JPH06142033A - Curved pipe of endoscope - Google Patents

Abstract

PURPOSE:To obtain a curved pipe for an endoscope which is easily automatically assemblable. CONSTITUTION:An introducing channel 7 extending from a peripheral edge part of a connecting part 5 to a connecting hole 6 is formed on the connecting part 5 positioned on the outside of the connecting parts 3 and 5 where knot ring 1 constituting a curved pipe connected rotatably with a rivet 2 is piled up each other and the rivet 2 is inserted into a connecting hole 6 from this introducing channel 7 and the head part 2c of the rivet and the connecting part 5 positioned on the outside are welded together by means of a laser. For positioning of each member, at first, a knot ring 1a to which the connecting part is positioned inside and the rivet 2 are positioned and assembled. Then, a knot ring 1b to which the connecting part is positioned outside is assembled to a rivet 2 in the axial direction of the knot ring 1. Therefore, only two members are required simultaneously for positioning. In assembling the knot ring 1 where an introducing channel 7 is formed on the connecting part, as the introducing channel 7 follows the rivet 2 for assembling by holding with a freedom the knot ring 1, it is not necessary to have a high positioning accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending tube for an endoscope.

[0002]

2. Description of the Related Art Conventionally, as a curved tube for an endoscope, for example, one disclosed in Japanese Patent Publication No. 3-40606 is known. Generally, this type of flexible endoscope is configured as shown in FIG. 16, and will be described in detail with reference to FIGS. 16 to 20.

The endoscope 20 is composed of an operating section 21 and an insertion section 22. The insertion portion 22 includes a flexible tube 23, a curved portion 24 provided at the tip thereof, a tip forming portion 25, and the like, and an observation window 26 is provided in the tip forming portion 25. The operation frame part 27 of the operation part 21 has an operation knob 28 for bending the bending part 24 of the insertion part 22, and an eyepiece part 2 for observing the inside of the body cavity in cooperation with the observation window 26.
9, a universal cord 30 connected to a light source device (not shown) and an operation button 31 for supplying air and liquid are provided.

A bending tube 32 as shown in FIG. 17 is installed in the bending portion 24. The bending tube 32 is constructed by connecting a plurality of node rings 33 as described below, thereby operating the operating portion 21. By operating the operation knob 28, the so-called bending operation in the vertical and horizontal directions can be performed.

That is, a plurality of node rings 3 forming the bending tube 32.
As shown in FIG. 18, 3 is composed of a thin cylindrical short tube. 18A is a side view of the node ring 33, and FIG. 18B is a front view of the node ring 33. Each joint ring 3
A connecting portion 34 for connecting the adjacent node ring 33 and the adjacent node ring 33 via the rivet 2 having the shape shown in FIG. Two connecting portions 34 are extended at positions equidistantly arranged on the circumference, that is, at positions shifted from each other by 180 degrees. A connecting hole 35 is formed in the connecting portion 34 for connecting the adjacent node ring 33 and the rivet 2 in a rotatable manner.

On the other end face of each node ring 33, a connecting portion 36 similar to the connecting portion 34 extending on the one end face is extended, and the connecting portion 36 on the other end face is Two pieces are arranged at positions so-called crossing with a line connecting the connecting portions 34 on the side end faces.

As shown in FIG. 19, each of the wheels 33 having the above structure has a connecting hole 35 formed in the connecting portion 34 on one end face and a connecting hole 3 formed in the connecting portion 36 on the other end face.
7 are piled up, and the rivet 2 is inserted from inside the node ring 33. FIG. 20 is a sectional view showing a state in which the two node rings 33 and the rivet 2 are assembled. The tip end of the inserted rivet 2 and the connecting portion 36 located outside are integrally connected by the welding portion 9 by the laser 8, and each node ring 33 is rotatably connected by the rivet 2.

As shown in FIG. 17, a tubular wire receiver 12 for inserting and supporting an operating wire 38 is fixedly mounted on the inner peripheral surface of each node ring 33 by means such as brazing. As the bending tube 32, the wire receiver 12 is arranged at a position where the circumference 4 is evenly arranged, and four operation wires 38 are inserted. One end of the operation wire 38 is fixed to a node ring located from the tip of the bending tube 32, and the other end is interlockingly connected with the operation unit 21, and the node rings 33 are displaced from each other by 180 degrees in the circumferential direction. The pair of operation wires 38 are interlocked with the operation knob 28 by interlocking them so that when one is pulled, the other is pushed. According to the endoscope 20 having the above structure, the bending tube 32 can be bent in the vertical and horizontal directions via the four operation wires 38 by operating the operation knob 28.

