JP7124754B2 - Buoyancy adjustment device and underwater vehicle - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a buoyancy adjustment device and an underwater vehicle equipped with the buoyancy adjustment device.

Patent Documents 1 and 2 disclose devices for adjusting the floating amount. The float adjustment device of Patent Document 1 controls the ratio of the volume occupied by water and the volume occupied by air inside the vehicle. The buoyancy adjustment device changes the ratio between the volume occupied by water and the volume occupied by air by expanding and contracting the float from the watertight compartment. The float adjustment device of Patent Document 2 includes an air chamber and a submerged chamber. The air chamber and the immersion chamber are separated by a circular partition plate. By changing the position of the circular partition plate, the ratio between the volume of the air chamber and the volume of the immersion chamber is adjusted, and as a result, the buoyancy is adjusted. A seal ring is provided between the circular partition plate and the cylindrical container.

JP 2008-120316 A JP 2010-188865 A

An underwater vehicle requires a device for adjusting the buoyancy in order to control its position and attitude in water. By changing the ratio of the volume occupied by water and the volume occupied by gas inside the underwater vehicle, the buoyancy can be controlled. That is, the buoyancy adjustment device includes a portion occupied by water and a portion occupied by gas. These parts need to be watertight and airtight so that water and gas cannot move between each other.

However, if the ratio of the volume occupied by water to the volume occupied by gas is to be changed, the device requires moving parts. It is difficult to keep watertightness and airtightness in this moving part. As a result, when the underwater vehicle is operated for a long period of time and the float is repeatedly adjusted, the watertightness and airtightness of the movable parts may deteriorate. If the watertightness and airtightness are lowered, the desired floating amount cannot be obtained. As a result, it becomes necessary to stop operation such as performing maintenance.

Therefore, the present disclosure describes a buoyancy adjustment device that can withstand long-term operation and an underwater vehicle equipped with the buoyancy adjustment device.

A float adjustment device according to one embodiment of the present disclosure includes a cylinder, a piston inserted into the cylinder and dividing the inside of the piston into a front region and a rear region, arranged in the front region and attached to the cylinder, A variable storage portion that divides the front region into a first region and a second region, and a variable storage portion formed on the inner peripheral surface of the cylinder and the outer peripheral surface of the piston, to allow the movement of gas and liquid from one to the other in the front region and the rear region and a second sealing portion provided at the connection portion between the cylinder and the variable housing portion, the variable housing portion for adjusting the float according to the movement of the piston. Increase or decrease the volume of the first region containing the liquid.

The piston reciprocates with respect to the cylinder when adjusting the float. Since the buoyancy adjusting device has the first sealing portion, mutual movement of gas and liquid between the front region and the rear region is inhibited. Additionally, the buoyancy adjuster takes in liquid as it reduces the buoyancy. This liquid is taken into the variable reservoir. The variable housing portion is connected to the cylinder through the second sealing portion. As a result, when liquid is introduced into the variable storage portion, the liquid is prevented from entering the second region in the front region. In other words, the buoyancy adjusting device can ensure the desired watertightness and airtightness by providing the two sets of sealing portions, so that the desired buoyancy can be maintained. Therefore, the float adjustment device can withstand long-term operation.

In one form of the float adjustment device, the variable housing portion may have a fixed portion fixed to the piston. According to this configuration, a desired relationship can be achieved between the amount of movement of the piston and the volume of the liquid taken into the variable storage portion. Therefore, the floating amount can be adjusted with high accuracy.

In one form of the float adjustment device, the variable housing portion may be a bellows member. According to this configuration, it is possible to more preferably control the relationship between the amount of movement of the piston and the volume of liquid taken into the variable storage portion. As a result, the floating amount can be adjusted with higher accuracy.

