WO2018207663A1

WO2018207663A1 - Actuator and moving body

Info

Publication number: WO2018207663A1
Application number: PCT/JP2018/017152
Authority: WO
Inventors: 塚越　秀行; 光一寺島; 雄二郎高井
Original assignee: 国立大学法人東京工業大学; 学校法人東邦大学
Priority date: 2017-05-08
Filing date: 2018-04-27
Publication date: 2018-11-15
Also published as: JP2018189169A; JP6895660B2

Abstract

This rotary actuator 100 is provided with an expandable balloon 102 which radially and axially expands by pressurization. The expandable balloon 102 is restrained such that the expandable balloon 102 hardly stretches in the direction along a helix 108 and hardly expands in a radial direction.

Description

Actuator and moving body

The present invention relates to an actuator using fluid pressure.

Endoscopes for observation inside the body, catheters for administration of drug solutions, and catheters for discharge of body fluids are known as important medical devices. Since these instruments are used by being inserted into a thin tube in the body, there is a limitation in the radial size, and it is difficult to incorporate a complicated mechanism. For this reason, such a device does not have its own propulsive force, and accordingly, conventionally, a medical practitioner must apply force from the outside to push or pull it out into the body.

In recent years, active catheters and active endoscopes have been developed. For example, Patent Documents 1 to 3 disclose a self-propelled device using an air pressure, an endoscope propulsion device, and a tube insertion device.

Bronchi can be mentioned as a complex observation object in the body. The bronchi have a complex structure that branches. When an active catheter is inserted into the bronchus, it is necessary to select a direction for each branch. Therefore, it is desired to provide an actuator that can control the direction with a simple structure.

Also, the bronchus has a smaller inner diameter as it goes to the tip. Specifically, each branch is referred to as the 0th generation to the 5th generation, and the inner diameter largely changes in the range of 18 mm from the 0th generation to 3.6 mm from the 5th generation. Therefore, the function of propelling a wide inner diameter pipe line is desired.

Such a request may occur not only in a biological tube such as a bronchus or a large intestine tube, but also in an industrial pipeline such as a drain tube or a gas tube.

JP 2009-240713 A JP 2012-81130 A JP-A-5-293077

Conventional actuators that utilize fluid pressure have been limited to those that provide an expansion / contraction operation in the axial direction or a bending operation in one direction. If there is an actuator that can rotate around an axis, the utility value of the fluid pressure actuator is considered to increase.

The present invention has been made in view of such a situation, and one of exemplary purposes of an aspect thereof is to provide an actuator capable of operating differently from the conventional one. Another exemplary object of another aspect is to provide a movable body that can be propelled from a narrow line to a wide line.

An aspect of the present invention relates to an actuator. The actuator includes a telescopic balloon that expands in a radial direction and an axial direction by pressurization. The telescopic balloon is constrained to hardly extend in the direction along the spiral and to hardly expand in the radial direction.

When pressurizing the telescopic balloon, it cannot expand in the radial direction, so that the force to extend in the axial direction acts in a direction that further inclines the spiral in the axial direction. As a result, the telescopic balloon rotates around the axis. This actuator can provide rotational motion and the rotational angle can be controlled according to pressure.

The telescopic balloon may be restrained in a further curved state. Thereby, the member curved by pressurization can be rotated.

The stretchable balloon may be non-uniform in the circumferential direction in terms of ease of elongation in the axial direction. When the telescopic balloon is pressurized, the telescopic balloon is bent while being expanded. As a result, it is possible to generate an operation in which stretching, bending, and rotational motion are mixed.

The thickness of the cross section of the telescopic balloon may be uneven in the circumferential direction. Thereby, the distribution of the circumferential direction can be given to the elongating balloon in the easiness of extending in the axial direction.

Another aspect of the present invention also relates to an actuator. The actuator includes a tube whose tip is closed and expands in a radial direction and an axial direction by pressurization, and a thread-like member wound spirally around the surface of the tube.
When the tube is pressurized, it cannot expand in the radial direction, so that a force to extend in the axial direction acts in a direction that further inclines the spiral in the axial direction. As a result, the tube rotates around the axis. This actuator can provide rotational motion and the rotational angle can be controlled according to pressure.

The actuator may further include a bending restraining member that is provided inside the tube and restrains the tube in a curved state.

The tube may be non-uniform in the axial direction but easy to extend in the axial direction. When the tube is pressurized, the tube is curved while extending. As a result, it is possible to generate an operation in which stretching, bending, and rotational motion are mixed.

The thickness of the cross section of the tube may be uneven in the circumferential direction. Thereby, the distribution of the circumferential direction can be given to the elongating balloon in the easiness of extending in the axial direction.

