JP3450785B2 - Operation wire drive mechanism for endoscope - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation wire drive mechanism for an endoscope in which an operation wire is pulled by a gear, and more particularly to an improvement of a rack and pinion drive mechanism.

[0002]

2. Description of the Related Art For example, in a bending operation device for an endoscope, a pinion (that is, a gear) rotated by an operation knob (or an operation lever) is engaged with a rack connected to a proximal end of an operation wire. A mechanism in which the rack is linearly moved back and forth by rotating the gear to drive the operation wire forward and backward is well known.

[0003]

However, in such a rack and pinion mechanism, the rack length needs to be at least twice the stroke of the operating wire, and the rack moving space is opposite to the pulling direction of the operating wire from the gear as the rack moving space. A space at least as long as the stroke of the operating wire is required in the direction. For this reason, the operation knob is forced to be located near the center of the operation unit, and the grip portion of the operation unit cannot be sufficiently long, resulting in impaired operability.

Therefore, the present invention provides an operation wire drive mechanism for an endoscope in which a gear can be arranged at a position near the upper end of the operation portion, and a sufficient grip portion length can be secured to obtain good operability. The purpose is to provide.

[0005]

In order to achieve the above object, the operation wire drive mechanism for an endoscope of the present invention pulls and drives the operation wire by a gear wheel that is rotated in the operation portion of the endoscope. In the operation wire drive mechanism of the endoscope described above, the cord-like body is spirally wound around the outer peripheral surface near the proximal end of the operation wire at a pitch corresponding to the pitch of the gear and fixed, and a part of the portion is fixed to the gear. The free end side of the operating wire is extended in a direction different from the extension line of the pulling direction of the operating wire by making it curve along and engaging with the gear.

If the teeth of the gear are formed in an oblique direction corresponding to the direction of the operation wire, the engagement with the cord-shaped body is favorably performed. If the free end side of the operation wire is oriented in a direction bent by 45 ° or more with respect to the extension line in the pulling direction of the operation wire, a considerable effect is obtained, and if it is 90 ° or more, a larger effect is obtained. The free end side of the operation wire may be oriented in a direction in which it is returned in a substantially U shape with respect to the pulling direction of the operation wire.

[0007]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows the entire configuration of the endoscope, in which an insertion portion flexible tube 2 is connected to the lower end of an operation portion 1 which is held and operated by an operator.

A bending portion 3 which can be arbitrarily bent by remote control is connected to the distal end of the insertion portion flexible tube 2,
A tip body 4 having a built-in objective optical system and the like is connected to the tip of the bending portion 3.

A bending operation knob 5 for bending the bending portion 3 is arranged in the upper half of the operation portion 1, and a portion of the operation portion 1 below the bending operation knob 5 is a grip portion 1a. There is. 6 is a treatment instrument 10 passed through the treatment instrument insertion channel
It is an elevator operating knob for remotely changing the protruding direction of the tip portion 100a of 0.

FIG. 1 shows a bending operation wire driving device provided in the operation portion 1 so as to pull the operation wire 10 for bending the bending portion 3, and FIG. FIG.

The pair of operating wires 10 are connected at their distal ends to the distal ends of the bending portions 3, respectively, and pass through a guide tube 12 made of a tightly wound coil pipe which is inserted and arranged in the flexible tube 2 of the insertion portion, and a proximal end. The side is introduced into the operating part 1. Thirteen
Is the frame 1 in the operation part 1 with the base end portion of the guide tube 12
It is a fixed seat fixed to 4.

Two gears 17 are arranged side by side so as to be directly connected to a shaft body 16 which is rotationally driven by the bending operation knob 5, and a pair of operations are arranged along the gear 17 in a substantially U-shaped curve. The curved portion of the wire 10 is wound around each gear 17 about half a turn.