In one form of the float adjustment device, the piston has a piston shaft that protrudes through an end face of the cylinder from the back surface that forms the rear region, and the cylinder has a through hole that allows the piston shaft to pass through. A third sealing portion may be further provided which is formed on the inner peripheral surface of the hole and the outer peripheral surface of the piston shaft and which inhibits the movement of gas from one side to the other in the rear region to the outer region of the cylinder. In a buoyancy adjuster, the buoyancy is determined by the ratio of the volume of liquid taken in the front region to the volume of gas contained in the rear region. In the rear region, the first sealing portion prevents gas from leaking out to the front region. Furthermore, in the rear region, the third sealing portion prevents gas from leaking out of the cylinder. That is, the gas sealed in the rear area does not increase or decrease even if the buoyancy is repeatedly adjusted. Therefore, the float height adjustment device can repeatedly adjust the float height during long-term operation.

An underwater vehicle that is another aspect of the present disclosure includes a floating body body, a power generating section provided in the floating body body for generating power for moving the floating body body, and a floating body body provided in the floating body body. a buoyancy adjusting device for adjusting the buoyancy of the cylinder, the buoyancy adjusting device comprising a cylinder, a piston inserted into the cylinder to divide the inside of the piston into a front region and a rear region, and a front region and attached to the cylinder to divide the front region into a first region and a second region; and a second sealing portion provided at the connection portion between the cylinder and the variable housing portion, wherein the variable housing portion moves according to the movement of the piston. to increase or decrease the volume of the first area that contains the liquid for adjusting the float.

Since this underwater vehicle is provided with the buoyancy adjusting device, it can withstand long-term operation.

The buoyancy adjustment device and underwater vehicle of the present disclosure can withstand long-term operation.

FIG. 1 is a diagram showing how an underwater vehicle according to the present disclosure is operated. 2 is a cross-sectional view of a buoyancy adjusting device provided in the underwater vehicle shown in FIG. 1. FIG. FIG. 3 is a cross-sectional view showing a modified float adjustment device.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 1 shows a system utilizing the underwater vehicle of the present disclosure. This system performs underwater exploration and surveillance. The system includes a surveillance robot 1 (underwater vehicle), multiple exploration robots 101 and a support vessel 102 . The exploration robot 101 has, for example, a sonar for seabed exploration, and explores the state of the seabed S1. The exploration robot 101 is capable of autonomous navigation. The exploration robot 101 is connected to the monitoring robot 1 by acoustic communication, which is wireless communication. The monitoring robot 1 leads a plurality of exploration robots 101 and enables cooperative navigation by the plurality of exploration robots 101 . The monitoring robot 1 is connected with the exploration robot 101 by acoustic communication as described above. Also, the monitoring robot 1 is connected to the support ship 102 by wireless communication such as satellite communication. The monitoring robot 1 transmits the information obtained from the exploration robot 101 to the support ship 102 and also obtains commands necessary for navigation from the support ship 102 . The support ship 102 comprehensively operates these systems.

The surveillance robot 1 has an antenna 2 for wireless communication with the support vessel 102 . The position of this antenna 2 is above the water surface S2. Therefore, the monitoring robot 1 needs to maintain a depth that allows the antenna 2 to be positioned above the water surface. This depth control is performed by the float adjustment device 10 .

A monitoring robot 1 that is an underwater vehicle includes a floating body main body 4 , a power generator 6 , antennas 2 and 7 , and a buoyancy adjustment device 10 . The floating body main body 4 accommodates equipment such as the buoyancy adjusting device 10 . The floating body main body 4 has an area that does not allow seawater (liquid) to enter and an area K1 that allows seawater to enter. For example, computers and communication equipment for autonomous navigation are placed in areas that do not allow seawater intrusion. For example, the buoyancy adjusting device 10 is arranged in the area K1 that allows seawater to enter. The power generator 6 generates a thrust for moving the monitoring robot 1 . Antenna 2 is used for wireless communication with support vessel 102 . Antenna 7 is used for wireless communication with exploration robot 101 . The float adjustment device 10 generates a float for depth adjustment of the monitoring robot 1 . Also, the buoyancy adjusting devices 10 are arranged at the front and the rear of the floating body main body 4, respectively. The posture (pitch angle) of the monitoring robot 1 is controlled by varying the float generated by each float adjusting device 10 .

