JPH07120683A - Fluid pressure-driving type actuator - Google Patents

Abstract

PURPOSE:To provide a fluid pressure-driving type actuator which is capable of having the more extra fine diameter or being micronized, and can be returned to the initial form by its own restoring force at non-pressurization because a regulating member has elastic restoring force to improve responsiveness. CONSTITUTION:In the fluid pressure driving type actuator having an elastic member having a pressure chamber and a regulating member 8 for regulating the expansion of the elastic member at pressurization in a specified direction, the regulating member 8 is formed from an elastic pipe, and a slit 9 laid along the axial direction or circumferential direction is formed on the elastic pipe. Thus, since the axial extension of the elastic member is regulated by the regulating member 8, when a fluid is supplied to the pressure chamber and pressurized, and the slit 9 formed along the axial or circumferential direction of the elastic pipe is radially opened and expanded, the elastic member is axially contracted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure drive type actuator provided in an insertion portion of an endoscope, a treatment tool and the like.

[0002]

2. Description of the Related Art A fluid pressure drive type actuator in which gas or liquid is supplied to a rubber tube having a pressurizing chamber to pressurize the rubber tube to expand the rubber tube in a radial direction and to contract the rubber tube in an axial direction is known as a lavaator. (Bridgestone brand name).

This is constructed such that the outer circumference of a rubber tube is covered with a mesh tube, and the expansion in the axial direction during pressurization is restricted by the mesh tube so as to expand in the radial direction and contract in the axial direction.

Further, as disclosed in Japanese Patent Application Laid-Open No. 4-197330, a tubular elastic body made of a resin tube separated into a plurality of pressure chambers by partition walls is provided in a curved portion of an endoscope, and a tubular elastic body is added into the resin tube. Fibers that regulate the expansion direction under pressure are embedded, and pressure is selectively applied to the pressure chambers to bend the bending portion in a desired direction.

[0005]

However, in the conventional actuator described above, a restricting member for restricting the expansion of the rubber tube in a specific direction is covered with a mesh tube, and when considering the actuator to have an extremely small diameter, It is difficult to make a mesh tube, and it is difficult to make the outer diameter of the entire actuator smaller and smaller.

Further, the above-mentioned endoscope is one in which fibers for controlling the expansion direction at the time of pressurization are embedded in the resin tube, and in this case also, in consideration of the ultrafine diameter, the tube in which the fibers are embedded is considered. Is difficult to manufacture, and it is difficult to make the outer circumference of the actuator thinner and smaller.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fluid pressure drive type actuator which is easy to manufacture and which can be made extremely small in diameter and micro. .

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises an elastic member having a pressurizing chamber,
In a fluid pressure drive type actuator provided with a restriction member for restricting expansion of the elastic member at the time of pressurization in a specific direction, the restriction member is formed of an elastic pipe, and a slit along the axial direction or the circumferential direction is formed in the elastic pipe. Has been formed.

When a fluid is supplied to the pressurizing chamber to pressurize it, the axial expansion of the elastic member is restricted by the restricting member, and a slit formed along the axial or circumferential direction of the elastic pipe is opened in the radial direction. As a result, the elastic member contracts in the axial direction.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment and show a fluid pressure microactuator 1 as a fluid pressure drive type actuator. This fluid pressure microactuator 1 has an elastic member 2 made of a cylindrical rubber tube, and the front end opening and the rear end opening of this elastic member 2 are hermetically sealed by front and rear mouthpieces 3 and 4, A pressure chamber 5 is formed inside. The rear mouthpiece 4 is provided with a through hole 6, which is connected to a pressurizing pipe line 7.
Is connected to a fluid pressure source (not shown).

Further, a regulating member 8 is provided so as to be fitted on the outer periphery of the elastic member 2. The regulating member 8 is an elastic pipe formed of an ultrathin metal pipe such as stainless steel, and both ends thereof are fixed to the front and rear mouthpieces 3, 4.

A plurality of slits 9 are provided on the outer periphery of the regulating member 8 along the axial direction by electric discharge machining, laser machining or the like. That is, the regulating member 8 serves to regulate the expansion of the elastic member 2 in the axial direction and allow the radial expansion by the opening of the slit 9.

