JP2004236684A - Curved tube for endoscope, and method of connecting joint ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curved tube for an endoscope capable of securing the reduction of the diameter of the curved tube for the endoscope near a place where adjacent joint rings are connected and securing the sufficient connection strength and easiness in the assembly at a low cost, and to provide a method of connecting the joint rings thereof. <P>SOLUTION: In the curved tube 15 for the endoscope, a plurality of joint rings 21 are arranged in the longitudinal axial direction, and tongue pieces 21a and 21b formed in the joint rings 21 are rotatably connected with a shaft pin 22. The shaft pin 22 is divided into a plurality of layers. The shaft pins 22, each of which is divided into the plurality of layers, are integrally formed with each other or with a connection part located on the outer side by optical energy. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a bending tube for an endoscope in which a plurality of node rings are connected, and a method of connecting the node rings.
[0002]
[Prior art]
Generally, the insertion portion of the endoscope is provided with a bending portion between the distal end portion and the flexible portion on the hand side, and the bending portion is forcibly bent via an operation wire by operation on the operation portion, and inserted. By changing the direction of the tip of the part as appropriate, a wide range of target parts can be observed without blind spots. The curved portion is roughly divided into a curved tube formed by connecting a plurality of node rings, and an outer tube covered on the outer periphery of the curved tube. In general, a curved tube is configured by arranging a plurality of node rings in a line in a longitudinal axis direction of an insertion portion, and sequentially connecting adjacent node rings. The connecting portion of the bending tube formed a tongue protruding toward the adjacent node ring at both ends of each node ring, formed an insertion hole in each tongue piece, and overlapped the tongue pieces of adjacent node rings. In this state, the rivet-shaped shaft pin is inserted through the fitting holes of both overlapping tongue pieces, and both ends of the shaft pin are mechanically caulked, so that the node rings are rotatably connected. .
[0003]
However, in such a connection method that forms a mechanical caulked portion, caulked portions are formed relatively large at both ends of the shaft pin in order to prevent the shaft pin from coming off, and the caulked portions are formed inside and outside the node ring. It had a structure that protruded in the direction. The caulked portion increases the outside diameter of the curved portion even if it is local. However, in endoscopes in recent years, it is desired to further reduce the diameter of the insertion portion, and therefore, an improvement in a method of connecting the articulation rings has been desired.
[0004]
As an example of this improvement, there is a connecting method of a node ring proposed in Japanese Patent Application Laid-Open No. 10-248796 (Patent Document 1). In this method, the tongue located on the outside and the rivet-type shaft pin fitted in the insertion hole of the tongue located on the inside are joined, and the laser is irradiated from the outer surface of the tongue located on the outside. The node ring is rotatably connected by welding a shaft pin and a tongue piece joined by light energy.
[0005]
According to this connection method, each node ring is connected via the shaft pin, and excellent rotation property is obtained, and the amount of protruding caulked portions as in the case of mechanical caulking is small, and particularly, Therefore, the diameter of the curved tube can be reduced without the crimped portion protruding toward.
[0006]
As another example, there is an articulated ring connecting method proposed in Japanese Utility Model Laid-Open No. 60-187702 (Patent Document 2). In this method, a shaft pin having a length corresponding to the total thickness of the overlapped tongue pieces is fitted into the fitting holes of the tongue pieces overlapping the node rings, thereby connecting the two node rings.
[0007]
[Patent Document 1]
JP-A-10-248796 (FIGS. 4 and 5)
[0008]
[Patent Document 2]
Japanese Utility Model Publication No. 60-187702 (FIG. 2)
[0009]
[Problems to be solved by the invention]
(Problems of conventional technology)
The distance between the tongue pieces that form a pair of node rings varies from one node ring to another. Therefore, for example, as shown in FIG. 3, the total thickness L of the tongue pieces when the tongue pieces of the adjacent node rings are superimposed on each other in the longitudinal axis direction is different depending on each connection portion. However, it is necessary to use a shaft pin having a length corresponding to the total thickness L of both tongue pieces in order to secure a sufficient and stable strength for connecting the tongue pieces with the shaft pin. For this reason, conventionally, it was necessary to prepare a plurality of types of shaft pins having a length suitable for each part.