The float adjustment device 10 will be described in detail below with reference to FIG.

The buoyancy adjusting device 10 has a cylinder 11, a piston 12, a driving portion 13, and a bellows 14 (bellows member). Furthermore, the buoyancy adjusting device 10 has a first sealing portion 16 , a second sealing portion 17 , a third sealing portion 18 , and a fourth sealing portion 19 . The buoyancy adjusting device 10 adjusts the volume of seawater taken into the bellows 14 by moving the piston 12 . The buoyancy changes according to the volume of seawater taken into the bellows 14 . For example, increasing the volume of sea water will decrease the buoyancy. Decreasing the volume of seawater increases the buoyancy.

The shape of the cylinder 11 is cylindrical. The cylinder 11 is made of a hard material such as a metal material. The front end face 11a of the cylinder 11 is provided with a front hole 11aH. This front hole 11aH is for the bellows 14. As shown in FIG. A rear end surface 11b of the cylinder 11 is also provided with a rear hole 11bH (through hole). The rear hole 11bH is for the piston 12. As shown in FIG.

The piston 12 has a piston body 21 and a piston shaft 22 . The piston body 21 is inserted into the cylinder 11 and arranged to be movable in the direction of the cylinder axis A. As shown in FIG. The piston body 21 partitions the interior of the cylinder 11 into a water chamber 23 (front area) and an air chamber 24 (rear area). The piston main body 21 has a piston main surface 21a, a piston back surface 21b, and a piston outer peripheral surface 21c. The piston main surface 21a is a surface on the front end surface 11a side of the cylinder 11 and forms a water chamber 23 together with the cylinder inner peripheral surface 11c. The piston back surface 21 b is a surface on the rear end surface 11 b side of the cylinder 11 and forms an air chamber 24 together with the cylinder inner peripheral surface 11 c and the rear end surface 11 b of the cylinder 11 . The piston outer peripheral surface 21c faces the cylinder inner peripheral surface 11c. The piston outer peripheral surface 21c is configured to be slidable with respect to the cylinder inner peripheral surface 11c. Further, an O-ring 26 that constitutes the first sealing portion 16 is provided on the outer peripheral surface 21c of the piston. The O-ring 26 prevents seawater from moving from the water chamber 23 side to the air chamber 24 side. Further, the O-ring 26 prevents air from moving from the air chamber 24 side to the water chamber 23 side.

A piston shaft 22 is provided on the back surface 21b of the piston. The axis of the piston shaft 22 overlaps with the cylinder axis A. The front end of the piston shaft 22 is connected to the piston back surface 21b. A rear end of the piston shaft 22 is arranged outside the cylinder 11 . That is, the piston shaft 22 extends to the outside of the cylinder 11 through the rear hole 11bH provided in the rear end surface 11b of the cylinder 11. As shown in FIG. A third sealing portion 18 is provided between the outer peripheral surface 22c of the piston shaft 22 and the rear hole 11bH. The third sealing portion 18 allows the outer peripheral surface of the piston shaft 22 to slide with respect to the cylinder inner peripheral surface 11c surrounding the rear hole 11bH, and allows air to enter the air chamber 24 and prevent the drive portion 13 from entering the air chamber 24. block the outflow of air to A rear end of the piston shaft 22 is connected to the driving portion 13 .

The driving portion 13 provides the piston 12 with a force that reciprocates the piston 12 along the cylinder axis A. As shown in FIG. The driving portion 13 is provided on the rear end face 11b side of the cylinder 11 . The configuration of the drive unit 13 is not particularly limited as long as it can generate a force for reciprocating the piston 12 . For example, a mechanism combining a motor and a ball screw may be used.