Another aspect of the present invention relates to a moving body in a pipeline. The moving body includes a tip portion provided with the above-described actuator and a propulsion unit. The telescopic balloon of the actuator may be restrained in a curved state. When the telescopic balloon is pressurized, it rotates in a curved state. Thereby, the advancing direction of a mobile body can be selected.

The propulsion unit has an inner tube that receives a controllable pressure from the outside at the rear end, expands in the radial direction by pressurization, and can shrink in the axial direction, and a plurality of N pieces (N ≧ And a telescopic member forming the chamber chamber of 2). The inner tube has at least one opening for each chamber chamber, the axial length of the i-th (1 ≦ i ≦ N) chamber chamber is L _i , and at least one aperture corresponding to the i-th chamber chamber S _i / L _i may be different for each chamber, where S _i is the total area.
According to this propulsion unit, by controlling the pressure of one system supplied to the other end of the inner tube, a plurality of chamber chambers can be expanded and contracted at different timings according to the ratio S / L. Thus, the moving body can be deformed like an earthworm to generate a propulsive force (peristaltic motion).

Pressure may be supplied to the expandable balloon via an inner tube. The inner tube may be provided with at least one opening for supplying pressure to the telescopic balloon. When the total area of at least one opening corresponding to the expandable balloon is S ₀ , S ₀ <S _i (i = 1,... N) may be satisfied.
Thus, both propulsion and direction can be controlled by a single inner tube, in other words, by a single pressure system.

The propulsion unit may further include a plurality of restraining members provided at the boundary between adjacent chamber chambers. According to this structure, the inside of a thick pipe line can be propelled not by a peristaltic motion but by a bending motion.

Yet another embodiment of the present invention is also a mobile object. This moving body is an inner tube that receives a controllable pressure from the outside at the rear end, and a telescopic member that expands in the radial direction by pressurization and contracts in the axial direction. And an elastic member that forms a single chamber chamber, and a plurality of restraining members provided at the boundary between adjacent chamber chambers. The inner tube has at least one opening for each chamber chamber. When the i-th (1 ≦ i ≦ N) chamber chamber axial length of which is L _i, a total area of at least one opening corresponding to the i-th chamber chamber and S _i, S _i for each chamber compartment / _Li is different.

According to this aspect, the restraining member does not act on the expansion / contraction member in the narrow pipe, and can be propelled by a peristaltic motion. When the inner diameter of the pipe line is increased, the restraining member acts on the expansion / contraction member, and therefore can be propelled by a bending operation.

The expansion / contraction member is tubular, the inner tube is inserted into the expansion / contraction member, and the inner wall of the expansion / contraction member and the outer wall of the inner tube may be in close contact with each boundary portion of the plurality of chamber chambers.

The length L may be as short as the tip, and the area S may be as large as the tip. Thereby, a large driving force in the distal direction can be obtained.

Note that any combination of the above components is also effective as an aspect of the present invention.

According to an aspect of the present invention, an actuator that can operate differently from the conventional one can be provided. Moreover, according to another aspect, the moving body which can be propelled in a wide pipe line from a narrow pipe line can be provided.

It is a figure which shows the basic composition of a rotary actuator. 2A and 2B are views for explaining the operation of the rotary actuator of FIG. It is a figure which shows the structural example of a rotation actuator. 4A and 4B are views showing a rotary actuator according to a first modification. It is a figure which shows the measurement result of the relationship between the pressure of a rotary actuator which concerns on a 1st modification, and a rotation angle. FIGS. 6A and 6B are views showing a rotary actuator according to a second modification. Fig.7 (a) is a figure which shows a mobile body provided with a rotation actuator, and FIG.7 (b) is a figure explaining the direction steering of the mobile body in a pipe line. Fig.8 (a) is sectional drawing of the propulsion part which concerns on embodiment, FIG.8 (b) is the external view. FIGS. 9A to 9G are diagrams for explaining the operation of the propulsion unit in FIG. FIGS. 10A to 10G are diagrams for explaining the operation of another propulsion unit. FIGS. 11A to 11C are diagrams showing design examples of the area S _i and the length L _i . FIGS. 12A to 12C are diagrams showing design examples of the area S when S ₁ > S ₂ > S ₃ . 13A to 13D are diagrams showing a method for manufacturing the propulsion unit. It is a figure which shows a moving body. It is a figure which shows the response of the pressure (i) inside the expansion-contraction balloon of a rotation actuator, and the pressure (ii) of the air chamber inside the expansion-contraction member of a propulsion part. FIGS. 16A to 16G are diagrams for explaining the operation of the moving body of FIG. FIG. 17A is a view showing a propulsion unit according to a modification, and FIG. 17B shows a state of restraint by a restraining member. 18 (a) to 18 (g) are diagrams showing the operation of the propulsion unit in FIG. 17 (a).

