WO2019146068A1

WO2019146068A1 - Endoscope

Info

Publication number: WO2019146068A1
Application number: PCT/JP2018/002472
Authority: WO
Inventors: 紀明山中
Original assignee: オリンパス株式会社
Priority date: 2018-01-26
Filing date: 2018-01-26
Publication date: 2019-08-01

Abstract

An endoscope (1) includes: an insertion part (5) that has a bendable portion (7) on the tip thereof; a wire (9) that is disposed along the longitudinal axis of the insertion part (5) and transmits tension; a pulley (8) that is disposed on the base end of the insertion part (5) and has the wire (9) wound thereover; an actuator (10) that generates a rotary drive force; a flexible shaft (11) that transmits the rotary drive force generated by the actuator (10); a first speed reducing mechanism that slows the rotation of the flexible shaft (11); and a second speed reducing mechanism that further slows the rotation slowed by the first speed reducing mechanism and transmits same to the pulley (8).

Description

Endoscope

The present invention relates to an endoscope.

Conventionally, in an endoscope in which the bending portion at the tip of the elongated insertion portion is bent by the power transmitted by the wire disposed along the longitudinal direction of the insertion portion, the torque generated by the motor is transmitted to the wire through the flexible shaft The endoscope which does is known, for example (, patent literature 1 reference).
The flexible shaft has different transmittable torque magnitudes depending on the twisting direction, so the endoscope of Patent Document 1 prepares two flexible shafts having different twisting directions and attempts to transmit the flexible shafts. Two flexible shafts are used according to the direction.

Unexamined-Japanese-Patent No. 2010-213969

However, in the case of using two flexible shafts for power transmission, there is a disadvantage that the flexibility of the connection portion connecting the motor and the endoscope main body is lost. In order to avoid this, it is necessary to reduce the diameter of the flexible shaft, but simply reducing the diameter reduces the transmittable torque, and there is a disadvantage that sufficient strength can not be maintained.

The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to provide an endoscope capable of achieving both sufficient flexibility and strength of a connection portion connecting an actuator and an endoscope main body. The purpose is.

One aspect of the present invention is an insertion portion having a curved portion at its tip, a wire disposed along the longitudinal axis of the insertion portion for transmitting tension, and a pulley disposed at the proximal end of the insertion portion for winding the wire. An actuator for generating a rotational drive force, a flexible shaft for transmitting the rotational drive force generated by the actuator, a first reduction gear mechanism for decelerating the rotation of the flexible shaft, and a rotation reduced by the first reduction gear mechanism And a second decelerating mechanism for decelerating and transmitting the same to the pulley.

According to this aspect, when the actuator is operated to generate the rotational drive force, the rotational drive force generated by the actuator is input to the first reduction gear mechanism by the flexible shaft. The rotational driving force transmitted by the flexible shaft is decelerated by the first decelerating mechanism, decelerated again by the second decelerating mechanism, transmitted to the pulley, and is along the longitudinal axis of the insertion portion by the wire wound around the pulley. By transmitting tension, the bending portion disposed at the distal end of the insertion portion is bent.

In addition, since the rotational driving force transmitted by the flexible shaft is decelerated and transmitted to the pulley, even if the rotational driving force transmittable by the flexible shaft is small, the curved portion at the tip of the insertion portion is driven with a large driving force. be able to. That is, even if the flexible shaft is made thin, sufficient strength can be secured, and sufficient flexibility and strength of the connection portion connecting the actuator and the endoscope main body can be achieved.

In the above aspect, the first reduction gear mechanism and the second reduction gear mechanism may reduce the rotation of the flexible shaft to 1⁄4 or less.
In this way, sufficient rotational driving force can be transmitted while maintaining the soundness of the flexible shaft.

In the above aspect, the first reduction gear mechanism and the second reduction gear mechanism may reduce the rotation of the flexible shaft to 1⁄8 or less.
By doing this, it is possible to transmit the rotational driving force to operate the bending portion smoothly.

