阅读说明：本技术 屈曲机构和医疗用机械手 (Buckling mechanism and medical manipulator ) 是由 高山裕行 于 2017-06-08 设计创作，主要内容包括：以避免过大的应力作用于各部且实现插入部的细径化为目的,本发明的屈曲机构(5)具有：细长的支承部件(6)；摆动部件(7),其以能够绕与长度轴交叉的轴线摆动的方式支承于支承部件的前端；驱动力传递部件(8a、8b),其沿着支承部件的长度轴配置,传递在基端施加的驱动力,使摆动部件摆动；以及应力调节部(15),其进行调节,以使得在摆动部件相对于支承部件的各摆动位置,驱动力传递部件中产生的应力不会超过规定的阈值,驱动力传递部件具有与摆动部件连接的第1传递部件(9a、9b)、以及配置于比第1传递部件更靠基端侧的第2传递部件(14a、14b),应力调节部具有在第1传递部件和第2传递部件在长度轴方向上相对移动时在规定的方向上移动的可动部件(16)、以及在阻碍可动部件的移动的方向上施力的施力部件(17)。(In order to avoid excessive stress acting on each part and to reduce the diameter of the insertion part, the buckling mechanism (5) of the present invention comprises: an elongated support member (6); a swinging member (7) supported at the front end of the support member in a manner of swinging around an axis crossed with the length shaft; driving force transmission members (8a, 8b) which are arranged along the longitudinal axis of the support member, transmit the driving force applied to the base end, and swing the swing member; and a stress adjustment unit (15) that adjusts so that stress generated in the driving force transmission member does not exceed a predetermined threshold value at each swing position of the swing member relative to the support member, the driving force transmission member including a 1 st transmission member (9a, 9b) connected to the swing member and a 2 nd transmission member (14a, 14b) disposed on the base end side of the 1 st transmission member, the stress adjustment unit including a movable member (16) that moves in a predetermined direction when the 1 st transmission member and the 2 nd transmission member move relative to each other in the longitudinal axis direction, and a biasing member (17) that biases in a direction that blocks the movement of the movable member.)

1. A buckling mechanism having:

an elongated support member;

a swinging member supported at the tip of the support member so as to be capable of swinging about an axis intersecting the longitudinal axis of the support member;

a driving force transmission member that is disposed along the longitudinal axis of the support member, transmits a driving force applied to a base end, and swings the swing member with respect to the support member; and

a stress adjustment unit that adjusts stress generated in the driving force transmission member so that the stress does not exceed a predetermined threshold value at each rocking position of the rocking member with respect to the support member,

the driving force transmission member includes: a 1 st transmission member disposed on a distal end side and connected to the swing member; and a 2 nd transmission member disposed on the base end side of the 1 st transmission member,

the stress adjustment portion has: a movable member that moves in a predetermined direction when the 1 st transmission member and the 2 nd transmission member move relative to each other in the longitudinal axis direction; and a biasing member that biases in a direction that hinders movement of the movable member.

2. The buckling mechanism as recited in claim 1,

the stress adjustment unit allows the 1 st transmission member to move in a direction to reduce the stress generated in the driving force transmission member when the stress reaches the threshold value.

3. The buckling mechanism as claimed in claim 1 or 2,

the threshold value is set to a different value depending on the swing angle of the swing member with respect to the support member.

4. The buckling mechanism as recited in claim 3,

the buckling mechanism includes an operation portion that swings the swing member relative to the support member at an angle corresponding to an operation amount,

the threshold value is set to different values according to the operation amount.

5. The buckling mechanism as recited in claim 4,

the buckling mechanism has an acting force adjusting mechanism that adjusts the acting force of the force application member in accordance with the operation amount.

6. The buckling mechanism as claimed in any one of claims 1 to 5, wherein,

the driving force transmission member is capable of transmitting the driving force in two directions along the longitudinal axis of the support member.

7. The buckling mechanism as claimed in any one of claims 1 to 6,

a cam portion is provided on the base end of the 1 st transmission member,

the movable member is attached to a distal end of the 2 nd transmission member so as to be movable in a direction orthogonal to the longitudinal axis,

the movable member is provided with 2 inclined surfaces which are inclined in different directions with respect to 2 directions of a moving direction of the movable member and a direction of the longitudinal axis of the support member and abut against the cam portion.

8. The buckling mechanism as claimed in any one of claims 1 to 6,

the movable member has:

a crank supported to be swingable about a predetermined axis; and

and a lever member that swings by the swing of the crank.

9. A medical manipulator includes:

the buckling mechanism as claimed in any one of claims 1 to 8; and

and a treatment instrument attached to the swing member.

Technical Field

The present invention relates to a buckling mechanism and a medical manipulator.

