JPH0664240B2 - Bending tube for endoscope and method of manufacturing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a bending tube installed in a bending portion of a flexible endoscope and a method for manufacturing the bending tube.

BACKGROUND ART FIG. 1 schematically shows a conventionally known endoscope.

In the figure, reference numeral 1 is an endoscope including an operation portion 2 and an insertion portion 3, and the insertion portion 3 of the endoscope 1 has a distal end forming portion 6 on a distal end side of a flexible tube portion 4 via a bending portion 5. Is provided.

Further, the operation section 22 of the endoscope 1 has an operation knob 7 for bending the bending section 5 as described later, and an eyepiece section for observing the inside of the body cavity through an observation window 8 formed in the distal end forming section 6. 9, a universal cord 10 connected to a light source device (not shown), and an operation button 11 for supplying air and liquid are provided.

Further, a bending tube 12 is provided in the bending portion 5,
As shown in FIG. 2, the bending tube 12 is composed of a plurality of node rings 13 rotatably connected to each other.

That is, the node ring 13 consists of a cylindrical short tube 14, and this short tube
A pair of connecting portions 15 are provided on both end faces of the circumferential portion 180 in the circumferential direction.
Adjacent node rings 13 of each node ring 13 that are projecting along the axial direction of the short pipe 14 at positions displaced by 90 degrees on both ends
The respective connecting portions 15 corresponding to each other are rotatably connected by the rivets 16.

Further, the node ring 13 has the above-mentioned connecting portions at both axial end portions of this peripheral wall.
Four concave portions 17 are formed on the inner peripheral surface of the node ring 13 by forming a portion that is deviated from 15 by 90 degrees so as to project radially outward in an arc shape. A wire receiver 18 made of a metal pipe having the same curvature as that of the recess 17 is fixed to these recesses 17 by brazing.

That is, four wire receivers 18 are fixed to the inner peripheral surface of the node ring 13 at intervals of 90 degrees in the circumferential direction. The operation wires 19 are inserted into the wire receivers 18 of the node rings 13 located at the corresponding positions in the circumferential direction. One end of each of these operation wires 19 is fixed to the node ring 13 (not shown) located at the most distal end, and the other end is guided to the operation part 2 where it is displaced 180 degrees in the circumferential direction of the node ring 13. Each pair of operation wires 19 are coupled to the operation knob 7 so as to interlock with each other. That is, with respect to each pair of operation wires 19 located at a position shifted by 180 degrees, when one is pulled, the other is pushed. Therefore, the bending tube 12 that constitutes the bending portion 5 is configured to be bendable in the vertical and horizontal directions via the four operation wires 19 by operating the operation knob 7.

Now, as described above, the wire receivers 18 in the bending tube 12 of the endoscope 1 having the above-described configuration have the recesses on the inner peripheral surface of each node ring 13 as described above.
It is fixed to 17 by brazing.

However, the brazing process for this wire receiver 18
The brazing material flows out to a portion other than the joint portion between the recess 17 of the wire receiver 18 and the wire receiver 18, so that the brazing material enters the wire insertion hole 18a of the wire receiver 18 or each node ring 1
This causes solidification in the connecting portion 15 of 3 and the like to cause a hole clogging, a rotational movement failure, and the like, which requires repair and shaping work.

In addition, it is difficult to simultaneously perform the brazing work of each wire receiver 18 on the inner peripheral surface of the node ring 13, and the brazing work of one wire receiver 18 is not performed on the brazing part of the wire receiver 18 already brazed. This will affect the occurrence of dropouts, misalignments, etc., and repairs or re-brazing will be required.

Further, the complexity of brazing work varies depending on the degree of skill among workers, and it is difficult to always expect uniform stability in the fixed state of the wire receiver 18, etc. It has drawbacks.

In view of the above, the present invention can solve the above-mentioned drawbacks of the wire receiver fixed to each nodal ring of the bending tube in the bending portion of the endoscope by the brazing portion, and the manufacturing method thereof. It is intended to provide a method.

