JP2009008108A - Expansion and contraction actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive mechanism not using a slide part seal requiring periodical replacement in a submerged robot and the like. <P>SOLUTION: An electrical wire penetration part 25 in which an electrical wire 26 for electric power supply and the transfer of a control signal to the inside of an airtight chamber is electrically insulated and penetrates an end plate in a state that pressure resistance and airtightness for withstanding a pressure difference between an inside and an outside is provided in a linear motion mechanism unit 10 having a linear motion mechanism element 11 comprising a spiral screw shaft 20, a female screw (motor rotor) 21, and a motor stator 22 built in an airtight chamber 40 comprising an end plate A23, an end plate B23a, and a stretchable cylindrical film member 30, and the airtight chamber is filled with liquid 50 having an electrical insulation property. Consequently, an expansion and contraction actuator suitable to used underwater or under the sea is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a telescopic actuator suitable for linear drive of equipment used underwater or in the sea.

    Japan is a marine nation surrounded by the sea and has enjoyed great benefits from the sea. In recent years, however, various developments and overfishing have contributed to the danger of extinction. Under these circumstances, efforts aimed at “natural regeneration” have become active, and the need for marine research using underwater robots has become stronger than before. Most of the underwater robots used in these surveys employ screws as the propulsion method and boast a wealth of achievements in terms of performance and reliability, but leave room for improvement in terms of being friendly to marine life. Yes. The inventors have so far developed a fish-type robot that applies elastic vibrating wings and swims by generating a thrust with a fin. From the experience of development conducted so far, it has been found that fins using elastic vibrating wings have excellent characteristics that they are friendly to the environment and marine organisms. I am paying attention.

FIG. 5 shows a configuration example in which a rocking arm mechanism 72 and a tension wire 71 are applied to an elastic vibrating wing as an example of a conventional fish robot 70. FIG. 5A shows a side sectional view, and FIG. 5B shows a plan sectional view. Here, the fins of the elastic oscillating wings swing the spring plate member 68 to the left and right by stretching the tension wire 71 on both sides of the elastic spring plate member 68 and alternately pulling the ends in water (or in the sea). Thrust is generated by using the bending that occurs in Since the locking arm mechanism 72 is used underwater (or underwater), a driving motor 75 is accommodated in the main body waterproof container 76, and a shaft seal 74 such as an O-ring is provided on the sliding portion of the rotary drive shaft 73 to form the main body container. The end plate 64 is penetrated.
Here, 66 is a fixing portion of the pulling wire 71, and 76 is a main body waterproof container. Reference numeral 78 denotes a battery, 77 denotes a control device, and 67 denotes a motor control command / electric power supply wire.

Japanese Patent Application 2006-326055 "Fish Robot Structure"

    The screw used in most conventional underwater robots has a rotating shaft, and the sliding part is sealed with an O-ring, etc., but the seal of the sliding part is worn or damaged after a certain period of use. Leakage (leakage) occurs because it receives. If there is a water leak (leak), there is no other way than to replace the seal, so even if you are performing a marine research mission, you will need to replace the seal by interrupting it once and raising the underwater robot on land. . For this reason, it is difficult to use an underwater robot for ocean surveys that require continuous data collection over a long period of time, and this is the biggest challenge for underwater robots. Further, as described with reference to FIG. 5, even a fish-type robot that generates thrust by the fins of elastic vibrating blades has a similar problem with the seal of the sliding portion used for the rotating shaft of the rocking arm mechanism.

On the other hand, there is a magnetic coupling method as a drive mechanism that does not use a sliding part seal that needs to be replaced periodically. For the screw shaft of an underwater robot and the rotation shaft of a rocking arm mechanism of a fish-shaped robot, it is possible to eliminate the seal by cutting the shaft in a center and connecting it with a magnetic coupling. However, magnetic coupling has the following problems in terms of the characteristics of transmitting torque by magnetic force: (1) Power transmission efficiency is low (2) There is an upper limit to transmission torque (3) The mechanism itself has to use a strong magnet. There are many practical risks, such as becoming heavier, and there are few actual examples.
The present invention has been made in view of the above-described conventional problems, and an object thereof is to realize a drive mechanism that does not use a seal of a sliding portion.