Background

The following medical manipulator is known: a distal end portion of the elongated insertion portion has a flexion joint for changing the direction of the treatment instrument positioned at the distal end (see, for example, patent document 1).

The medical manipulator is disposed along the insertion portion, and swings the swing member by pushing and pulling 2 links connected to the swing member on the distal end side of the flexion joint, thereby swinging the treatment instrument fixed to the swing member.

Disclosure of Invention

Problems to be solved by the invention

However, in the medical manipulator of patent document 1, when a large external force is applied to the distal end of the treatment instrument, the stress applied to one link may be excessive, and in order to improve durability, it is necessary to thicken 2 links, which is a disadvantage that it is difficult to reduce the diameter of the insertion portion.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a buckling mechanism and a medical manipulator capable of avoiding excessive stress from acting on each portion and reducing the diameter of an insertion portion.

Means for solving the problems

One aspect of the present invention is a buckling mechanism including: an elongated support member; a swinging member supported at the tip of the support member so as to be capable of swinging about an axis intersecting the longitudinal axis of the support member; a driving force transmission member that is disposed along the longitudinal axis of the support member, transmits a driving force applied to a base end, and swings the swing member with respect to the support member; and a stress adjustment unit that adjusts stress generated in the driving force transmission member so that the stress does not exceed a predetermined threshold value at each of rocking positions of the rocking member with respect to the support member, the driving force transmission member including: a 1 st transmission member disposed on a distal end side and connected to the swing member; and a 2 nd transmission member disposed closer to the base end side than the 1 st transmission member, the stress adjustment portion including: a movable member that moves in a predetermined direction when the 1 st transmission member and the 2 nd transmission member move relative to each other in the longitudinal axis direction; and a biasing member that biases in a direction that hinders movement of the movable member.

According to this aspect, when the driving force is applied to the driving force transmitting member on the proximal end side of the support member, the driving force transmitted by the driving force transmitting member is transmitted to the swinging member, and the swinging member swings around the axis at the distal end of the support member. In this case, the stress generated in the driving force transmitting member is adjusted by the operation of the stress adjusting portion so that the stress does not exceed a predetermined threshold value at each rocking position of the rocking member with respect to the support member.

Thus, even if the rigidity of the swing member varies according to the swing angle, excessive stress can be prevented from acting on each part. In this case, since the stress itself is adjusted instead of increasing the rigidity of each portion to increase the stress, such as the driving force transmission member, it is possible to reduce the diameter of the insertion portion while preventing an increase in the cross-sectional dimension of each portion.

That is, in a state where excessive stress is not applied to the driving force transmission member, the urging force of the urging member maintains the movable member not to move, the 1 st transmission member and the 2 nd transmission member are fixed so as not to move relative to each other, and the driving force applied to the base end of the 2 nd transmission member is directly transmitted to the 1 st transmission member, thereby swinging the swinging member. On the other hand, when excessive stress acts on the driving force transmission member, the movable member moves against the urging force of the urging member, so that the 1 st transmission member and the 2 nd transmission member move relatively in the longitudinal axis direction. This can alleviate the stress acting on the driving force transmission member.

In the above aspect, the stress adjustment unit may allow the 1 st transmission member to move in a direction to reduce the stress generated in the driving force transmission member when the stress becomes the threshold value.

Thus, when stress of a predetermined threshold value is generated in the driving force transmission member, the stress adjustment unit allows the 1 st transmission member to move in a direction to reduce the stress, and avoids the application of excessive stress exceeding the predetermined threshold value.

In the above aspect, the threshold value may be set to a different value depending on a swing angle of the swing member with respect to the support member.

Accordingly, the threshold value is increased for a swing angle having high rigidity and decreased for a swing angle having low rigidity in accordance with rigidity that varies according to the swing angle of the swing member, and thus, excessive stress can be prevented from acting on each part.

In the above aspect, the buckling mechanism may include an operating portion that swings the swing member relative to the support member at an angle corresponding to an operation amount, and the threshold value may be set to a value different depending on the operation amount.

Accordingly, the threshold value is increased for a swing angle having high rigidity and decreased for a swing angle having low rigidity in accordance with the rigidity that varies in accordance with the swing angle of the swing member in accordance with the operation amount of the operation unit, and thus, it is possible to prevent excessive stress from acting on each portion.

In the above aspect, the buckling mechanism may include an urging force adjustment mechanism that adjusts the urging force of the urging member in accordance with the operation amount.

Thus, the adjustment of the biasing force of the biasing member by the biasing force adjustment mechanism can be easily set as follows: the threshold is increased for a swing angle having a high rigidity and decreased for a swing angle having a low rigidity in accordance with the rigidity that varies in accordance with the swing angle of the swing member.

In the above aspect, the driving force transmitting member may be configured to transmit the driving force in two directions along the longitudinal axis of the support member.