In summary, the present invention is to fix the wire receiving member to the inner peripheral surface of each node ring in the bending tube for an endoscope by a welded portion by laser welding, and the inner peripheral surface of the node ring and the wire in the welded portion. It is characterized in that a deformed portion having a shape corresponding to each other is provided at a joint portion of the receiving member, and is fixed by the welding portion having a large welding area.

Example 3 A third embodiment of the method for manufacturing the endoscope bending tube of the present invention will be described below.
This will be specifically described with reference to FIGS.

(First Embodiment) Fig. 3a is a node ring used in the construction of the bending tube for an endoscope of the present invention.
20 is a vertical sectional front view, and FIG. 3b is a vertical sectional side view showing only the main parts, and the other structure is the same as that of each node ring 13 shown in the above-mentioned second illustration, and the description thereof is omitted. To do.

Thus, the node ring 20 does not have the recess 17 for each wire receiver 18 in the configuration with the node ring 13 shown in the second illustration, but the main body 20a is formed by a simple circular tube.

Therefore, in fixing the wire receivers 18 to the inner peripheral surface 20b of the main body 20a, the respective wire receivers 18 are arranged at the fixing positions (similar to the fixing positions shown in FIG. 2) in the circumferential direction. After the wire receivers 18 are joined, a laser beam is applied to the joints between the wire receivers 18 and the inner peripheral surface 20b, and the joints are welded, so that the wire receivers 18 are connected to each other via the welded portions 21.
It can be integrally fixed to the fixing position of the inner peripheral surface 20b of 20.

Further, as shown in FIG. 3b, the welded portions 21 by the laser light are the two welded portions 21 at the front and rear ends of the wire receiver 18.
It is fixed by.

In addition, the joint portion and the wire receiver 1 on the inner peripheral surface 20b of the node ring 20
Due to the shape of 8, the joining parts of both are in line contact, and the fixing force is determined by the size of the area of the welded portion 21, but it can be adjusted according to the conditions such as the laser output of the laser light. Is.

The conditions such as the type of laser light or the diameter of the laser spot are not particularly limited, and the optimum conditions are set.

However, with respect to the conditions such as the spot diameter of the laser light, it is required to implement it within a range that does not adversely affect the fixing portion 21 of the wire receiver 18 that has already been fixed such as a heat effect.

(Second Embodiment) FIG. 4 is a vertical sectional front view of a main part of a node ring showing a second embodiment of the present invention.

Thus, the node ring 22 has a configuration in which a recess 17 having a shape corresponding to the outer shape of the wire receiver 18 is provided at the fixed position of the wire receiver 18 similarly to the node ring 13 shown in FIG.

Therefore, after fitting the wire receivers 18 into the recesses 17, as in the first embodiment described above, a laser beam is applied to the joining portions of the two, and the joining portions are welded to each other through the welding portion 23. As a result, each wire receiver 18 can be integrally fixed to the inner peripheral surface 22b of the node ring 22 in each recess 17.

In addition, the recess 17 and the wire receiver 18 are different from the joint portion by the line contact in the first embodiment in that the joint portion by the surface contact in the embodiment is as shown in FIG.
The fixing portion 23 can be formed by the multi-point welded portions along the curved surface of 18, and the fixing strength between the two can be improved.

Furthermore, since the laser welding work can be performed with the wire receiver 18 fitted in the recess 17, workability can be improved.

(Third Embodiment) FIG. 5 is a vertical sectional front view of a main part of a node ring, showing a third embodiment of the present invention.

In this embodiment, the outer shape of each wire receiver 24 fixed at the same position is made flat by corresponding to the shape of each fixed position on the inner peripheral surface 20b of the node ring 20 having the configuration of the first embodiment. It shows an embodiment constituted by doing.

That is, in each wire receiver 24, the joint surface 24a with the inner peripheral surface 20b of the node ring 20 is formed by a spherical shape having a curvature that can correspond to the curvature of the inner peripheral surface 20b.

Therefore, as in the second embodiment, the bonding surface 24 of the wire receiver 24 is
After the a is joined to the fixing position of the inner peripheral surface 20b of the node ring 20 and positioned, the joining portion of the both is irradiated with a laser beam and the joining portion is welded, so that the wire receiver 24 Can be integrally fixed to the inner peripheral surface 20a of the node ring 20.