On the outer peripheral surface of each operation wire 10, a cord-shaped body 2 is formed.
0 is spirally wound and fixed at the same pitch as the pitch of the gear 17, and the teeth of the gear 17 are fitted and engaged in the gaps between the pitches of the string-like body 20.

Therefore, as shown in FIG. 4, the gear 17 is a "helical gear" in which the direction of the teeth is formed in the same oblique direction as the direction of the cord 20. The tooth profile may have any shape as long as it does not come out of the gap between the pitches of the string-shaped body 20.
In such a configuration, the gear 17 may mesh with the operation wire 10 anywhere in the rotational position, and the freedom of assembly is great.

In order to prevent the engagement state between the operation wire 10 and the gear 17 at the portion around which the cord 20 is wound from coming off, the outer surface cover 18 surrounding the portion from the outer surface side is provided with a machine screw 19.
It is fixed to the frame 14 by.

A tip 11 is attached to the free end of the operating wire 10 on which no pulling force acts. In this embodiment, the free end side of the operating wire 10 to which the tip 11 is attached pulls the operating wire 10. It extends from the engaging portion with the gear 17 in a direction returning to a substantially U shape with respect to the direction.

With this structure, when the bending operation knob 5 is rotated to rotate the gear 17, the operation wire 10 moves in the axial direction together with the teeth of the gear 17, and one of the pair of operation wires 10 is pulled. Then, the other is pushed out, and the bending portion 3 is bent by an angle corresponding to the pulling amount.

The free end side of the operating wire 10 is the operating wire 1
Gear 1 in the direction returned to a substantially U shape with respect to the pulling direction of 0
Since it extends from the 7th part, no space for bending operation is required above the gear 17. Therefore, the length of the grip portion 1a of the operation portion 1 can be sufficiently secured.

The cord-like body 20 is wound around the operation wire 10 to the extent that the engagement with the gear 17 cannot be disengaged even when the bending portion 3 is bent to the maximum extent, and the operation wire 10 is provided at both ends of the winding. The movement stopper 23 is fixed to the. Reference numeral 24 is a fixed stopper for abutting the movement stopper 23 attached to the slack side operation wire 10.

In the present invention, the operation wire 10 and the cord-like body 20 may be fixed to each other by any means. For example, as shown in FIG.
For each of the above, the metal wires 10a, 20a are coated with a coating 10b, 20b of, for example, a thermoplastic synthetic resin material (for example, polyamide resin or polyurethane resin).
The coating may be applied in a thickness of about 1 to 0.3 mm, and the string-like body 20 may be heated while being wound around the operation wire 10 to weld both coatings 10b and 20b.

Metal wire 1 used for operating wire 10
As 0a, for example, a stainless steel twisted wire having a diameter of about 0.3 to 1 mm, such as a 1 × 7 twist or a 1 × 3 twist, is used, and the outer diameter of the portion around which the cord 20 is wound is the metal wire 10a. The diameter may be about 3 to 5 times (for example, about 1 to 5 mm). In addition, when the endoscope is inserted into a thick lumen as an industrial endoscope, the diameter of the operation wire 10 may be increased according to the usage situation.

The present invention is not limited to the above embodiment, and for example, two of the above devices may be combined and used in a so-called four-direction bending operation device. Further, the extending direction of the free end of the operation wire 10 is a direction perpendicular to the extension line of the operation wire 10 in the pulling direction from the engaging portion with the gear 17, as schematically shown in FIGS. 6 and 7. Or in other directions. If it is more than a right angle,
No space above the gear 17 is required.

FIG. 8 shows an example in which the free end of the operating wire 10 extends in an obtuse angle direction with respect to the extension line of the operating wire 10 in the pulling direction. If it is extended in a direction bent by 45 ° or more, the space required above the gear 17 can be shortened at an effective level.

FIG. 9 shows an example in which the present invention is applied to an operating device for the treatment instrument raising base 7 arranged on the distal end portion main body 4. By rotating the treatment instrument raising base 7 with the operation wire 10. , The treatment instrument 10 passed through the treatment instrument insertion channel 8
It is possible to change the protruding direction of the tip portion 100a of 0.

