JPH0147171B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curved member forming a curved portion of an endoscope.

As shown in Fig. 1, an endoscope generally has a distal end 1 with an observation lens and an illumination window open, a curved section 2 connected to the distal end, a flexible tube section 3 connected to the curved section, and a flexible tube section 3 connected to the curved section. The operating section 4 is connected to the operating section 4, and the eyepiece section 5 is provided on the end surface of the operating section.
Built-in components such as optical fiber bundles extend inside the curved part 2 and the flexible tube part 3 until the operation part is connected to the light guide flexible tube part 6 that connects to the illumination light source. The curved portion 2 rotates and the distal end portion 1 swings. As shown in FIG. 2, the curved portion 2 includes a blade 9 (generally made of thin metal wire woven into a cylindrical shape) on a curved member 8 having a diameter sufficient to accommodate built-in items such as an optical fiber bundle. The outer cover 10 (generally made of synthetic resin) is placed on top of the outer cover 10, and is curved with a predetermined degree of curvature so as to define the swing angle of the tip or the observation field of view. This invention relates to the curved member 8, which is a member that is bent to a predetermined degree of curvature to form a curved portion.

Conventionally, as such a curved member, those having the configuration shown in FIGS. 3 to 5 have been known. The curved member shown in FIG. 3 is made up of a large number of joint rings a connected in the longitudinal direction, and each joint ring is connected with a pin b as a curved support shaft so that it can be bent.
As the number of parts increases, it ends up being more expensive.
Furthermore, as the diameter of the curved portion becomes narrower, it becomes more difficult to connect the pin b with the pin b, and there is also a problem in the construction that it becomes difficult to bend the pin b depending on the condition of the caulking connection. Therefore, in order to connect the joint rings without caulking them with pins, the fourth
As shown in the figure, the apexes c of each node ring are brought into contact with each other,
A structure has been considered in which a hole d is passed through this abutting portion and a curved wire is inserted therethrough. However, in a curved member with this structure, if the abutment part does not have a certain thickness, there is a risk that the abutment part will shift during assembly, resulting in defective products. There was also a manufacturing constraint in which the wall thickness of the transition part e up to the plate was thicker than the plate thickness of the one shown in FIG. 3, and there was a tendency for the outer diameter of the curved part to become thicker. Therefore, as shown in FIG. 5, a flexible body was devised in which a metal band plate f was spirally wound without using a joint ring. However, when the curved member of this flexible body is bent in one direction to form a curvature, the tip fixed to the curved member tends to move in the winding direction of the flexible body, such as untwisting. This repulsion effect makes it difficult to obtain or adjust the desired degree of curvature.In order to overcome this, if flexes wound in opposite directions are stacked, the wall thickness of the curved member will increase, and the thickness of the curved portion will eventually increase. A problem occurred in that the outer diameter became thicker. In general, these conventional curved members have the disadvantage that the number of parts and assembly steps are large, and the outside diameter of the curved portion is large.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a curved member for an endoscope that can reduce the number of parts and assembly steps, and reduce the outer diameter of the curved portion.

This invention focuses on a superelastic alloy, and by utilizing it, eliminates the nodal ring curved support shaft and flex required for conventional curved members. Superelastic alloys are metals that, like rubber, return to their original shape after being stretched or bent when the force is removed. It is said that this happens over time. The elasticity of metals is usually around 0.5%, with the highest being around 1%, while the elasticity of superelastic alloys is generally between 4 and 6%, and some are around 10%. Superelastic alloys include Ni-Ti
(Titanium) based, Cu (Copper) - Al (Aluminum) - Ni
(nickel) type, Pb (lead)-Zn (zinc) type, Ag (silver) type
-Cd (cadmium)-based and In (indium)-Ta (tantalum)-based materials have been discovered.

According to this invention, a tube material made of a superelastic alloy is used, wedge-shaped grooves are cut into the tube material from both sides at right angles to the tube axis, close to the tube axis, and a guide hole for inserting a curved wire is bored in the tube wall. By forming such grooves and holes at several locations along the length of the pipe material, it is possible to obtain a curved member that does not use a nodal ring curved support shaft.