Similar to the second embodiment, the joining portions of both are in surface contact with each other and can be fixed along the joining surface by welding with laser light at multiple points.

Further, the inner circumference of the wire receiver 24 needs to have an inner diameter and an area that do not hinder the insertion and operation of the operation wire 19.

Therefore, in the case of FIG. 5, the wire receiver 24 is shown in which the whole is deformed to a flat shape, but the inner peripheral shape is formed to have a circular cross section as in the first and second embodiments, and in the outer peripheral shape, the node ring is formed. 20 inner peripheral surface 20
It is also possible to use a wire receiver (not shown) formed by deforming only the shape of the joint with b.

In addition, the gist of the second and third embodiments is achieved by the mutually corresponding shapes of the inner peripheral surface of the node ring and the joining surface between the wire receivers for this, and the second embodiment corresponds to the outer shape of the wire receiver 18. In the third embodiment, the joint surface 24a of the wire receiver 24 corresponding to the inner peripheral surface 20b of the node ring 20 constitutes the joint surface of the inner peripheral surface of the node ring and the joint surface of the wire receiver. Corresponding shape deformation part between both (not shown)
It is also possible to implement each by providing each of them, and in this case, there is an advantage that the positioning work of the fixed position of the wire receiver and the irradiation work by the laser light can be simplified and optimized.

EFFECTS OF THE INVENTION As is clear from the above description, according to the present invention, the wire receiver is fixed to the node ring under extremely stable conditions by the welded portion by laser welding or other welding means capable of obtaining the same effect as this. You can

Further, in addition to being able to simplify and speed up the fixing work of the wire receiver, compared to the conventional fixing work by brazing,
Since no brazing material is used, there is no clogging of the wire insertion part of the wire receiver that occurs during brazing, and the step of removing the wax that has flowed out to other parts can be omitted altogether, which is extremely effective in reducing man-hours. is there.

What is most effective is that the spot diameter of the laser beam can be selected in the range of several tens of microns to several hundreds of microns, etc. Alternatively, it is possible to prevent positional deviation and stabilize quality and accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view of an endoscope, FIG. 2 is a partial vertical side view of a bending tube, FIGS. 3 to 5 show first to third embodiments of the present invention, and FIGS. FIGS. 5 and 5 are partial vertical front views of the node ring, and FIG. 3b is a partial vertical side view of FIG. 3a. 1 ... Endoscope 2 ... Operation part 3 ... Insertion part 4 ... Flexible tube part 5 ... Bending part 6 ... Tip part 7 ... Operation knob 8 ... Observation window 9 ... Ocular part 10 …… Universal code 11 …… Operation buttons for air supply and liquid supply 12 …… Bending tube 13,20,22 …… Knot ring 14 …… Short tube 15 …… Coupling 16 …… Rivet 17 …… Concave 18, 24 …… Wire receiver 19 …… Operating wires 21, 23, 25 …… Welding part

Claims (2)

[Claims] 1. A bending tube having a plurality of node rings rotatably connected to each other, which is installed in a bending portion of an endoscope, and has a cylindrical node ring and an inner peripheral surface of the node ring. A pipe-shaped wire receiving member having an outer peripheral surface; a joint formed by bringing the outer peripheral surface of the wire receiving member and the inner peripheral surface of the node ring into contact with each other in the axial direction of the node ring; A bending tube for an endoscope, comprising: a welded portion formed by irradiating a laser beam only to the joint portions at both ends of the joint portion in the axial direction. 2. A method of manufacturing a bending tube, which is installed in a bending portion of an endoscope and is composed of a plurality of node rings that are rotatably connected to each other, wherein a wire receiving member is positioned on an inner peripheral surface of the node ring. To bond the outer peripheral surface of the wire receiving member, and to irradiate laser light to the joints with the node rings at the front and rear ends of the wire receiving member respectively, and to bond the wire receiving member with one or more laser spots. A method for manufacturing a bending tube for an endoscope, which comprises welding to an inner peripheral surface of a ring.