JP2003184817A - Pump integrated type flexible actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high output of a pump by improving the suction efficiency by increasing a pump flow rate by enlarging the pressure difference between the suction side of a plurality of liquid chambers connected to a pump part and the inside of a pump chamber of the pump part and to reduce the weight and the size of the pump. <P>SOLUTION: A tube 16 constituting a movable part 6 is made of a material having stronger contraction force. A reservoir chamber 10 built-in an actuator body 8 is also made of the material having the stronger contraction force. One suction and discharge port 12a of the pump part 12 built-in the actuator body is connected to a lower end opening part of the tube 16 and the other suction and discharge port 12b is connected to a bag body 28. When a flexible actuator 2 is assembled, working oil S is forcibly fed so as to expand the tube 16 and the bag body 28 in prescribed volume. Internal pressure of the main liquid chamber 4 and the reservoir chamber 10 is enhanced by generation of the contraction force of the tube 16 and the bag body 28. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump-integrated flexible actuator suitable for a pet robot that comes into contact with human beings, a work robot that holds irregularly fragile fruits and the like in agricultural work.

[0002]

2. Description of the Related Art As an actuator for gripping an object, for example, Japanese Patent Laid-Open No. 5-172118 and Japanese Patent Laid-Open No. 5-172118 are known.
As disclosed in Japanese Patent Laid-Open No. 164112, an actuator that includes a cylindrical elastic body whose inside is divided into a plurality of pressure chambers, adjusts a fluid pressure acting on each pressure chamber, and bends and deforms the cylindrical elastic body. Is known (hereinafter, referred to as the first related art). Since the first tubular elastic body of this actuator is soft, it can be brought into soft contact with a person or an object.

In the first prior art, a pump for connecting and disconnecting the fluid in each pressure chamber is connected in order to adjust the fluid pressure in each pressure chamber. However, in order to operate the tubular elastic body swiftly, A high-power pump is required to instantly move the fluid in and out of the chamber. Further, in order to improve the portability and operability of the device, a small and lightweight pump that can be integrated with the actuator is required.

[0004]

During the suction operation of the pump, the internal pressure of the pump chamber decreases, fluid is sucked from the valve on the suction side into the pump chamber, and the magnitude of the differential pressure between the suction side and the pump chamber and the suction The pump suction amount is determined by the resistance, and this pump suction amount is the pump flow rate. That is, since the pump suction amount influences the flow rate of the pump, it is necessary to increase the differential pressure or reduce the suction resistance in order to increase the output of the pump.

However, in order to increase the differential pressure, even if it is attempted to lower the pressure in the pump chamber during the suction operation of the pump, in principle, it does not fall below 0 atmosphere or the vapor pressure of the fluid. Even if the pressure in the pump chamber is lowered below the above pressure, bubbles are generated due to cavitation, and the pressure difference between the suction side and the pump chamber is only atmospheric pressure, so the pump flow rate does not increase and high output is achieved. I can't plan. Here, for example, Japanese Patent Application Laid-Open No. 2-17204 discloses an actuator in which a drive source and a pump are integrally incorporated into a hydraulic cylinder (hereinafter referred to as a second conventional technique). FIGS. 5 and 7 of the second conventional technique show an embodiment in which an accumulator is connected to a hydraulic cylinder, and the accumulator is used for the differential pressure between the suction side (atmospheric pressure state) and the pump chamber described above. May be used as a means to increase However, if a pump structure in which the accumulator is connected is used, the size and weight of the pump cannot be reduced.

Therefore, the present invention improves the suction efficiency by increasing the differential pressure between the suction side of the plurality of liquid chambers connected to the pump section and the pump chamber of the pump section to increase the pump flow rate. It is an object of the present invention to provide a pump-integrated flexible actuator that is optimal as a pet robot or a work robot by increasing the output of the pump and reducing the weight and size of the pump.

[0007]

Therefore, in the flexible actuator integrated with a pump according to claim 1, at least two liquid chambers in which liquid is sealed and the liquid chamber shape is changed by performing liquid movement between these liquid chambers. A flexible pump-integrated actuator comprising: a movable part that deforms and operates; and a pump part that is integrally connected to the movable part and is connected to the plurality of liquid chambers to control the movement of the liquid. The internal pressure of the chamber was above atmospheric pressure.