[0010]
However, preparing a large number of shaft pins of different lengths is costly, and it is very difficult to accurately select shaft pins of an optimal length. Had become.
[0011]
(Object of the invention)
The present invention has been made in view of the above-mentioned problems, and the object thereof is to secure a small diameter in the vicinity of connecting the adjacent articulating rings in the bending tube for an endoscope, and at a low cost, An object of the present invention is to provide a method for connecting a bending tube for an endoscope and a node ring, which can ensure sufficient connection strength and easy assembling.
[0012]
[Means for Solving the Invention]
The invention according to claim 1 has a configuration in which a plurality of node rings are arranged in the longitudinal axis direction, each node ring has a connection portion formed with a connection opening, and the connection portions of adjacent node rings are overlapped with each other, The shaft member is inserted into the connection hole formed in the connection portion, and the joint ring is rotated by welding the connection opening portion formed in the connection portion disposed outside and the end of the shaft member. In the bending tube for an endoscope that is movably connected, the shaft member is divided into a plurality of layers, and the shaft members divided into a plurality of layers and the shaft member and a connecting portion disposed outside are formed. A bending tube for an endoscope, which is integrated by welding.
[0013]
The invention according to claim 2 is a method of connecting a node ring constituting a curved tube,
The first node ring and the second connection ring are provided such that the first connection hole provided in the connection portion of the first node ring and the second connection hole provided in the connection portion of the second node ring are aligned with each other. An opening alignment step of arranging a second node ring, a shaft member inserting step of inserting a shaft member into the first connection opening and the second connection opening, and an insertion into the connection opening A spacer disposing step of disposing a spacer on the end surface of the shaft member so that the shaft length of the shaft member is extended; and connecting the shaft member and the spacer such that the shaft member and the spacer are integrated. And a welding step of welding and integrating the parts.
[0014]
According to a third aspect of the present invention, in the welding method of the second aspect, the welding is performed such that the spacer and a connecting portion of the node ring adjacent to the spacer are integrated. It is.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS.
[0016]
(Constitution)
FIG. 1 shows a schematic configuration of the entire endoscope 1 of the present embodiment. As shown in FIG. 1, the endoscope 1 has an insertion section 2 to be inserted into a body cavity of a patient, and an operation section 3 connected to a proximal end of the insertion section 2 on the proximal side. An eyepiece 4 is provided at the base end of the eyepiece. In the insertion section 2, a bending section 7 is connected to a distal end of an elongated flexible tube 5 via a connecting pipe 6 (see FIG. 2), and a distal end rigid section (tip section) 8 is connected to the distal end of the bending section 7. I have.
[0017]
The operation unit 3 is provided with an angle operation knob 9 for performing a bending operation on the bending unit 7. By rotating the angle operation knob 9, an operation wire 10 (see FIG. 2) described later is provided. Thus, the bending portion 7 can be remotely bent in both up and down directions.
[0018]
FIG. 2 is a longitudinal sectional view showing the configuration of the distal end portion of the insertion section 2, particularly the vicinity of the bending section 7. In the insertion section 2, a channel 11 serving as an insertion passage for water supply, suction, or a treatment tool, an image guide fiber 12 for transmitting an image of an observation target, and illumination light for illuminating the observation target are applied to the distal end of the distal end rigid portion 8. A light guide fiber (not shown) and the like for supplying the light to an observation window (not shown) are installed. The distal end portions of these built-in components are all connected to the distal rigid portion 8. The base end of the channel 11 is connected to a channel opening 13 provided in the operation unit 3. The base end of the image guide fiber 12 is connected to the eyepiece 4 of the operation unit 3. The base end of the light guide fiber is connected to a connector (not shown) connected to an external light source device.