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate. The embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

1. Rotation Actuator An actuator (rotation actuator) that uses a fluid pressure and can provide a new operation different from an expansion / contraction operation or a bending operation in a specific direction will be described.

1.1 Basic Configuration FIG. 1 is a diagram illustrating a basic configuration of the rotary actuator 100. The dimensions of each member shown in the drawings referred to in this specification are appropriately scaled up for ease of understanding and simplification of description. The rotary actuator 100 includes a telescopic balloon 102. The expandable balloon 102 has an air chamber 104 therein and is connected to a pressure controller 110 (not shown) via a pneumatic tube 106. Is expanded in the radial direction and the axial direction. The expandable balloon 102 is constrained to hardly extend in the direction along the spiral 108 and to hardly expand in the radial direction. The spiral 108 does not have to be a mathematically exact spiral.

The above is the basic configuration of the rotary actuator. Next, the operation will be described. 2A and 2B are views for explaining the operation of the rotary actuator of FIG. FIG. 2A shows a non-pressurized state, and FIG. 2B shows a pressurized state. 2A and 2B also show a cross-sectional view viewed from the Z direction. When the expandable balloon 102 is pressurized, it tends to extend in the radial direction and the axial direction. It cannot expand in the radial direction (R direction) due to restraint, but extends in the axial direction (Z direction). At this time, the spiral 108 of the expandable balloon 102 further tilts in the axial direction, and the angle φ increases (φ ₁ > φ ₀ ).

Focus on two points P ₀ and P ₁ on the spiral 108. Considering the relative positional relationship between the two points, it is assumed that the position of the point P ₀ is fixed. Since the length l along the spiral 108 between the points P ₀ and P ₁ is constrained to be constant, when the angle φ increases, the point P ₂ rotates in the θ direction when viewed from the Z direction. Considering these two points P ₀ and P ₁ as one deformation element, the relationship is as follows: a deformation element between another two points P ₁ and P ₂ , a deformation element between two points P ₂ and P ₃ , The same holds true for deformation elements between any two points. Focusing on a point P _z of the tip of the rotary actuator 100, the displacement of the point P _Z can be regarded as the integral of the deformation of the plurality of deformation elements and rotates θ around the axis.

According to this rotary actuator 100, it is possible to provide a motion that rotates (twists) while extending in the axial direction (Z) direction, and it is possible to control the rotation angle θ according to the pressure (or the amount of air supplied).

1.2 Specific Configuration Example FIG. 3 is a diagram illustrating a configuration example of the rotary actuator 100. The rotary actuator 100 includes a tube 120 having elasticity and a thread-like member 122 having no elasticity. The tube 120 is, for example, a silicon tube, the tip of which is closed, and forms the telescopic balloon 102. A rubber tube may be used instead of the silicon tube. The thread-like member 122 is, for example, a fiber, and is wound around the surface of the tube 120 in a spiral shape. The above is an example configuration of the rotary actuator 100.

1.3 First Modification FIGS. 4A and 4B are views showing a rotary actuator 100A according to a first modification. As shown in FIG. 4A, the rotary actuator 100A is restrained with the expandable balloon 102 being curved. For example, when the rotation actuator 100 of FIG. 3 is used as a basic configuration, the bending restraining member 124 may be provided inside the tube 120. FIG. 4B shows an operation when the rotary actuator 100A of FIG. 4A is pressurized. By applying pressure, the direction of the tube 120 can be rotated while the curve of the tube 120 is maintained.

FIG. 5 is a diagram showing the measurement result of the relationship between the pressure and the rotation angle. As a sample used for the measurement, a silicon tube 120 having an inner diameter of 1.6 mm, an outer diameter of 2.6 mm, and a length of 50 mm was used. As the thread-like member 122, water thread was used. The bending restraining member 124 is a vinyl tie. As is apparent from FIG. 5, according to the rotary actuator 100A, it is possible to realize a rotational motion of 360 ° or more as a movable range. Note that the movable range can be designed according to the pitch and inclination of the thread-like member 122.

