JP2002209832A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope which improves the insertability of instruments for medical treatment and the durability of built-in objects and has excellent bending operability and observation performance by improving a bending shape to locally change the radii of curvature of a bending pipe constituting a bending section. SOLUTION: When the bending pipe 30 is formed by freely turnably combining four-way bending barrels 64 and 65 bending in four ways with two-way bending barrels 66 bending in two ways by means of connecting pins 34, the relationships 1.5 <= the distances between the two-way bending barrel pins/the distances between the four-way bending barrel pins < 2.5 are set between the distances between the connecting pins of the two-way bending barrels 66 constituting the bending pipe 30 arranged near the center of the bending section 12 and the distances between the first four-way bending barrels 64 or the second four-way bending barrels 65, by which the locally changing sections of the radii of curvature in the bending state are eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope provided with a curved portion that bends in four directions, that is, a vertical direction and a horizontal direction.

[0002]

2. Description of the Related Art Conventionally, an elongated insertion portion is inserted into a body cavity to observe organs in the body cavity, and, when necessary, to perform various treatments using a treatment tool inserted into a treatment tool channel. Medical endoscopes that can be used are widely used. Also, in the industrial field, industrial endoscopes capable of observing and inspecting internal scratches and corrosion of boilers, turbines, engines, chemical plants, and the like are widely used. These endoscopes are provided with a curved portion so that the insertion portion can be smoothly inserted into a complicatedly bent lumen or pipe.

For example, Japanese Utility Model Laid-Open Publication No. 64-12501 discloses that when a bending tube is bent in one of the vertical and horizontal directions, it is not bent in the other direction.
A plurality of two-way bending pieces are connected to the distal end side of the insertion portion, and a four-way bending piece is connected to the proximal side of the insertion part. The endoscope shown is thicker than a portion covering the bending piece. In this endoscope, the distance between the pins of the two-way bending piece (L2 in FIG. 1) is obtained by connecting two four-way bending pieces.
By positively shortening the distance between the pins of the set (L1 in FIG. 1 in the official gazette), the overall length of the bending tube is shortened, and the bending portion can be bent with a small radius of curvature.

Japanese Patent Application Laid-Open No. 7-194518 discloses a four-way bending piece and a two-way bending piece in the insertion direction of the insertion portion in order to improve the bending shape of the bending portion and facilitate observation and treatment. In the side-by-side connection, the bending between the sum of the bending angles of the adjacent bending pieces that rotate in the same direction as the bending direction of the bending portion and the bending angle at the time of the bending operation are set to be substantially the same. An endoscope provided with angle setting means is shown. In this endoscope, as shown in FIG. 3 of the publication, the position of the wire guide of the two-way bending piece is different between the pins of the two-way bending piece and the set of pins connecting two four-way bending pieces. Adjustments were made so that the number and spacing of the upward wire guides was the same as the number and spacing of the downward wire guides.

[0005]

However, in the endoscopes disclosed in Japanese Utility Model Laid-Open Publication No. 64-12501 and Japanese Unexamined Patent Publication No. 7-194518, two pins are connected between two pins in a two-way bending piece and two pieces in a four-way bending piece are connected. The set of pins differed. Therefore, for example, as shown in FIG. 20, in the case where the bending tube 100 is connected and formed by combining a unit 103 or the like in which two two-way bending pieces 101 and four-way bending pieces 102 are connected, 21, the radius of curvature of the distal end side and the proximal side of the curved portion becomes smaller than that of the intermediate portion as shown in FIG. 21, or the curved shape becomes a rattling shape that is not smooth.

As a result, when the treatment tool is inserted into the treatment tool insertion channel in a curved state, the treatment tool inserted into the treatment tool insertion channel may have a locally small radius of curvature or a rattle-shaped portion. In addition to being a factor of causing poor insertion, there is a risk that a forcible insertion of the treatment instrument may cause a hole in the channel or damage other built-in endoscope components.

In an endoscope for the upper gastrointestinal tract, the upward bending angle is usually 180 ° or more. Therefore, if the bending angle created by two adjacent frames is less than 15 °,
In order to obtain a bending angle of 0 °, it is necessary to connect 11 or more units in which two two-way bending pieces and four-way bending pieces are connected, and as a result, the total pin interval becomes longer, and the stomach and the like become longer. In this case, the small turning is not effective in the body cavity, and the observation performance as well as the bending operability is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an object to improve a curved shape in which a radius of curvature of a curved tube constituting a curved portion is locally changed, to improve treatment tool insertion property and to improve durability of a built-in member. It is an object of the present invention to provide an endoscope having improved operability and excellent bending operability and observation performance.

[0009]

An endoscope according to the present invention comprises a four-way bending piece which is bent in four directions and a two-way bending piece which is bent in two upper and lower directions, rotatably combined with a connecting pin. An endoscope having a curved portion formed by a formed curved tube and an outer skin covering the curved tube, wherein a connecting pin of a two-way bending piece is disposed at least near a center of the curved tube constituting the curved portion. 1.5 ≦ A / B <between the distance (A) and the distance (B) between the connecting pins of the four-way bending piece.
2.5 is set.