According to a second aspect of the present invention, there is provided a pump-integrated flexible actuator according to the first aspect. In the above, the plurality of liquid chambers are connected to the pump unit and a main liquid chamber which is disposed in the movable unit and operates to move the liquid by inflow and outflow of the liquid. It was composed of a moving reservoir chamber. According to a third aspect of the present invention, in the pump-integrated flexible actuator according to the second aspect, the main liquid chamber and the reservoir chamber are formed by a bag-shaped member that can freely expand and contract, and particularly has a strong contracting force. However, the internal pressure of the main liquid chamber and the reservoir chamber is made higher than the atmospheric pressure by the contracting force generated when the liquid is sealed in these bag-shaped members.

According to a fourth aspect of the present invention, in the pump-integrated flexible actuator according to the second aspect, the reservoir chamber is formed of a bag-shaped member that can be expanded and contracted freely, and has a particularly strong contracting force. A posture holding member for holding the posture of the movable portion is formed of a member that generates an elastic restoring force, and a contracting force generated when a liquid is sealed in the bag-shaped member and an elastic restoring force of the posture holding member. By acting on the liquid in the main liquid chamber, the internal pressures of the main liquid chamber and the reservoir chamber are made higher than the atmospheric pressure.

According to a fifth aspect of the present invention, in the pump-integrated flexible actuator according to the fourth aspect, the movable portion is a long tube for enclosing a liquid to form the main liquid chamber, and this tube. A plurality of bone members arranged at a predetermined interval in the longitudinal direction of the tube, and an elastically deformable core material that holds the array of these bone members, and the tube is formed of a material that can expand and contract freely. It is composed of a plurality of flat-shaped bulging hollow portions provided at predetermined intervals and a reduced-diameter hollow portion that communicates between these bulging hollow portions, and the core material is the tube as the posture maintaining member. The elastic restoring force is applied in the direction of crushing the plurality of bulging hollow portions.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a pump-integrated flexible actuator according to the present invention will be described below with reference to the drawings. FIG. 1 shows the flexible actuator 2 of the first embodiment used as one pseudo finger of a robot. This flexible actuator 2
Is a long movable part 6 that bends when liquid moves to the main liquid chamber 4, an actuator body 8 that is integrated with the base end of the movable part 6, and a built-in actuator body 8. A reservoir chamber 10 in which a hydraulic oil S such as liquid silicon moves between the main chamber 4 and the main liquid chamber 4, a pump unit 12 for moving the reservoir chamber 10 and the main liquid chamber 4, and a pump unit 1.
And a pump drive unit 14 for performing drive control of the second.
The actuator body 8 serves as the base of the pseudo finger and is fixed to the hand of the robot (not shown).

The movable part 6 includes a long tube 16 forming the main liquid chamber 4, a plurality of bone members 18a, 18b ... Arranged at equal intervals in the longitudinal direction of the tube 16, and these bone members 18a, 18b. It is comprised with the core material 20 which hold | maintains the arrangement | sequence of ... The tube 16 is a semi-transparent member made of synthetic resin, which can expand and contract freely, but is made of a material having particularly strong contraction force. The tube 16 has a reduced-diameter hollow portion 24 between the flattened hollow portions 22a, 22b ...
It has a fern-like appearance of plants communicating with each other.

The plurality of bone members 18a, 18b ... Are hollow members made of synthetic resin and having a substantially rectangular shape in plan view. The bone member 18i shown in FIG. 2 has a recess 2 provided on the side that abuts the core member 20.
6, the reduced diameter hollow portion 24 of the tube 16 is inserted,
The tube 16 is sandwiched between the bulging hollow portions 22i and 22j from above and below. Further, the bone members other than the bone member 18i also have the reduced-diameter hollow portion 24 of the tube 16 inserted into the recess 26 and sandwiched between the bulging hollow portions 22a, 22b ... The uppermost bone member (18
The member arranged above j) is a cap member 30 formed of a synthetic resin or the like.

The core member 20 is a plate-like member made of elastically deformable synthetic resin or the like, and a plurality of screws 27 are used to fix the respective bone members 18a, 18b, ... At the same time, the lower end is fixed to the actuator body 8. Then, a sheet-shaped flexible material (not shown) is stretched over the entire surface of the core material 20 to which the screw 27 is attached.
Further, the actuator body 8 is fixed to the hand part of the robot via a fixing screw 32.