1.4 Second Modification FIGS. 6A and 6B are views showing a rotary actuator 100B according to a second modification. FIG. 6A shows a cross-sectional view and a perspective view. The expandable balloon 102 is configured such that the easiness of extension in the axial direction (Z direction) is not uniform in the circumferential direction. For example, as shown in the cross-sectional view, the thickness of the cross section of the expandable balloon 102 may be non-uniform in the circumferential direction. Thereby, the distribution of the circumferential direction can be given to the elongating balloon in the easiness of extending in the axial direction. Similar to FIG. 3, the rotary actuator 100 B may be formed of the tube 120 and the thread-like member 122. In this case, the thickness of the tube 120 may be uneven. For example, the hollow portion 121 of the tube 120 may be eccentric with respect to the central axis Z.

FIG. 6B shows the rotary actuator 100B in a pressurized state. When the inside of the expandable balloon 102 (tube 120) is pressurized, the thin wall side is easier to extend in the axial direction than the thick side, so the expandable balloon 102 is curved while extending (arrow A in the figure). The aforementioned twisting motion (arrow B in the figure) occurs. As a result, a motion with a mixture of stretching, bending, and rotation (twisting) is generated, and the bending direction can be controlled according to the pressure.

In addition, in the rotary actuator 100B according to the second modification, means for introducing the non-uniformity of the easiness of elongation in the axial direction to the expandable balloon 102 is not limited. For example, a non-uniformity may be introduced by sticking a restraining member other than the thread-like member 122 to the tube 120 having uniform easiness of elongation. Specifically, two sheet-like or strip-like restraining members having different easiness of extension in the axial direction may be attached around the telescopic balloon 102.

Alternatively, the expandable balloon 102 may be divided into two regions in the circumferential direction, and the tube 120 may be configured by bonding two half tubes corresponding to the two regions. The materials and characteristics of the two half tubes may be made different.

2. Next, the application of the

rotary actuator

100A or 100B will be described. The application of the

rotary actuators

100A and 100B is not limited. For example, the

rotary actuators

100A and 100B can be used as a steering actuator that is attached to the tip of a moving body that propels in a pipeline and selects a direction. Fig.7 (a) is a figure which shows the mobile body 30 provided with the rotation actuator 100A. In the following description, the rotary actuator 100A may be replaced with 100B. The moving body 130 includes a rotary actuator 100A and the propulsion unit 1. The rotary actuator 100A is provided at the distal end portion 134 of the moving body 130 and functions as a steering actuator.

FIG. 7B is a diagram for explaining the direction steering of the moving body 130 in the pipeline 140. A branch 142 exists inside the pipeline 140. With the moving body 130 positioned in front of the branch 142, the rotary actuator 100A is pressurized, and the rotary actuator 100A is rotated in the direction of the branch 144A desired to travel. In this state, when the propulsion unit 1 is driven to generate a propulsive force, the moving body 130 can be propelled in the direction of the branch 144A. When propelled to the opposite side of the branch 144B, the pressure is adjusted and the rotary actuator 100A is rotated in the direction of the branch 142B as indicated by a broken line.

Thus, according to the rotary actuator 100A, it is possible to propel the moving body 130 by selecting a desired branch in a pipe having a branch.

When the rotary actuator 100B is used instead of the rotary actuator 100A, the rotary actuator 100B can maintain a linear shape during a normal traveling operation. Therefore, it can be said that the rotary actuator 100B is more advantageous from the viewpoint of resistance to the wall surface of the pipe line, and that the rotary actuator 100B is more advantageous in that the angle of curvature can be controlled.

2.2 Propulsion unit Next, a configuration example of the propulsion unit 1 will be described. When the rotary actuator 100A is used as a steering actuator, it is desirable that the propulsion unit 1 can also be driven by air pressure. Below, the suitable structure of the propulsion part 1 is demonstrated.

FIG. 8A is a cross-sectional view of the propulsion unit 1 according to the embodiment, and FIG. 8B is an external view thereof. The propulsion unit 1 is a flexible linear actuator and propels it while deforming like an earthworm (peristaltic motion). The propulsion unit 1 includes an elastic member 10 and an inner tube 20.

The expansion / contraction member 10 expands in the radial direction by pressurization from the inside and contracts in the axial direction. As the elastic member 10 having such properties, a McKibben type pneumatic rubber artificial muscle or a tube having a similar structure can be used. The material of the tube is not particularly limited, but for example, a silicone rubber material can be used.

The inner tube 20 has one end (also referred to as a tip) 22 closed. The other end (also referred to as rear end) 24 of the inner tube 20 is connected to the pressure controller 2 so that the pressure (air flow rate and direction) at the rear end 24 can be controlled from the outside. For example, the pressure controller 2 may include a pneumatic pump, a compressor, and a pressure control valve.