[0019]
Next, the configuration of the bending portion 7 will be described with reference to FIG. The bending portion 7 includes a bending tube 15 as a bending portion base, and a covering tube 16 covering the outer periphery of the bending tube 15. The bending tube 15 has a plurality of node rings 21 arranged in a line in the longitudinal axis direction of the insertion section 2, and adjacent node rings 21 are rotatable by rivet type shaft pins 22 as shaft members. It is connected to. Among the node rings 21 constituting the bending tube 15, the distal end node ring 21 connects the distal end portion of the operation wire 10 to each of two opposing positions substantially in the vertical direction. The proximal end of each operation wire 10 extends through the insertion section 2 into the operation section 3 and is connected to a bending operation mechanism (not shown) incorporated in the operation section 3. The bending operation mechanism is operated by the angle operation knob 9. Then, by turning the angle operation knob 9, the bending operation mechanism selects one of the two operation wires 10 according to the direction in which the angle operation knob 9 turns, and pulls it. For this reason, the bending portion 7 bends in the direction of the pulled operation wire 10 as a whole of the node ring 21 that rotates with each shaft pin 22 as a shaft member.
[0020]
Next, a connection structure for connecting the node rings 21 constituting the curved tube 15 to each other will be described with reference to FIG. FIG. 3 is a longitudinal sectional view of the connecting portion along the line AA in FIG. Here, the node ring 21 forming the curved tube 15 is formed of a metal-made cylindrical member. A pair of right and left tongue pieces (connecting portions) 21a are formed at the distal end portion of the node ring 21 so as to protrude in the longitudinal axis direction of the insertion portion 2, respectively. A pair of right and left tongue pieces (connecting portions) 21 b are formed at the base end portion of the node ring 21 so as to protrude in the longitudinal axis direction of the insertion portion 2.
[0021]
The distance between the outer surfaces of the pair of left and right tongue pieces 21b formed on the base end side of each node ring 21 is the distance between the inner surfaces of the pair of left and right tongue pieces 21a protruding from the distal end side of each node ring 21. It is formed slightly smaller than. For this reason, as shown in FIG. 3, in a state where the plurality of node rings 21 are arranged in a line in the longitudinal axis direction of the insertion portion 2, the tongue piece 21 a on the front side of the node ring 21 and the rear of another node ring 21. The tongue piece 21b on the side can be overlapped.
[0022]
As described above, the tongue pieces 21a and 21b formed at the distal end and the proximal end of each node ring 21 are formed at the distal end of the node ring 21 as described above, and are formed at the proximal end of the node ring 21. The tongue pieces 21a, 21b are not limited to this arrangement, but may be in any relationship as long as the tongue pieces 21a, 21b overlap each other. The positional relationship between the inside and the outside of the tongue pieces 21a, 21b is limited to this. It is not done.
[0023]
As shown in FIG. 3, the tongue pieces 21a and 21b are formed with fitting holes 23a and 23b as connecting holes located in the overlapping regions. Then, the shaft pin 22 is inserted from the inside and inserted through both the fitting holes 23a and 23b of the tongue pieces 21a and 21b.
[0024]
The shaft pin 22 is formed of a large-diameter portion 22a as a head and a small-diameter portion 22b as an insertion shaft portion smaller in diameter than the large-diameter portion 22a. It is formed with a diameter that can be inserted over 23a and 23b. The large-diameter portion 22a of the shaft pin 22 is formed to have a larger diameter than at least the fitting holes 23a and 23b, and the small-diameter portion 22b of the shaft pin 22 is inserted into the fitting holes 23a and 23b as shown in FIG. Then, the end face of the large-diameter portion 22a of the shaft pin 22 on the insertion side hits the inner surface of the tongue piece 21b located on the inside, and the insertion depth of the shaft pin 22 into the fitting holes 23a and 23b is regulated. I have.