This prevents excessive stress from being generated in any direction when driving force is transmitted in both directions in the longitudinal axis direction of the support member.

In the above aspect, a cam portion may be provided at a base end of the 1 st transmission member, the movable member may be movably attached to a tip end of the 2 nd transmission member in a direction orthogonal to the longitudinal axis, and the movable member may be provided with 2 inclined surfaces that are inclined in a direction different from 2 directions of a moving direction of the movable member and a direction of the longitudinal axis of the support member and abut against the cam portion.

Accordingly, the driving force is transmitted by the contact between the cam portion and the inclined surface in a state where the movable member does not move, and when the movable member moves due to an increase in stress, the contact position between the cam portion and the inclined surface changes, and the 1 st transmission member and the 2 nd transmission member move relative to each other in the longitudinal axis direction, whereby the stress acting on the driving force transmission member can be relaxed.

In the above aspect, the movable member may include: a crank supported to be swingable about a predetermined axis; and a lever member that swings by the swing of the crank.

Thus, the crank is swung in any one direction around the predetermined axis by the relative movement in the longitudinal axis direction of the 1 st transmission member and the 2 nd transmission member, and the lever member is swung in one direction by the swing of the crank. The urging member acts in a direction of inhibiting the swing of the lever member, and therefore inhibits the swing of the crank until the stress of the driving force transmission member reaches a threshold value, and when the stress reaches the threshold value, the crank swings, the 1 st transmission member and the 2 nd transmission member move relatively in the longitudinal axis direction, and the stress acting on the driving force transmission member can be relaxed.

Another aspect of the present invention is a medical manipulator including: the buckling mechanism of any one of the above; and a treatment instrument attached to the swing member.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the effect of reducing the diameter of the insertion portion can be achieved while avoiding excessive stress from acting on each portion.

Drawings

Fig. 1 is an overall configuration diagram illustrating a medical manipulator according to an embodiment of the present invention.

Fig. 2 is a plan view showing an operation portion of the medical manipulator of fig. 1.

Fig. 3 is a partial plan view illustrating the operation of the operation unit when an external force of a predetermined magnitude or more is applied to the distal end of the medical manipulator of fig. 1.

Fig. 4 is a graph showing a relationship between the allowable axial force and the bending angle of each of the inner 1 st link and the outer 1 st link of the medical manipulator of fig. 1.

Fig. 5 is a plan view illustrating the operation of the operation unit of the medical manipulator of fig. 1.

Fig. 6 is a plan view showing a 1 st modification of the medical manipulator of fig. 1.

Fig. 7 is a plan view showing a 2 nd modification of the medical manipulator of fig. 1.

Fig. 8 is a plan view showing a 3 rd modification of the medical manipulator of fig. 1.

Fig. 9 is a partial plan view illustrating the operation of the medical manipulator of fig. 8 in one direction.

Fig. 10 is a plan view showing a 4 th modification of the medical manipulator of fig. 1.

Fig. 11 is a partial plan view illustrating the operation of the medical manipulator of fig. 10.

Detailed Description

The buckling mechanism 5 and the medical manipulator 1 according to one embodiment of the present invention will be described below with reference to the drawings.

As shown in fig. 1, a medical manipulator 1 of the present embodiment includes a treatment instrument 2 for treating an affected part, an elongated insertion portion 3, and an operation portion 4 connected to a proximal end of the insertion portion 3. The insertion portion 3 and the operation portion 4 constitute a buckling mechanism 5. The treatment instrument 2 is attached to a swinging member 7 of the insertion portion 3 described later.

As shown in fig. 1, the insertion portion 3 has: an elongated support member 6; a swing member 7 supported at the tip of the support member 6 so as to be swingable about a swing axis orthogonal to the longitudinal axis of the support member 6; and 2 sets of links (driving force transmitting members) 8a and 8b that transmit the driving force applied to the operating portion 4 at the base end of the support member 6 and swing the swing member 7 with respect to the support member 6. Each set of links 8a, 8b has a long 1 st link (1 st transmission member) 9a, 9b arranged along the longitudinal axis of the support member 6, and a short 2 nd link 10a, 10b connected to the 1 st link 9a, 9b and the swinging member 7 so as to be swingable about an axis parallel to the swing axis.

As shown in fig. 2 and 3, the operation portion 4 includes a handle 11 to which a driving force is applied by an operator, and a driving force conversion portion 12 that supplies the driving force applied to the handle 11 to the 2 sets of links 8a, 8 b.