[0010] When a two-way bending piece and a four-way bending piece arranged at least in the vicinity of the center of the bending tube constituting the bending portion are rotatably combined, an upward direction formed by these two pieces is formed. The bending angle is set to 15 ° or more.

A bending tube formed by combining a four-way bending piece and a two-way bending piece so as to be rotatable with a connecting pin, and a minimum unit connecting unit rotatably with a connecting pin. An endoscope having a curved portion composed of an outer skin covering a curved tube, wherein a distance between coupling pins of a plurality of coupling units at least near a center of the curved tube constituting the curved portion is set to be substantially the same. In addition, the bending angle between two adjacent pieces formed by two adjacent bending pieces is set to 20 ° or more.

According to this structure, the distance between the pins of the two-way bending piece and the distance between the pins connected to the two four-way bending pieces are substantially the same. Therefore, when the bending tube is bent vertically, for example, the two-way bending piece is bent. Even if the piece and the four-way bending piece are connected alternately,
Even when properly connected, the curved shape becomes a smooth shape without play.

By setting the upward bending angle formed by the two pieces to 15 ° or more, a desired bending angle can be obtained without connecting more bending pieces than necessary, and the total distance between pins can be obtained. Becomes shorter.

Further, by connecting the units formed by connecting the two two-way bending pieces and the four-way bending pieces, the pins of the units are made substantially the same, and the bending shape becomes smooth without play. By setting the bending angle generated by the adjacent bending pieces to 20 ° or more, the total distance between pins becomes shorter.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 12 show the first embodiment of the present invention.
FIG. 1 is a diagram showing a schematic configuration of an entire system of an electronic endoscope according to an embodiment, and FIG. 2 is a longitudinal sectional view illustrating a configuration of a distal end portion including a part of a curved portion of the electronic endoscope. 3 is a cross-sectional view orthogonal to the longitudinal axis of the distal end portion, FIG. 4 is a cross-sectional view orthogonal to the longitudinal axis of the flexible tube portion, and FIG. 5 is a curve obtained by connecting a two-way bending piece and a four-way bending piece with a connecting pin. FIG. 6 is a vertical cross-sectional view in the vertical direction illustrating the space between the pins of the tube, FIG. 6 is a diagram illustrating the width dimension of the vertical wire guide provided on the curved tube and the relationship between the wire guides, and FIG. FIG. 8 is a vertical cross-sectional view illustrating the relationship between the bending angles between adjacent pieces of the curved portion covered with the outer cover, FIG. 8 is a diagram illustrating a state in which the bending portion is bent in the vertical direction, and FIG. 9 is a bending tube. FIG. 1 is a longitudinal cross-sectional view in the left-right direction, illustrating a space between pins when the camera is viewed from above.
0 is a view for explaining the width dimension of the wire guides provided in the bending tube in the left-right direction and the relationship between the wire guides. FIG. 11 shows adjacent bending portions in which the outer circumference of the bending tube is covered with an outer skin when viewed from above. FIG. 12 is a longitudinal sectional view in the left-right direction for explaining the relationship of the bending angle between the pieces, and FIG. 12 is a diagram illustrating a state in which the bending portion is bent in the left-right direction. Note that FIG. 3A shows A in FIG.
FIG. 3B is a sectional view taken along line BB of FIG. 2.

As shown in FIG. 1, an electronic endoscope 1 according to this embodiment has a flexible insertion section 2 inserted into a lumen to be observed, and an oleome It mainly comprises an operation section 4 connected via the section 3 and a flexible universal cord 6 extending from the operation section 4 and having a connector section 5 at a base end.

The connector unit 5 includes, for example, a video processor 7 having a light source device and an air / water supply device (not shown).
It is designed to be detachably connected to. The video processor 7 includes a signal processing circuit (not shown) for processing an image signal, which is photoelectrically converted by a solid-state image sensor (not shown) provided at the distal end of the electronic endoscope 1, into a video signal. I have. The video signal processed by this signal processing circuit is
The image is output to a monitor 9 via a connection cable 8 extending from a video processor 7, and an endoscope image is displayed on a screen of the monitor 9.

The insertion portion 2 is constituted by connecting a hard tip portion 11, a bending portion 12 formed to bend up, down, left and right, and a flexible tube portion 13 in this order from the tip side. The operation section 4 includes an up / down bending operation knob 14 for bending the bending section 12 vertically by remote control, and a bending section 1.
A left-right bending operation knob 15 is provided for bending the knob 2 in the left-right direction. By simultaneously operating the up-down bending operation knob 14 and the left-right bending operation knob 15, an intermediate direction (twisted) between the up-down direction and the left-right direction is provided. Direction).