[0025]
By the way, as described above, the distance between the pair of tongue pieces 21a and 21b has some variation due to the dimensional difference between the individual node rings 21. For this reason, as shown in FIG. 4, the tongue pieces 21a and 21b of the adjacent node rings 21 are overlapped by arranging the plurality of node rings 21 in the longitudinal axis direction, and the total thickness L of the tongue pieces 21a and 21b at this time is Will be slightly different. For example, the total thicknesses La and Lb at the respective connecting portions shown in FIG. 3 are different, and have a relationship of La> Lb.
[0026]
As shown in FIG. 4, the length of the small-diameter portion 22b of the shaft pin 22 is set to be equal to the fitting hole 23a of the tongue piece 21a located on the outside, assuming a combination that maximizes the total thickness L of the tongue pieces 21a and 21b. Is set to a length that allows at least a slight insertion state to be obtained. In this case, as the total thickness L of the tongue pieces 21a and 21b is larger, the insertion side end face of the small diameter portion 22b as a shaft part inserted into the fitting hole 23b of the outer tongue piece 16a and the outer surface of the outer tongue piece 16a The gap (distance) M as a dimension between them increases.
[0027]
In the combination of the tongue pieces 21a and 21b in which the gap M is generated, a cylindrical spacer having substantially the same diameter as the small diameter portion 22b of the shaft pin 22 and having a thickness substantially equal to the gap M is provided in the space of the gap M. 25, the tongue piece 21a, the spacer 25, and the shaft pin 22 which are arranged outside are welded together, whereby the two joint rings 21 are rotatably connected via the shaft pin 22. I have.
[0028]
Here, a large number of types of the spacer 25 having different thicknesses are prepared in advance, and the spacer 25 having a thickness substantially equal to the gap M is selected according to the total thickness L of the tongue pieces 21a and 21b to be combined. Then, the selected spacer 25 is used. The spacer 25 is preferably made of the same material as the node ring 21.
[0029]
(Action)
Next, a procedure for manufacturing or assembling the curved tube 15 having the above structure will be described. FIG. 7 is a flowchart of the assembling procedure.
[0030]
First, a plurality of node rings 21 constituting the curved tube 15 are arranged in a line in the longitudinal axis direction of the insertion section 2 with respect to the jig of the curved tube manufacturing apparatus. At this time, as shown in FIG. 4, the tongue pieces 21a, 21b of the adjacent node rings 21 are overlapped, and the central axes of the fitting holes 23a, 23b of the overlapping tongue pieces 21a, 21b are aligned (opening alignment step). ).
[0031]
Thereafter, as shown in FIG. 4, the small-diameter portion 22b of the rivet-type shaft pin 22 is inserted into the insertion hole 23 formed in the tongue piece 21b of the node ring 21 located inside, and the insertion holes of the tongue pieces 21a and 21b are inserted. It is inserted so as to be inserted over 23a and 23b (shaft member fitting step).
[0032]
At this time, as shown in FIG. 4, when a gap M is formed between the tip end surface of the shaft pin 22 and the outer surface of the tongue piece 21a located outside, a spacer having a thickness equivalent to the gap M is formed. 25 is dropped into the hole of the gap M. Thereafter, as shown in FIG. 4, the spacer 25 and the shaft pin 22 are integrated by irradiating light energy J such as laser from the outer surface side of the tongue piece 21a located outside toward the axial center of the spacer 25. The spacer 25 and the shaft pin 22 are integrally welded together with the tongue piece 21a located on the outside to integrate them.
[0033]
In this manner, the adjacent node rings 21 are rotatably connected to each other via the shaft pins 22.
[0034]
Here, due to the action of the light energy J, the inner peripheral portion of the fitting hole 23a of the tongue piece 21a located outside and the outer peripheral portion of the spacer 25 are welded, and the bottom portion of the spacer 25 and the shaft pin 22 are welded. Are welded to the front end surface on the side where they are inserted. Then, the spacer 25 and the shaft pin 22 are integrally welded at the connection opening of the tongue piece 21a located on the outside.
[0035]
Therefore, the node rings 21 are securely and sufficiently fixed to the shaft pins 22, and are connected with sufficient strength in a state where each of the node rings 21 can rotate about the shaft pins 22.