In the above aspect, at least one of the first reduction gear and the second reduction gear may be a planetary gear reducer.
In this way, a sufficiently large reduction ratio can be secured with a compact configuration, and sufficient rotational driving force can be transmitted.

Further, in the above aspect, the second reduction mechanism may be a planetary gear reducer.
In this way, the reduction gear mechanism can be made smaller by configuring the second reduction gear mechanism on the output side to the pulley, which requires a large rotational driving force, from the planetary gear reducer.

In the above aspect, the reduction gear ratio of the second reduction gear mechanism may be larger than the reduction gear ratio of the first reduction gear mechanism.
In this way, a large reduction ratio can be obtained in a narrow space by making the reduction ratio of the second reduction mechanism disposed on the output side to the pulley larger than the reduction ratio of the first reduction mechanism on the input side. Can.

In the above aspect, the first reduction gear mechanism may include a gear made of resin.
In the above aspect, the first reduction gear mechanism and the second reduction gear mechanism may be provided with a gear made of resin.
By doing this, it is possible to operate the curve more smoothly by suppressing the fluctuation of the rotational driving force transmitted by the elastic deformation of the resin gear.

Further, in the above aspect, the input shafts of the first reduction gear mechanism and the second reduction gear mechanism may not be arranged on the same straight line.
By doing this, the first reduction gear mechanism and the second reduction gear mechanism can be arranged in parallel in the direction crossing the input shaft, and the dimension in the direction along the input shaft can be reduced to achieve thinning. Can. In addition, the input side to the first reduction gear mechanism and the output side to the second reduction gear mechanism can be arranged on the same side.

In the above aspect, the planetary gear reducer includes a sun gear and a plurality of planet gears simultaneously meshing with the sun gear, and the product of the number of each planetary gear and the number of teeth of each planetary gear is 360. The sun gear may be meshed with a phase shifted by an angle divided by °.
By doing this, the meshing state of the plurality of planetary gears meshing with the same sun gear with the sun gear can be averaged to suppress the fluctuation of the transmission efficiency, and the curved portion can be operated more smoothly.

In the above aspect, the first reduction gear mechanism and the second reduction gear mechanism may have gears, and the gears may be helical gears.
By so doing, a plurality of teeth can be meshed simultaneously, fluctuations in transmission efficiency can be suppressed, and the curved portion can be operated more smoothly.

In the above aspect, the flexible shaft may transmit rotation in both directions with one.
In this way, sufficient flexibility of the connecting portion for connecting the actuator and the endoscope main body can be secured.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram which shows the endoscope which concerns on one Embodiment of this invention. It is a front view explaining the deceleration mechanism of the endoscope of FIG. It is a top view of the deceleration mechanism of FIG. It is a figure which shows the time change of the angle of a bending part in case the reduction gear of the deceleration mechanism of the endoscope of FIG. 1 is 4: 1. It is a figure which shows the time change of the angle of a bending part in case the reduction gear of the deceleration mechanism of the endoscope of FIG. 1 is 8: 1. It is a modification of the endoscope of FIG. 1, Comprising: It is a schematic diagram which shows the case where a reduction mechanism is provided with two planetary gear reduction gears. It is a modification of the endoscope of FIG. 1, Comprising: It is a schematic diagram which shows the case where a decelerating mechanism equips an output side with a planetary gear reducer. It is a modification of the endoscope of FIG. 1, Comprising: It is a schematic diagram which shows the case where a decelerating mechanism equips an input side with a planetary gear reducer. It is a modification of the endoscope of FIG. 1, Comprising: It is a schematic diagram which shows the case where the direction of an input axis and an output axis is the same. It is a top view which shows the modification of the deceleration mechanism of FIG. It is a longitudinal cross-sectional view of the operation part of the endoscope of FIG.