On the other hand, the reservoir chamber 10 which is built in the actuator body 8 and in which the liquid moves between the main liquid chamber 4 and the main liquid chamber 4 is formed inside a bag 28 made of synthetic resin. The bag body 28 can be freely expanded and contracted, but is formed of a material having a particularly strong contraction force. The pump unit 12 incorporated in the actuator body 8 uses, for example, a piezo-type diaphragm pump, and although not shown, an active valve and a diaphragm defining a pump chamber between the active valve and the diaphragm. And a piezo element (piezoelectric element) that is stacked on top of each other. Two suction / discharge ports 12a and 12b are connected to the active valve, and one suction / discharge port is connected.
The discharge port 12a is connected to the lower end opening of the tube 16, and the other suction / discharge port 12b is connected to the bag body 28.

The pump section 12 is controlled by the pump drive section 14 so that the suction / discharge port 12 connected to the bag body 28 can be controlled.
b is the suction side, and the suction / discharge port 12a connected to the tube 16 is the discharge side to perform the operation of supplying the hydraulic oil S of the reservoir chamber 10 into the tube 16, or
The suction / discharge port 12a connected to the tube 16 is used as the suction side, and the suction / discharge port 12b connected to the bag body 28 is used as the discharge side.
The operation to return to 0 is performed.

Further, the actuator body 8 is provided with a light emitting / receiving portion 34 including a light emitting element such as a light emitting diode and a light receiving element such as a photodiode, and the tube 16 is connected to the light receiving and emitting portion 34. At the lower surface position of the lowermost bone member 18a facing through the bulging hollow portion 22a,
A reflector 36 such as a mirror is provided. Then, the light emitting / receiving unit 34 sends the detection information of the reflected light amount emitted toward the reflecting unit 36 to the pump driving unit 14 at any time.

The pump drive section 14 has an input interface circuit for reading the detection signal from the light emitting / receiving section 34,
An arithmetic processing unit for performing a predetermined arithmetic process for driving and controlling the pump unit 12 according to a predetermined program;
A storage device such as M and ROM, and an output interface circuit that outputs a voltage control signal to the piezo element of the piezo-type diaphragm pump obtained by the arithmetic processing device are provided. A storage table for estimating the amount of displacement of the movable portion 6 based on the change in hydraulic pressure and the change in the amount of received light input from the light emitting / receiving unit 34 is stored. Then, the arithmetic processing device is configured to perform a predetermined arithmetic processing for driving and controlling the pump unit 12 with reference to the above-mentioned storage table.

Next, the main liquid chamber 4 and the reservoir chamber 10 in the initial state of the flexible actuator 2 having the above structure.
The state of the internal pressure will be described. The initial state is
When the drive of the pump unit 12 is stopped, the hydraulic fluid S is not moved between the main liquid chamber 4 and the reservoir chamber 10,
As shown in FIG. 1, the movable portion 6 is in an upright state. Then, when assembling the flexible actuator 2, the hydraulic oil S is press-fitted so that the tube 16 and the bag body 28 expand by a predetermined volume, and the tube 16 and the bag body 28 holding the state are sucked and discharged by the pump 12. Exit 1
Connect to 2a and 12b.

Here, the tube 1 in which the hydraulic oil S is press-fitted
6 and the bag body 28 are formed of a material having a strong contraction force as described above, and the tube 16 and the bag body 28 generate the contraction force, so that the internal pressures of the main liquid chamber 4 and the reservoir chamber 10 are equal to or higher than the atmospheric pressure. Has become. The tube 16 and the bag 2
The contracting forces of both 8 are adjusted so that the internal pressures of the main liquid chamber 4 and the reservoir chamber 10 are balanced via the pump 12 and the movable portion 6 is in the initial state.

Next, the operation of the flexible actuator 2 having the above structure will be described with reference to FIG. When the bending drive control current is output from the pump drive unit 14 to the pump unit 12, the pump unit 12 causes the hydraulic oil S in the reservoir chamber 10 sucked from the suction / discharge port 12b to flow into the suction / discharge port 1.
It is supplied to the main liquid chamber 4 via 2a. As a result, each bulging hollow portion 22 of the tube 16 into which the hydraulic oil S has flown
.. expand, the core members 20 are bent, and the bone members 18a, 18b .. are displaced, so that the entire movable portion 6 is bent with a predetermined curvature.