Next, the operation of the fluid pressure microactuator 1 constructed as described above will be described. The fluid pressure supply source applies air, liquid or the like to the pressure chamber 5 of the elastic member 2 through the pressure pipe 7. When a pressurized fluid is supplied, the elastic member 2
Since the expansion is restricted in the axial direction by the restriction member 8, it does not expand, but the slit 9 provided in the restriction member 8 is expanded by the elastic member 2 and expanded in the radial direction.

Therefore, the elastic member 2 becomes L1 with respect to the entire length L0 and contracts by Δx, and when the pressurized fluid supplied to the pressure chamber 5 is discharged, the elastic member 2 contracts in the radial direction by the elastic restoring force, and the elastic member 2 returns to full length L0.

By thus forming the regulating member 8 with an extremely thin metal pipe, the structure is brought into close contact with the elastic member 2, and the fluid pressure microactuator 1 can be made extremely thin and micro. Furthermore, since the regulating member 8 has an elastic restoring force, the restoring force of the restraining member 8 returns to the initial shape by itself to improve the responsiveness.

Further, since the regulating member 8 can be brought into close contact with the elastic member 2, useless expansion can be suppressed, the drive stroke can be improved, and partial expansion of the elastic member 2 at the time of initial pressurization can be suppressed. Member 2 expands evenly,
This has the effect of improving durability.

FIG. 4 shows a second embodiment, and the same components as those of the first embodiment are designated by the same reference numerals and their description will be omitted. The pressure chamber 5 of the elastic member 2 is filled with a thermal expansion member 10 that expands in volume by heating paraffin, freon, alcohol or the like, and a heater 11 is inserted in the thermal expansion member 10. The heater 11 is led out to the outside through a lead wire 13 that passes through the wiring passage 12 of the rear base 4, is connected to a power source (not shown), and the wiring passage 12 is sealed with an adhesive 14.

Next, the operation of the fluid pressure microactuator 1 having the above-described structure will be described. When the heater 11 is energized and heated, the volume of the thermal expansion member 10 expands. Works the same as the example.

Therefore, in addition to the effects of the first embodiment,
The pressurizing pipe line 7 is not required, the structure on the rear side can be simplified and the diameter can be reduced, and the long remote drive becomes easier.

The slit 9 provided in the regulating member 8 is
In addition to the above processing method, a method of removing by etching may be used, or a plating method may be used. Further, the material may be a super elastic alloy such as phosphor bronze or NiTi alloy.

FIG. 5 shows a third embodiment. The same components as those of the first embodiment are designated by the same reference numerals and their description will be omitted. In this embodiment, the fluid pressure microactuator 1 is adopted as a bending mechanism of an endoscope. The insertion section 16 of the endoscope 15 includes a distal end forming section 17, a bending tube section 18, and a flexible tube section 19.
It consists of and.

A plurality of angle wires 20 are arranged along the axial direction of the bending tube portion 18, the tip of which is connected to the tip forming portion 17 and the other end of which is connected to the tip of the fluid pressure microactuator 1. ing. The fluid pressure microactuator 1 is housed in a coil sheath 21 fixed to the tip end side in the flexible tube portion 19, and the rear base 4 of the fluid pressure microactuator 1 is fixed to the rear end of the coil sheath 21.

Therefore, the angle wires 20 can be pulled by selectively pressurizing the plurality of fluid pressure microactuators 1 in the same manner as in the first embodiment and expanding the elastic member 2, and the insertion portion 16 can be pulled. The bending tube portion 18 can be bent in a desired direction. In addition, with the above-described configuration, the insertion portion 16 of the endoscope 15 can be made smaller in diameter, the insertion into the body cavity can be facilitated, and the patient's pain can be reduced.

FIG. 6 shows a fourth embodiment. The same components as those of the first embodiment are designated by the same reference numerals and their description will be omitted. In this embodiment, the fluid pressure microactuator 1 is adopted for the biopsy forceps 22.

A cup portion 24 is provided at the distal end portion of the sheath 23 of the biopsy forceps 22, and an opening / closing link portion 25 is provided in the cup portion 24. The opening / closing link portion 25 is fluidized via a wire 26. The front end cap 3 of the pressure microactuator 1 is connected, and the rear end cap 4 of the fluid pressure microactuator 1 is connected to the sheath 23.

