JP4554804B2 - Endoscope bending operation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bending operation device for an endoscope.
[0002]
[Prior art]
In an endoscope, generally, a bending portion formed near the distal end of an insertion portion can be arbitrarily bent by a remote operation from an operation portion connected to a proximal end of the insertion portion.
[0003]
Various mechanisms are employed in such a bending operation device for performing the bending operation, and a mechanism in which the chain is pulled by a sprocket gear that is rotationally driven by an operation member is well known (for example, Japanese Patent No. 2627549).
[0004]
[Problems to be solved by the invention]
In general, an endoscope bending operation device is configured to pull one of a pair of operation wires whose distal ends are connected to a bending portion and push one in the opposite direction.
[0005]
However, as a characteristic feature of the bending operation device of the endoscope, since the movement amount of the operation wire in the pushing direction is smaller than the movement amount of the operation wire in the pulling direction, it is necessary to absorb slack generated in the operation wire in the pushing direction. is there.
[0006]
Various types of bending operation mechanisms have been devised in the past so as to absorb such slack of the operation wire, but all of them ensure a straight space as long as the traction stroke in the pushing direction from the neutral position. Since it is necessary, there is a problem that the operation portion becomes long and large as the pulling stroke of the operation wire increases.
[0007]
Accordingly, an object of the present invention is to provide a bending operation device for an endoscope that can reduce the length of the bending operation mechanism and can secure a sufficient pulling stroke even with a small operation portion.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an endoscope bending operation device according to the present invention includes a driving sprocket gear that is rotationally driven by an operating member, and a driven sprocket gear that is disposed with a space between the driving sprocket gear. A timing belt that is parallel to the two sprocket gears without slack, and rotationally drives the driving sprocket gear so that one of the pair of operation wires whose base ends are connected to the timing belt is the driving sprocket gear. In the bending operation device of the endoscope that is pulled back to the other side and pushed back, the proximal end portion of the operation wire that is pushed back when the driving sprocket gear is driven to rotate is along the outer periphery of the driven sprocket gear. To move.
[0009]
Then, at the connecting portion between the proximal end portion of the operation wire and the timing belt, the proximal end portion of the operation wire is configured to be rotatable around an axis parallel to the axis of the driven sprocket gear, thereby enabling the operation wire on the side to be pushed back. Unreasonable force does not work.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows an endoscope according to an embodiment of the present invention. A bending portion 3 that is bent by a remote operation from the operation portion 1 is provided at the distal end portion of the insertion portion 2 whose base end is connected to the operation portion 1. A tip body 4 formed and containing an objective optical system or the like is connected to the tip of the bending portion 3.
[0011]
A bending operation mechanism 10 for pulling a pair of operation wires 5 whose tips are connected to the bending portion 3 is disposed in the operation unit 1, and a bending operation knob for operating the bending operation mechanism 10. 6 is disposed on the side surface of the upper half of the operation unit 1.
[0012]
The proximal end portion of the flexible guide tube 7 that guides the operation wire 5 in the insertion portion 2 is fixed to the frame in the operation portion 1, and the distal end portion (not shown) is fixed to the distal end of the insertion portion 2.
[0013]
FIG. 3 shows a bending operation mechanism 10 disposed in the operation unit 1. A driving sprocket gear 11 that is rotationally driven by the bending operation knob 6 is disposed at an upper position of the operation unit 1 and below (insertion unit) The driven sprocket gear 12 is rotatably arranged at a distance from the driving sprocket gear 11 at a position close to 2).
[0014]
The timing belt 13 is substantially parallel to the driving sprocket gear 11 and the driven sprocket gear 12 with no slack. When the driving sprocket gear 11 rotates, the timing belt 13 is moved in a parallel state. The driven sprocket gear 12 rotates accordingly. Reference numeral 19 denotes a rotatable idle roller for preventing the timing belt 13 from coming off.
[0015]
The base end portions of the pair of operation wires 5 are divided into both sides of the parallel portion of the timing belt 13 that is parallel to the driving sprocket gear 11 and the driven sprocket gear 12, and each is connected to the timing belt 13 by the connecting member 15. ing.
[0016]
The connecting member 15 includes a plate-like piece 15a fixed to the timing belt 13 with a rivet or the like and an annular piece 15b fixed to the proximal end of the operation wire 5, and the annular piece 15b is formed in the plate-like piece 15a. By being loosely passed through the hole, the proximal end portion of the operation wire 5 can freely rotate around an axis parallel to the axis of the driven sprocket gear 12.
