JP4360934B2 - Endoscope curvature - Google Patents

Description

  The present invention relates to a bending portion of an endoscope.

  In general, a bending portion of an endoscope forms a bending tube by relatively rotatingly connecting a plurality of node rings formed in a short cylindrical shape, and is inwardly connected to the inner surface of all or part of the node rings. The distal end of the operation wire that passes through the wire guide projecting toward the end is connected to the vicinity of the distal end of the bending tube, and the bending tube is bent by pulling the operation wire from the proximal end side.

  However, the bending portion of the endoscope configured as described above always starts to bend from the base portion of the proximal end when the operation wire is pulled, for example, a bending portion having a maximum bending angle of 180 ° in the middle of 90 °. 5, the curved portion 2 swings greatly in a state where the front half is in a straight rod shape, as shown by a broken line in FIG. Therefore, it is very difficult to guide as expected in a narrow luminal organ.

  Therefore, conventionally, in the range near the base end in the longitudinal direction of the bending tube, the coil spring is sandwiched between the wire guides arranged at adjacent positions, and both end surfaces of the coil spring are brought into contact with the wire guides, An operation wire was passed through the coil springs.

With such a configuration, when the operation wire is pulled, the compression force of the coil spring becomes resistance to bending, so that the start of bending of the portion is delayed and the bending portion starts bending from the front side portion (for example, patent References 1, 2).
Shokai 55-143801 2-55906

  However, as described above, when the coil spring is sandwiched between two wire guides arranged at adjacent positions, the amount of compression of the coil spring when the portion is bent with respect to the entire length of the coil spring ( That is, since the compression ratio is considerably large, the compression resistance increases rapidly with the change in bending due to the bending operation, and the bending operation becomes very heavy. As a result, the bending operability is deteriorated and the operation wire is deformed. Causes premature breakage.

  Therefore, the present invention reduces the compression rate of the coil spring accompanying the bending operation in the bending portion of the endoscope that uses the compression force of the coil spring as a resistance so that the bending portion starts bending from the distal end portion. An object of the present invention is to provide a bending portion of an endoscope in which bending operation is not heavy and the durability of an operation wire is excellent.

  In order to achieve the above object, the bending portion of the endoscope of the present invention forms a bending tube by relatively rotatingly connecting a plurality of node rings formed in a short cylindrical shape, By connecting the distal end of the operation wire passing through the wire guide protruding inwardly on all or part of the inner surface to the vicinity of the distal end of the curved tube, and pulling the operation wire from the proximal end side, the curved tube In the bending portion of the endoscope that is bent, a coil spring is loosely fitted to the operation wire in a range near the base end in the longitudinal direction of the bending tube, and the wire provided at the base end position in the range The base end surface of the coil spring is brought into contact with the guide, and the middle part of the coil spring is disposed so as to pass loosely through at least one wire guide, and the coil spring is placed on the wire guide provided at the tip position in the above range. Tip surface It is obtained by contact.

  According to the present invention, in the bending portion of the endoscope in which the bending portion starts to bend from the distal end portion using the compression force of the coil spring as a resistance, the compression rate of the coil spring accompanying the bending operation is reduced. Therefore, the bending operation does not become heavy, and as a result, the operation wire can have excellent durability.

  A coil spring is loosely fitted to the operation wire in a range close to the base end in the longitudinal direction of the bending tube, and the base end surface of the coil spring is brought into contact with a wire guide provided at the base end position in the range. The intermediate portion of the coil spring is disposed so as to pass loosely through at least one wire guide, and the tip end surface of the coil spring is brought into contact with the wire guide provided at the tip position within the above range.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows the overall configuration of the endoscope. A bending portion 2 is formed in the vicinity of the distal end of the insertion portion flexible tube 1, and the distal end portion main body 3 on which an observation window, an illumination window and the like are arranged is the bending portion 2. It is connected to the most advanced part.

  An operation unit 4 in which various operation members are arranged is connected to the proximal end of the insertion portion flexible tube 1, and a bending operation knob 5 (5UD for up and down direction, 5RL for left and right direction) arranged in the operation unit 4. By rotating and operating the four operating wires, the bending portion 2 can be bent in a desired direction by a desired angle.