Therefore, by pressing the fluid pressure microactuator 1 in the same manner as in the first embodiment and expanding the elastic member 2, the wire 26 can be pulled, and the cup portion via the opening / closing link portion 25. The cup portion 24 can be closed via the opening / closing link portion 25 by opening 24 and discharging the fluid supplied to the pressure chamber 2.

FIG. 7 shows a fifth embodiment, and the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the fluid pressure microactuator 1 is adopted to drive the forceps raising base 28 of the side-view endoscope 27.

A tip forming portion 30 of the insertion portion 29 of the endoscope 27.
A cutout portion 31 that opens to the side is provided in the cutout portion 31, and the cutout portion 31 is rotatable around a support shaft 32 as a fulcrum.
8 are provided. One end of a wire 33 is connected to the free end portion of the forceps raising base 28, the other end of the wire 33 is connected to the front end cap 3 of the fluid pressure microactuator 1, and the rear end cap 4 is seen inside. It is connected to the tip forming portion 30 of the mirror 27.

Therefore, by pressing the fluid pressure microactuator 1 in the same manner as in the first embodiment and expanding the elastic member 2, the wire 33 can be pulled, and the forceps raising base 28 is supported by the support shaft 32. The forceps raising base 28 can be laid down by discharging the fluid supplied to the pressure chamber 2.

FIG. 8 shows a sixth embodiment. The same components as those of the first embodiment are designated by the same reference numerals and their description will be omitted. In this embodiment, the fluid pressure microactuator 1 is adopted to drive a movable optical system 35 for focusing, zooming, etc. of the observation optical system 34 at the tip of the endoscope.

The observation optical system 34 is composed of a movable optical system 35 and a fixed optical system 36. The front end cap 3 of the fluid pressure microactuator 1 is connected to a frame 35a of the movable optical system 35 via a rod 37. The rear end cap 4 is a fixed optical system 36.
Is connected to the frame 36a or the endoscope body.

Accordingly, the movable optical system 35 can be moved rearward via the rod 37 by pressurizing the fluid pressure microactuator 1 in the same manner as in the first embodiment and expanding the elastic member 2. The movable optical system 35 can be moved forward by discharging the fluid supplied to the pressure chamber 2.

9 to 11 show a seventh embodiment, in which the fluid pressure microactuator 38 is adopted in the bending mechanism of the endoscope 39. The insertion section 40 of the endoscope 39 is composed of a distal end forming section 41, a bending tube section 42 and a flexible tube section 43, and the insertion section 40 has an image guide fiber 44.
(Or CCD cable), light guide fiber 45
The channel 46 and the like are interpolated.

The curved tube portion 43 has a fluid pressure microactuator 38 having an elastic member 47 made of a cylindrical rubber tube. The elastic member 47 has a front end on the tip forming portion 41 and a rear end on a flexible tube. It is connected to the portion 43. An arcuate cut is formed in the elastic member 47 over a range of 120 ° that divides the circumference into three equal parts, and the cut forms the inner layer 4
A pressure chamber 48a is formed separately in 7a and the outer layer 47b. The pressure chambers 48a are connected to a fluid pressure supply source (not shown) via an independently provided pressure pipe (not shown).

Further, a regulating member 49 is fitted and provided on the outer periphery of the elastic member 47. This regulation member 49
Is an elastic pipe formed of an ultrathin metal pipe such as stainless steel, the front end of which is connected to the tip forming portion 41 and the rear end of which is connected to the flexible tube portion 43.

The pressure chamber 48a is provided on the outer periphery of the regulating member 49.
Corresponding to the slit 5 in the circumferential direction over a range of 120 °
0a are provided alternately. That is, the regulation member 49 serves to regulate the expansion of the elastic member 47 in the radial direction, allow the elastic member 47 to expand in the axial direction by opening the slit 50a, and bend the bending tube portion 43.

Next, the operation of the fluid pressure microactuator 38 constructed as described above will be explained. Air, liquid, etc. are selectively supplied from the fluid pressure supply source to the pressure chamber 48a of the elastic member 47 through the pressurizing conduit. When the pressurized fluid is supplied, the elastic member 47, for example, in the portion of the pressure chamber 48a to which the pressurized fluid is supplied extends in the axial direction and the regulating member 4 in the radial direction.
Since the expansion is regulated by 9, the slit 50a corresponding to the pressure chamber 48a is widened, the elastic member 47 is curved together with the regulation member 49, and the bending tube portion 42 is curved as shown in FIG.