The stretchable member 10 forms a plurality of chamber chambers 40_1 to 40_N in the axial direction outside the inner tube 20. The chamber room 40_1 is located at the forefront, and the chamber room 40_N is located at the end. Although N = 3 is illustrated in FIG. 8, N is arbitrary.

For example, the elastic member 10 is tubular, and the inner tube 20 is inserted into the elastic member 10. The inner wall of the elastic member 10 and the outer wall of the inner tube 20 are in close contact with each boundary portion of the plurality of chamber chambers 40_1 to 40_3. For example, the propulsion unit 1 may include an annular restraining member 50 that presses the elastic member 10 from the outside in the radial direction. The restraining member 50 can be a thread, string, rubber, metal wire, or the like, and the material is not particularly limited. Alternatively, the inner wall of the elastic member 10 and the outer wall of the inner tube 20 may be bonded or welded at the boundary between the adjacent chamber chambers 40.

The inner tube 20 has at least one opening 26_i for each chamber chamber 40_i (i = 1, 2,... N). Here, in order to simplify the explanation for easy understanding, one opening 26 is provided for each chamber 40. The flow path 21 inside the inner tube 20 communicates with the corresponding chamber chamber 40_i through the opening 26_i.

i-th chamber chamber of the axial length _{L i} of 40_i, when the total area of the at least one opening 26_i corresponding to the chamber room 40_i the _{S i,} the ratio in each of a plurality of chambers chambers 40_i _S i / _{L i} Is different. Preferably, the ratio S _i / L _i changes monotonously in the axial direction.

The above is the configuration of the propulsion unit 1. Next, the operation will be described.

(I) S _i / L _i ≧ S _j / L _j (i <j)
FIGS. 9A to 9G are diagrams for explaining the operation of the propulsion unit 1 of FIG. It is assumed that S _i / L _i ≧ S _j / L _j holds for the two chamber chambers 40 — i and 40 — j (i <j). The propulsion unit 1 propels the inside of the pipe line 140 in the right direction. FIG. 9A shows an initial state. When the inner tube 20 is pressurized by the pressure controller 2, air flows into the chamber chamber 40 through the opening 26 of the inner tube 20. Assuming that the air pressure inside the inner tube 20 is constant, the flow rate of air flowing into each chamber chamber 40 is proportional to the area S of the opening 26 corresponding to the chamber chamber 40. The expansion rate of the chamber 40 is proportional to the flow rate per unit volume. Assuming that the inner diameter of the elastic member 10 is uniform, the volume of each chamber is proportional to the length L in the axial direction. Therefore, each chamber chamber 40 — _i expands at an expansion rate corresponding to the ratio S _i / L _i .

That is, as shown in FIG. 9B, the chamber chamber 40_1 on the tip 22 side having a large ratio S _i / L _i expands first. The expanded chamber chamber 40_1 is brought into contact with the inner wall 141 of the pipe line 140, whereby the position in the propulsion direction (axial direction) is fixed. When the chamber chamber 40_1 is expanded, the length of the chamber chamber 40_1 is shortened due to the nature of the elastic member 10, and the subsequent chamber chambers 40_2 and 40_3 are drawn forward. When the pressurization is further continued, as shown in FIG. 9C, the second chamber chamber 40_2 expands, the length thereof becomes shorter, and the subsequent chamber chamber 40_3 is drawn forward. Then, as shown in FIG. 9D, all the chamber chambers 40_1 to 40_3 are in an expanded state.

Subsequently, the inner tube 20 is switched to a reduced pressure state by the pressure controller 2. Then, as shown in FIG. 9E, the chamber chamber 40_1 on the tip 22 side having a large ratio S _i / L _i contracts first. When the chamber chamber 40_1 contracts, the length of the chamber chamber 40_1 increases due to the nature of the elastic member 10, and the chamber chamber 40_1 is extended in the axial direction. When the pressure is further reduced, the second chamber chamber 40_2 contracts as shown in FIG. 9 (f), the length thereof becomes longer, and the chamber chambers 40_1 and 40_2 are fed out in the axial direction. When the pressure is further reduced, as shown in FIG. 9G, the third chamber chamber 40_3 contracts, its length increases, and the chamber chambers 40_1 to 40_3 are fed out in the axial direction. By repeating pressurization and depressurization by the pressure controller 2, the operations shown in FIGS. 9A to 9G are repeated, and the propulsion unit 1 propels rightward, that is, toward the tip 22 side.

Here, for the sake of clarity, the chamber chambers 40_1 to 40_3 are shown to sequentially expand and contract, but in reality, the chamber chambers 40_2 and 40_3 also expand while the chamber chamber 40_1 is expanding. Conversely, while the chamber chamber 40_1 is contracting, the chamber chambers 40_2 and 40_3 may also contract.