  FIG. 3 shows the bending portion 2. A plurality of (several to several tens of) node rings 21 formed in a short cylinder shape are connected to each other by rivets 22 so as to be relatively rotatable. A snake toy-shaped curved tube which is a framework is configured, and an outer skin 23 made of a rubber tube having elasticity is coated on the outermost surface thereof.

  In this embodiment, the node rings 21 are connected by rivets 22 with their directions alternately changed by 90 °, and the four operation wires 24 correspond to the arrangement positions of the rivets 22 and the axis of the bending portion 2. Are arranged along the inner surface of the bending tube in a direction parallel to the inner surface of the bending tube.

  Each operation wire 24 is inserted into a wire guide 25 projecting inwardly from each node ring 21 so as to freely advance and retreat, and is connected and fixed to the most advanced wire guide 25. In the tube 1, it is loosely inserted into the guide coil 10 over the entire length.

  As a result, when one operation wire 24 is pulled in the proximal direction by the bending operation knob 5, the bending portion 2 rotates relative to the adjacent node rings 21 around the rivet 22. By narrowing the gap in the direction in which the operation wire 24 is disposed, the bending is performed in that direction (that is, the direction in which the pulled operation wire 24 is disposed).

  In such a range near the base end in the longitudinal direction of the bending portion 2, the coil spring 26 is loosely fitted to each operation wire 24. The coil spring 26 is, for example, a spring stainless steel wire wound in a coil shape with a gap.

  Then, the proximal end surface of the coil spring 26 is brought into contact with the wire guide 25 (25A) provided at the most rearward position in the range where the coil spring 26 is disposed, and an intermediate portion of the coil spring 26 is illustrated in FIG. 4, the wire guide is disposed so as to pass loosely through the plurality of wire guides 25 (25 </ b> B), and the distal end surface of the coil spring 26 is located at the distal end position in the range where the coil spring 26 is disposed. 25 (25C).

  As a result, when the operation wire 24 is pulled, the compression force of the coil spring 26 becomes resistance to bending, so that the portion near the proximal end of the bending portion 2 where the coil spring 26 is arranged as shown in FIG. The bend starts late, the bending portion 2 begins to bend from the front part, and after the front part finishes bending, the base part starts to bend.

  Each coil spring 26 passes through the plurality of wire guides 25 (25B) loosely and is compressed between the wire guides 25A and 25C at both ends of each coil spring 26. Since the compression amount (that is, the compression ratio) of the coil spring 26 is relatively small with respect to the entire length, the compression resistance does not increase rapidly with the change of the bending state due to the bending operation, and a favorable bending operability is obtained. The operation wire 24 is not deteriorated.

  In addition, this invention is not limited to the said Example, For example, the coil spring 26 should just pass the inside of at least 1 wire guide 25 (25B) loosely in the middle.

It is side surface sectional drawing of the state which the bending part of the endoscope of the Example of this invention bent. 1 is a side view showing an overall configuration of an endoscope according to an embodiment of the present invention. It is side surface sectional drawing of the curved part of the endoscope of the Example of this invention. It is a partial expanded side sectional view of the curved part of the endoscope of the example of the present invention. It is a side view which shows the whole structure of the endoscope in the state where the bending part of the conventional endoscope was bent.

Explanation of symbols

2 bending portion 21 node ring 22 rivet 24 operation wire 25 wire guide 25A wire guide with which the base end face of the coil spring abuts 25B wire guide through which the coil spring passes 25C wire guide with which the tip end face of the coil spring abuts 26 coil spring

Claims (1)

A wire guide is formed by connecting a plurality of node rings formed in a short cylindrical shape so as to be relatively rotatable so as to form a curved tube and projecting inwardly on the inner surface of all or part of the node rings. In the bending portion of the endoscope, the distal end of the operation wire passing through the inside is connected to the vicinity of the distal end of the bending tube, and the bending tube is bent by pulling the operation wire from the proximal end side.
A coil spring is loosely fitted to the operation wire in a range near the base end in the longitudinal direction of the bending tube, and the base end surface of the coil spring is brought into contact with a wire guide provided at the base end position in the range. The intermediate portion of the coil spring is arranged so as to pass loosely through at least one wire guide, and the tip surface of the coil spring is brought into contact with the wire guide provided at the tip position in the range. A curved portion of an endoscope as a feature.

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