Therefore, the bending tube portion 42 can be bent in an arbitrary direction by selectively supplying a pressurized fluid such as air or liquid to the pressure chamber 48a. With such a configuration, the insertion portion 40 of the endoscope 39 can be made smaller in diameter, the insertion into the body cavity is facilitated, and the patient's pain can be reduced.

12 and 13 show the eighth embodiment. The slits 50a of the seventh embodiment are arranged alternately, but in this embodiment, the slits 50a are arranged on the same circumference. Since the basic configuration is the same, the description is omitted.

FIG. 14 shows a ninth embodiment, in which the regulating member 4
The slit 51 provided in 9 has an angle θ, and the bending tube portion has flexibility. FIG. 15 shows a tenth embodiment in which a rounded portion 51a is provided at the end of the slit 51. , Is configured to avoid stress concentration.

FIG. 16 shows a modification of the slit 9 of the first embodiment, and FIG. 16A shows a plurality of opening slits 52, which are elongated holes along the axial direction and are arranged in a zigzag manner in the regulating member 8. (B) of the figure shows that the regulating member 8 is provided with a plurality of opening slits 53 formed of long rhombic holes along the axial direction. In any of the modified examples, there is an effect that the bending tube portion can have flexibility, and there is an effect that the bending angle can be increased.

[0042]

As described above, according to the present invention, the restricting member for restricting the expansion of the elastic member in the specific direction is formed of the elastic pipe, and the elastic pipe is provided with the slit along the axial direction or the circumferential direction thereof. By forming the structure, the manufacturing is facilitated, and the restricting member is in close contact with the elastic member, so that the fluid actuator can be made extremely thin and micro. Further, since the regulating member has an elastic restoring force, there is an effect that the restoring force of the restraining member restores the initial shape to improve the responsiveness when the pressure is not applied.

[Brief description of drawings]

FIG. 1 is a perspective view of a fluid pressure microactuator showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view of the fluid pressure microactuator according to the embodiment.

FIG. 3 is an enlarged side view of a part of the fluid pressure microactuator of the same embodiment.

FIG. 4 is a vertical sectional side view of a fluid pressure microactuator showing a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a third embodiment of the present invention, in which a fluid pressure microactuator is adopted in a bending mechanism of an endoscope.

FIG. 6 is a configuration diagram showing a fourth embodiment of the present invention in which a fluid pressure microactuator is used as biopsy forceps.

FIG. 7 is a block diagram showing a fifth embodiment of the present invention, in which a fluid pressure microactuator is adopted in a forceps raising base.

FIG. 8 is a perspective view showing a sixth embodiment of the present invention in which a fluid pressure microactuator is used in an observation optical system.

FIG. 9 is a perspective view showing a seventh embodiment of the present invention in which a fluid pressure microactuator is used in a bending mechanism of an endoscope.

FIG. 10 is a cross-sectional view of the bending tube portion of the same embodiment.

FIG. 11 is a perspective view showing a state where the bending tube portion of the embodiment is bent.

FIG. 12 is a perspective view showing an eighth embodiment of the present invention in which a fluid pressure microactuator is adopted in a bending mechanism of an endoscope.

FIG. 13 is a vertical sectional side view of the bending tube portion of the embodiment.

FIG. 14 is a side view, partly in section, of a regulating member showing a ninth embodiment of the present invention.

FIG. 15 is a side view in which a part of a regulating member is shown in section, showing a tenth embodiment of the present invention.

FIG. 16 is a side view showing a modified example of the regulating member according to the first embodiment of the present invention.

[Explanation of symbols]

 1 ... Fluid pressure microactuator 2 ... Elastic member 3 ... Pressure chamber 8 ... Regulator member 9 ... Slit

Claims (1)

[Claims] 1. A fluid pressure drive type actuator having an elastic member having a pressurizing chamber and a restricting member for restricting expansion of the elastic member at the time of pressurization in a specific direction, wherein the restricting member is formed of an elastic pipe. A fluid pressure drive type actuator characterized in that a slit is formed in the elastic pipe along the axial direction or the circumferential direction thereof.