[0009]

However, the bending tube 32 of the endoscope 20 having the above-described conventional structure has the following problems. That is, in order to smoothly perform the bending operation of the bending portion 24, it is desired that the rattling of the node ring 33 and the connecting portion of the node ring 33 that configure the bending tube 32 be as small as possible. Therefore, the clearance between the connecting holes 35 and 37 of the connecting portions 34 and 36 and the rivet 2 is required to have an accuracy of several hundredths of a millimeter.

Therefore, the node ring 33 and the node ring 33 are rivets 2
Therefore, in the work of rotatably connecting the rivet 2 to the connecting hole 35 unless the connecting holes 35 of the connecting portions 34 and 36 of the two node rings 33 to be connected and the connecting hole 37 are accurately overlapped. It cannot be inserted into the connecting hole 37. That is, it was necessary to accurately and accurately position the two node rings 33 and the three components of the rivet 2 at the same time.

However, since the node ring 33 is formed by pressing a metal pipe, the positional accuracy of the connecting holes 35 and 37 of the connecting portions 34 and 36 with respect to the outer shape of the node ring 33 is low, and the node ring 33 is It was impossible to assemble the rivet 2 based on the outer shape of the wheel 33. Therefore, the node ring 33 of the bending tube 32
In order to realize the automation of the assembly by the rivet 2, it is necessary to perform the positioning by directly detecting the positions of the connecting holes 35 and 37 of the connecting portions 34 and 36 of the node ring 33 by image processing or the like. Further, it is necessary to simultaneously and accurately position the two connection holes 35 and 37 of the node ring 33 and the rivet 2 which are difficult to be positioned, which makes automatic assembly more difficult, requires complicated equipment, and is expensive. It was supposed to be.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a bending tube for an endoscope which can be easily assembled automatically.

[0013]

A bending tube of an endoscope according to the present invention includes a connecting portion located outside an overlapping connecting portion of node rings rotatably connected by a rivet, from a peripheral portion of the connecting portion. An introducing groove reaching the connecting hole is formed, a rivet is fitted into the connecting hole through the introducing groove, and the rivet end portion and the connecting portion located outside are welded.

[0014]

In the positioning of each member, first, the node ring having the connecting portion positioned inside and the rivet are positioned and assembled. After that, the node ring with the connecting portion located outside is assembled to the rivet in the axial direction of the node ring. Therefore, only two parts need to be positioned at the same time. Further, in the assembly of the node ring having the introduction groove formed in the connecting portion, since the introduction groove is assembled along the rivet by holding the node ring with a degree of freedom, high positioning accuracy is required. do not do.

[0015]

Embodiment 1 FIGS. 1 to 11 show a bending tube of an endoscope of this embodiment. The node ring that constitutes the curved tube of the present embodiment is configured by a thin tubular short tube, and the node ring 1 is shown in FIG.
Indicates. On one end surface on the right side of the nodal ring 1 in the figure, a connecting portion 3 for rotatably connecting to an adjacent nodal ring via the rivet 2 shown in FIG. 2 is provided. The connecting portion 3 includes
Similar to a conventional wheel, a connecting hole 4 for rotatably connecting with an adjacent node wheel and a rivet 2 is formed. Two connecting portions 3 are extended at positions where the node ring 1 is equally distributed around the circumference 2, that is, at positions shifted by 180 degrees.

Similarly to the one side surface, a connecting portion 5 for rotatably connecting to an adjacent node ring via a rivet 2 is also provided on the other end face on the left side of the node ring 1 in the figure. Two connecting portions 5 on the other end surface are arranged at a position that is offset by 90 degrees from the connecting portion 3 on the one end surface, that is, at a position that intersects with a line connecting the connecting portions 3 on the one end surface.