The operating section 4 has a treatment instrument insertion port 16 provided in the insertion section 2 and serves as an insertion port for a treatment instrument insertion channel to be described later, and an air supply / air supply section for remotely controlling an air supply / water supply operation. An operation unit switch 19 for remotely controlling the functions of the video processor 7, such as a water supply button 17, a suction button 18 for remotely controlling a suction operation, an image still button, a release button, and a light control method switching button, is provided.

As shown in FIG. 2, the distal end portion 11 comprises a substantially conical distal end body 21 having a narrow distal end side, and a curved portion 12 disposed at the base end of the distal end body 21. A distal end piece 31 disposed at the foremost end of the bending tube 30 and an outer skin 22 formed of an elastic tube body constituting the bending portion 12 which is disposed at the base end of the distal end portion main body 21 similarly to the distal end piece 31. It is configured. An R-chamfered portion 21a is provided on the entire periphery of the distal end portion main body 21, and the outer skin 22 is provided.
Is fixed integrally to the tip main body 21 by thread winding adhesive 23.

A light guide 24 for transmitting illuminating light is inserted through the inside of the tip main body 21, and an illumination lens 25 is adhered and fixed to the tip surface of the light guide 24. An observation lens 26 is disposed near the illumination lens 25.
On the optical axis, an objective lens group 43 constituted by arranging a plurality of optical lenses 41 in a lens frame 42 and an imaging unit 40 are adhesively fixed at predetermined positions. Therefore,
Illumination light emitted from the light source device of the video processor 7 is transmitted through the light guide 24, passes through the illumination lens 25, and is emitted forward.

The imaging unit 40 includes a solid-state imaging device 44 for converting optical information in which an imaging surface is arranged at a focal position of the objective lens group 43 into an imaging signal, an electric board 45 on which electronic components (not shown) are mounted, and the video processor. 7 is provided.

The proximal end of the lens frame 42 and the distal end of the signal cable 46 are covered with an end of a flexible tube 47 such as a heat-shrinkable tube. Is filled with an adhesive 48. Reference numeral 49 denotes a rear lens constituting the objective lens group 43.

The solid-state image pickup device 44 and the rear end lens 49 are separated from each other by the pulling force applied to the image pickup unit 40 during a bending operation or the like in the image pickup unit housing hole 21b formed in the front end main body 21. A reinforcing pipe 51 is inserted in advance to prevent a malfunction in the image pickup unit 40 due to disconnection or short circuit of the signal cable 46.

The reinforcing pipe 51 is integrally formed by surrounding the outer periphery of the flexible tube 47 in a range of at least half the circumference (see FIG. 3A) in a state where the imaging unit 40 is assembled to the distal end main body 21. Adhesively fixed. The reinforcing pipe 51 is made of, for example, stainless steel and has a cutout 51 formed by cutting out a part of the pipe over its entire length.
a is provided. The notch 51a of the reinforcing pipe 51 is arranged so as to face the direction in which other internal components such as the light guide 24 and the treatment tool insertion channel 52 are located. As a result, the distance between the internal components is shortened, and the outer diameter of the distal end portion is reduced.

As shown in FIG. 3 (a), the distal end piece 31 is provided with bending concave portions 32 formed by bending inward at substantially four positions, that is, up, down, left and right. The tip of the wire 33 is firmly fixed by brazing or the like. Of the operation wires 33, use a wire whose outer diameter is large and hard to cut in the upward direction,
As the lower and left / right operation wires 33, wires having a smaller diameter than the upper operation wires 33 are used.

In the above description, the reinforcing pipe 51 is used.
Is fixed to the distal end body 21 in advance, and then fixed to the outer surface of the flexible tube 47. The reinforcing pipe 51 is fixed to the lens frame 42 inside the flexible tube 47 in advance, and After the adhesive is filled, the periphery of the reinforcing pipe 51 may be covered with a flexible tube 47.

A sealing material such as a silicone adhesive is filled between the image pickup unit 40 and the image pickup unit accommodating hole 21b to secure water tightness. It may be configured to be detachably fixed.

The bending tube 30 is formed by combining a plurality of bending pieces with a rivet-shaped connecting pin 34 so as to be rotatable. The outer cover 22 is arranged so as to cover the outer periphery of a tubular blade 35 formed by braiding a thin metal wire covering the outer periphery of the curved tube 30.

On the inner surface of the bending piece of the bending tube 30, a wire guide 3 which is a guide member for smoothly guiding the movement of the operation wire 33 for bending the bending portion 12 is provided.
6 are provided.

Among the wire guides 36, the upward wire guide 36 is formed by fixing a pipe member 37, which is another member, to the inner surface of a bending piece constituting the bending tube 30 by fixing means such as brazing. On the other hand, the wire guide 36 in the downward direction and the left and right direction is the bent concave portion 32 formed by bending a part of the bending piece. In addition, R chamfers are applied to inner and outer surfaces of both ends of the pipe member 37 so as to prevent the operation wire 33 from being caught.