[0036]
(effect)
According to the present embodiment, even if the total thickness L between the tongue pieces 21a and 21b differs depending on the portion, the shaft pin 22 is welded over the entire inner circumference of the tongue piece 21a located outside via the spacer 25. Therefore, stable and high connection strength can be ensured. In addition, since the operation of replacing the shaft pin 22 without fitting the shaft pin 22 once inserted becomes unnecessary, the assembling property is excellent. In addition, it is not necessary to prepare a large number of shaft pins 22 having different lengths in advance, and the dimensional accuracy of the connecting portion of the node ring 21 is not required to be high, so that the bending tube 15 can be manufactured at low cost. Can be. Further, in the connection opening of the connecting portion of the node ring 21, the shaft pin 22 is securely and sufficiently fixed to the connecting portion, and has sufficient strength in a state where the shaft pin 22 can rotate the node ring 21. Can be linked.
[0037]
Although the assembling procedure in this embodiment involves performing the shaft member fitting step after the opening position aligning step, the shaft member fitting step is performed halfway before the opening position aligning step. You may. That is, the small-diameter portion 22b of the shaft pin 22 is inserted into the fitting hole 23b of the inner tongue piece 21b to such an extent that the small diameter portion 22b does not interfere with the outer tongue piece 21a, and the openings of the fitting holes 23a, 23b of the tongue pieces 21a, 21b to be overlapped in this state. Only after the positioning process is performed, the shaft pin 22 is completely inserted into both the fitting holes 23a and 23b. According to such a procedure, when the openings of the fitting holes 23a and 23b of the tongue pieces 21a and 21b to be overlapped are aligned, the shaft pin 22 can be completely inserted, and the matching of the openings of the fitting holes 23a and 23b can be confirmed. This simplifies the operation of the opening alignment step.
[0038]
[Second embodiment]
A second embodiment of the present invention will be described with reference to FIG.
[0039]
(Constitution)
In the present embodiment, as shown in FIG. 6, a thin spacer 25 is used. At least one kind of spacer 25 is prepared in advance, and a plurality of these are superimposed to form a spacer M substantially equivalent to the gap M. Laminate until the thickness is reached. Then, the plurality of spacers 25 arranged in the fitting holes 22a of the tongue pieces 16a located outside and the shaft pins 22 are integrally welded by light energy J such as a laser, and the plurality of spacers 25 are separated. The inner peripheral portion of the inserted fitting hole 22a is also integrally welded. Other configurations are the same as those of the first embodiment.
[0040]
(Action)
This embodiment can be assembled in the same procedure as the first embodiment.
[0041]
(effect)
In the present embodiment, it is not necessary to prepare a large number of spacers 25 of a plurality of types, so that they can be manufactured at low cost. In this embodiment, the spacers 25 having substantially the same thickness are stacked until the distance of the gap M is reached, and when the spacers 25 are integrated at the same height as the outer surface of the tongue piece 21a, the work of adding a new spacer 25 is stopped. This eliminates the need for complicated sorting and checking of spacers 25, and reduces the number of assembling steps. Since there is no need to prepare a large number of shaft members and spacers having different lengths in advance, it is possible to manufacture the shaft member at low cost.
[0042]
Note that the present invention is not limited to the above-described embodiment, and various modifications are possible. In the above embodiment, the connecting portion of the node ring is formed to project as a clear tongue piece, but the present invention is not limited to the form formed as a tongue piece projecting from the node ring, and at least a part of the adjacent node rings are mutually connected. The portions may be used as connecting portions so as to overlap.
[0043]
<Appendix>
1. A plurality of node rings are arranged in the longitudinal axis direction, and the connection portion formed on the node ring is overlapped with the connection portion formed on another node ring, and the fitting hole formed in the connection portion arranged inside is In the bending tube for an endoscope in which a plurality of articulation rings are rotatably connected by inserting a shaft member and welding a connecting portion disposed outside and an end of the shaft member, the shaft member is In addition to being formed in a plurality of layers, the shaft members divided and formed in a plurality of layers and the connecting member arranged outside and the shaft member are welded and integrated by welding means or welding by light energy. Bending tube for endoscope.