(Ii) S _i / L _i ≦ S _j / L _j (i <j)
FIGS. 10A to 10G are diagrams for explaining the operation of another propulsion unit 1. Here, S _i / L _i ≦ S _j / L _j is established for the two chamber chambers 40 — _i and 40 — j that satisfy i <j. In this case, the order in which the plurality of chamber chambers 40 expand and contract is opposite to that shown in FIGS. As a result, the propulsion unit 1 propels leftward, that is, toward the rear end 24.

The above is the operation of the propulsion unit 1. According to the propulsion unit 1, by providing a gradient to the ratio S _i / L _i , the chamber chambers 40_1 to 40_3 are sequentially expanded and contracted only by controlling the pressure of one system to the inner tube 20. Thus, the propulsion unit 1 can be deformed like an earthworm to generate a propulsive force.

Also, as described in FIGS. 9 and 10, the direction of the propulsive force can be designed according to the direction of the gradient. Further, the propulsive force and the propulsive speed can be designed based on the area S of the opening 26 and the length L of the space. Further, in the propulsion unit 1, the plurality of chamber chambers 40 can be controlled by one system of air pressure source, and the cost and size can be greatly reduced as compared with the conventional moving body.

FIGS. 11A to 11C are diagrams showing design examples of the area S _i and the length L _i . In FIG. 11A, the lengths L ₁ to L ₃ are equal, and S ₁ > S ₂ > S ₃ holds.

In FIG. 11B, the areas S ₁ to S ₃ are equal, and L ₁ <L ₂ <L ₃ holds. In FIG. 11C, S ₁ > S ₂ > S ₃ and L ₁ <L ₂ <L ₃ are established. If the direction of travel is reversed, the direction of the inequality sign may be reversed.

FIGS. 12A to 12C are diagrams showing design examples of the area S when S ₁ > S ₂ > S ₃ . In FIG. 12A, each chamber chamber 40 is provided with one opening having a different area. In FIG. 12B, different numbers of openings of the same size are provided. In FIG. 12C, different numbers of openings having different sizes are provided. Alternatively, as shown in FIG. 13A described later, the same number of openings having different sizes may be provided.

Subsequently, an example of a specific manufacturing method of the propulsion unit 1 will be described. FIGS. 13A to 13D are diagrams showing a method for manufacturing the propulsion unit 1. As shown in FIG. 13A, the inner tube 20 has a plurality of openings 26_1 to 26_3. For example, the opening 26 may be formed using a needle-like instrument.

Referring to FIG. 13B, an example of a method for manufacturing the elastic member 10 will be described. Silicon (for example, Ecoflex 00-50: registered trademark) 14 is applied to the surface while rotating the carbon tube 12 to produce a silicon tube. Then, the thread 16 is wound around the surface of the silicon tube so as to have a network structure like McKibben. Then, the silicon 14 is soaked into the thread 16 to obtain a reduced pressure state (negative pressure), and the silicon 14 is coated on the thread 16 and cured. The stretchable member 10 may be a commercially available Mackiben type artificial muscle rubber.

As shown in FIG. 13 (c), the inner tube 20 is inserted into the elastic member 10. And as shown to phrase 6 (d), the restraint member 50 is mounted | worn so that the expansion-contraction member 10 may closely_contact | adhere with the inner tube 20 in the boundary of each of the some chamber chamber 40. For example, the restraining member 50 may be a nylon fiber, a polyamide-based synthetic fiber, or a metal wire such as a wire or a piano wire.

The above is the manufacturing method of the propulsion unit 1. The prototype of the propulsion unit 1 manufactured by the inventor by this manufacturing method was 2.5 g in weight, 18.5 cm in length, 2 mm in inner diameter of the elastic member 10, and 4 mm in outer diameter. This prototype confirms propulsion in a pipeline with an inner diameter of 6 mm to 8 mm, and a moving speed of 8 mm / sec (50 cm / min) has been obtained, making it practical for medical applications including active catheters. Is confirmed to be high.

In this prototype, the expansion / contraction member 10 could not sufficiently expand in the pipeline 140 narrower than the inner diameter of 6 mm, and the propulsive force was reduced. In other words, the diameter of the expansion / contraction member 10 may be optimized in consideration of the inner diameter of the conduit 140.

By combining the rotary actuator 100A and the propulsion unit 1, propulsion and direction steering can be controlled only by air pressure control.