The driving force conversion portion 12 includes: a base 13 that rotatably mounts the handle 11; 23 rd links (driving force transmitting members, 2 nd transmitting members) 14a, 14b supported by the base 13 so as to be linearly movable in the longitudinal direction of the links 8a, 8 b; a rack, not shown, attached to the 3 rd links 14a and 14 b; a pinion gear, not shown, provided on the handle 11, disposed between the 2 parallel 3 rd links 14a and 14b, and engaged with the rack gear; and a stress adjustment portion 15 that adjusts the axial force applied to the 1 st links 9a, 9 b.

The stress adjustment portion 15 has: a movable member 16 disposed between the 1 st links 9a, 9b and the 3 rd links 14a, 14b, the movable member 16 moving in a direction (predetermined direction) orthogonal to the longitudinal axis direction when the 1 st links 9a, 9b and the 3 rd links 14a, 14b move relative to each other in the longitudinal axis direction of the 1 st links 9a, 9 b; and a torsion coil spring (urging member) 17 that urges in a direction to block the movement of the movable member 16.

The movable member 16 includes: a shaft portion 19 fitted in the through holes 18a and 18b so as to be movable in the axial direction of the through holes 18a and 18b, the through holes 18a and 18b being provided through the 3 rd links 14a and 14b in a direction orthogonal to the longitudinal axis; a 4 th link 20 fixed to one end of the shaft portion 19 and extending in the longitudinal axis direction; and a V-block portion 21 provided on the front end side of the 4 th link 20.

The other end of the shaft portion 19 is provided with a stopper 22 having a larger diameter than the through holes 18a and 18 b. The shaft portion 19 is prevented from further moving in one axial direction by abutting the stopper 22 against the 3 rd links 14a and 14 b. Further, the shaft portion 19 is restrained by being inserted into the through holes 18a, 18b so as not to relatively move in the longitudinal axis direction with respect to the 3 rd links 14a, 14b, and when the 3 rd links 14a, 14b move in the longitudinal axis direction, the shaft portion 19, the 4 th link 20, and the V-block portion 21 move in the longitudinal axis direction together with the 3 rd links 14a, 14 b.

The torsion coil spring 17 includes a coil spring portion 23 and 2 rod portions 24 extending in substantially the same direction from both ends of the coil spring portion 23 and gradually widening. The torsion coil spring 17 is fixed to the base 13 at a coil spring portion 23, and is sandwiched between the 3 rd links 14a and 14b and the 4 th link 20 in a state of being elastically deformed in a direction in which the 2 rod portions 24 approach each other. Each lever 24 has a bent portion 24a which bends the tip sides thereof in a direction approaching each other at a position midway in the longitudinal direction. The torsion coil spring 17 causes the 2 lever portions 24 to open each other by the coil spring portion 23, and generates a biasing force in a direction of enlarging the interval between the 3 rd links 14a and 14b and the 4 th link 20.

At positions of the 3 rd links 14a and 14b and the 4 th link 20 facing the lever portion 24 of the torsion coil spring 17, projections (urging force adjusting mechanisms) 25 are provided, which are in contact with the lever portion 24 and press the lever portion 24.

The V block portion 21 has 2 inclined surfaces 21a, and the 2 inclined surfaces 21a are inclined in opposite directions at an angle of 45 ° with respect to both the moving direction in which the shaft portion 19 moves along the through holes 18a, 18b and the longitudinal axis direction of the 1 st links 9a, 9 b. The 2 inclined surfaces 21a are arranged to open in the direction opposite to the stopper 22. A cylindrical pin (cam portion) 26 is provided at the base end of the 1 st link 9a, 9b, and the pin 26 is disposed at a position where it simultaneously contacts both of the 2 inclined surfaces 21 a.

The movable member 16 is constantly biased by the biasing force of the torsion coil spring 17 at a position where the stopper 22 of the shaft portion 19 abuts against the 3 rd links 14a and 14 b. In a state where the pin 26 is in contact with both of the 2 inclined surfaces 21a, the force in the longitudinal axis direction applied to the 3 rd links 14a, 14b is transmitted to the 1 st links 9a, 9b via the inclined surfaces 21a and the pin 26, and the 1 st links 9a, 9b move in the longitudinal axis direction.

When a large axial force acts in any one of the longitudinal axial directions of the 1 st links 9a and 9b, the pin 26 presses any one of the inclined surfaces 21a, and as a result, when the force in the longitudinal direction of the shaft portion 19 generated by the pressing force exceeds the biasing force (threshold value) of the torsion coil spring 17, the movable member 16 moves in the longitudinal direction of the shaft portion 19 (direction in which the stress is reduced). Thereby, the pin 26 moves along any one of the inclined surfaces 21a, and the 1 st links 9a, 9b and the 3 rd links 14a, 14b move relatively in the longitudinal axis direction.