An endoscope 1 according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the endoscope 1 according to the present embodiment is provided with an endoscope body 2 and a rotational driving force installed at a position separated from the endoscope body 2 and driving the endoscope body 2. And a connection unit 4 for connecting the endoscope main body 2 and the drive unit 3.

The endoscope main body 2 includes an elongated insertion portion 5 having an observation optical system (not shown) at its tip, and an operation portion 6 disposed at a proximal end of the insertion portion 5 and operated by the operator. The distal end portion of the insertion portion 5 is provided with a bending portion 7 for moving the distal end of the insertion portion 5 in a direction intersecting the longitudinal axis.
A sensor (encoder: see FIG. 11) 65 connected to the lever is built in the operation unit 6 so as to detect the amount of rotation or the direction of the force.

Alternatively, assist driving may be performed. A wire 9 whose tip is connected to the bending portion 7 is wound around the pulley 8. When the pulley 8 is rotated about the rotation axis, the tension is transmitted by the wire 9 and the bending portion 7 is bent by the tension.

The drive unit 3 is provided with a motor 10 and a control unit (not shown) for controlling the motor 10.
The control unit operates the motor 10 based on the lever operation of the operator detected by the sensor provided in the operation unit 6, and causes the motor 10 to have a rotational driving force for the bending operation of the bending portion 7 by the lever operation of the operator. It is supposed to generate.

The connection portion 4 includes a single flexible shaft 11 whose proximal end is connected to the motor 10 and a speed reduction mechanism 12 connected to the distal end of the flexible shaft 11. The flexible shaft 11 is, for example, a metal coil tube, has rigidity capable of transmitting a twisting torque, has flexibility capable of bending in an arbitrary shape, and the operator holds the operation unit 6 When moved, the movement of the operation unit 6 is not inhibited by curving according to the movement.

In the present embodiment, as shown in FIGS. 2 and 3, the reduction gear mechanism 12 includes an input gear 13 rotationally driven by torsional rotation of the flexible shaft 11, and an intermediate gear member 14 meshed with the input gear 13. The intermediate gear member 14 meshes with an output gear 15 fixed to the pulley 8. The intermediate gear member 14 has a first gear 16 meshing with the input gear 13 and a second gear 17 meshing with the output gear 15 fixed to the same rotation shaft.

The number of teeth of the input gear 13 is sufficiently smaller than the number of teeth of the first gear 16, and the number of teeth of the second gear 17 is set sufficiently smaller than the number of teeth of the output gear 15. Thus, the input gear 13 and the first gear 16 constitute a first reduction mechanism with a first reduction ratio, and the second gear 17 and the output gear 15 constitute a second reduction mechanism with a second reduction ratio. ing.
In the present embodiment, the total reduction ratio of the first reduction mechanism and the second reduction mechanism is 4: 1 or more.

The operation of the endoscope 1 according to the present embodiment configured as described above will be described below.
In order to observe the inside of the patient's body using the endoscope 1 according to the present embodiment, the insertion portion 5 is inserted into the body cavity from the distal end side, and the observation optical system at the distal end is opposed to the affected area.

In this state, when the operator grips the operation unit 6 and operates the lever 64, the added amount of rotation is detected by the sensor, a detection signal from the sensor is sent to the drive unit 3, and the control unit activates the motor 10. Be When the motor 10 is operated, the rotational driving force of the motor 10 is input to the flexible shaft 11, and the flexible shaft 11 is twisted to transmit the rotational driving force. Then, the rotational driving force transmitted by the flexible shaft 11 is input to the input shaft 18 disposed at the tip of the flexible shaft 11, and the input shaft 18 is rotationally driven.