When a control current for releasing the bent state is output from the pump drive section 14 to the pump section 12, the pump section 12 causes the hydraulic oil S in the main liquid chamber 4 sucked from the suction / discharge port 12a to Reservoir chamber 1 through suction / discharge port 12b
Supply to 0. As a result, the volume of the bulging hollow portions 22a, 22b, ... Of the tube 16 decreases and the core material 2
The elastic restoring force of 0 returns each of the bone members 18a, 18b ... To their original positions. Thereby, as shown in FIG. 1, the movable portion 6 is in an upright state.

Next, the function and effect of this embodiment will be described below. The pump unit 12 of the present embodiment performs the suction operation by increasing the volume of the pump chamber and decreasing the internal pressure of the pump chamber. At that time, the minimum value of the pump chamber pressure is approximately 0 atm. On the other hand, the pressure of the hydraulic oil S, which is larger than the atmospheric pressure, acts on the suction / discharge ports 12a and 12b. The pump portion 12 performs an inhaling operation by the pressure difference between the two. Therefore, for example, when the pump portion 12 is driven when the movable portion 6 bends with a predetermined curvature, the pump portion 12 is connected to the bag body 28 on the inhalation side. The differential pressure between the suction / discharge port 12b side and the pump chamber increases, and the pump flow rate increases.

Further, when the pump portion 12 is driven when the bent state of the movable portion 6 is released, the tube 16 on the suction side is provided.
The pressure difference between the suction / discharge port 12a side connected to the pump chamber and the pump chamber increases, and the pump flow rate also increases. Therefore, since the pump suction efficiency is improved, the pump section 12 with high output can be obtained. Further, the pump unit 12 is
Since only the tube 16 and the bag body 28 constituting the flexible actuator 2 are used as parts for increasing the pressure difference between the suction side and the pump chamber, no additional parts such as an accumulator are needed. The size and weight can be reduced.

Therefore, the pump unit 12 has a small size, a light weight, and a high output, so that it is an optimum device as a pump unit for a pseudo finger of a robot, which must move quickly. Further, since the internal pressures of the main liquid chamber 4 and the reservoir chamber 10 are increased, the gas contained in the hydraulic oil S is less likely to generate bubbles that adversely affect the performance of the pump unit 12.

Further, since the tube 16 and the bag body 28 are formed of a material having a strong contraction force, even if the hydraulic oil S decreases due to leakage or volatilization, the tube 16 and the bag body 2
The contraction of 8 can reduce the influence on the performance of the actuator. Next, FIG. 4 shows a flexible actuator 40 of a second embodiment according to the present invention.
The same components as those of the first embodiment shown in FIGS. 1 to 3 are designated by the same reference numerals and the description thereof will be omitted.

The movable portion 6 of the flexible actuator 40 of this embodiment includes a long tube 42 forming the main liquid chamber 4, a plurality of bone members 18a arranged at equal intervals in the longitudinal direction of the tube 42, 18b ... and these bone members 1
8a, 18b ... And the core material 44 which holds the arrangement. The tube 42 is a semi-transparent member made of synthetic resin and can freely expand and contract, but unlike the tube 16 of the first embodiment, it is not formed of a material having a strong contracting force. The tube 42 has a flat bulging hollow portion 46 provided at a predetermined interval in the longitudinal direction.
It has an appearance like a fern of a plant in which a reduced diameter hollow portion 48 communicates between a, 46b ....

The core member 44 is a plate member made of elastically deformable synthetic resin or the like, and a plurality of screws 27 are used to fix the respective bone members 18a, 18b, ... At the same time, the lower end is fixed to the actuator body 8. Here, the core material 44 is a member that is bent in an unloaded state as shown by the solid line in FIG. 5, and as shown by the broken line in FIG. 5, the above-mentioned bone members 18a, 18b ... When it is opened and fixed to maintain the upright state, the elastic restoring force acts to return to the original bent state. The core material 44 is arranged so that the elastic restoring force acts in the direction in which the bulging hollow portions 46a, 46b, ... Of the tube 42 are arranged.