  In order to achieve the above object, the present invention devised an appropriate expansion / contraction actuator, and by using this expansion / contraction actuator instead of a tension wire, the spring plate member is swung left and right, and thrust is generated by utilizing the bending generated at that time. The method to generate. By adopting this method, it is possible to realize a drive mechanism that does not use a seal for the sliding portion, and there are hardly any problems associated with the mechanism change.

The invention of claim 1 proposes this appropriate telescopic actuator, and the configuration is shown in FIGS. Here, FIG. 1 is a diagram illustrating a state where the telescopic actuator is extended, and FIG. 2 is a diagram illustrating a state where the telescopic actuator is contracted. The configuration of the present invention includes a helical screw shaft 20, a female screw component (motor rotor) 21 that is screwed to the helical screw shaft 20, and a motor for rotating the female screw component (motor rotor) 21 <female screw component (motor rotor) 21 and motor stator. 22> and a female screw part (motor rotor) 21 is rotatably fixed to the motor stator 22. In the linear motion mechanism element 11 in which the spiral screw shaft 20 is linearly reciprocated, an end plate A23 fixed to the end of the spiral screw shaft 20 and an end plate B23a fixed to the motor stator 22 are connected to the spiral screw shaft 20. A state in which the linear motion mechanism element 11 is enclosed in an airtight chamber 40 composed of an end plate A23, an end plate B23a, and a stretchable tubular membrane member 30 with the range of linear reciprocating motion interposed therebetween. It is the linear motion mechanism unit 10 comprised by these. Here, the motor stator 22 is fixed to one end plate B 23 a by a fixing component 27. The electric wire 26 for supplying electric power to the inside of the hermetic chamber 40 and for transmitting / receiving control signals is electrically insulated and has a pressure resistance and an air tightness that can withstand a pressure difference between the inside and the outside. It penetrates the end plate B23a or both end plates. The airtight chamber 40 is filled with a liquid 50 having electrical insulation.
Here, 24 and 24a are clasps for wires or the like.

    Next, regarding the expansion / contraction actuator of the present invention, the necessity of filling the liquid 50 in the hermetic chamber 40, which is a requirement on the mechanism, will be described. A linear motion mechanism element 11 is built in an airtight chamber 40 composed of the end plates A23, B23a and the elastic tubular membrane member 30, and the linear motion mechanism element 11 is used when used in water (or in seawater). However, it does not come into direct contact with water (or seawater). On the other hand, in water (or in seawater), water pressure is applied to the hermetic chamber 40, and deformation tends to occur in the compression direction. If the force against the water pressure does not act on the airtight chamber 40, the shrinkage of the airtight chamber 40 proceeds as the water pressure rises, and finally, until the tubular member 30 having elasticity is stuck to the linear motion mechanical element 11. As the deformation progresses, the telescopic actuator becomes impeded by the linear motion and does not operate. For this reason, a structural measure for suppressing shrinkage deformation is indispensable, but filling of the airtight chamber 40 with the liquid 50 is the best measure. That is, by filling the airtight chamber 40 with the liquid 50 having a volume compressibility corresponding to water, a pressure that balances the water pressure is generated in the airtight chamber 40 so that the deformation of the airtight chamber 40 hardly occurs. Can do. In addition, when the telescopic actuator is operated under water pressure, the volume of the airtight chamber 40 does not change in any state of the telescopic operation, so that the linear motion mechanism element 11 works against water pressure in water (or in the sea). (Loss) does not occur. That is, the expansion / contraction of the linear motion mechanism element 11 does not require a force against the water pressure, and therefore can be used basically at any depth. In addition, it is necessary to use what has electrical insulation, such as electrical insulation oil, for the liquid 50 which contacts electrical components, such as a motor.

