JPH0315045Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] This invention relates to a curved tube of an endoscope.

[Conventional technology]

An endoscope is constructed by connecting a curved tube section to the operation section main body via a flexible section, and by inserting the flexible section together with the curved tube section into the body cavity, the inside of the body cavity can be observed or treated. ing.

Conventionally, the curved tube part of such an endoscope has a ninth
As shown in the figure, a plurality of approximately annular joint fittings b each having a pivoting part a at the end are arranged along the axial direction, and the pivoting parts a of adjacent joint fittings b are overlapped so that they can rotate freely relative to each other. A structure in which the shaft is attached to the shaft is used.

[Problem that the invention attempts to solve]

However, it has been pointed out that the conventional joint fitting b has a thin peripheral wall and is easily deformed when subjected to external force. When such deformation occurs, pressure is applied to the built-in items (optical fiber bundles, etc.) passed through the curved tube, causing the optical fiber bundle to break or even distorting the entire curved tube, making it impossible to obtain a sufficient bending angle. If it runs out, problems will occur.

Therefore, as a countermeasure to this problem, it may be possible to increase the thickness of each joint metal fitting b, but this would make it difficult to process the joint metal fittings b. Moreover, if the outer diameter of the joint fitting b is not made large so as not to impair the insertability into the body cavity, the connecting part c (the shaft-mounting parts a, part)
Then, twice the wall thickness increase Δt with respect to the wall thickness t,
If the inner diameter is secured, the outer diameter will become 2 of the wall thickness increase Δt, as shown in Figure 11.
This increases the size significantly, impairing the ease of insertion into body cavities. For this reason, it is difficult to increase the thickness.

As a prior art similar to this, Japanese Utility Model Application Publication No. 55-75301 discloses deformation along the width direction of the joint fittings in order to prevent the joint fittings from entering each other when the curved pipe section is bent. In Utility Model Publication No. 57-20162,
There are joint fittings that have cutouts to prevent the outer skin from digging into them, but none of these have been able to prevent the joint fittings from deforming due to external forces.

This invention was made in view of these problems, and aims to improve the deformation resistance of individual joint fittings without increasing the wall thickness.

[Means for solving problems]

In this curved tube, a concave or convex deformation portion 14 formed by plastic deformation is provided on the peripheral wall 10a of the joint fitting 10 along substantially the entire circumferential direction thereof in order to increase rigidity.

[Effect]

Providing the deformable portion 14 makes it difficult for the joint fitting 14 to deform due to external forces due to work hardening and an increase in cross-sectional moment.

〔Example〕

This invention will be explained below based on a first embodiment shown in FIGS. 1 to 3. FIG. 3 shows an endoscope, in which 1 is the main body of the operation part, 2 is the flexible part, 3 is the curved tube part, 4 is the tip component, and 5 is the light guide case.
It is bull. A flexible part 2, a curved tube part 3, and a tip structure part 4 are connected in series to the operating part main body 1, and a base of a light guide cable 5 is connected to the operating part main body 1. Observe from the eyepiece 6 to the front of the objective window (not shown) provided in the tip component 4, and from the light guide cable 5 to the observation area through the illumination window (not shown) provided in the tip component 4. It is possible to supply illumination light. Further, the operating section main body 1 is provided with a bending operation knob 7 connected to the above-mentioned bending tube section 3 by an operation wire (not shown), and by rotating the bending operation knob 7, the bending tube section 3 can be moved left and right. It is designed to be able to bend in four directions (or two directions), up and down. This curved tube section 3 is shown in FIG.

Here, if the structure of the curved pipe part 3 is explained, 8 is a curved pipe. The curved pipe 8 has a plurality of approximately annular joint fittings 10 each having a pair of shaft fittings 9, 9 molded at the ends thereof spaced apart by 90 degrees, and arranged along the axial direction.
The pivoting parts 9, 9 of adjacent joint fittings 10, 10 are overlapped, and both are bendably connected by a connecting pin 11. The outer periphery of the curved tube 8 is covered with a mesh tube 12, and the outer periphery of the mesh tube 12 is further covered with a tube skin 13 made of synthetic rubber to form the curved tube section 3.