As shown in FIG. 4, the flexible tube portion 13 is a tube member 53 having a three-layer structure composed of, for example, a flex, a blade, and a water-tight resin in this order from the inside. Operation wire 33 in left and right direction
There are arranged four coil pipes 54 which are guide members whose inner diameter dimension for smoothly guiding the inner diameter of the operation wire 33 is larger than the outer diameter dimension of the operation wire 33 by a predetermined clearance.
These coil pipes 54 are inserted up to the operation unit 4. Of the coil pipes 54, the upper coil pipe 54 corresponding to the upward operation wire 33 has a larger outer diameter than the lower and left and right coil pipes 54, and has a large wall thickness. I have.

The air or water from the air / water supply device of the video processor 7 is supplied through an air / water supply line 55 (not shown) through the insertion section 2 of the endoscope 1. It can be ejected from the nozzle toward the surface of the observation lens 26 when necessary.

Here, with reference to FIGS. 5 to 8, a specific configuration of the bending portion 12 in the vertical direction and a bending operation as an operation thereof will be described. As shown in FIG. 5, a bending tube 30 constituting the bending portion 12 of the endoscope 1 according to the present embodiment is combined with a tip piece 31 and a connecting pin 34 so as to bend vertically with respect to the tip piece 31. A plurality of bending piece groups 60 configured by combining the second bending piece 62 having a short inter-pin distance and the connecting pin 34 so as to bend in the vertical and horizontal directions.
And a last piece 61 positioned at the rearmost end and fixed to the front end of the flexible tube portion 13.

The bending piece group 60 is composed of a first four-way bending piece 64 and a second four-way bending piece 65 which are combined with each other by connecting pins 34 having a predetermined interval between the pins and rotate left and right.
And a two-way bending piece 66 which is combined with the second four-way bending piece 65 so as to be vertically rotated by the connecting pin 34 with a predetermined interval between pins.

In the bending piece group 60, the distance L1 between the pins of the two-way bending piece 66 is set to, for example, 6.3 mm. On the other hand, the distance L3 between the pins of the first four-way bending piece 64 is set to, for example, 2.9 mm, and the distance L4 between the pins of the second four-way bending piece 65 is set to, for example, 3.5 mm. For this reason, the inter-pin distance L2 in the state where the first four-way bending piece 64 and the second four-way bending piece 65 are combined is 6.4 mm. That is, in the present embodiment, a relationship of L1 / L3 = 2.17 L1 / L4 = 1.8 L1 / L2 = 0.98 is established between L1, L2, and L3.

In the present embodiment, the inter-pin distance L5 of the second bending piece 62 is set to, for example, 2.5 mm. As a result, the connecting pin 34 that connects the tip piece 31 and the first four-way bending piece 64 to rotate in the vertical direction, and the second four-way bending piece 65 and the final piece 61 rotate in the vertical direction. The distance LZ1 between the pins in the vertical direction, which is the distance between the connecting pins 34 and the connecting pins 34 connected to each other in the vertical direction, is 59.7 mm.

As shown in FIG. 6, the width WU of the pipe member 37, which is the upward wire guide 36, is set to 1 mm, and the interval LU between the upward wire guides is set to 5.35 mm. On the other hand, the downward wire guide 36
Is set to 0.6 mm, and the distance LD between the downward wire guides 36 is set to 12.1 mm. Thus, nine pipe members 37 and five downward wire guides 36 are provided. That is, the number of the upward wire guides 36 is smaller than the number of the upward wire guides 36.
Is the minimum required number.

Further, as shown in FIG. 7, the maximum upward bending angle QU 1 formed by the adjacent bending piece, the leading piece 31 and the second bending piece 62, is set to 12 °, and the adjacent bending piece The maximum upward bending angle QU2 formed by the two bending pieces 62 and the first four-way bending piece 64 is set to 16 °, and the adjacent four-way bending pieces 65 and the two-way bending pieces 66 are bent. The maximum upward bending angle QU3 to be formed is set to 26 °, and the two-way bending piece 66 and the first four-way bending piece 6 which are adjacent bending pieces are set.
4 is set to 26 °, and the maximum upward bending angle QU4 formed by the adjacent four-way bending piece 65 and the last piece 61 is set to 20 °. are doing.

As a result, the maximum upward bending angle of the bending tube 30 alone is an angle obtained by combining the upward maximum bending angles, the total bending angle (nominal value) is 256 °, and the endoscope is used. The bending angle (nominal value) in the completed state is 210 ° in the bending state as shown by the solid line in FIG.

On the other hand, the maximum downward bending angle QD 1 formed by the leading bending piece 31 and the second bending piece 62 which are adjacent bending pieces is set to 8
°, and the maximum downward bending angle QD2 formed by the adjacent bending pieces 62 and 64, which are adjacent bending pieces.
Is set to 16 °, the maximum downward bending angle QD3 formed by the adjacent two-way bending pieces 65 and 66 is set to 16 °, and the adjacent bending pieces The maximum downward bending angle QD3 formed by the direction bending piece 66 and the first four-way bending piece 64 is set to 16 °, and the downward direction formed by the adjacent bending pieces, ie, the second four-way bending piece 65 and the final piece 61. The maximum bending angle QD4 is set to 16 degrees.