FIG. 3 is a partially enlarged view showing the shape of the connecting portion 5 on the other end surface side. The connecting portion 5 on the other end surface side includes the rivet 2
A connecting hole 6 for connecting with each other and an introducing groove 7 extending from the peripheral portion of the connecting portion 5 to the connecting hole 6 are formed. The introduction groove 7 has the same width as the diameter of the connecting hole 6 and is provided parallel to the axial direction of the node ring 1.

In this embodiment, since the diameter of the connecting hole 6 and the width of the introducing groove 7 are equal, both can be regarded as a connecting groove, but since the functions required for both are different, here. The description will be made separately. Further, in the node ring 1, a wire receiver 12 for inserting and supporting an operation wire (not shown) is fixed to the inner surface of the node ring 1 by means of brazing or the like, similarly to the node ring of the prior art. There is.

FIG. 2 shows a rivet 2 for connecting the wheel 1, which has a small diameter shaft portion 2a inserted into a connecting hole 6 of a connecting portion 5 of the wheel 1 and a connecting hole of a connecting portion 3 of the wheel 1. 4 has a large-diameter shaft portion 2b to be inserted, and a head portion 2c larger than the diameter of the connecting hole 4. FIG. 4 shows a state before connecting the node ring 1a and the node ring 1b with the rivet 2 shown in FIG. 2, and FIG. 5 shows a state after the connection. FIG. 6 is a sectional view of FIG.

The connecting hole 4 of the connecting portion 3 of one node ring 1a is positioned at a predetermined position, and the rivet 2 is inserted into the connecting hole 4 from the inside of the node ring 1a. At this time, since the clearance between the connecting hole 4 and the large-diameter shaft portion 2c of the rivet 2 is only a few hundredths of a millimeter, the rivet 2 is assembled after the position of the connecting hole 4 is accurately positioned by means of image processing or the like.

While maintaining this state, the other node ring 1b
The small diameter shaft portion 2a of the rivet 2 is attached to the connecting portion 5 in which the introduction groove 7 is formed at the position of the connection hole 6 at the back of the introduction groove 7 from the right side in the drawing via the introduction groove 7. The connecting portion 3 and the connecting portion 5 of the node ring 1 are formed such that, when assembled, the connecting portion 5 in which the introduction portion 7 is formed is assembled to the outside. At this time, by holding the node ring 1b with a degree of freedom, even if the positioning accuracy of the rivet 2 and the introduction groove 7 is low, the introduction groove 7 can follow the rivet 2 and be assembled.

In this state, as shown in FIG. 7, the laser beam 8 welds the connecting portion 5 having the introduction groove 7 located outside and the small-diameter shaft portion 2a of the rivet 2 to the welding portion 9. By forming and integrally connecting, node ring 1a and node ring 1b
Are rotatably connected by rivets 2.

The case of connecting a set of node rings 1 has been described above, but by connecting the node rings 1 in the same manner, a curved tube having a required length can be obtained.

In the above description of the present embodiment, the case where the rivet 2 including the small diameter shaft portion 2a, the large diameter shaft portion 2b and the head portion 2c as shown in FIG. 2 is used is explained. However, the present invention is not limited to this, and the rivet 10 including the shaft portion 10a and the head portion 10b as shown in FIG. 8 may be used. In FIG. 9, the node ring 1 a and the node ring 1 are made by the rivets 10.
It is a sectional view of a state where b is assembled.

The shape of the connecting portion 5 having the introduction groove 7 is
The shape is not limited to that shown in FIG.
As shown by 0, the introduction groove 7 may be inclined toward the circumferential direction of the node ring 1. That is, when a plurality of node rings 1 are connected to form a bending tube and the bending tube is bent, the end faces in the axial direction of the node ring 1 may come into contact with each other. A rotational moment about the contact portion of the end face is generated. Since the direction of the moment acting on the rivet member 2 and the direction in which the introduction groove 7 is provided are substantially the same, the force applied to the welded portion 9 connecting the rivet member 2 and the node ring 1 is large. However, if the introduction groove 7 is provided so as to be inclined in the circumferential direction, the moment acting on the rivet member 2 when the bending tube is bent is received by the portion other than the introduction groove 7 of the connecting portion 5, so that Compared with the case where the introduction groove 7 is provided as in the embodiment (see FIG. 3), the force directly applied to the welded portion 9 becomes smaller, and the welding (coupling) of the node ring 1 and the rivet member 2 is made more reliable. can do.

