect, and even when the flexible tube 4 is bent, the difference in resistance causes the fiber bundles 17 to move toward the distal end side of the flexible tube 4. The hand side becomes harder.

Thus, the technique of changing the flexibility of the flexible tube 4 by using the difference between the reaction force of the strands 10a and the surface density of the braid 10, obtained by changing the braiding angle of the strands 10a, is as follows:
Since the outer skin 11 only needs to be a single layer, the outer diameter of the flexible tube 4 does not increase.

Moreover, since the braiding of the braid 8 can be carried out by simply changing the advancing speed of the core material 16, the work is easy.
It is certain.

Further, FIG. 8 shows a second embodiment of the present invention.

In this embodiment, instead of gradually changing from al to θ2 over the entire length of the flexible tube 4, for example, [2
The braid angle is suddenly changed at a certain part within the range of 50 to 45 cm J. In addition, 30 is the strand 10a
shows the part where the angle changes rapidly.

Of course, there may be two or more angle changing portions 30 instead of one. In other words, the angle may be changed to "θ1-02" in several steps from the tip of the flexible tube 4 toward the proximal side.

Further, the angle changing portion 30 may have a certain width. For example, r25 cm to 45 cm from the tip of the insertion section 3.
The range of j is the entire angle changing portion 30 (in this range, the flexible tube 4
The flexibility of the material may gradually change).

In addition, in both the first and second embodiments, θl was set to "65°" and θ2 was set to r45'J, but "θl>
θ2'', this is not the case.

However, for assembly purposes, it is desirable that θl is r65' or less, and for durability, it is desirable that θ2 be r45'45a, and that θl and θ2 are
It is desirable that the difference is approximately 10° or more.

Further, flex may be multiplexed. Furthermore, the flexibility of the outer skin of the flexible tube may vary in the axial direction. For example, the use of outer skins having different hardnesses in the axial direction can be used, and the use of such outer skins, combined with the effect of the braid angle, effectively brings about changes in the flexibility of the flexible tube.

In addition, the outer skin of the flexible tube may be made of thermoplastic elastomer by dip or extrusion molding (tubing).
It may also be made by fitting a tube and reheating and welding it.

Further, in the above-described embodiment, the curved portion side of the flexible tube is made soft, but the braid angle may be changed so that the vicinity of the curved portion side and the stopper member is made soft. By making the area near the clasp member soft, the operation part side becomes flexible, so you can use the flexibility to rotate and twist.
Improves operability.

[Effects of the Invention] As explained above, according to the present invention, the flexibility in the axial direction can be changed without increasing the outer diameter.

[Brief explanation of the drawing]

1 to 7 show a first embodiment of the invention,
Figure 1 is a partially cutaway side view showing the main part of the reticular tube with varying braid angles, Figure 2 is a sectional view showing the structure of the flexible tube of the endoscope, and Figure 3 is the curved tube. FIG. 6 is a perspective view showing the braided wire on the tip side of the flexible tube, together with the displacement of the wire when the flexible tube is bent, and FIG. A diagram showing the braided strands on the proximal side of the tube together with the displacement of the strands when the flexible tube is bent. FIG. 8 is a partially cutaway side view showing the main part of the second embodiment of the present invention. It is. DESCRIPTION OF SYMBOLS 1... Operation part, 3... Insertion part, 4... Flexible tube, 5
...Curved part, 9...Flex (helical tube) 10...
・Blade (mesh tube) 10a...Element wire, 11...
・Outer skin, θ1. θ2... Braid angle. Figure 3

Claims (1)

[Claims] In a flexible tube for an endoscope, which is constructed by sequentially laminating a reticular tube formed by braiding a plurality of wires and a flexible outer skin around the outer periphery of the helical tube, the reticular tube is A flexible tube for an endoscope, characterized in that the braiding angle of the wires is changed in the axial direction.