That is, in a state where an axial force smaller than a predetermined magnitude is applied to the 1 st links 9a, 9b and the 3 rd links 14a, 14b, the movement of the movable member 16 is inhibited by the biasing force of the torsion coil spring 17, and the longitudinal axial force applied to the 3 rd links 14a, 14b is directly transmitted to the 1 st links 9a, 9b while the 1 st links 9a, 9b and the 3 rd links 14a, 14b are kept from moving relatively in the longitudinal direction. On the other hand, when an axial force of a predetermined magnitude acts on the 1 st links 9a, 9b and the 3 rd links 14a, 14b, the movable member 16 is moved against the urging force of the torsion coil spring 17, and the 1 st links 9a, 9b and the 3 rd links 14a, 14b are relatively moved, so that an excessive axial force is prevented from acting on the 1 st links 9a, 9 b.

In this case, in the case of the buckling mechanism 5 having the above-described structure, as shown in fig. 4, the 1 st link 9b on the inner side and the 1 st link 9a on the outer side of buckling in the buckling joint tend to be as follows: when the buckling angle (rocking angle) is large, the allowable axial force of the 1 st link 9a on the outer side of buckling is greatly reduced, whereas the allowable axial force of the 1 st link 9b on the inner side of buckling is slightly reduced.

In the present embodiment, when the bending angle is increased with reference to the position where the bending angle is 0 °, the contact point between the protrusion 25 and the lever 24 of the torsion coil spring 17 that biases the movable member 16 connected to the outer 1 st link 9a is moved to the tip side of the bending portion 24a of the lever 24, and the contact point between the protrusion 25 and the lever 24 of the torsion coil spring 17 that biases the movable member 16 connected to the inner 1 st link 9b is moved to the base side of the bending portion 24a of the lever 24.

Thus, when the contact point between the protrusion 25 and the lever 24 moves to the front end side of the bent portion 24a, the angle between the levers 24 of the torsion coil spring 17 increases, and the distance between the point of action of the force from the protrusion 25 toward the lever 24 and the fulcrum increases, so that the rigidity of the torsion coil spring 17 greatly decreases, and the movable member 16 easily moves even with a smaller force. On the other hand, when the contact point between the protrusion 25 and the lever 24 moves to the base end side of the bent portion 24a, the angle between the levers 24 increases and the rigidity of the torsion coil spring 17 decreases, but the distance between the point of action of the force from the protrusion 25 toward the lever 24 and the fulcrum decreases, so that the rigidity increases and the rigidity of the torsion coil spring 17 as a whole decreases slightly.

Therefore, the rigidity of the torsion coil spring 17 is appropriately changed according to the position at which the bending angle is changed, and an excessive axial force exceeding the allowable axial force does not act on the 1 st links 9a and 9 b.

The operation of the buckling mechanism 5 and the medical manipulator 1 of the present embodiment configured as described above will be described below.

When a treatment of an affected part is performed using the medical manipulator 1 of the present embodiment, the insertion portion 3 is inserted into the body, the distal treatment instrument 2 is disposed in the vicinity of the affected part, the handle 11 provided in the operation portion 4 is operated, and the swinging member 7 is swung with respect to the support member 6, thereby adjusting the posture of the treatment instrument 2 with respect to the affected part.

After the handle 11 is operated to rotate in one direction, as shown in fig. 5, the 2 rd links 14a and 14b coupled to the handle 11 via the rack and pinion move in the longitudinal axis direction, and the 1 st links 9a and 9b move in the longitudinal axis direction by pressing the pin 26 with the inclined surface 21a of the V-block portion 21 provided in the movable member 16.

The rod 24 of the torsion coil spring 17 and the projection 25 provided on the 3 rd link 14a, 14b and the 4 th link 20 are formed so as to be disposed at appropriate relative positions based on the swing angle of the swing member 7 corresponding to the rotation angle of the handle 11, and therefore, the rigidity of the torsion coil spring 17 is appropriately set according to the swing angle of the swing member 7.

That is, when the rocking member 7 rocks with respect to the support member 6, as shown in fig. 5, the relative angle of the rod portion 24 of the torsion coil spring 17 is increased on the 1 st link 9a side disposed on the outer side of the buckling, and the rigidity is greatly reduced, and the rigidity of the torsion coil spring 17 is slightly reduced on the 1 st link 9b side disposed on the inner side of the buckling. Thereby, the urging force of the torsion coil spring 17 is greatly reduced on the outer side of the buckling, and the urging force of the torsion coil spring 17 is slightly reduced on the inner side of the buckling.