Further, as shown in FIG. 11, the opening of the peripheral portion of the connecting portion 5 of the introducing groove 7 may be wider than the diameter of the connecting hole 6. The node ring 1 having a wide opening of the introduction groove 7 as shown in FIG. 11 has an effect that it can be assembled even if the positioning accuracy with the rivet 2 is lower.

In this embodiment, the connecting portion 5 having the introduction groove 7 located on the outer side and the small-diameter shaft portion 2a of the rivet 2 are integrally formed by the welding portion 9 formed by the laser 8. Although joined, the means for forming the welded portion is not particularly limited to laser welding, and for example, electron beam welding, plasma arc welding, or the like, the connecting portion 5 and the small-diameter shaft portion 2a of the rivet 2 are integrally formed. Any means capable of welding can be used.

[0028]

[Embodiment 2] FIGS. 12 to 14 show a bending tube and a rivet of the present embodiment. FIG. 12 shows a perspective view of the rivet, and FIG. 13 shows a joint ring 1a and a joint by the rivet 11 of FIG. FIG. 15 is a sectional view showing a state in which the wheel 1b is assembled, and FIG. 14 is a perspective view showing a state where laser welding is performed.

The rivet 11 comprises a retaining portion 11a, a small diameter shaft portion 11b, a large diameter shaft portion 11c and a head portion 11d. The diameter of the retaining portion 11a is formed to be equal to or smaller than the diameter of the connecting hole 4 of the connecting portion 3 located inside when assembled, and larger than the diameter of the connecting hole 6 of the connecting portion 5 located outside.

The connecting hole 4 of the connecting portion 3 of the node ring 1a is connected to the large diameter shaft portion 11c of the rivet 11, and the connecting hole 6 of the connecting portion 5 of the node ring 1b is inserted into the connecting hole 6 through the introduction groove 7. It is attached to the small-diameter shaft portion 11b. With the rivets 11 assembled to the node rings 1a and 1b as described above, the rivet 1
By forming the welded portion 9 of the retaining portion 11a of 1 and the connecting portion 5 by the laser 8 and integrally connecting both members, the node rings 1a and 1b are rotatably connected by the rivet 2.

In this embodiment, the retaining portion 11a is formed on the rivet 11 so that the rivet 11 can be prevented from coming off in the state where the node ring 1a, the node ring 1b and the rivet 11 are assembled before welding with the laser 8. Since the connecting portion 5 is sandwiched by the portion 11a and the large-diameter shaft portion 11c, the rivet 11 does not fall off without holding the rivet 11. Therefore, it is unnecessary to hold the rivet 11 after assembling, and it is possible to hold only two parts of the node ring 1a and the node ring 1b.

[0032]

[Embodiment 3] FIG. 15 shows a connecting portion in a bending tube of the present embodiment. The configuration in this embodiment is
Since the structure is the same as that of the first embodiment except for the structure of the introduction groove 7, the description in the assembled state will be described with reference to FIG. 5 described above.

That is, the dimension A in FIG.
Is the dimension of the contacting portion of the introducing groove 7, B dimension is the dimension of the connecting hole 6, and C dimension is the dimension of the introducing groove 7 at the peripheral portion of the connecting portion 5. At this time, the dimensions A, B and C and the connecting hole 6
The relation of the diameters of the rivet shafts inserted into the shaft is configured as follows: "A <rivet shaft diameter <B <C".

When the node ring 1 having the connecting portion 5 shown in FIG. 15 is assembled to the adjacent node ring 1a and the rivet 2 as in the first embodiment, "A <rivet shaft diameter <B <C" is satisfied. Therefore, the rivet 2 is pushed into the connecting hole 6 through the introduction groove 7 to be assembled. Therefore, once assembled, the positional relationship between the node ring 1b and the rivet 2 is fixed. In the above-mentioned state, similarly to the first embodiment, the welding portion 9 is formed by the laser 8 on the small-diameter shaft portion 2a of the rivet 2 and the connecting portion 5, and both members are integrally connected to each other, so that the node ring 1a and the node ring The wheel 1b is rotatably connected by a rivet 2.

