JPH0531065A - Insertion section for endoscope - Google Patents

Abstract

PURPOSE:To provide the variable hardness at the desired level very easily by spot-welding double spiral pipes constituting a soft section. CONSTITUTION:Double spiral pipes 3 consisting of inner and outer spiral pipes 3a, 3b spirally wound with springy metal belt pieces such as stainless steel in opposite directions to each other are provided as the structure of a soft section, and the spiral pipes 3a, 3b are connected by spot welding with a YAG laser or another laser welding machine. They are spot-welded at three positions S at an angle 120 deg. in the peripheral direction, the welding pitch interval is made shorter on the root side in the axial direction, the welding pitch interval is made longer toward the tip side, and the hardness is continuously changed from the root side to the tip side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insertion portion of an endoscope used for medical purposes, industrial purposes, etc., into the body.

[0002]

2. Description of the Related Art An endoscope has a body cavity, and a body cavity, and an insertion section which is inserted into a target section to be inspected, observed, treated, repaired, etc. Most of the insertion portion has a flexible portion that freely bends along the insertion path from the connection portion to the main body operation portion, and an angle portion and a distal end hard portion are sequentially connected to the flexible portion.

Here, as a condition that the flexible portion must have, it must first be able to bend freely along the insertion path. Also, various members inside,
That is, a light guide for transmitting illumination light, an image guide for transmitting an observation image (in an electronic endoscope, a signal cable connected to a solid-state image sensor), a treatment instrument insertion channel,
Since the air and water pipes are designed to be inserted,
It must have sufficient strength to protect these inserted members and have good shape retention and crush resistance. For this,
The soft portion is formed by braiding a metal wire in a net shape on the double spiral tube, which is a double spiral tube in which metal strips having a predetermined width are wound at a constant pitch interval. A structure in which a braided body is covered and an outer skin layer made of urethane resin or the like is laminated on the braided body by a molding means or the like is widely used.

[0004]

In addition to the above requirements, the thrust required for the flexible portion is sufficient in consideration of the resistance when inserting along a narrow path such as a body cavity. In order to convey to, the root portion of the flexible portion needs to be harder than the tip side, and this hardness is preferably configured to continuously change from the root side to the tip side. For this purpose, for example, the hardness of the outer skin layer is changed between the tip side and the root side, the braid pitch interval of the braid is changed, and the width of the metal strip forming the spiral tube is changed to the root side. There is also a structure in which the width is reduced continuously from the end to the tip side. According to this structure, the soft portion can have a certain degree of difference in hardness, but it cannot be changed to a required degree. In addition, from the viewpoint of manufacturing, it is not always easy to configure as described above.

The present invention has been made to solve the above-mentioned drawbacks and problems of the prior art. The object of the present invention is to provide a soft portion with a hardness of a desired degree extremely easily. Is to be able to have a change.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a substantially equal angular spacing in the circumferential direction between both inner and outer spiral tubes formed by spirally winding a metal strip. In this configuration, both spiral pipes are connected by spot welding at least at three points, with a pitch interval in which the connecting side to the angle portion is wider than the connecting side to the main body operating portion in the axial direction. That is the feature.

[0007]

When the inner and outer spiral pipes are spot-welded in the axial direction at a predetermined pitch interval, the spot-welded portions become nodes and the resistance against bending increases and becomes harder. The smaller the width, the higher the hardness. Therefore, if the welding pitch interval on the root side, that is, the side that is connected to the main body operation section is shortened, and the welding pitch interval on the tip side, that is, the side that is connected to the angle section, is increased, The hardness can be changed almost continuously toward the tip side. Further, since this soft portion is bent in any direction, at least three places are welded in the circumferential direction at substantially equal angular intervals so that the hardness does not change depending on the bending direction. This makes it possible to have equal hardness in all directions.

Spot welding can be carried out by laser welding, and after forming the double spiral tube, while the double spiral tube is being fed while being rotated, the spot welding is carried out at each position preset by the laser welding machine. It is extremely easy to weld by welding to. Further, even if the width, thickness and winding pitch of the metal strips constituting the double spiral tube are constant, if the number of spot weldings is increased, the soft portion becomes harder and the spot welding points are reduced. Since the soft portion becomes softer, the hardness of the soft portion can be freely controlled, so that the soft portion can have a desired hardness for various purposes.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, FIG. 1 shows a schematic configuration of an endoscope. In the figure, 1 is a main body operation part, 2 is an insertion part, and most parts of the insertion part 2 from the side connected to the main body operation part 1 consist of a flexible part 2a, and this flexible part 2a has an angle. Part 2b
And the tip hard portion 2c are sequentially connected. In addition, a light guide for transmitting illumination light for illuminating an observation target portion in the insertion portion 2, an image guide in an optical endoscope for guiding an observation image to the outside, an electronic guide In the endoscope, a signal cable from the solid-state image sensor provided in the distal end hard portion 2c, a treatment instrument insertion channel, an air / water supply pipe, an angle operation wire, etc. are inserted, but these insertion portions 2 are built-in. Since objects are well known in the art, their illustration and description are omitted.