Accordingly, the downward bending angle of the bending tube 30 alone is the sum of the respective downward maximum bending angles, the total bending angle (nominal value) is 168 °, and the endoscope is completed. The bending angle (nominal value) in the state is 90 ° in the bending state as shown by the two-dot chain line in FIG.

That is, as shown in FIG.
Is up to 210 ° in the upward direction (UP) as shown by the solid line.
In a bent state, and in a state of being bent at a maximum of 90 ° in a downward direction (DOWN) as shown by a two-dot chain line, the curvature radius of the bending portion 12 is not changed locally but is smoothly curved. I do.

In this embodiment, the outer skin 22 having a uniform thickness is covered over the entire length of the curved tube 30. For this reason, the bending shape when bending the bending portion 12 is a hand-side bent shape. Specifically, the radius of curvature inside the curved portion 12 is R11.5 m in a maximum upward bending state.
m, R19.5 mm in the maximum downward bending state.

Next, a specific configuration of the bending portion 12 in the left-right direction and a bending operation as an operation thereof will be described with reference to FIGS. Note that the configuration of the bending tube 30 is shown in FIG. 5, and the connection pins 34 are omitted in FIGS. The figure shows a state in which the outer skin 22 having a uniform wall thickness is covered.

As shown in FIG. 9, in the bending tube 30, a mechanism for bending in the left-right direction is provided by a second four-way bending piece 65, a two-way bending piece 66, and a first four-way bending piece 6 arranged in order from the distal end.
A plurality (four in the present embodiment) of the minimum unit connection units 70 each of which is configured to rotate with the connection pin 34 are connected to each other.

The distance L6 between pins of the connecting unit 70 is set to 12.7 mm, and the total distance LZ2 between the pins in the horizontal direction of the bending tube 30 is set to 50.9 mm. The distances L6 between the pins of the four connection units 70 are all the same.

As shown in FIG. 10, the width dimension WR of the wire guide 36 in the right direction is set to 0.6 mm, and the distance LR between the wire guides 36 is set to 12.1 mm.
On the other hand, the width dimension WL of the left wire guide 36 is also 0.6.
mm, and the distance LL between the wire guides 36 is also 12.1 mm.
mm. That is, the five wire guides 36 in the left-right direction are provided, and the distance between the wire guides is the same in the upward and downward directions.

As shown in FIG. 11, the maximum bending angles QL and QR formed by the adjacent four-way bending pieces 64 and 65 which bend in the left-right direction are set to 25 °. As a result, the total bending angle (nominal value) of the bending tube 30 alone in the left-right direction is 125 °, and the bending angle (nominal value) in the completed state of the endoscope is 100 ° in both the left-right direction.

Then, as shown in FIG.
IGHT) and at a maximum of 100 ° in the left direction (LEFT), the radius of curvature of the bending portion 12 is locally increased, as in the case of bending in the vertical direction. It curves in a smooth shape without change. The radius of curvature inside the curved portion 12 at this time is R26.5 mm in both the left and right directions.

In this embodiment, since the bending tube 30 is covered with the outer skin 22 having a uniform thickness over the entire length, the bending in the left-right direction is the same as the vertical bending. The shape is.

Therefore, when an electronic endoscope is inserted into the body cavity of a subject to observe and diagnose a target site such as the stomach,
The treatment tool for an endoscope such as a biopsy forceps is inserted into the treatment tool insertion channel 5.
2 to smoothly carry out procedures such as biopsy of the target site.

As described above, the distance between the pins of adjacent bending pieces or connecting units that bend in the same direction is substantially equal not only in the vertical direction but also in the horizontal direction. A smooth curved shape with little change can be obtained.

As a result, since there is no portion where the radius of curvature of the curved portion locally changes, the amount of force for inserting and removing the treatment tool at the time of bending is reduced, the number of hooks is reduced, and the penetration of the treatment tool at the time of bending is greatly improved. In addition to the above, the damage to the internal components when the bending operation is repeatedly performed is reduced, and the damage to the treatment tool insertion channel when the treatment tool is inserted and removed can be reduced.

Further, the tip end body of the insertion portion has a thin tip,
Along with forming a conical shape with a smooth outer diameter,
By providing a notch in the reinforcing pipe to reduce the outer diameter in the vicinity of the distal end of the curved portion, it is possible to improve the penetration of the endoscope into the body cavity.

Further, the outer diameter of the upward operation wire, the wire guide, and the coil pipe, which require the largest amount of pulling force of the operation wire required for bending, is the largest.
By setting it larger than the other three directions on the right and left, the outer diameter of the curved portion and the flexible tube is made smaller than that of the conventional product in which all four directions are formed with the same outer diameter. The penetrability into a body cavity can be improved.

