JPH0221836A - Endoscope - Google Patents

Abstract

PURPOSE:To effectively reconcile the bending performance, strength and insertion ability of a bent portion by rotatably coupling joint rings on the forward end side at least by shafts with a small diameter and rotatably coupling joint rings at the side in hand by shafts with a large diameter to form a bent pipe. CONSTITUTION:Used rivets 9a-9f of a bent pipe 7 have different outside diameters. To be concrete, joint rings 8a-8c on the forward end side in a portion which has a small bending angle and difficult to cause looseness are coupled using rivets 9a, 9b with a small diameter, and joint rings 8c-8f in the center with a large bending angle are connected using rivets 9c-9e with a large diameter. Further, joint rings 8f, 8g on the side in band (operation part side) where the bending angle is small but large force is applied in the axial direction and in the radial direction are also coupled using the rivet 9f with a large diameter. Thus, the peripheral sizes of connecting portions indicated by 'D1-D6' are larger on the side in hand which requires large strength and smaller on the forward end side of the bent pipe 7 largely related to insertion ability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an endoscope having a curved tube consisting of a plurality of segment rings.

[Prior Art] In an endoscope, the curved section provided at the distal end of the insertion section is bent downward or in the left-right direction by remote control.
The tip is guided to the desired position.

Traditionally, the curved part of these endoscopes has been
A curved tube as shown in Japanese Patent No. 7829 is also used. This has a structure in which a plurality of nodal rings are arranged along the axial direction, and these adjacent nodal rings are rotatably connected using rivets (shaft bodies).

[Problems to be Solved by the Invention] By the way, curved pipes are required to have good bending performance, strength, insertability, and the like. This is greatly influenced by the size of the rivet that connects the node rings.

That is, if the flange portion of the rivet opening is small (the outer diameter of the rivet is thin), tilting or the like is likely to occur between the connected joint rings, and the bending direction may be tilted when the rivet is bent. Moreover, the mechanical strength in the non-curving direction is weak. For example, when an external force is applied to a curved part that curves in two directions (up and down (UD)) to bend it from the left and right (RL) directions, it easily deforms or breaks. do.

Conversely, if the flange of the rivet is made large (the outer diameter of the rivet is thick), the outer diameter of the curved portion becomes thicker as a whole, impairing the insertability of the insertion portion. Moreover, in the part where the connecting protrusion becomes larger, in addition to the larger outer diameter,
Furthermore, uneven areas are formed where the diameter locally increases, causing unnecessary pain to the patient.

However, conventionally, the rivets of curved pipes were
As disclosed in No. 8-7829, all rivets having the same outer diameter are used, and no technology has been found that achieves both bending performance, strength, and insertability using rivets.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscope that can effectively balance the bending performance, strength, and insertability of the bending portion.

[Means for Solving the Problems] In order to achieve the above object, the endoscope of claim 1 has at least the nodal ring on the distal side rotatably connected by a shaft with a small diameter, and the nodal ring on the proximal side. are rotatably connected by a large-diameter shaft to form a curved pipe.

In addition, in the endoscope of claim 2, the joint rings having a small defined curvature angle are rotatably connected by a small-diameter shaft, and the other joint rings are rotatably connected by a large-diameter shaft. Connect to.

[Function] According to the endoscope of claim 1, insertability is ensured by using a small-diameter shaft body to connect the nodal ring on the distal end side of the curved tube, which has a small bending angle and is less prone to looseness, and also ensures ease of insertion in the axial direction. In addition, a large diameter shaft body is used to connect the joints on the proximal side of the curved pipe, where large external forces are easily applied in the radial direction, and there is little effect on insertability. We will balance both.

According to the endoscope of claim 2, insertability is ensured by using a small-diameter shaft body to connect the nodal rings with a small bending angle that requires less external force applied in the radial direction, and the other nodal rings By using a large-diameter shaft to connect between the two, we will ensure strength and achieve both bending performance and insertion strength.

[Example] The present invention will be described below based on a first example shown in FIGS. 1 to 3. FIG. 1 shows the distal end side of an insertion section 1 of an endoscope, and 2 is a flexible section formed by covering the outer peripheral surface of a flex (helical tube) 3 with an outer skin 2a. A curved portion 5 and a tip forming portion 6 are sequentially connected to the tip of the flexible portion 2 via a cylindrical connecting member 4.

The present invention is applied to this curved portion 5.

To explain the curved portion 5, 7 is a curved tube whose outer periphery is covered with an outer skin 7a. The curved tube 7 has seven (plural) joint rings 8a to 8g arranged in series along the axial direction, and is rotatable by a pair of rivets 9a to 9f (each set of two) serving as a shaft body. It has a connected structure. For more information, see Section 8.
A pair of connecting inner protrusions 10.b to 8f are provided at both ends of the node ring.
10 and a pair of connecting outer protrusions 11, 1.1 are used. The remaining end nodes 8a and 8g are provided with protrusions 10.degree. 10 and outer connection protrusions 11 and 11 on the inner side for connection that combines with the nodes 8b and 8f. The inner connecting protrusion 10 and the outer connecting protrusion 11 that fit together between the joint rings are rotatably caulked and fixed by rivets 9a to 9f. Note that the curved tube 7 has, for example, a defined bending angle that is small at the tip and proximal portions and large at the center.

As shown in FIGS. 2 and 3, the rivets 9a to 9f of the curved tube 7 have different outer diameters. Specifically, the nodal rings 8a to 8a on the distal side, which have a small bending angle and are difficult to generate looseness.
Small diameter rivets 9a and 9b are used to connect 8C. Further, large diameter rivets 90 to 9e are used to connect the central node rings 8C to 8f, which have a large curvature angle. Furthermore, although the bending angle is small, the node rings 8f and 8g on the proximal side (operation unit side) are subjected to large forces in the axial and radial directions.
A large-diameter rivet 9f is also used for the connection. Then, in Fig. 2, the size of the area around the connecting portion indicated by D1 to D6J is increased, and the proximal side where strength is required is larger.
The distal end side of the curved tube 7, which greatly affects insertability, is made small.