    The invention of claim 2 proposes application of a bellows-like or bellows-like stretchable member as the stretchable tubular membrane member 30 of claim 1. In contrast to the configuration example shown in FIG. 2, by forming the cylindrical membrane member 30 in a bellows shape or a bellows shape as shown in FIG. 3, the strain generated in the member during expansion and contraction can be kept low.

    The invention of claim 3 is an adaptation example in which the telescopic actuator of the present invention described in claims 1 and 2 is incorporated in a fish-type underwater robot.

  According to the present invention, instead of the tension wire of the elastic vibration wing of the fish-type robot, the drive mechanism without a seal in the sliding portion can be obtained by using an expansion / contraction actuator. Is no longer necessary. As a result, it is possible to provide a fish-type underwater robot suitable for oceanographic surveys that require continuous data collection, and to greatly improve the quality of data obtained by oceanographic surveys.

    The best embodiment 1 of the telescopic actuator of the present invention will be described with reference to FIG. Here, FIG. 1 is an explanatory view showing a state in which the telescopic actuator is extended, that is, a state in which the linear motion mechanism element 11 is at the right end of the helical screw shaft 20. In this case, the cylindrical member 30 is in an extended state as shown in the drawing. On the other hand, FIG. 2 is an explanatory view of the contracted state, that is, the state in which the linear motion mechanism element 11 is moved to the left end of the spiral screw shaft 20. In this case, as shown in the figure, the cylindrical member 30 is inflated by the amount of the entire length being shortened. The drive mechanism element 11 is an example in which a built-in type motor is employed to form a telescopic actuator compactly. The screw component (motor rotor) 21 is rotatably fixed to the motor stator 22 by a bearing. The screw part (motor rotor) 21 is screwed with the spiral screw shaft 20. As the screw part (motor rotor) 21 rotates, the spiral screw shaft 20 makes a linear reciprocating motion in the forward and backward directions. The motor stator 22 is fixed to the end plate B23a with a fixing component 27. The cylindrical member 30 needs to follow the linear reciprocation of the linear motion mechanism unit 10 and is made of a material having an appropriate stretchability such as an air laster. In addition, since the cylindrical member 30 is a member in which expansion and contraction is repeated, it is necessary to consider fatigue. However, as illustrated in FIG. It is effective to have a structure that keeps low. Electric power is supplied to the motor and control signals are exchanged through the electric wire 26. The electric wire 26 penetrates the end plate B23a and is provided with a wire penetration portion 25 that is electrically insulated and has pressure resistance and airtightness for use in water (or underwater). Since the liquid 50 filling the hermetic chamber 40 is in direct contact with the coil part and the electric parts of the motor 22 and the female screw part (motor rotor) 21 and the wiring 26, it is suitable to use an electric insulating oil having an electric insulating property. Further, the liquid 50 needs to have a function of suppressing the shrinkage of the hermetic chamber due to water pressure, and for this purpose, a liquid having a volume compressibility corresponding to water is selected.

  Next, the best embodiment 2 in which the telescopic actuator of the present invention is applied to a fish robot will be described with reference to FIGS. 4 (a), 4 (b), and 4 (c). Here, FIG. 4 is a plan sectional view showing a schematic configuration of the fish robot. As described with reference to FIG. 5, the conventional system has a structure in which the tension wire 71 is stretched on both surfaces of the spring plate member 68, the ends are alternately pulled by the locking arm mechanism 72, and the tail fin spring plate member 68 is swung left and right. there were. On the other hand, in the present invention, as shown in FIG. 4A, the expansion and contraction actuators 61 and 61 a are arranged on the left and right sides of the spring plate member 68, assuming the role of the locking arm mechanism 72. The telescopic actuators 61 and 61a are fixed to the spring plate member 68 and the main body container end plate 64 via wires 62 and 63, respectively. The spring plate member 68 is fixed to the main body container end plate 64 by a spring plate member fixing portion 65, and the expansion and contraction actuators 61 and 61a are expanded and contracted alternately left and right to swing the tail fin spring plate member 68 left and right. FIG. 4B shows a state in which the lower extension actuator 61a is contracted and the opposite extension actuator 61 is extended. As a result, the spring plate member 68 is bent downward in the figure. In a state opposite to this state, that is, as shown in FIG. 4C, when the telescopic actuator 61a in the lower part of the figure is extended and the telescopic actuator 61 on the opposite side is contracted, the spring plate member 68 is bent upward in the figure. . By repeating such movement continuously, thrust is generated by the tail fin spring plate member 68, and the fish robot 60 can be propelled. Control commands and power supply for motor operation of the telescopic actuators 61 and 61a are performed through a motor control command / power supply wire 80 from a control device 77 and a battery 78 mounted on the fish robot 60. A fish-type robot 60 with this configuration was manufactured, and when a swimming test was actually conducted in a test tank with a water depth of 5 m, it was confirmed that it exhibited the same swimming characteristics as a fish-type robot using a conventional tension wire. It was.