2. A connection method of a node ring forming a curved tube, wherein a first connection opening provided in a connection portion of a first node ring and a second connection opening provided in a connection portion of a second node ring. An opening alignment step in which the two connecting portions are overlapped at a predetermined position so that the holes are aligned with each other; and an opening connecting step of the connecting portion located inside is directed toward the connecting opening of the other connecting portion located outside. A shaft member inserting step of inserting a shaft member over the connection opening, and when the tip end surface of the shaft member inserted into the connection opening is located in the connection opening, A spacer arranging step of arranging a spacer such that the axial length of the shaft member is extended in a space to be formed; and welding a connecting portion between the shaft member and the spacer so that the shaft member and the spacer are integrated. And a connecting method of a node ring, comprising:
[0044]
【The invention's effect】
As described above, according to the present invention, even if the total thickness between the connecting portions of the node ring differs depending on the portion, the connecting portion located outside and the shaft member can be welded in a wide area. Therefore, it is possible to secure a sufficient connection strength. Further, since it is not necessary to remove the shaft member once inserted and disposed from the connecting portion in order to replace the shaft member with another shaft member, the assembling property is excellent. Further, in the invention according to claim 3, since it is not necessary to prepare a large number of shaft members and spacers having different lengths in advance, it is possible to manufacture the shaft member at low cost.
[Brief description of the drawings]
FIG. 1 is an external view of an endoscope according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a portion near a curved portion in an insertion portion of the endoscope according to the first embodiment of the present invention.
FIG. 3 is a longitudinal sectional view of a connecting portion of a node ring taken along the line AA in FIG. 2;
FIG. 4 is an enlarged longitudinal sectional view showing a connecting portion B of the node ring at the time of assembly.
FIG. 5 is a vertical cross-sectional view of the joint portion of the node ring when assembly is completed.
FIG. 6 is a longitudinal cross-sectional view of the insertion portion of the endoscope according to the second embodiment of the present invention when the connecting portion of the node ring of the bending portion is assembled.
FIG. 7 is a flowchart of an assembling procedure of the joint portion of the node ring.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Endoscope, 2 ... Insertion part, 5 ... Flexible tube, 6 ... Connection tube,
7: curved portion, 8: rigid tip portion, 15: curved tube, 16: coated tube,
21 ... articulated ring, 21a ... tongue piece, 21b ... tongue piece, 22 ... shaft pin,
23: fitting hole, 25: spacer.

Claims (3)

A plurality of node rings are arranged in the longitudinal axis direction, each of the node rings has a connection portion having a connection opening, and the connection portions of adjacent node rings are overlapped with each other, and the connection portion formed in the connection portion is formed. An endoscope in which a shaft member is inserted through an opening and a joint ring is rotatably connected by welding a connection opening formed in a connection portion arranged outside and an end of the shaft member. In the bending tube for
An endoscope, wherein the shaft member is divided into a plurality of layers, and the shaft members divided into a plurality of layers are integrated with each other and the shaft member and a connecting portion disposed outside are integrated by welding. For curved tubes. A method of connecting a node ring constituting a curved tube,
The first node ring and the second connection ring are provided such that the first connection hole provided in the connection portion of the first node ring and the second connection hole provided in the connection portion of the second node ring are aligned with each other. An opening alignment step of arranging the second node ring;
A shaft member inserting step of inserting a shaft member into the first connection opening and the second connection opening;
A spacer arranging step of arranging a spacer on an end surface of the shaft member inserted into the connection opening so that the shaft length of the shaft member is extended;
A welding step of welding and integrating a connection portion between the shaft member and the spacer so that the shaft member and the spacer are integrated,
A method for connecting a node ring, comprising: The method according to claim 2, wherein in the welding step, the spacer is welded so as to be integrated with a connecting portion of the node ring adjacent to the spacer.

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