Therefore, when an external force acts on the distal end of the treatment instrument 2 fixed to the pivoting member 7, the outer side of the flexion more easily compresses the torsion coil spring 17 with a smaller external force than the inner side of the flexion to move the movable member 16 in the direction orthogonal to the longitudinal axis of the 1 st link 9a, 9b, and the pin 26 moves relative to the inclined surface 21a of the V-block portion 21 to allow the 1 st link 9a and the 3 rd link 14a to move relative to each other in the longitudinal axis direction. Although the allowable axial force of the 1 st link 9a is greatly reduced on the outer side of the buckling, the 1 st link 9a and the 3 rd link 14a are allowed to move relative to each other even with a small external force, and therefore, there is an advantage that an excessive axial force exceeding the allowable axial force can be prevented from acting on the 1 st link 9 a.

In this case, the allowable axial force of the 1 st link 9b is not so much reduced on the inner side of the buckling, and therefore the base end side of the 1 st link 9b is kept from moving by a small external force. As a result, the outer 1 st link 9a that allows buckling after the axial force is reduced can be prevented from being broken, and the outer force can be received by the inner 1 st link 9b that allows buckling without a significant reduction in the axial force.

When the axial force applied to the bent inner 1 st link 9b approaches the allowable axial force, the 1 st link 9b and the 3 rd link 14b are relatively moved in the longitudinal axial direction by compressing the torsion coil spring 17 with respect to the inner 1 st link 9b, and an excessive axial force exceeding the allowable axial force can be prevented from acting on the 1 st link 9 b. This eliminates the need to increase the cross section of the 1 st link 9b in consideration of the reduction of the allowable axial force, and has an advantage that the diameter of the insertion portion 3 can be reduced while preventing breakage.

In the present embodiment, the 3 rd links 14a, 14b and the 4 th link 20 are moved relative to the torsion coil spring 17 fixed to the base 13, and the opening angle of the lever portion 24 of the torsion coil spring 17 is adjusted to an appropriate rigidity corresponding to the swing angle of the swing member 7, but instead, as shown in fig. 6, the torsion coil spring 17 may be fixed to the movable member 16 by a fixing portion 28, and a spring pusher 27 that presses one lever portion 24 may be fixed to the base 13. Further, the V-block 21 may be provided at the base end of the 1 st links 9a and 9b, and the pin 26 abutting against the inclined surface 21a of the V-block 21 may be provided on the movable member 16.

Instead of the torsion coil spring 17, a compression coil spring (urging member) 29 may be used as shown in fig. 7. By providing the spring push rod 27 with the slope 30, the rigidity of the compression coil spring 29 can be reduced outside the buckling, and the rigidity of the compression coil spring 29 can be increased outside the buckling.

Further, although the movable member 16 is moved by the pin 26 and the V-block portion 21 when the axial force is large, the movable member 16 may be replaced with a movable member 16 having: a crank 31 provided to the 3 rd links 14a and 14b so as to be swingable about a predetermined axis, and coupled to the base ends of the 1 st links 9a and 9b at a position apart from the axis; and a lever (テ コ) member 32 provided swingably to the 3 rd links 14a, 14b, and swung in one direction by the swinging in both directions of the crank 31. By compressing the torsion coil spring 17 according to the swing of the lever member 32, the rigidity of the torsion coil spring 17 can be adjusted according to the swing angle of the swing member 7. Fig. 9 shows an example of the stress adjustment portion 15 on the side corresponding to the 1 st link 9 a.

That is, as shown in fig. 8 and 9, the stress adjustment portion 15 is provided such that the rotation shaft of the lever member 32 is fixed to the 3 rd links 14a and 14b via the fixing member 32a, and the crank 31 is swingable about the rotation shaft provided on the fixing member 31a fixed to the 3 rd links 14a and 14 b.

When the operator operates the handle 11 to move the medical manipulator 1 in one direction, for example, as shown in fig. 8, when the handle 11 is rotated counterclockwise, the 3 rd link 14a moves toward the distal end side (left side in the drawing) and the 3 rd link 14b moves toward the proximal end side (right side in the drawing).

Thus, the 1 st link 9a is pressed toward the tip end side as indicated by an arrow via the crank 31 supported by the fixing member 31a fixed to the 3 rd link 14a, while the 1 st link 9b is pulled toward the base end side as indicated by an arrow via the crank 31 supported by the fixing member 31a fixed to the 3 rd link 14 b. As a result, the swing member 7 swings counterclockwise.

In this case, as shown in fig. 9, the 1 st link 9a is pressed toward the distal end side, the crank 31 swings clockwise, a force is applied in a direction of pushing up the lever member 32, the projection 25 provided on the 3 rd link 14a and the projection 25 provided on the lever member 32 move toward the distal end side with respect to the torsion coil spring 17, and thereby, the position where the two projections 25 press the torsion coil spring 17 changes toward the distal end side. As a result, the pressing position moves toward the tip side of the torsion coil spring 17 whose interval becomes narrower toward the tip, and thus, the decrease in rigidity due to the change in the position of the force point toward the tip side and the decrease in rigidity due to the expansion of the rod portion 24 of the torsion coil spring 17 interact with each other, so that the force received by the lever member 32 from the torsion coil spring 17 decreases, and the lever member 32 is easily swung by a small force.