Further, the number of the wire guides in the upward direction having the largest bending angle is made larger than the number of the wire guides in the other three directions, lower, right and left, so that the same number is used in all four directions. As compared with the product, the manufacturing cost of the endoscope having the operability and durability required for the operation wire can be reduced.

Further, since the pipe member is used only for the upper wire guide having the largest bending angle, the vertical direction can be easily determined, and the possibility of erroneous assembly can be reduced. Cost can be reduced.

FIGS. 13 to 17 relate to a second embodiment of the present invention. FIG. 13 is a view for explaining the structure of a curved portion characteristic of an outer cover for covering the periphery of a curved tube, and FIG. FIG. 15 is a longitudinal cross-sectional view of the vicinity of the bending portion in the left-right direction when the bending portion is viewed from above, FIG. 16 is a diagram illustrating a state in which the bending portion is bent at a desired angle, and FIG.
FIG. 4 is a cross-sectional view orthogonal to the longitudinal axis of the bending portion.

In this embodiment, the outer circumference of the bending tube 30 having the same bending piece arrangement as that of the first embodiment is covered with a blade 35, and the outer circumference of the blade 35 is reduced to a thickness of about 0.3 mm at the tip end. A set thin portion 75, a thickness changing portion 76 that changes so that the thickness gradually increases toward the hand side,
A stepped outer cover 7 made of a flexible material such as elastic rubber integrally formed with a thick portion 77 having a thickness on the hand side set to about 0.5 mm.
8 is slightly tightened. The two ends of the stepped outer cover 78 are respectively connected to the distal end 11 and the flexible tube 13.
And water-tightly fixed by means of a bobbin adhesive 23, respectively.

As shown in FIG. 13 and FIG. 15, the thickness change portion 76 of the stepped outer cover 78 removes the gap formed between the connecting pin 34 and the bending piece, that is, at a position on the bending piece. It is mounted on the bending tube 30 as shown in FIG. In particular,
Connecting pin 34 on the front side of second four-way bending piece 65 from the tip
When the distance to the rear connecting pin 34 is 49 mm, the distance from the tip to the front side of the thickness changing portion 76 is set to 47 mm, and the distance to the rear side is set to 48 mm. The thickness changing portion 76 is arranged.

As shown in FIG. 17, the bending portion 1 of the present embodiment
The light guide among the built-in parts in 2 is a bifurcated light guide 79a formed by covering a large number of flexible glass fibers divided into two inside the insertion portion 2 with a soft tube such as a silicon tube. Yes, at least the curved portion 12 of the outer periphery
The entire inner length is slightly tightened and reinforced by a reinforcing tube 79b such as a silicon tube or a heat-shrinkable tube.

In this embodiment, the upward wire guide 36 and the downward wire guide 36 are connected to the first wire guide 36.
Same as the embodiment, except that the wire guide 36
The same pipe member 37 as used in the upward direction is used.

Further, the operation wire 33 has a smaller diameter in the other three directions (down, right, left) with respect to the upward direction. And the pipe member 3 which is the wire guide 36 in the left-right direction
7 has the same thickness as the pipe member 37 of the upward wire guide 36, but has a smaller inner and outer diameter in accordance with the operation wire 33. Other configurations and operations are the same as those of the above-described embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted.

The operation of the bending portion 12 configured as described above will be described. In this embodiment, the thickness of the stepped outer skin 78 at the hand side is set to be larger than the thickness at the tip side, so that the hand side is less likely to bend than the tip side. As a result, when the operation wire 33 is pulled by operating the vertical bending operation knob 14 to bend upward or downward, as shown in FIG. 14, the distal end of the bending tube 30 covered with the thin portion 75 on the distal end side The thickness change portion 76 and the thick portion 77 bend after bending from the side, and after the tip side is completely bent. Similarly, when trying to bend rightward or leftward, as shown in FIG. 16, after the thin portion 75 is completely bent, the thick portion 76 and the thick portion 77 bend.

As described above, by forming the curved portion by covering the outer skin having a greater thickness on the hand side than on the tip side,
The curved shape at the time of bending can be made into a smooth curved shape.

Thus, the operability in the body cavity is further improved. Specifically, compared with the case of the first embodiment where the outer skin 22 is covered with a uniform thickness, the distance from the tip to the outer periphery of the curved portion 12 is from 41 mm to 31 mm in the upward direction.
mm and 10 mm shorter, from 67 mm down to 36 mm in the downward direction.
mm and 31 mm are also shortened, and in the left-right direction, they are shortened from 63 mm to 51 mm and 12 mm. The radius of curvature at this time is the same as in the first embodiment.

Further, since the thickness change portion of the outer skin is arranged on the outer periphery of the bending piece having no connecting pin, expansion and contraction during bending is not so large, and damage can be prevented.

Furthermore, by using a bifurcated light guide and arranging the signal cable and the treatment instrument insertion channel between the signal cable and the treatment instrument, even when the treatment instrument is used, the light distribution does not matter and a good observation image can be obtained. Obtainable.