FIG. 1 is an example of the best mode for carrying out the present invention, and FIG. Shrinked state It is the figure which showed the example which applied the member of the bellows shape or the bellows shape as an elastic cylindrical membrane member. It is the figure which showed the example which applied this invention to the elastic vibration wing | blade of a fish type robot. (A) Left and right (upper and lower in the figure) extension actuators are equal in length (b) Left (upper and lower) extension actuator is extended and right (lower in the figure) is contracted (C) is a state in which the telescopic actuator on the left side (upper side in the figure) is contracted, and a state in which the right side (lower side in the figure is extended) is extended, and the tail fin is moved to the right side (lower side in the figure). It is the figure which showed the state swung to the left side (in the illustration upper side). It is the figure which showed the example which applied the rocking arm mechanism and the tension | pulling wire to the elastic vibration wing | blade of the conventional fish type robot. (A) is a side view and (b) is a plan view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Linear motion mechanism unit 11 Linear motion mechanism element 20 Spiral screw shaft 21 Female thread component (motor rotor)
22 Motor stator 23 End plate A
23a End plate B
24 Clasp A
24a Clasp B
DESCRIPTION OF SYMBOLS 25 Electric wire penetration part 26 Electric wire 27 Fixed part 30 Cylindrical membrane member 32 Bellows-shaped or bellows-shaped member 40 Airtight chamber 50 Liquid 60 The example of the fish-type robot to which the expansion / contraction actuator of this invention is applied 61 Telescopic actuator 61a Telescopic actuator 62 Wire 62a Wire 63 Wire 63 A Wire 64 Main body container end plate 65 Spring plate member fixing portion 66 Wire fixing portion 67 Motor control command / power supply wire 68 Spring plate member
70 Example of Conventional Fish Robot 71 Tension Wire 71a Tension Wire 72 Locking Arm Mechanism 73 Rotation Drive Shaft 74 Axis Seal 75 Motor 76 Main Body Waterproof Container 77 Controller 78 Battery 80 Motor Control Command / Power Supply Wire

Claims (3)

A helical screw shaft, a female screw component screwed to the helical screw shaft, and a motor for rotationally driving the female screw component are provided, and the female screw component is rotatably fixed to the motor stator so that the helical screw shaft is linearly reciprocated. In the linear motion mechanism element, the end plate A fixed to the motor stator and the end plate B fixed to the end of the helical screw shaft are installed across the range of linear reciprocation of the helical screw shaft, and the end plate A and the end plate In the linear motion mechanism unit configured to wrap the linear motion mechanism element inside the hermetic chamber composed of B and the elastic tubular membrane member, power supply and control signal transmission / reception to the airtight chamber are performed. Is a wire penetrating portion that is electrically insulated and has pressure resistance and airtightness that can withstand pressure difference between inside and outside, and penetrates end plate A or end plate B or both end plates, and Liquid with electrical insulation in hermetic chamber Wherein the filled in, expansion actuators suitable for use in water or in the sea. The linear motion mechanism unit according to claim 1, suitable for use in water or in the sea, characterized by using a bellows-like or bellows-like stretchable member as a stretchable tubular membrane member Telescopic actuator. An underwater robot comprising the telescopic actuator having the configuration described in claim 1 or 2 as a propulsion mechanism of the underwater robot.

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