When the input shaft 18 is rotated, the intermediate gear member 14 having the first gear 16 meshing with the input gear 13 fixed to the input shaft 18 is rotated, and an output meshing with the second gear 17 fixed to the intermediate gear member 14 The output shaft 19 to which the gear 15 is fixed is rotated. The rotation of the input shaft 18 is decelerated according to a first reduction ratio, which is a gear ratio of the input gear 13 and the first gear 16, to rotate the intermediate gear member 14. The pulley fixed at the output shaft 19 rotates the output shaft 19 by being decelerated according to the second reduction ratio, which is the gear ratio of the second gear 17 and the output gear 15, for the rotation of the intermediate gear member 14. Rotate 8

That is, since the rotation of the flexible shaft 11 is reduced in two steps by the reduction mechanism 12 and transmitted to the pulley 8, the reduction can be performed at a large reduction ratio even if the reduction ratio of each step is small. As a result, the reduction gear mechanism 12 can be made compact, and the operation of the operation unit 6 by the operator can be facilitated. Further, since the motor is decelerated at a large reduction ratio, there is an advantage that the bending portion 7 can be bent with a sufficient force even if a flexible shaft having a small diameter and capable of transmitting only a small rotational driving force is used as the flexible shaft 11. Thereby, the flexibility of the connection part 4 provided with the flexible shaft 11 can be ensured, and the ease of operation of the operation part 6 by the operator can be improved.

In addition, since the reduction ratio of the reduction mechanism 12 including the first reduction mechanism and the second reduction mechanism is set to 4: 1 or more, the allowable torque of the flexible shaft 11 is 1/1 of the torque necessary for the bending of the bending portion 7 It can be 4 or less. If the speed reduction ratio is smaller than 4: 1, the allowable torque required for the flexible shaft 11 is increased, so that a larger thickness is required, and the flexibility is reduced to deteriorate the operability.

By setting the reduction ratio of the reduction mechanism 12 consisting of the first reduction mechanism and the second reduction mechanism to 8: 1 or more, as compared with the case where the reduction ratio shown in FIG. 4 is 4: 1, FIG. There is an advantage that the movement of the bending portion 7 can be made smoother as shown in FIG.

In the present embodiment, a two-stage gear mechanism is adopted as the reduction mechanism 12, but instead, as shown in FIGS. 6 to 8, at least one of the first reduction mechanism and the second reduction mechanism May be constituted by the planetary gear reducer 20.
The planetary gear reducer 20 can obtain a large reduction ratio with a compact configuration, and can achieve downsizing of the operation unit 6 to improve operability, and can reduce the diameter of the flexible shaft 11. There is.

In particular, by configuring the second reduction mechanism connected to the pulley 8 with the planetary gear reducer 20, the high strength planetary gear reducer 20 is disposed on the output side with a large required torque, and the reduction mechanism 12 is miniaturized. It has the advantage of being able to

Moreover, in order to obtain the gear strength of the reduction mechanism 12, it is preferable to increase the diameter and thickness of the gear, but in order to realize the same operability while maintaining the size of the operation portion 6 of the endoscope 1. In view of the structure inside the holding portion, the outer diameter of the speed reduction mechanism 12 is required to be accommodated in the space in the operation portion 6 and to be thin. Therefore, the gear diameter is secured as much as possible within the structural constraints to reduce the thickness.

By configuring the second reduction mechanism with the planetary gear reducer 20, it is possible to reduce the thickness of the spur gear by load distribution, but if the reduction ratio of the first reduction mechanism is equal to or greater than the reduction ratio of the second reduction mechanism, Since the load on the gear teeth of the reduction gear is not reduced, it can not be thinned. By making the reduction ratio of the second reduction mechanism larger than the reduction ratio of the first reduction mechanism, the load applied to the teeth of the gear of the first reduction mechanism can be reduced, and the thickness of the first reduction mechanism can be reduced. As a result, while high speed reduction is realized, both the first speed reduction mechanism and the second speed reduction mechanism can be thinned, the speed reduction mechanism 12 can be miniaturized, and a certain operability can be maintained.