On the other hand, the 1 st link 9b is pulled toward the base end side, the crank 31 swings clockwise in fig. 8, and a force is applied in a direction of pressing the lever member 32, and the protrusion 25 provided on the 3 rd link 14b and the protrusion 25 provided on the lever member 32 move toward the base end side with respect to the torsion coil spring 17, whereby the position where the two protrusions 25 press the torsion coil spring 17 changes toward the base end side. As a result, the pressing position moves toward the proximal end side of the torsion coil spring 17, and the increase in rigidity due to the change in the position of the force point toward the proximal end side and the decrease in rigidity due to the expansion of the rod portion 24 of the torsion coil spring 17 cancel each other out, so that the rigidity of the torsion coil spring 17 is maintained constant.

Therefore, when an external force acts on the distal end of the treatment instrument 2, the lever member 32 and the crank 31 are more easily swung on the outer side of the flexion than on the inner side of the flexion, and the 1 st link 9a is moved in the longitudinal axis direction so as to compress the torsion coil spring 17 by a small external force, so that it is possible to avoid an excessive axial force exceeding the allowable axial force from acting on the 1 st link 9 a.

In this case, the allowable axial force of the 1 st link 9b is not so much reduced inside the buckling, and therefore the base end side of the 1 st link 9b is maintained not to move by a small external force. As a result, the outer 1 st link 9a that allows buckling with reduced axial force is prevented from being damaged, and the inner 1 st link 9b that allows buckling without significantly reduced axial force receives external force. Further, the crank 31 functions as follows: the lever member 32 is pressed (pushed up or pressed down) in a certain direction regardless of the swing direction. Thus, even when the 1 st links 9a and 9b are forced in any direction of the proximal end side or the distal end side by the external force acting on the distal end of the treatment instrument 2, the torsion coil spring 17 can function to receive the external force.

When the operator rotates the handle 11 clockwise to move the medical manipulator 1 in the other direction, the 3 rd link 14a moves toward the base end side (right side in the figure), and the 3 rd link 14b moves toward the tip end side (left side in the figure).

Thus, the 1 st link 9a is pulled toward the base end side via the crank 31 supported by the fixing member 31a fixed to the 3 rd link 14a, while the 1 st link 9b is pushed toward the tip end side via the crank 31 supported by the fixing member 31a fixed to the 3 rd link 14 b. As a result, the swing member 7 swings clockwise.

In this case, the 1 st link 9a is pulled toward the base end side, the crank 31 swings counterclockwise, a force is applied in a direction of pushing up the lever member 32, and the projecting portion 25 provided on the 3 rd link 14a and the projecting portion 25 provided on the lever member 32 move toward the base end side with respect to the torsion coil spring 17, whereby the position where the two projecting portions 25 press the torsion coil spring 17 changes toward the base end side. Thereby, the pressing position moves to the base end side of the torsion coil spring 17 whose interval becomes narrower toward the coil spring portion 23 at the base end.

On the other hand, the 1 st link 9b is pressed toward the distal end side, the crank 31 swings counterclockwise, and the force is applied in the direction of pressing the lever member 32, and the projection 25 provided on the 3 rd link 14b and the projection 25 provided on the lever member 32 move toward the distal end side with respect to the torsion coil spring 17, whereby the positions at which the two projections 25 press the torsion coil spring 17 are changed toward the distal end side. Thereby, the pressed position moves to the tip side of the torsion coil spring 17.

In addition, instead of the method of directly biasing the V-block 21 in the moving direction of the movable member 16 by the compression coil spring 29 as shown in fig. 7, the moving direction of the V-block 21 may be switched by 2 wedge members 33 and 34 as shown in fig. 10 and 11, and the compression coil spring 29 may be disposed in the switched direction. Fig. 11 shows an example of the stress adjustment portion 15 on the side corresponding to the 1 st link 9 a.

That is, as shown in fig. 10 and 11, the stress adjustment portion 15 includes: a 1 st wedge member 36 fixed to the 3 rd links 14a and 14b by a fixing portion 35; a shaft 37 disposed parallel to the 3 rd links 14a and 14b and penetrating the 1 st wedge member 36; a 2 nd wedge member 38 having a slope surface facing the slope surface of the 1 st wedge member 36, the shaft 37 being inserted through the second wedge member 38 and movably attached in the longitudinal direction thereof; and a 3 rd wedge part 39 of a V shape having 2 inclined surfaces sandwiched between the inclined surfaces of these 1 st wedge parts 36 and the inclined surfaces of the 2 nd wedge parts 38.