As shown in FIG. 2, the flexible portion 2a, which is the most part of the insertion portion 2, is formed by spirally winding a metal strip having a spring property such as stainless steel. The double spiral tube 3 including the spiral tubes 3a and 3b is included as a structure, and the inner spiral tube 3a and the outer spiral tube 3b are wound in opposite directions. The double spiral tube 3 is covered with a braided net 4 which is braided with a predetermined number of metal wires and the number of taps. The braided net 4 is fixed to the double spiral tube 3 with an adhesive. Has been done. Further, an outer skin layer 5 formed of a resin such as urethane resin or a material such as rubber is laminated on the braided net 4 by a molding means or the like. With this, the flexibility and strength that must be provided for the flexible portion 2a, that is, the characteristics such as shape retention and crush resistance are maintained. In FIG. 2, 6 is a metal fitting for connecting to the main body operating portion 1, and 7 is a metal fitting for connecting to the angle portion 2b.

Next, the flexible portion 2a has a certain degree of hardness on the side connected to the main body operating portion 1, that is, on the base side, and the softness increases continuously toward the side connected to the angle portion 2b. Must be In order to impart a change in hardness in the axial direction of the flexible portion 2a in this manner, in the present invention, a YAG laser or the like is provided between the inner spiral tube 3a and the outer spiral tube 3b forming the double spiral tube 3. The spot welding is performed by using the laser welding machine or the like. As shown in FIG. 3 (a), the welding spots S are provided at three positions at an angle of 120 ° in the circumferential direction, and in the axial direction as shown in FIG. 3 (b). As described above, the welding pitch interval on the base side where the connection fittings 6 are connected is short, and the welding pitch interval is set to be longer toward the tip side which is the connection side of the connection fittings 7. That is, on the root side, welding is performed by 1 pitch interval, 1 pitch is vacant in the middle, spot welding is performed every 2 pitch intervals, and further on the tip side, 3 pitches, 4 pitches and so on. Increase the interval.
As a result, the knots are formed at every welding pitch interval in the axial direction, so the hardness increases, and the shorter the welding pitch interval, the harder it becomes, so from the hardest root side to the tip side. The flexibility will increase continuously. In addition, the same hardness can be obtained in any direction by welding three places every 120 ° in the circumferential direction.

Here, in the double spiral tube 3, as shown in FIG. 4A, the space D between the outer spiral tubes 3b is set to the inner spiral tube 3a.
4 (b), when the flexible portion 2a is bent, the adjacent edge portions of the outermost spiral tube 3b located on the innermost side in the curved portion are set to be wider than the distance d. Of the inner spiral tube 3a located outside of the inner spiral tube 3a is prevented from coming into contact with the edge portions of the inner spiral tube 3a before the adjacent edge portions of the inner spiral tube 3a, and the inner spiral tube 3a is prevented from further bending. Spiral tube 3a
The edge portions adjacent to each other are brought into contact with each other at the same time. Therefore, the inner spiral tube 3a and the outer spiral tube 3
The winding pitch interval with b is not the same, and the widths of the strips forming the both spiral tubes 3a and 3b may be different depending on the purpose. Moreover, the winding directions of the inner spiral tube 3a and the outer spiral tube 3b are opposite to each other. The spot where the two spiral tubes 3a and 3b are welded is preferably at the center position in the width direction of the both spiral tubes 3a and 3b. To this end, the center line of the inner spiral tube 3a and the center line of the outer spiral tube 3b are 0 °, 120 ° and 24 °.
It would have to intersect at each 0 ° position.

From the above requirements, in FIG. 5, the center line winding locus of the inner spiral tube 3a in the width direction is shown by a dotted line L1, and the center line winding locus of the outer spiral tube 3b in the width direction is shown by a solid line L2. As shown, while the outer spiral tube 3b is wound by one pitch, the inner spiral tube 3a is wound by two pitches. Accordingly, while the outer spiral tube 3b is wound by one pitch, the outer spiral tube 3a and the inner spiral tube 3a are at least zero.
It will intersect at the respective positions of °, 120 ° and 240 °. Therefore, at these three spots, both can be welded at the center position in the width direction.