2.3 Integration of Pneumatic System If the rotary actuator 100A and the propulsion unit 1 are simply combined, two systems, that is, the pressure control system of the rotary actuator 100 and the pressure control system of the propulsion unit 1 are required. This is an obstacle to reducing the diameter of the propulsion unit 1 because two pneumatic tubes are provided between the pressure controller 110 and the propulsion unit 1. Hereinafter, the moving body 130B that can control the rotary actuator 100A and the propulsion unit 1 by one pressure system will be described.

FIG. 14 is a diagram showing the moving body 130B. In the moving body 130B, pressure is supplied to the expandable balloon 102 of the rotary actuator 100A via the inner tube 20 of the propulsion unit 1. That is, the inner tube 20 also serves as the pneumatic tube 106.

The inner tube 20 is provided with at least one opening 28 for supplying pressure to the telescopic balloon 102. When the total area of the at least one opening 28 is S ₀ , S ₀ <S ₁ ,. _N holds. In the case of N = 3, when L ₁ = L ₂ = L ₃ , S ₀ <S ₃ <S ₂ <S ₁ holds.

The above is the configuration of the moving object 130B. Next, the operation will be described. FIG. 15 is a diagram showing the responsiveness of the pressure (i) inside the telescopic balloon 102 of the rotary actuator 100A and the pressure (ii) of the air chamber inside the telescopic member 10 of the propulsion unit 1. As can be seen from FIG. 15, since the flow passage area S ₀ of the rotary actuator 100A is the smallest, the response speed when pressurized becomes slowest. Specifically, the response speed of the expansion / contraction balloon 102 is about 1 second, and the response speed of the expansion / contraction member 10 is about 0.1 second, and the former is about 10 times larger.

As shown in FIGS. 9B to 9G, the pressure supplied to the inner tube 20 is pulsed. The pressurization time of the inner tube 20 in the normal propulsion motion is set to be shorter than the response time of the telescopic balloon 102. Therefore, during the normal propulsion motion, a pressure change does not substantially occur in the telescopic balloon 102. The rotary actuator 100A does not rotate.

When the rotary actuator 100A is to be rotated, the pressurization time of the inner tube 20 is lengthened. Thereby, the telescopic balloon 102 is pressurized, and the rotary actuator 100A can be rotated.

FIGS. 16A to 16G are diagrams for explaining the operation of the moving body 130B of FIG. FIGS. 16A to 16C correspond to FIGS. 9B to 9D. In these states, no pressure change has occurred in the rotary actuator 100A.

If the pressurization is further continued from the state of FIG. 16C, the expandable balloon 102 of the rotary actuator 100A is pressurized as shown in FIG. 16D, and the rotary actuator 100A rotates. When the rotary actuator 100A rotates to a desired angle, it is switched to a reduced pressure state as shown in FIG. FIGS. 16E to 16G correspond to FIGS. 9E to 9G. In the reduced pressure state, the pressure change occurs in the order of the chamber chambers 40_1, 40_2, and 40_3, and the pressure change of the expandable balloon 102 of the rotary actuator 100A hardly occurs. Therefore, the propulsion unit 1 can be propelled while maintaining the angle of the rotary actuator 100A.

When it is desired to propel the rotary actuator 100A without changing the direction, the state shown in FIG. 16D is not passed, that is, the time of the pressurized state is shortened, and FIGS. 16A to 16C and 16E are displayed. It is sufficient to repeat the states (g) to (g).

The above is the operation of the moving body 130. According to this moving body 130, the rotary actuator 100A and the propulsion unit 1 can be controlled by one system of pressure control.

2.4 Modification of the Propulsion Unit 1 The above-described propulsion unit 1 cannot propel the pipeline 140 having a large inner diameter because the expanded chamber chamber 40 needs to contact the inner wall 141 of the pipeline 140. Hereinafter, the propulsion unit 1A capable of propelling a pipe having a large inner diameter will be described.

FIG. 17 (a) is a diagram showing a propulsion unit 1A according to a modification. The propulsion unit 1A includes a plurality of restraining members 52 in addition to the propulsion unit 1 of FIG. The plurality of restraining members 52 are provided at the boundary between the adjacent chamber chambers 40. Specifically, the restraining members 52_1 and 52_2 are disposed substantially 180 degrees apart in the circumferential direction. FIG. 17B shows the state of restraint by the restraining member 52. When the chambers 40 _ 2 and 40 _ 3 are expanded by pressurization, the boundary (joint) thereof is bent to the side opposite to the restraining member 52.