The bellows 14 actually receives seawater in the water chamber 23 . That is, the water chamber 23 includes two regions separated from each other by the bellows 14 . The water chamber 23 is partitioned by the bellows 14 into a bellows inner chamber 27 (first region) and a bellows outer chamber 28 (second region). The length of the bellows 14 and the volume of the bellows inner chamber 27 generally satisfy a proportional relationship. For example, when the length of the bellows 14 increases, the volume of the bellows inner chamber 27 increases. Furthermore, the relationship between the length of the bellows 14 and the volume of the bellows inner chamber 27 also has a predetermined reproducibility. For example, the length of the bellows 14 is set to the first length, and the volume of the bellows inner chamber 27 is set to the first volume. Next, the length of the bellows 14 is changed to the second length, and the volume of the bellows inner chamber 27 changes along with the change. Then, the length of the bellows 14 is changed again to the first length. Then, the volume of the bellows inner chamber 27 reproduces the first volume. Such properties are said to be, for example, that the shape of the bellows 14 is memorized and that the bellows 14 are not irregular.

A front end 14 a of the bellows 14 is fixed to the front end surface 11 a of the cylinder 11 . For example, the front end face 11 a of the bellows 14 is sandwiched between the retaining ring 29 and the front end face 11 a of the cylinder 11 . When the bellows 14 is a flexible member such as rubber, the pinching crushes the front end 14a of the bellows 14, so that the connection between the bellows 14 and the cylinder 11 is watertight. That is, the second sealing portion 17 is formed.

A rear end 14b (fixed portion) of the bellows 14 is fixed to the piston main surface 21a. Therefore, the movement of the piston 12 causes the bellows 14 to expand and contract. That is, by controlling the position of the piston 12, the volume of the bellows inner chamber 27 can be controlled to a desired size. In this fixing structure, as with the front end 14a of the bellows 14, the rear end 14b of the bellows 14 is sandwiched between the retaining ring 31 and the piston main surface 21a. This structure ensures watertightness between the rear end of the bellows 14 and the piston main surface 21a. That is, the fourth sealing portion 19 is formed.

The piston 12 reciprocates with respect to the cylinder 11 when adjusting the float. Since the buoyancy adjusting device 10 has the first sealing portion 16 , mutual movement of air and seawater between the water chamber 23 and the air chamber 24 is inhibited. Furthermore, the buoyancy adjusting device 10 takes in seawater when reducing the buoyancy. This seawater is taken into the bellows inner chamber 27 . The bellows 14 is connected to the cylinder 11 by a second sealing portion 17 . As a result, when seawater is taken into the bellows 14 , the seawater is prevented from entering the bellows outer chamber 28 in the water chamber 23 . In other words, the buoyancy adjusting device 10 can ensure the desired watertightness and airtightness by providing the first sealing portion 16 and the second sealing portion 17, so that the desired floatation can be achieved. be. Therefore, the float adjustment device 10 can withstand long-term operation.

In the buoyancy adjusting device 10 , the buoyancy is determined by the ratio of the volume of seawater taken into the bellows inner chamber 27 and the volume of air accommodated in the air chamber 24 . The air chamber 24 is prevented from leaking air to the water chamber 23 by the first sealing portion 16 . Furthermore, the third sealing portion 18 prevents gas from leaking out of the cylinder 11 from the air chamber 24 . That is, the air sealed in the air chamber 24 does not increase or decrease even if the floating amount is repeatedly adjusted. That is, the buoyancy adjusting device 10 does not need to supply air from a gas tank or the like in accordance with the increase or decrease in buoyancy. Therefore, the float height adjustment device 10 can repeatedly adjust the float height during long-term operation.

The buoyancy adjusting device of the present disclosure and the underwater vehicle provided with the buoyancy adjusting device have been described above. However, the float adjusting device and the float adjusting device of the present disclosure may be implemented in various forms without being limited to the above embodiments.