In this embodiment, one operating wire 10 is arranged in the operating portion 1, and a gear 117 having teeth formed on its side surface is connected to the raising base operating knob 6 and arranged in the operating portion 1. There is. 10c is a connecting pipe for connecting the operation wire 10.

FIG. 10 shows an example in which the present invention is applied to a focusing operation device for an endoscope, in which an objective lens barrel 9 arranged in the tip end main body 4 is moved forward and backward in the optical axis direction by an operation wire 10. Thus, focusing can be performed.

Also in this embodiment, one operating wire 10 is arranged in the operating portion 1 and is moved forward and backward in the axial direction by the gear 17 similar to that of the first embodiment.

[0028]

According to the present invention, the free end side of the operating wire in which the cord is spirally wound is extended from the engaging portion with the gear in a direction different from the extension line of the pulling direction of the operating wire. As a result, the gear can be arranged at a position near the upper end of the operation portion, and the grip portion length of the endoscope operation portion can be sufficiently secured to obtain good operability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a bending operation wire driving device according to a first embodiment of the present invention.

FIG. 2 is an external view showing the overall configuration of the endoscope according to the first embodiment of the present invention.

FIG. 3 is a schematic perspective view of a main part of the bending operation wire driving device according to the first embodiment of the present invention.

FIG. 4 is a view of a gear that engages with the operation wire according to the first embodiment of the present invention, as viewed from the addendum side.

FIG. 5 is an enlarged side view showing a cross section of a part of the operation wire according to the first embodiment of the present invention.

FIG. 6 is a schematic view of a modification of the bending operation wire driving device according to the first embodiment of the present invention.

FIG. 7 is a schematic view of a modified example of the bending operation wire driving device according to the first embodiment of the present invention.

FIG. 8 is a schematic view of a modified example of the bending operation wire driving device according to the first embodiment of the present invention.

FIG. 9 is a cross-sectional view showing an elevator operating wire drive unit according to a second embodiment of the present invention with an intermediate portion omitted.

FIG. 10 is a sectional view showing a focusing operation wire driving device according to a third embodiment of the present invention with an intermediate portion omitted.

[Explanation of symbols]

1 Operation part 1a grip 3 curved part 5 Bending operation knob 6 Elevator operation knob 7 Treatment tool raising stand 9 Objective lens tube 10 operation wire 11 Tip (free end) 16 axis 17 gears 20 String

Claims (5)

(57) [Claims] 1. An operation wire drive mechanism for an endoscope, wherein an operation wire is pulled and driven by a gear that is rotationally operated in an operation section of the endoscope, and a cord-shaped body is provided around an outer periphery of the operation wire. The surface is spirally wound and fixed at a pitch corresponding to the pitch of the gear, a part of the portion is curved along the gear to engage the gear, and the free end side of the operation wire is operated by the operation. An operation wire drive mechanism for an endoscope, wherein the operation wire drive mechanism is extended in a direction different from the extension line of the pulling direction of the wire. 2. The operation wire drive mechanism for an endoscope according to claim 1, wherein the teeth of the gear are formed in an oblique direction corresponding to the direction of the operation wire. 3. The operation wire drive for an endoscope according to claim 1, wherein the free end side of the operation wire is oriented in a direction bent by 45 ° or more with respect to an extension line of the operation wire in the pulling direction. mechanism. 4. The operation wire drive for an endoscope according to claim 1, wherein the free end side of the operation wire is oriented in a direction bent by 90 ° or more with respect to an extension line of the operation wire in the pulling direction. mechanism. 5. The operation wire drive mechanism for an endoscope according to claim 1, wherein the free end side of the operation wire is oriented in a direction in which it is returned in a substantially U shape with respect to the pulling direction of the operation wire. .