Further, the bag body 28 constituting the reservoir chamber 10 can be expanded and contracted freely as in the first embodiment, and is made of a material having a particularly strong contraction force. Also,
The suction / discharge port 12a on one side of the pump unit 12 is connected to the tube 4
2 is connected to the lower end opening, and the other suction / discharge port 12b is connected to the bag body 28. Next, the internal pressure states of the main liquid chamber 4 and the reservoir chamber 10 in the initial state of the flexible actuator 40 having the above configuration will be described. In addition,
Also in the initial state of the present embodiment, when the drive of the pump unit 12 is stopped, the hydraulic oil S is not moved between the main liquid chamber 4 and the reservoir chamber 10, and the movable portion is moved as shown in FIG. It means that 6 is upright.

When the flexible actuator 40 is assembled, the hydraulic oil S is press-fitted so that the tube 42 and the bag body 28 expand by a predetermined volume, and the tube 42 and the bag body 28 holding the state are sucked and discharged by the pump 12. Exit 1
Connect to 2a and 12b. Since the bag body 28 into which the hydraulic oil S is press-fitted is made of a material having a strong contraction force,
The contraction force of the bag body 28 increases the internal pressure of the reservoir chamber 10. On the other hand, the core material 44 that holds the upright state
Because the elastic restoring force acts in the direction of crushing the bulging hollow portions 46a, 46b ... Of the tube 42,
The internal pressure of the main liquid chamber 4 is increased.

The contracting force of the bag body 28 and the elastic restoring force of the core material 44 balance the internal pressures of the main liquid chamber 4 and the reservoir chamber 10 via the pump 12, so that the movable portion 6 is in the initial state. It is adjusted to power. Therefore, the flexible actuator 40 of the present embodiment also sucks and sucks the pump portion 12.
A pressure larger than the atmospheric pressure acts on the discharge ports 12a and 12b. Next, the operation of the flexible actuator 40 having the above structure will be described with reference to FIG.

When a control current for the bending operation is output from the pump drive section 14 to the pump section 12, the pump section 12 causes the hydraulic oil S of the reservoir chamber 10 sucked from the suction / discharge port 12b.
Is supplied to the main liquid chamber 4 through the suction / discharge port 12a. As a result, the tube 42 into which the hydraulic oil S has flown
The expanded hollow portions 46a, 46b ... Are expanded, the core members 44 are bent, the respective bone members 18a, 18b ... Are displaced, and the entire movable portion 6 is bent with a predetermined curvature.

When a control current for releasing the bent state is output from the pump drive unit 14 to the pump unit 12, the pump unit 12 causes the hydraulic oil S in the main liquid chamber 4 sucked from the suction / discharge port 12a to Reservoir chamber 1 through suction / discharge port 12b
Supply to 0. As a result, the volume of the bulging hollow portions 46a, 46b, ... Of the tube 42 decreases and the core material 4
By the elastic restoring force of 4, the bone members 18a, 18b ... Are returned to their original positions. Thereby, as shown in FIG. 1, the movable portion 6 is in an upright state.

Therefore, the pump portion 12 of this embodiment is
Also, since the pressure of the hydraulic oil S larger than the atmospheric pressure acts on the suction / discharge ports 12a and 12b, for example, when the pump portion 12 is driven when the movable portion 6 bends with a predetermined curvature, the suction The differential pressure between the suction / discharge port 12b side connected to the side bag body 28 and the pump chamber increases, and the pump flow rate increases. Further, when the pump portion 12 is driven when the bent state of the movable portion 6 is released, the differential pressure between the suction / discharge port 12a side connected to the tube 42 on the suction side and the pump chamber becomes large, and Pump flow rate increases.
Therefore, since the pump suction efficiency is improved, the pump section 12 with high output can be obtained.

Further, since the pump portion 12 does not require any additional component for increasing the pressure difference between the suction side and the pump chamber, the size and weight can be reduced. Therefore,
The present embodiment also provides the pump unit 12 that is downsized, lightweight, and has high output, and is therefore an optimum device as a pump unit for a pseudo finger of a robot that must perform agile operation.
Further, since the internal pressures of the main liquid chamber 4 and the reservoir chamber 10 are increased by the contracting force of the bag body 28 and the elastic restoring force of the core material 44, bubbles are generated by the gas contained in the hydraulic oil S. And the durability of the pump unit 12 is not affected. The pump unit 12 is not limited to the device integrated with the pseudo finger of the robot shown in the first and second embodiments, but is optimal as a pump unit integrated with a pet robot or a work robot.