Next, the operation of the propulsion unit 1A will be described. 18 (a) to 18 (g) are diagrams showing the operation of the propulsion unit 1A of FIG. 17 (a). When pressurization of the propulsion unit 1A is continued in the thick duct, the first joint, the second joint, and the third joint are bent in order as shown in FIGS. 18 (b) to 18 (d). When the pressure is subsequently reduced, as shown in FIGS. 18E to 18G, the first joint, the second joint, and the third joint expand in this order. By repeating this operation, the propulsion unit 1A can be propelled in a thick pipe.

The propulsion unit 1A propels in a narrow pipeline with a peristaltic motion as shown in FIGS. 9 (a) to (g). That is, the propulsion unit 1A has an advantage that the peristaltic motion and the bending motion are passively switched according to the diameter of the pipe line.

By combining the propulsion unit 1A and the rotary actuator 100A, it is possible to provide a moving body that can freely propel the inside of a pipe line in which the inner diameter is not constant and a branch exists.

The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. is there. Hereinafter, such modifications will be described.

In the embodiment, the case of using air pressure has been described, but depending on the application, fluid pressure such as water pressure or hydraulic pressure can be used.

Although the present invention has been described using specific terms based on the embodiments, the embodiments only illustrate the principles and applications of the present invention, and the embodiments are defined in the claims. Many variations and modifications of the arrangement are permitted without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Propulsion part, 2 ... Pressure controller, 10 ... Elastic member, 12 ... Carbon tube, 14 ... Silicon, 20 ... Inner tube, 21 ... Flow path, 22 ... Tip, 24 ... Rear end, 26 ... Opening, 40 ...

Chamber Chamber

50, 52 ... Restraining member 140 ... Pipe line 142 ... Branch 144 ... Branch 100 ... Rotary actuator 102 ... Telescopic balloon 104 ... Air chamber 106 ... Pneumatic tube 108 ... Spiral 110 ... Pressure controller , 120 ... tube, 122 ... thread-like member, 124 ... bending restraint member, 130 ... moving body.

The present invention can be used for an actuator using fluid pressure.

Claims

An actuator comprising an expandable balloon that expands in a radial direction and an axial direction by pressurization, wherein the expandable balloon is not easily expanded in a direction along a spiral and is not easily expanded in a radial direction and is restrained.
The actuator according to claim 1, wherein the telescopic balloon is further restrained in a curved state.
2. The actuator according to claim 1, wherein the expandable balloon has a non-uniform stretchability in the axial direction in the circumferential direction.
A tube whose tip is closed and expands in the radial and axial directions by pressurization;
A thread-like member wound spirally around the surface of the tube;
An actuator comprising:
The actuator according to claim 4, further comprising a bending restraining member provided inside the tube and restraining the tube in a curved state.
The actuator according to claim 5, wherein the tube is uneven in the axial direction with respect to the circumferential direction.
A tip portion provided with the actuator according to any one of claims 2, 3, 5, and 6,
The Promotion Department,
A moving body in a pipeline, comprising:
The propulsion unit
An inner tube that receives controllable pressure from the outside at the rear end;
An expandable member that expands in the radial direction by pressurization and contracts in the axial direction, and forms a plurality of N (N ≧ 2) chamber chambers in the axial direction outside the inner tube;
Including
The inner tube has at least one opening for each chamber chamber,
When the i-th (1 ≦ i ≦ N) chamber chamber axial length of which is L i, a total area of at least one opening corresponding to the i-th chamber chamber and S i, S i for each chamber compartment The moving body according to claim 7, wherein / L i is different.
Pressure is supplied to the telescopic balloon through the inner tube,
The inner tube is provided with at least one opening for supplying pressure to the telescopic balloon, and when the total area of the at least one opening is S 0 , S 0 <S 1 ,. The moving body according to claim 8, characterized in that:
The moving body according to claim 8 or 9, wherein the propulsion unit further includes a restraining member provided at a boundary between adjacent chamber chambers.
An inner tube that receives controllable pressure from the outside at the rear end;
An elastic member that expands in the radial direction by pressurization and contracts in the axial direction, and forms a plurality of chamber chambers in the axial direction outside the inner tube; and
A restraining member provided at the boundary between adjacent chamber chambers;
With
The inner tube has at least one opening for each chamber chamber,
The ratio S / L of each of the plurality of chamber chambers is different, where L is the length in the axial direction of the chamber chamber and S is the total area of at least one opening corresponding to the chamber chamber. Moving body.
The elastic member is tubular, and the inner tube is inserted into the elastic member,
The movable body according to any one of claims 8 to 11, wherein an inner wall of the elastic member and an outer wall of the inner tube are in close contact with each other at a boundary portion between the plurality of chamber chambers.
The moving body according to any one of claims 8 to 12, wherein the length L is shorter at the tip and the area S is larger at the tip.