For example, as shown in FIG. 3, a bladder 32 may be provided in place of the bellows 14 as the variable housing portion. The bladder 32 is, for example, a bag made of rubber, and divides the water chamber 23 into a bladder inner chamber 33 and a bladder outer chamber 34 . Unlike the bellows 14, the bladder 32 does not remember its shape and may be irregular. An open end 32a of the bladder 32 is attached to the front end face 11a of the cylinder 11 in a watertight manner. This configuration is similar to the attachment structure of the front end face 11a of the bellows 14. As shown in FIG. On the other hand, unlike the bellows 14, the bladder 32 may or may not be fixed to the piston main surface 21a. In the example shown in FIG. 3, the bladder 32 is not fixed to the piston main surface 21a. Even with such a structure, the buoyancy adjusting device 10 has the first sealing portion 16 and the second sealing portion 17 arranged up to the air chamber 24, so that seawater can be prevented from entering the air chamber 24. can be suppressed to Furthermore, according to the modified float adjustment device 10A, the structure of the float adjustment device 10 can be simplified.

1 Surveillance robot (underwater vehicle)
2 Antenna 4 Floating body main body 6 Power generating part 7 Antenna 10, 10A Floating amount adjusting device 11 Cylinder 11a Front end surface 11aH Front hole 11b Rear end surface 11bH Rear hole 11c Cylinder inner peripheral surface 12 Piston 13 Driving part 14 Bellows (bellows member, variable accommodation part)
14a front end 14b rear end (fixed portion)
16 First sealing portion 17 Second sealing portion 18 Third sealing portion 19 Fourth sealing portion 21 Piston main body 21a Piston main surface 21b Piston back surface 21c Piston outer peripheral surface 22 Piston shaft 22c Outer peripheral surface 23 Water chamber (front area )
24 air chamber (rear region)
26 O-ring 27 Bellows inner chamber (first area)
28 Bellows Outer Chamber (Second Area)
29 retaining ring 32 bladder (variable housing)
32a Open end 101 Exploration robot 102 Support ship S1 Seabed S2 Water surface K1 Area A Cylinder axis

Claims (5)

a cylinder;
a piston that is inserted into the cylinder and divides the interior of the cylinder into a front area and a rear area;
a variable housing portion disposed in the front region and attached to the cylinder to divide the front region into a first region and a second region;
a first sealing portion formed on the inner peripheral surface of the cylinder and the outer peripheral surface of the piston and inhibiting movement of gas and liquid from one to the other in the front region and the rear region;
a second sealing portion provided at a connection portion between the cylinder and the variable housing portion;
The variable storage portion increases or decreases the volume of the first region that stores liquid for adjusting the float according to the movement of the piston. 2. The float adjustment device according to claim 1, wherein said variable housing portion has a fixed portion fixed to said piston. 3. The buoyancy adjustment device according to claim 1, wherein said variable housing portion is a bellows member. The piston has a piston shaft projecting through an end surface of the cylinder from a back surface forming the rear region,
The cylinder has a through hole through which the piston shaft passes,
Further comprising a third sealing portion formed on the inner peripheral surface of the through-hole and the outer peripheral surface of the piston shaft and inhibiting movement of gas from one side of the rear region to the other in the external region of the cylinder. Item 4. The buoyancy adjusting device according to any one of Items 1 to 3. a floating body body;
a power generator provided in the floating body body for generating power for moving the floating body body;
a buoyancy adjusting device provided in the floating body body for adjusting the buoyancy of the floating body body,
The float adjustment device is
a cylinder;
a piston that is inserted into the cylinder and divides the interior of the cylinder into a front area and a rear area;
a variable housing portion disposed in the front region and attached to the cylinder to divide the front region into a first region and a second region;
a first sealing portion formed on the inner peripheral surface of the cylinder and the outer peripheral surface of the piston and inhibiting movement of gas and liquid from one to the other in the front region and the rear region;
a second sealing portion provided at a connection portion between the cylinder and the variable housing portion;
The underwater vehicle, wherein the variable storage section increases or decreases the volume of the first region that stores liquid for adjusting the buoyancy according to the movement of the piston.

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