[0036]

As described above, according to the pump-integrated flexible actuator of the present invention, the pressure of the liquid chamber on the suction side with respect to the pump portion is set to a pressure higher than the atmospheric pressure, so that when the pump portion is driven. The pressure difference between the suction side and the pump chamber increases, and the pump flow rate increases. As a result, the pump suction efficiency is improved and a high-output pump section can be obtained, so that the movable section can be moved with agile operation.

Further, in the pump-integrated flexible actuator of the present invention, the internal pressure of the liquid chamber (main liquid chamber 4, reservoir chamber) is increased, so that the performance of the pump portion is improved by the gas contained in the liquid. It is possible to reduce problematic bubbles. And, in particular, according to the inventions of claims 3 to 5, as a component for increasing the differential pressure between the suction side and the pump chamber, a bag-shaped member forming the main liquid chamber and the reservoir chamber of the flexible actuator, Since only the core material is used and no additional parts such as an accumulator are required, it is possible to reduce the size and weight of the pump portion.

[Brief description of drawings]

FIG. 1 is a diagram showing a vertical cross-sectional view of a pump-integrated flexible actuator of a first embodiment used as a pseudo finger of the present invention.

FIG. 2 is a view taken along the line II-II of FIG.

FIG. 3 is a diagram showing a state where the pump-integrated flexible actuator of the first embodiment is bent.

FIG. 4 is a diagram showing a vertical sectional view of a pump-integrated flexible actuator according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a core material used in the second embodiment, in which an elastic restoring force is generated.

[Explanation of symbols]

2,40 Flexible actuator 4 Main liquid chamber 6 moving parts 10 Reservoir chamber 12 Pump section 12a, 12b Suction / discharge port 14 Pump drive 16,42 tube (bag-shaped member) 18a, 18b ... Bone member 20 heartwood 22a, 22b ... Swelling hollow part 24,48 Reduced diameter hollow part 28 Bag (bag-shaped member) 34 Light emitting / receiving unit 36 Reflector 44 Core material (posture holding member) 46a, 46b ... Swelling hollow part S hydraulic oil (liquid)

Claims (5)

[Claims] 1. At least two liquid chambers enclosing a liquid, a movable part that deforms and operates when the liquid is moved between the liquid chambers, and is integrally connected to the movable part, In a pump-integrated flexible actuator including a pump unit that is connected to the plurality of liquid chambers and controls liquid movement, the internal pressure of the plurality of liquid chambers is set to a pressure higher than atmospheric pressure. Flexible actuator with integrated pump. 2. A plurality of liquid chambers are provided between a main liquid chamber which is arranged in the movable part and operates to move by inflow and outflow of liquid, and a main liquid chamber which is connected to the pump part. 2. The pump-integrated flexible actuator according to claim 1, wherein the flexible actuator comprises a reservoir chamber for moving the liquid. 3. The main liquid chamber and the reservoir chamber are formed by a bag-shaped member that can be expanded and contracted freely and has a particularly strong contraction force, and a contraction force generated when a liquid is sealed in these bag-shaped members. 3. The pump-integrated flexible actuator according to claim 2, wherein the internal pressures of the main liquid chamber and the reservoir chamber are set to be higher than atmospheric pressure. 4. The reservoir chamber is formed of a bag-shaped member that can expand and contract freely and has a particularly strong contracting force, while an elastic restoring force is generated in an attitude holding member that holds the attitude of the movable portion. The main liquid chamber and the reservoir are formed by applying a contracting force generated when a liquid is sealed in the bag-shaped member and an elastic restoring force of the posture holding member to the liquid in the main liquid chamber. The pump-integrated flexible actuator according to claim 2, wherein the internal pressure of the chamber is set to a pressure higher than atmospheric pressure. 5. The movable part includes a long tube that encloses a liquid to form the main liquid chamber, a plurality of bone members arranged at predetermined intervals in the longitudinal direction of the tube, and a plurality of bone members of these bone members. An elastically deformable core material for holding the arrangement, the tube is formed of a material that can expand and contract freely, and a plurality of flat-shaped bulging hollow portions provided at predetermined intervals in the longitudinal direction, and these bulging portions. It is configured with a reduced-diameter hollow portion that communicates between the protruding hollow portions, and the core material acts as an elastic restoring force in a direction of crushing the plurality of protruding hollow portions of the tube as the posture maintaining member. The pump-integrated flexible actuator according to claim 4, which is characterized in that.