Further, as shown in FIG. 7 to FIG. 9, the input shaft 18 of the rotational drive force to the first reduction gear mechanism and the output shaft 19 of the rotational drive force from the second reduction gear mechanism are arranged on the same straight line Preferably not. By doing this, the first speed reduction mechanism and the second speed reduction mechanism can be arranged in parallel in the direction intersecting the input shaft 18, as compared with the case where they are arranged coaxially as shown in FIG. Thus, the dimension in the direction along the input shaft 18 can be reduced to achieve thinning. Further, as shown in FIG. 9, the input side to the first reduction gear mechanism and the output side to the second reduction gear mechanism can be disposed on the same side.

When the planetary gear reducer 20 is used, it is preferable that a plurality of planetary gears 22 meshing with a single sun gear 21 be arranged so as to be shifted little by little in the circumferential direction. For example, in the case where the number of teeth of the planetary gear 22 is 20, the phase is the same when it is shifted by 18 ° with respect to the sun gear 21. Therefore, when the number of the planetary gears 22 is 5, 18 ° / 5 = 3.6 It may be arranged to be out of phase by degrees. As a result, the meshing state of the planetary gear 22 and the sun gear 21 is averaged, and there is an advantage that fluctuations in transmission efficiency can be suppressed. As a result, there is an advantage that the output shaft 19 can be smoothly rotated according to the rotation of the input shaft 18.

The operation in the case of using the planetary gear reducer 20 will be described in more detail. As the wire 9, as shown in FIG. 11, the manual wires 91 and 92 and the electric wire 93 are provided. In addition, the operation unit 6 pulls the manual wire 91 based on the operation input by the operator to bend the bending portion 7 in one direction, the RL knob 62, and the manual wire 92 based on the operation input by the operator. A UD knob 63 which pulls and bends the bending portion 7 in the other direction crossing the bending direction by the RL knob 62, and an electric pulling of the electric wire 93 causes the bending portion 7 in the same direction as the bending direction by the UD knob 63 And a lever 64 for bending. In the figure, reference numeral 65 denotes an encoder for detecting the rotation angle of the lever 64.

In this case, by manually operating the RL knob 62 and the UD knob 63 by the operator, the manual wires 91 and 92 are pulled based on the operation input, and the bending portion 7 is bent in any direction. ing. Further, when the operation input of the lever 64 is detected by the encoder 65 by operating the lever 64, the power from the motor 10 is input to the gear 66 via the drive shaft 68, and the gear 66 operates to rotate. Power is transmitted to the unit 67. The power transmitted to the operation unit 67 is transmitted to the reduction mechanism 12 to reduce its rotation.

The pulley 8 is rotated by the planetary gear reducer 20 which is the first reduction mechanism and the second reduction mechanism of the reduction mechanism 12 and the pulley 8 is rotated, and the electric wire 93 is pulled by the rotation of the pulley 8. When the electric wire 93 is pulled, the bending portion 7 is bent in the other direction. By doing this, there is an advantage that the bending portion 7 can be operated efficiently by decelerating while maintaining the operability of the operation portion 6.

Even when the planetary gear reducer 20 is not used, two intermediate gear members 14 may be provided as shown in FIG. 10 to shift the phase of meshing. By doing this, there is an advantage that the meshing state can be averaged, and fluctuations in transmission efficiency can be suppressed. As a result, there is an advantage that the output shaft 19 can be smoothly rotated according to the rotation of the input shaft 18.

Further, in the present embodiment, the second reduction mechanism may be configured by a wave gear reducer. As a result, the meshing force is dispersed at two or more points, and the motor is decelerated according to the ratio of the number difference between the internal gear and the wave gear, so that there is an advantage that further downsizing can be achieved while greatly decelerating.

Moreover, it may replace with a spur gear as a gearwheel, and may employ | adopt a helical gear. There is an advantage that the meshing of the teeth can be made smooth and the output shaft 19 can be smoothly rotated according to the rotation of the input shaft 18.