Moreover, the shorter the interval between the nodes formed by this spot welding, the harder it becomes, and the longer the node becomes softer. With roughening, the hardness changes even if welding is performed at every pitch interval. Therefore, as described above, not only the welding spot interval is adjusted, but also the spiral tubes 3a, 3b are adjusted.
If the winding pitch interval is set to an appropriate value, the flexible portion 2a can have a desired hardness, and the hardness can be continuously changed from the root side to the tip side.

With this construction, the flexible portion 2a forming the insertion portion 2 is the hardest on the side connected to the main body operation portion 1, and the tip end side which is the connection portion to the angle portion 2b is soft, and Since this hardness changes almost continuously, the pushing thrust force from the root portion of the flexible portion 2a can be effectively transmitted when gripping the root portion of the flexible portion 2a and inserting it into the body cavity or the like. It is convenient to insert along a high resistance insertion path. In addition, this soft part 2
Since the portion of a, which is inserted into the body cavity, particularly the tip portion, retains its flexibility, it can be freely bent along the insertion path. Moreover, since the spot welding is provided at three locations at equal intervals in the circumferential direction, the hardness does not change depending on the bending direction.

Further, the insertion portion 2 has different required hardness depending on the portion into which it is inserted. For example, comparing the endoscope for the lower gastrointestinal tract and the endoscope for the upper gastrointestinal tract, the soft part 2a of the former must be harder than the latter. Therefore, by adjusting the above-mentioned spot welding interval, in the case of the flexible part of the endoscope for the lower digestive tract, it is possible to make the hardness according to the request, and also for the endoscope for the upper digestive tract. The mirror can be soft enough to meet its purpose.

At least three spot welding locations in the circumferential direction may be used, and spot welding can be performed at appropriate locations such as four and six locations. For example, when spot welding is performed at four locations, as shown in FIG. As shown in, the winding pitch L1 'of one of the inner and outer spiral tubes may be set to 1/3 of the winding pitch L2' of the other. In addition, these spot welding points do not necessarily have to have strictly equal angular intervals in the circumferential direction,
The purpose can be achieved if the intervals are substantially equal.
Further, it is preferable that the spot-welded portion is located at a central portion in the width direction of the inner and outer spiral tubes or a portion in the vicinity thereof, but it may be slightly deviated from this position.

[0018]

As described above, according to the present invention, the two spiral tubes of the double spiral tube forming the flexible portion are provided at least at three positions at substantially equal angular intervals in the circumferential direction and in the main body in the axial direction. Since both spiral pipes are connected by spot welding with a pitch interval that makes the side to the angle part wider than the side to the operation part, it is extremely easy to harden the flexible part in the axial direction. Can be changed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an endoscope.

FIG. 2 is a cross-sectional view of a flexible portion showing an embodiment of the present invention.

FIG. 3 is a diagram showing spot welding points of a double spiral pipe.

FIG. 4 is an operation explanatory diagram showing a space between winding portions of an inner spiral tube and an outer spiral tube of a double spiral tube in a straight state and a bent state.

FIG. 5 is a diagram showing a relationship between a winding pitch interval between an inner spiral pipe and an outer spiral pipe and a welding spot position when three welding spots are provided in a circumferential direction of a double spiral pipe.

FIG. 6 is a diagram showing a relationship between a winding pitch interval between an inner spiral tube and an outer spiral tube and a welding spot position when four welding spots are provided in a circumferential direction of a double spiral tube.

[Explanation of symbols]

 1 Main body operation part 2 Insertion part 2a Soft part 2b Angle part 2c Hard tip part 3 Double helix tube 3a Inner spiral tube 3b Outer spiral tube 4 Braided net 5 Outer skin layer S Spot welding location

Claims (1)

Claim: What is claimed is: 1. A main body operating portion is connected to the main body operating portion, and the main body operating portion includes a flexible portion, an angle portion, and a hard tip portion in this order. In the insertion portion of the endoscope in which a braided body is applied to the inner and outer double spiral tubes formed by spirally winding, and an outer skin layer is laminated, the two spiral tubes are circumferentially arranged between them. At least 3 with approximately equal angular spacing
It is characterized in that both spiral pipes are connected by spot welding with a pitch interval in which the connection side to the main body operation part is wider in the axial direction than in the connection part side to the main body operation part. The insertion part of the endoscope.