Endoscope

Abstract

There is provided an endoscope that prevents occurrence of buckling of a flexible body built in an insertion part of the endoscope without damaging other built-in components, and is easy to manufacture without impairing the curving manipulability. The endoscope includes a curvable portion, and an elongated insertion part being inserted into a subject. The endoscope has an elongated flexible body built in the insertion part, and a flexible protective tube that covers an outer periphery of the flexible body. The protective tube has a first region that covers the range of the flexible body, and a second region that covers the range of the soft portion. The elastic constant of the first region is smaller than the elastic constant of the second region, and the external diameter of the protective tube in the first region is larger than the external diameter of the protective tube of the second region.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the present invention[0002]The present invention relates to an endoscope including a curvable portion.[0003]2. Description of the Related Art[0004]Endoscopes widely used for medical and industrial uses have an insertion part to be inserted into a subject (into a body cavity), and a manipulating part that is manipulated by an operator, and built-in components, such as optical fibers for illumination, forceps channel through which a treatment tool is inserted, an air supply and water supply channel, are arranged in the insertion part. Moreover, a curvable portion that is operated to curve is provided at the distal end of the insertion part, and the curvable portion can be curved up and down and right and left in conjunction with angle knobs of the manipulating part (for example, refer to JP 2007-37649A).[0005]These built-in components, such as optical fibers, are flexible bodies that are apt to curve. JP 2007-37649A describes a configuratio...

AI Technical Summary

Benefits of technology

[0007]The present invention has been made in view of the above-mentioned problems and an object of the present invention is to provide an endoscope that prevents a flexible body with a reduced diameter, such as an optical fiber, which is built in an insertion part of the endoscope, from being damaged due to buckling, bending, or the like, without damaging other built-in components, and is easy to manufacture without impairing the curving manipulability of a curvable portion.

[0009]In the endoscope of the present invention, the flexible body that is built in the insertion part of the endoscope and is covered with the protective tube in which the elastic constant of the protective tube located at least in the curvable portion is smaller than the elastic constant of the protective tube located in the soft portion, and the external diameter of the protective tube in the first region is larger than the external diameter of the protective tube of the second region, so that this flexible body does not undergo any damage, and the buckling of the flexible body can be prevented without damaging other built-in components. Moreover, since the elastic constant of the protective tube of the curvable portion is small, the required torque for the curving manipulation of the curvable portion is suppressed to be small. Since the flexible body covered with the protective tube can be smoothly put into the insertion part during manufacture, the assemblability when the endoscope is manufactured improves.

Problems solved by technology

However, in the configuration in which the element wire is densely and spirally wound on the outer periphery of the flexible body, the manufacturing process becomes complicated and the costs become high.

Additionally, since a level difference caused by the element wires occurs outside the flexible body, and the surface of the element wire is hard, other built-in components are apt to be damaged.

Moreover, when the element wire that is densely and spirally wound is unwound from the outer periphery of the flexible body, there is a concern that other built-in components may be damaged or the element wire may catch.

Additionally, since the diameter of the flexible body is increased due to the spiral element wire, this configuration is disadvantageous to reducing the diameter of the insertion part.

If the flexible body with the reduced diameter is used, the durability of the flexible body is not sufficiently secured due to the reduction in diameter, and the flexible body is apt to be damaged due to buckling or bending of the flexible body when the endoscope is manufactured and when the endoscope is used.

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