Examples of the present invention will be described below. In FIG. 6 showing the first embodiment, the curved member is a wedge-shaped member that extends from both sides of the tube (up and down in the figure) at right angles to the tube axis along the length of the tube 11 made of a superelastic alloy. The grooves 12 and 13 are cut down until the apexes 12a and 13a of each groove on the tube circumference reach the vicinity of the tube axis, and are formed at several locations at equal pitches so that both side surfaces are continuous. Furthermore, a recess is formed in the continuous pipe wall portion on both sides between the grooves 12 and 12 and between 13 and 13, as shown in FIG. ,1
Guide hole 1 for a curved wire (not shown) that bridges 3
4 and 15 are drilled. On the other hand, holes 16 and 17 are formed at both ends of the pipe material 11, respectively.
As shown in the figure, the tip 1 and the flexible pipe connecting member 18
Pass the screws or pins 18a through the holes 16 and 17.
It is now possible to connect with

Using such a curved member, one end of the curved member is fixed to the distal end 1, and the end of the curved wire is fixed to the distal end 1, and the curved wire is inserted into the guide holes 14 and 15, respectively. The curved portion 2 is formed by covering the blade 9 and the outer skin 10.

Thus, when the bending member is bent in either the up or down direction as shown in FIG. The groove narrows, and a portion 19 between the vertices of the upper and lower wedge-shaped grooves extends, resulting in a curve, forming a curved portion 2 having a predetermined degree of curvature.

The second embodiment shown in FIG. 8 has a shape in which the width and pitch of wedge-shaped grooves 21 cut from the upper and lower side surfaces of a tube material 20 made of a superelastic alloy to near the tube axis are varied along the length of the tube material. 1 shows a curved member having: As a result, the bending angle is large in areas where the groove width and pitch are large, and the bending angle is small in areas where the groove width and pitch are small. Therefore, in general, in an endoscope, the distal end side of the curved section is difficult to curve, and the flexible tube section side is easy to curve, so the second embodiment is effective in dealing with such a case.

In the third embodiment shown in FIG. 9, a U-shaped groove 22 is bored in place of the wedge-shaped groove in the previous embodiment, and this aims at ease of processing and ease of bending. It is ivy.

In the fourth embodiment shown in FIG. 10, the machining depth of the U-shaped groove is varied along the length of the pipe material.
As a result, the smaller the remaining thickness near the tube axis, the easier it is to bend.
The same effects as in the example can be obtained.

The fifth embodiment shown in FIG. 11 has a structure in which wedge-shaped grooves are cut from the top and bottom directions and curved in two directions in the previous embodiment, whereas wedge-shaped grooves 23 are further cut from the left and right directions, and the grooves are curved in two directions. A guide hole 24 is formed in the tube wall between 23 and 23 in the same manner as in FIG. 7, and four bending wires are inserted through the guide hole 24, thereby showing a bending member having a structure that can be bent in four directions, up, down, left and right. Regarding the curved member of this fifth embodiment, the groove width, pitch, groove shape, and groove depth are adjusted to 8th to 1st.
By incorporating the configuration shown in FIG. 0, the same effects as in the second to fourth embodiments can be obtained.

In the embodiments described above, bendability and bendability can be varied by changing the wall thickness of the tube made of superelastic alloy. The groove to be cut into the tube material is not limited to a wedge shape or a U-shape, but may be a slit shape, a half-moon shape, or any other arbitrary shape. In addition, as shown in the sixth embodiment in Fig. 12, the cutting grooves are made by shifting adjacent grooves so that the apex of the groove reaches the pipe axis or beyond it, or so that it is not vertically symmetrical. It may also be provided. Although the bending wire has been described as being fixed to the distal end 1, the bending wire may be fixed to the end of the bending member on the distal end side. Guide holes for insertion of the curved wire may not be provided in each section, but may be provided in every other region or every second region, or a combination thereof may be used. It was explained that a part of the pipe wall should be recessed to provide a guide hole for the curved wire, but
If the curved wire is inserted freely into the tube wall of the curved member, a guide hole is not required, and the outer surface of the curved member is recessed to form this guide recess as shown in FIG. 13 as the seventh embodiment. It is also possible to insert a curved wire into the wire and hold it down with a blade. The curved member does not have a one-piece structure from the tip joint to the flexible pipe joint, but by connecting multiple pipes made of superelastic alloy using the joining method shown in Figure 3 in the middle. Alternatively, a curved member other than a superelastic alloy may be connected in the middle. The curved member can be manufactured by rolling a plate material into a tubular shape, or it can also be manufactured by forming grooves or the like by pressing or the like at the time of the plate material and then forming it into a tubular shape.