However, Dl is the diameter of the rivet that passes through the outer connecting projection 10, D2 is the diameter of the caulked part, D3 is the diameter of the flange inside the rivet, D4 is the diameter of the inner connecting projection 10, and D5 is the bulge of the outer connecting projection 11. The inner diameter, Db, is the diameter (external) of the convex portion of the outer connecting protrusion 11. Note that Dl and D2 particularly affect strength, so when strength is required, larger values are better.

D3 and D4 are preferably larger in terms of curved shape (curved performance). D. In order to ensure smooth rotation,
It has been found that slightly larger than D4 is better. Note that Dl indicates the maximum outer diameter of the curved portion 7.

Therefore, the curved portion 7 has a diameter that corresponds to the strength of the portion closer to the hand, and has a smaller diameter closer to the tip where the bending angle is small and the burden on the strength is small. However, rivet 98
By properly using ~9f, it is possible to achieve both a reduction in the diameter of the tip of the insertion portion (insertionability), bending performance, and strength.

Note that the node ring 8g at the final end of the curved tube 7 is connected by a connection structure using concave-convex fitting, so that the insertion portion 1 does not have a large diameter. Specifically, keyhole-shaped recesses 12 are provided on both sides of the connecting member 4 in the radial direction, and a protrusion 13 having a shape that interpolates the recess 12 is provided protruding from the end face of the node ring 8g. A structure is used in which these are slid from the radial direction, fitted so as to be coaxial, and then fixed with adhesive or solder. And, with this, the node ring 8g and the connecting member 4
Unlike the case where the two overlap in the radial direction, the diameter of the insertion portion 1 does not need to be increased. Of course,
The connection strength in two rotational directions in the axial direction of the insertion portion 1 is also high. In addition,
Nodal ring 8g and connecting member However, in the drawing, 14 is an observation window provided in the tip component 6, 15 is an image guide fiber inserted from behind the observation window 14 into the curved part 7 and into the flexible part 2. The light guide fiber 18 is inserted into the curved portion 7 and into the flexible portion 2 from behind the illumination window (not shown) provided in the tip component 6, and is fixed to the rear end of the tip component 6 and inserted into the curved portion 7.

The angle wire 19 inserted into the flexible part 2 is a wire guide fixed to the inner surface of the node rings 8b, 8d, and 8f.
Reference numeral 20 denotes a wire guide coil whose end portion is fixed to the inner surface of the connecting member 4 and inserted into the flexible portion 2 .

Of course, in this embodiment, two types of shafts with different thicknesses were used, but three or more types of shafts may be used depending on the part of the curved pipe 7 (for example, if the built-in parts in the nodal ring are (e.g. when it is too tight). Of course, D.

1)2. It is also possible to use a plurality of types of shaft bodies having partially different dimensions, such as I) 3.

Further, FIG. 4 shows a second embodiment of the present invention (an embodiment to which the invention described in claim 2 is applied).

In this embodiment, the nodal rings 8a and 8b have a curvature angle at the tip.

Rivets 98 to 9f of the curved pipe 7 are used properly, with small rivets between 8C and large rivets between 8d and 8g.

That is, according to such a curved pipe 7, the node rings 3a, 8b
, 8c, the defined curvature angle is small, so the force applied in the radial direction is small. Other remaining node rings 8d~
8g has a large bending angle, so a large force is applied in the radial direction.

Therefore, the joint rings 8a to 8c with small curvature angles are rotatably connected with small diameter rivets 9a and 9b, and the other joint rings 8
d to 8g are rotatably connected by large diameter rivets 9a to 9f.

In this way, as in the first embodiment, effective diameter reduction and strength of the curved tube 7 are ensured, and the bending performance of the curved portion 5, strength, and insertability are effectively compatible. I can do it.

However, in the second embodiment, the same parts as in the first embodiment are given the same reference numerals and their explanations are omitted.

In the above-described embodiments, the present invention was applied to an endoscope using a fiber, but it may also be applied to an endoscope using a solid-state image sensor. Of course, it may be curved using Aang's method. In addition, the present invention may be applied to an endoscope in which a blade (reticular tube) is provided on the outer periphery of the nodal ring and the flex.

[Effects of the Invention] As explained above, according to the endoscope described in claims 1 and 2, the bending performance is improved due to the reduction in diameter due to the small diameter shaft body and the increase in rigidity due to the large diameter shaft body. Both insertability and strength can be achieved without damage.

Therefore, it is possible to effectively achieve both bending performance, strength, and insertability of the curved portion.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the distal end of the endoscope, which is the main part of the first embodiment of the present invention, and FIG.
3 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. FIG. 5... Curved portion, 7... Curved pipe, 8a to 8g... Joint ring, 9a to 9f... Rivet (shaft body), 10... Inner protrusion for connection, 11... For connection Lateral process.

Claims (2)

[Claims] (1) In an endoscope having a curved tube formed by rotatably connecting node rings arranged in series along the axial direction by a shaft body,
The curved tube is characterized in that at least the nodal ring on the distal end side is rotatably connected with a small diameter shaft, and the nodal ring on the proximal side is rotatably connected with a large diameter shaft body. Endoscope. (2) In an endoscope having a curved tube formed by rotatably connecting node rings arranged in series along the axial direction by a shaft body,
It is characterized in that the joint rings with a small prescribed curvature angle are rotatably connected by a small diameter shaft, and the other joint rings are rotatably connected by a large diameter shaft. Endoscope.