Also, instead of metal gears, resin gears may be adopted. Only the gear of the first reduction mechanism with small torque transmission may be a resin gear, or if the second reduction mechanism is configured by the planetary gear reducer 20, the gear of the second reduction mechanism may also be a resin gear. It may be configured by By elastically deforming the gear itself, there is an advantage that fluctuation of the transmission efficiency can be suppressed and the output shaft 19 can be rotated smoothly.

When the planetary gear reducer 20 is employed, it is preferable to set the number of the planetary gears 22 to two or more and six or less when the reduction ratio is 8: 1. Thereby, a large reduction ratio can be obtained in a narrow space.

Further, in the present embodiment, the motor 10 generating the rotational driving force is exemplified as the actuator, but instead, a linear moving motor or a cylinder generating the linear driving force may be employed. Moreover, although the torque wire was illustrated as the flexible shaft 11, it may replace with this and may employ | adopt the wire which consists of a torque tube or a strand wire.

Moreover, although illustrated about the case where it has the single flexible shaft 11 in this embodiment, it may replace with this and may be provided with two flexible shafts 11. Thereby, the allowable torque of the flexible shaft 11 can be further suppressed, and the thinner flexible shaft 11 can be used.

Reference Signs List 1 endoscope 5 insertion portion 7 bending portion 8 pulley 9 wire 10 motor (actuator)
11 flexible shaft 13 input gear (first reduction mechanism)
15 Output gear (2nd reduction mechanism)
16 First gear (first reduction mechanism)
17 Second gear (second reduction mechanism)
18 input shaft 20 planetary gear reducer 21 sun gear 22 planetary gear

Claims

An insertion part provided with a curved part at its tip,
A wire disposed along the longitudinal axis of the insert for transmitting tension;
A pulley disposed at the proximal end of the insertion portion and configured to wind the wire;
An actuator that generates a rotational driving force,
A flexible shaft for transmitting a rotational drive force generated by the actuator;
A first reduction mechanism that reduces the rotation of the flexible shaft;
An endoscope comprising: a second decelerating mechanism for further decelerating the rotation decelerated by the first decelerating mechanism and transmitting the rotation to the pulley.
The endoscope according to claim 1, wherein the first reduction gear mechanism and the second reduction gear mechanism reduce the rotation of the flexible shaft to 1/4 or less.
The endoscope according to claim 2, wherein the first reduction gear mechanism and the second reduction gear mechanism reduce the rotation of the flexible shaft to 1/8 or less.
The endoscope according to any one of claims 1 to 3, wherein at least one of the first reduction mechanism and the second reduction mechanism is a planetary gear reducer.
The endoscope according to any one of claims 1 to 3, wherein the second reduction mechanism is a planetary gear reducer.
The endoscope according to claim 4 or 5, wherein a reduction ratio of the second reduction mechanism is larger than a reduction ratio of the first reduction mechanism.
The endoscope according to any one of claims 4 to 6, wherein the first reduction gear mechanism comprises a resin gear.
The endoscope according to claim 5 or 6, wherein the first decelerating mechanism and the second decelerating mechanism include gear wheels made of resin.
The endoscope according to any one of claims 4 to 8, wherein the input shafts of the first reduction gear mechanism and the second reduction gear mechanism are not arranged on the same straight line.
The planetary gear reducer includes a sun gear and a plurality of planet gears simultaneously meshing with the sun gear, and the shift is an angle divided by 360 ° by the product of the number of each planet gear and the number of teeth of each planet gear. The endoscope according to any one of claims 4 to 9, meshing with the sun gear in a different phase.
The endoscope according to any one of claims 1 to 10, wherein the first reduction gear mechanism and the second reduction gear mechanism have gears, and the gear is a helical gear.
The endoscope according to any one of claims 1 to 11, wherein the flexible shaft transmits rotation in both directions with one.