A deformed portion 14, which is a key part of this invention, is provided along substantially the entire circumference of the peripheral wall 10a of each joint fitting 10 constituting the curved tube 8. Its structure is shown in FIG.

That is, the deformable portions 14 are formed by forming rectangular concave portions 15 along the circumferential direction on the outer periphery of the peripheral wall 10a above the respective shaft attachment portions 9 by concave machining by plastic deformation.

Therefore, the joint fitting 10 having such a concave portion 15 on the peripheral wall is difficult to avoid from the periphery to the center without increasing the wall thickness due to the occurrence of work hardening due to plastic deformation of the deformed portion 14 and an increase in cross-sectional moment. This makes it possible to dramatically increase the resistance to external forces directed toward the shaft, that is, the resistance to external forces in the axial and perpendicular directions. In other words, each joint fitting 10
deformation due to external force is less likely to occur.

As a result, the rigidity and strength of the joint fitting 10 can be increased while eliminating problems such as pressure on built-in objects and distortion of the entire curved tube section 3. Moreover,
Since there is no significant inward protrusion or significant increase in outer diameter at the connecting portion, a sufficient bending angle can be obtained. In particular, since the concave portions 15 do not overlap, the concave portions 15
If it is placed, it will not become a practical obstacle.

Moreover, this invention is not limited to the first embodiment, but also the fourth embodiment.
The second embodiment shown in the figure, the third embodiment shown in FIG. 5, and the fourth embodiment shown in FIG. 6 may be used.

The second embodiment is a deformed portion 1 consisting of a concave portion 15.
4 is provided over the entire outer periphery of the peripheral wall 10a. In particular, in this case, since the concave portion 15 is ring-shaped, it is possible to obtain the same rigidity and strength as when the joint metal fitting 10 has a thicker wall thickness.

In the third embodiment, in the peripheral wall portion between the shaft attachment parts 9,
The deformed portion 14 is formed by forming the convex portion 20 by plastic deformation.
It is composed of

In the fourth embodiment, the convex portion 20 shown in the third embodiment is provided over the entire outer periphery of the peripheral wall 10a.

[Effect of idea]

As explained above, according to this invention, it is possible to make it difficult for the joint fitting to deform due to external force due to the occurrence of work hardening and increase in cross-sectional moment due to the provision of the deformable portion.

As a result, the deformation resistance of each joint fitting, that is, the resistance to external forces in the axial and perpendicular directions, can be increased by the plastically deformed portion without increasing the wall thickness. Moreover, there is no significant inward protrusion or significant increase in outer diameter at the connecting part, so
A sufficient bending angle can be obtained.

[Brief explanation of drawings]

1 to 3 show a first embodiment of this invention, FIG. 1 is a perspective view showing a joint fitting together with a deformed part, and FIG. 2 shows a curved pipe section made up of the joint fitting. 3 is a side view showing an endoscope employing the curved tube part, FIG. 4 is a perspective view showing the main part of the second embodiment of this invention, and FIG. FIG. 6 is a perspective view showing the main parts of the fourth embodiment of this invention; FIG. 7 is a perspective view showing the joint fittings constituting the conventional curved pipe; FIG. 8 is a cross-sectional view showing a problem when the wall thickness of the joint metal fitting is increased inwardly, and FIG. 9 is a cross-sectional view showing a problem when the joint metal fitting is thickened outward. 9... Pivot attachment part, 10... Joint metal fittings, 11... Connection pin, 14... Deformation part.

Claims (1)

[Claims for Utility Model Registration] (1) A plurality of approximately annular joint fittings each having a pivoting portion at the end are arranged in the axial direction, and the pivoting portions of adjacent joint fittings are rotatably connected to each other. In the curved tube of an endoscope, the peripheral wall of the joint fitting is provided with a concave or convex deformed portion formed by plastic deformation to increase rigidity along substantially the entire circumferential direction thereof. The characteristic curved tube of the endoscope. (2) The curved tube of an endoscope according to claim 1, wherein the concave or convex deformation portion is provided on the peripheral wall between the shaft attachment portions. (3) The curved tube of an endoscope according to claim 1, wherein the concave or convex deformed portion is provided on the entire circumference of the peripheral wall of the joint fitting.