Further, by covering the outer circumference of the bifurcated light guide in the bending portion with the reinforcing tube, the durability at the time of bending can be improved.

Further, since the left and right wire guides are made of pipe members having a smaller diameter than the upper direction, the space in the curved tube can be made larger than when all the wire guides have the same size as the upper direction. In addition to this, it is possible to further improve the durability of the operation wire by preventing a trouble due to the contact.

FIGS. 18 and 19 relate to a third embodiment of the present invention. FIG. 18 is a vertical sectional view for explaining the relationship between the pins by connecting the two-way bending piece and the four-way bending piece with connecting pins. FIG. 19 is a view for explaining a state in which a bending tube connected to a distal end portion and a flexible tube portion is bent upward.

As shown in FIG. 18, in the present embodiment, the inter-pin distance L3 ′ of the first four-way bending piece 64 connected to the second bending piece 62 is set to 3.5 mm, and The distance L4 ′ between the pins of the direction bending piece 65 is set to 3.5 mm,
The distance L1 'between the pins of the two-way bending piece 66 is set to 5.6 mm.

Therefore, in the present embodiment, the relationship between the distance between the pins of the two-way bending pieces 66 and the distance between the pins of the four-way bending pieces 64 and 65 is L1 '/ L3' = 1.6, L
1 ′ / L4 ′ = 1.6. Then, as shown in FIG. 19, the maximum upward bending angle is set to 180 °. Other configurations and operations are the same as those of the above-described embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted.

As described above, by setting the distance between the pins of the four-way bending piece to a predetermined size, the first four-way bending piece and the second four-way bending piece can be made the same bending piece and the manufacturing cost can be reduced. can do.

The present invention is not limited to the above-described embodiment. In the vertical direction, the distance between the pins of the two-way bending piece is 1.5 times or more and less than 2.5 times the distance between the pins of the four-way bending piece. (Approximately twice), when a bending tube is formed by arbitrarily combining a two-way bending piece and a four-way bending piece, there is little change in the local radius of curvature and the bending shape is small. It has been found by examination that smoothing is performed, so that it suffices to be in this range.

The endoscope is not limited to an electronic endoscope, but may be an endoscope using an image guide by a fiber bundle, an endoscope for the lower digestive tract or other organs, or an inside of a turbine. Naturally, the present invention may be applied to an industrial endoscope that performs inspections such as inspection.

Further, a modified embodiment in which the configurations of the above-described embodiments are appropriately combined or omitted may be employed.

[Appendix] According to the above-described embodiment of the present invention, the following configuration can be obtained.

(1) A bending tube formed by combining a four-way bending piece that bends in four directions and a two-way bending piece that bends in two upper and lower directions so as to be rotatable with a connecting pin, and covering this bending tube. An endoscope having a curved portion constituted by an outer skin to be formed, a distance between connection pins (A) of a two-way bending piece disposed at least near a center of a curved tube constituting the curved portion;
An endoscope in which a relation of 1.5 ≦ A / B <2.5 is set between the four-way bending piece and a distance (B) between connecting pins.

(2) When a two-way bending piece and a four-way bending piece arranged at least near the center of the bending tube constituting the bending portion are rotatably combined, these two pieces form 2. The endoscope according to claim 1, wherein the direction bending angle is set to 15 ° or more.

(3) A bending tube formed by combining a four-way bending piece and a two-way bending piece so as to be rotatable with a connection pin, and a minimum unit of a connection unit. In an endoscope having a curved portion configured with an outer skin covering the curved tube, the distance between the connecting pins of the plurality of connecting units at least near the center of the curved tube configuring the curved portion is set to be substantially the same, An endoscope in which a bending angle between two adjacent pieces formed by two adjacent bending pieces is set to 20 ° or more.

(4) The thickness of the outer skin covering the curved tube, wherein the thickness from the vicinity of the center of the curved tube to the hand side is set to be larger than the thickness from the vicinity of the center to the distal end side. Endoscope.

(5) A bending tube formed by combining a minimum unit of a four-way bending piece and a two-way bending piece so as to be rotatable with a connecting pin, and a rotatable combination pin. In an endoscope having a curved portion constituted by an outer sheath for covering the curved tube, the distance between the pins of the plurality of connection units is made substantially the same, and the thickness of the outer sheath for covering the curved tube is reduced. An endoscope that is set thicker near the center and nearer to the tip than near the center.

(6) The endoscope according to Supplementary Note 4 or 5, wherein the thickness change portion of the outer skin is disposed between the connecting pins when the outer skin is mounted on the curved tube.

(7) The number of upward wire guides is greater than the number of downward wire guides when a wire guide for smoothing the movement of the operation wire for bending the bending tube is arranged in the bending tube. The endoscope according to attachment 1.