The 3 rd wedge member 39 is provided to be movable in a direction orthogonal to the longitudinal direction of the shaft 37 by sliding the inclined surface with respect to the inclined surfaces of the 1 st wedge member 36 and the 2 nd wedge member 38. Further, when the 3 rd links 14a, 14b move in the front-rear direction, the 3 rd wedge member 39 moves along the slope of the slope 30 provided to the spring push rod 27, thereby moving in a direction orthogonal to the longitudinal direction of the shaft 37.

When the 3 rd wedge member 39 is moved in a direction orthogonal to the longitudinal direction of the shaft 37, the distance between the 1 st wedge member 36 and the 2 nd wedge member 38 along the longitudinal direction of the shaft 37 relatively changes. A wedge member 34 is fixed to the tip end of the shaft 37, a stopper 40 is provided on the base end of the shaft 37, and a compression coil spring 29 that biases the wedge member 34 and the 2 nd wedge member 38 in a direction to enlarge the gap therebetween is disposed between the two members. Further, the compression coil spring 29 is always urged in the direction of compressing the compression coil spring 29 from the 2 nd wedge member 38.

The wedge member 33 is attached to the distal ends of the 3 rd links 14a, 14b so as to be movable in a direction orthogonal to the longitudinal direction of the 3 rd links 14a, 14b via the shaft portion 19. The wedge member 33 is provided with a V-block portion 21, and the inclined surface of the wedge member 33 is in close contact with the inclined surface of the wedge member 34.

When the operator operates the handle 11 to move the medical manipulator 1 in one direction, for example, as shown in fig. 10, when the handle 11 is rotated counterclockwise, the 3 rd link 14a moves toward the distal end side (left side in the drawing) and the 3 rd link 14b moves toward the base end side (right side in the drawing).

Thereby, the 1 st link 9a is pressed toward the distal end side, the 3 rd wedge member 39 moves in the direction orthogonal to the longitudinal direction of the 3 rd link 14a (the direction approaching the 3 rd link 14 a) along the inclined surface of the slope 30 of the spring pusher 27, and the urging force from the 2 nd wedge member 38 to the compression coil spring 29 in the direction compressing the compression coil spring 29 decreases, and as a result, the 1 st wedge member 36 and the 2 nd wedge member 38 approach each other, and the compression coil spring 29 expands, and the rigidity decreases.

Therefore, when an external force acts on the distal end of the treatment instrument 2, the 2 wedge members 33 and 34 are easily moved more outward in flexion than inward in such a manner that the compression coil spring 29 is compressed by a small external force, and an excessive axial force exceeding the allowable axial force can be prevented from acting on the 1 st link 9 a. Further, the wedge member 33 is in contact with the pin 26 at 2 inclined surfaces 21a of the V-block portion 21. Thus, even when the 1 st links 9a and 9b are forced in any one of the proximal end side and the distal end side by an external force acting on the distal end of the treatment instrument 2, the compression coil spring 29 can function to receive the external force.

When the operator rotates the handle 11 clockwise to move the medical manipulator 1 in the other direction, the 3 rd link 14a moves toward the base end side (right side in the figure), and the 3 rd link 14b moves toward the tip end side (left side in the figure).

Thereby, the 1 st link 9a is pulled toward the base end side, the 3 rd wedge member 39 moves along the inclined surface of the slope 30 of the spring pusher 27 in the direction orthogonal to the longitudinal direction of the 3 rd link 14a (the direction away from the 3 rd link 14 a), and the force applied from the 2 nd wedge member 38 to the compression coil spring 29 in the direction of compressing the compression coil spring 29 increases, and as a result, the 1 st wedge member 36 and the 2 nd wedge member 38 are separated, and the compression coil spring 29 is further compressed, and the rigidity is improved.

In the present embodiment, the inclined surface 21a of the V-block portion 21 is inclined at an angle of 45 ° with respect to the longitudinal axis direction of the 1 st links 9a and 9b, but instead, an inclined surface 21a inclined at an arbitrary angle may be used. In this case, since the force applied in the moving direction of the movable member 16 changes depending on the inclination angle, the rigidity of the torsion coil spring 17 and the like may be designed in consideration of the force.

Description of the reference symbols

1 medical manipulator

2 treatment device

4 operating part

5 buckling mechanism

6 support part

7 swinging part

8a, 8b connecting rod (driving force transmission component)

9a, 9b the 1 st connecting rod (the 1 st transmission part)

14a, 14b 3 rd connecting rod (2 nd transmission part)

15 stress adjusting part

16 moving parts

Torsion coil spring (force application component)

21a inclined plane

25 projection (acting force adjusting mechanism)

26 Pin (cam part)

29 compression coil spring (forcing part)

31 crank

32 lever component