As is clear from the above explanation, this invention
As a curved member constituting the curved portion of an endoscope, it has the following special effects.

(1) Since the main component is a tube made of superelastic alloy, the number of parts is reduced and the cost can be reduced.

(2) There is no need to connect joint rings, so assembly man-hours are greatly reduced.

(3) Since the outer diameter of the curved member is determined by the tube material made of superelastic alloy without any particular restrictions, the outer diameter of the curved portion can be made thinner by minimizing the wall thickness and diameter of the tube material, if desired. can do.

(4) Since a superelastic alloy with extremely high elasticity is used, the bending angle at each part of the curved member is large, so the length of the curved part can be shortened, for example in the case of a medical endoscope. can alleviate the patient's pain.

(5) By reducing the outer diameter of the curved member and making the inner diameter large enough to accommodate optical fibers, etc., it is possible to satisfy the requirement of having a small outer diameter and a large inner diameter, which are essential for endoscopes.

(6) It can maintain strong resistance to fatigue fracture and extend its service life. In other words, superelastic alloys have excellent restoring force. Metal and plastic tubes break due to fatigue after repeated use, but superelastic alloys do not have that problem, and superelastic alloys are the best material for things that bend due to elastic deformation. .

[Brief explanation of drawings]

Figure 1 is a perspective view illustrating the appearance of the endoscope;
The figure is a partial sectional view showing the upper half in cross section to illustrate the configuration of the curved part of the endoscope, FIG. 3 is a perspective view showing a conventional curved member, and FIG. 4 is a perspective view showing a conventional curved member. , FIG. 5 is a perspective view showing a conventional curved member, FIG. 6 is a perspective view showing a first embodiment of the present invention, and FIG. 7 is a sectional view taken along line A-A in FIG. 6. , FIG. 8 is a schematic diagram showing a second embodiment of the invention, FIG. 9 is a schematic diagram showing a third embodiment of the invention, FIG. 10 is a schematic diagram showing a fourth embodiment of the invention, and FIG. FIG. 11 is a partial perspective view showing a fifth embodiment of the invention, FIG. 12 is a schematic diagram showing a sixth embodiment of the invention, and FIG. 13 is a partial perspective view showing a seventh embodiment of the invention. . DESCRIPTION OF SYMBOLS 1... Tip part, 2... Curved part, 8... Curved member, 9... Blade, 10... Outer skin, 11... Tube material, 12, 13... Groove, 14, 15... Guide hole,
16, 17... Connection hole.

Claims (1)

[Scope of Claims] 1. A curved member for an endoscope, characterized in that the curved member forming the curved portion of the endoscope is made of a superelastic alloy with grooves provided at least on the side surface of the curved side. 2. The curved member according to claim 1, characterized in that a tube made of a superelastic alloy is provided with grooves from at least both sides of the tube. 3. The curved member according to claim 2, wherein the apex of the groove on the tube circumference reaches near or beyond the tube axis. 4. The curved member according to claim 2, wherein the groove widths of the grooves provided at several locations along the length of the tube material are varied. 5. The curved member according to claim 2, wherein the depth of the grooves provided at several locations along the length of the tube material is varied. 6. The curved member according to claim 2, wherein the pitch of the grooves provided at several locations along the length of the tube material is varied. 7. The curved member according to claim 1, characterized in that the wall thickness of the tube material made of a superelastic alloy is changed.