Therefore, in this embodiment, since the rivet 2 is fitted and positioned and fixed in the connecting hole 6 of the connecting portion 5 of the node ring 1b, after the node ring 1a, the node ring 1b and the rivet 2 are assembled. (Before laser welding) has an effect that only two parts, that is, the node ring 1a and the rivet 2 need to be held.

[0036]

[Fourth Embodiment] The bending tube of this embodiment is the same as that of the first embodiment except for the structure of the introduction groove and the rivet, as in the third embodiment. Therefore, the description in the assembled state is as described above. Figure 5
Will be explained. That is, the present embodiment has a configuration in which the rivet 11 shown in FIG. 12 of the second embodiment and the connecting portion 5 of the third embodiment shown in FIG. 5 are combined.

In this embodiment, the rivet 11 of the second embodiment prevents the rivet 11 from falling off, and the rivet 11 of the third embodiment is used.
In order to push and position the rivet through the introducing groove 7 of the connecting portion 5 into the connecting hole 7, the positional relationship between the rivet 11 and the node ring 1b on the introducing groove 7 side is fixed. Therefore, in this embodiment, after assembling the node ring 1a and the node ring 1b with the rivet 11, it is sufficient to hold only the node ring 1a.

[0038]

EFFECTS OF THE INVENTION In connection with a joint ring of a bending tube of an endoscope and a joint ring with a rivet, conventionally, it was necessary to position three parts at the same time, whereas in the present invention, the joint is divided into two parts. Although the positioning is performed, only two parts need to be positioned at the same time, and when automatic assembly is performed, the equipment can be simplified. In addition, one of the two joint rings connected
For individual pieces, it is necessary to position the connecting holes accurately, but
The other node ring does not require high positioning accuracy, and this also makes it possible to greatly simplify the equipment.

As described above, the bending tube of the endoscope of the present invention greatly facilitates automated assembly as compared with the conventional bending tube. Further, even when assembled by an operator, workability is improved because the positioning accuracy of parts is unnecessary.
The work man-hour can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a node ring in a bending tube of an endoscope according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a rivet according to the first embodiment.

FIG. 3 is a front view of a connecting portion according to the first embodiment.

FIG. 4 is a perspective view showing a connecting method according to the first embodiment.

FIG. 5 is a perspective view showing a connected state in the first embodiment.

FIG. 6 is a cross-sectional view showing a connected state in the first embodiment.

FIG. 7 is a perspective view showing a laser welding method according to the first embodiment.

FIG. 8 is a perspective view showing a modified example of the rivet in the first embodiment.

FIG. 9 is a cross-sectional view showing a modified example of the rivet in the first embodiment.

FIG. 10 is a front view showing a modified example of the connecting portion according to the first embodiment.

FIG. 11 is a front view showing a modified example of the connecting portion according to the first embodiment.

FIG. 12 is a perspective view of a rivet in a bending tube of an endoscope according to a second embodiment of the present invention.

FIG. 13 is a cross-sectional view showing a connected state in the second embodiment.

FIG. 14 is a perspective view showing a connected state in the second embodiment.

FIG. 15 is a front view showing a connecting portion of the bending tube of the endoscope according to the third embodiment of the present invention.

FIG. 16 is a perspective view showing an endoscope.

FIG. 17 is a cross-sectional view of the bending tube of the bending section of the endoscope.

FIG. 18 is a view showing a conventional node ring.

FIG. 19 is a perspective view showing a conventional method for connecting node rings.

FIG. 20 is a cross-sectional view showing a conventional method for connecting node rings.

[Explanation of symbols]

 1 node ring 2 rivet 2a small diameter shaft portion 2b large diameter shaft portion 2c head portion 3 connecting portion 4 connecting hole 5 connecting portion 6 connecting hole 7 introducing groove

Claims (1)

[Claims] 1. A connecting portion is formed on a plurality of ring-shaped node rings forming a curved tube, the connecting portions of adjacent node rings are overlapped with each other, and a rivet member is provided in a connecting hole formed in these connecting portions. In the endoscope in which the node rings are movably connected to each other by being inserted, an introducing groove extending from the peripheral portion of the connecting portion to the connecting hole is provided in the connecting portion located outside the overlapping connecting portions. A bending tube for an endoscope, which is formed by inserting the rivet member into the connection hole through the introduction groove and welding the end portion of the rivet member and the connection portion located outside.