(8) A bending tube formed by combining a four-way bending piece and a two-way bending piece so as to be rotatable with a connecting pin so as to be rotatable with a connecting pin. In an endoscope having a curved portion formed by an outer skin covering the curved tube, the operation wires for bending the curved tube are formed while forming the pins of the plurality of connection units so as to be substantially the same. An endoscope in which the number of wire guides in the left-right direction and the distance between adjacent wire guides in the insertion axis direction are substantially matched when a wire guide for smooth movement is arranged in a curved tube.

[0088]

As described above, according to the present invention, the bending shape of the bending tube constituting the bending portion, in which the radius of curvature changes locally, is improved, and the penetration of the treatment tool and the durability of the built-in member are improved. And an endoscope having excellent bending operability and observation performance can be provided.

[Brief description of the drawings]

FIG. 1 to FIG. 12 relate to a first embodiment of the present invention, and FIG. 1 is a diagram showing a schematic configuration of an entire system of an electronic endoscope.

FIG. 2 is a longitudinal sectional view illustrating a configuration of a distal end portion including a part of a curved portion of the electronic endoscope.

FIG. 3 is a cross-sectional view perpendicular to a longitudinal axis of a tip portion.

FIG. 4 is a sectional view orthogonal to a longitudinal axis of a flexible tube portion.

FIG. 5 is a longitudinal cross-sectional view in the up-down direction for explaining the pins of a bending tube in which a two-way bending piece and a four-way bending piece are connected by connecting pins.

FIG. 6 is a view for explaining a width dimension of a wire guide in a vertical direction provided on a bending tube and a relationship between the wire guides;

FIG. 7 is a vertical cross-sectional view in the vertical direction for explaining a relationship between bending angles between adjacent pieces of a bending portion in which the periphery of a bending tube is covered with an outer skin.

FIG. 8 is a diagram illustrating a state in which a bending portion is bent in a vertical direction.

FIG. 9 is a longitudinal cross-sectional view in the left-right direction for explaining a pin interval when the bending tube is viewed from above.

FIG. 10 is a view for explaining a width dimension of a wire guide in a left-right direction provided on a curved tube and a relationship between the wire guides.

FIG. 11 is a cross-sectional view in the longitudinal direction in the left-right direction for explaining the relationship between the bending angles of adjacent pieces when the bending portion in which the periphery of the bending tube is covered with the outer skin is viewed from above.

FIG. 12 is a diagram illustrating a state in which a bending portion is bent in the left-right direction.

FIG. 13 to FIG. 17 relate to a second embodiment of the present invention, and FIG. 13 is a view for explaining a configuration of a curved portion having a characteristic of an outer cover surrounding a curved tube.

FIG. 14 is a diagram illustrating a state in which a bending portion is bent.

FIG. 15 is a longitudinal cross-sectional view of the periphery of the bending portion in the left-right direction when the bending portion is viewed from above.

FIG. 16 is a diagram illustrating a state in which a bending portion is bent at a desired angle.

FIG. 17 is a cross-sectional view orthogonal to the longitudinal axis of the bending portion.

18 and 19 relate to a third embodiment of the present invention, and FIG. 18 is a vertical direction illustrating the relationship between the pins by connecting a two-way bending piece and a four-way bending piece with a connecting pin. Longitudinal section

FIG. 19 is a diagram illustrating a state in which a bending tube connected to a distal end portion and a flexible tube portion is bent upward.

20 and 21 relate to a conventional embodiment,
FIG. 20 is a diagram illustrating a configuration example of a bending tube.

FIG. 21 is a diagram showing a bending state of a bending tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 12 ... Bending part 30 ... Bending tube 31 ... Tip piece 34 ... Connection pin 61 ... Last piece 62 ... Second bending piece 64 ... First four-way bending piece 65 ... Second four-way bending piece 66 ... Two-way curved piece

Claims (3)

[Claims] 1. A bending tube formed by combining a four-way bending piece that bends in four directions and a two-way bending piece that bends in two vertical directions with a connecting pin, and covers the bending tube. In an endoscope having a curved portion formed of an outer skin, a distance (A) between connection pins of two-way bending pieces disposed at least near the center of a bending tube forming the bending portion, and a connection pin of a four-way bending piece. An endoscope, wherein a relationship of 1.5 ≦ A / B <2.5 is set between the endoscope and the distance (B). 2. An upward direction formed by a two-way bending piece and a four-way bending piece that are rotatably combined at least near the center of a bending tube forming the bending portion. The endoscope according to claim 1, wherein the bending angle is set to 15 ° or more. 3. A bending tube formed by combining a minimum unit of a four-way bending piece and a two-way bending piece so as to be rotatable with a connecting pin so as to be rotatable with a connecting pin. In an endoscope having a curved portion constituted by an outer skin covering the curved tube, the distance between the connecting pins of the plurality of connecting units at least near the center of the curved tube constituting the curved portion is set to be substantially the same, and An endoscope, wherein a bending angle between two adjacent pieces formed by two adjacent bending pieces is set to 20 ° or more.