[0017]
In order to avoid interference with the connecting member 15 and the operation wire 5, as shown in FIG. 4, an outer peripheral groove 12 a that is recessed from both side portions is formed in the portion near the center of the tooth width of the driven sprocket gear 12. It is formed all around.
[0018]
Although not shown in the figure, the driving sprocket gear 11 is also formed in the same shape, and the connection belt 15 and the operation wire 5 are connected to the lower half of the timing belt 13 near the center. A slit 13a is formed to avoid interference.
[0019]
In the bending operation apparatus for an endoscope configured as described above, the driving sprocket gear 11 is rotationally driven by rotating the bending operation knob 6, thereby being connected to the timing belt 13 as shown in FIG. 1. One operation wire 5a of the pair of operation wires 5 thus pulled is pulled toward the driving sprocket gear 11 and the other operation wire 5b is pushed back.
[0020]
Then, the connecting member 15 of the operation wire 5a on the pulling side is pulled to a position along the outer periphery of the driving sprocket gear 11, and the connecting member 15 of the operation wire 5b on the pushed back side is returned to a position along the outer periphery of the driven sprocket gear 12. .
[0021]
At this time, the movement stroke of the operation wire 5b on the pushed back side is smaller than the movement stroke of the operation wire 5a on the towing side. By doing so, the amount of pushing back is shortened and the slack of the operation wire 5 is absorbed.
[0022]
Thus, by configuring the connecting member 15 of the operation wire 5b to be pushed back along the outer periphery of the driven sprocket gear 12, the entire length of the bending operation mechanism 10 can be shortened. Even if the operation unit 1 is downsized, a sufficient bending stroke can be secured.
[0023]
The annular piece 15b fixed to the proximal end portion of the operation wire 5b on the pushed back side can freely rotate around the axis parallel to the axis of the driven sprocket gear 12 with respect to the plate-like piece 15a. The operation wire 5b on the pushed back side maintains a natural direction and is not subjected to an excessive force.
[0024]
【The invention's effect】
According to the present invention, the base end portion of the operation wire is connected to the timing belt so that the base end portion of the operation wire pushed back when the driving sprocket gear is driven to rotate moves along the outer periphery of the driven sprocket gear. Thus, the length of the bending operation mechanism can be shortened, and a sufficient bending stroke can be ensured even with a small operation unit.
[Brief description of the drawings]
FIG. 1 is a plan view of a bending operation state of an bending operation apparatus for an endoscope according to an embodiment of the present invention.
FIG. 2 is an external view showing an overall configuration of an endoscope according to an embodiment of the present invention.
FIG. 3 is a plan view showing a part of the bending operation apparatus for an endoscope according to the embodiment of the present invention in cross section.
FIG. 4 is a partial perspective view of the bending operation device for the endoscope according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Operation part 2 Insertion part 3 Bending part 5 Operation wire 5a Pulling-side operation wire 5b Push-back side operation wire 6 Bending operation knob 10 Bending operation mechanism 11 Driving sprocket gear 12 Driven sprocket gear 12a Outer peripheral groove 13 Timing belt 13a Slit 15 Connecting member 15a Plate-like piece 15b Annular piece

Claims (2)

Since the bending portion provided at the distal end portion of the insertion portion of the endoscope is bent by remote operation, the pair of operation wires having the distal ends connected to the bending portion can be selectively pulled. A bending operation device for an endoscope provided in an operation unit connected to a proximal end of an insertion unit,
A driving sprocket gear that is rotationally driven by an operating member; a driven sprocket gear that is disposed with a gap between the driving sprocket gear; and, by rotating the aforementioned driver sprocket gear, endoscopic one of the pair of operation wires having a base end portion is connected to the timing belt is so other is pushed back, driven by the driver sprocket gear side In the mirror bending operation device,
A base end portion of each operation wire is connected to the timing belt in a state in which it can rotate around an axis parallel to the axis of the driven sprocket gear,
A bending operation device for an endoscope, characterized in that a proximal end portion of an operation wire on a side pushed back when the driving sprocket gear is driven to rotate moves along an outer periphery of the driven sprocket gear. The connecting member that connects the base end portion of the operation wire and the timing belt includes a plate-like piece attached to the timing belt and an annular piece attached to the base end of the operation wire, and the plate-like piece The bending operation apparatus for an endoscope according to claim 1, wherein the annular piece is loosely passed through a hole drilled in the endoscope.

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