Float dropping device

Abstract

To prevent falling of a rod float at an unintended position and furthermore to enable easy increase of the number of mountable rod floats.SOLUTION: A housing portion 3 houses a rod float 2, a holding portion 4 holds the housed rod float 2 and can release the holding on the basis of a drop command signal output by a user. An aviation portion can fly to a drop position while the rod float 2 housed in the housing portion 3 and held by the holding portion 4 is suspended. The rod float 2 includes a float body 21 with a weight, and a rod 22 whose proximal end is supported by the float body 21 and whose free end extends outward from the float body. The housing portion 3 houses the float body 21 while the rod 22 is exposed downward, the holding portion 4 holds the rod float 2 by supporting the lower end of the float body 21 housed in the housing portion 3 from below, and holding of the rod float 2 is released by performing movement of being disengaged from below the float body 21 without touching the rod 22.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a float dropping device.

Background Art

[0002] In order to observe the flow rate and flow velocity of a river, a method is known in which a float is dropped at an observation location of the river and the flow velocity of the float over a certain distance is measured. Here, the dropping of the float has been performed manually by a worker until now, but in recent years, attempts have been made to perform it automatically by a float dropping device.

[0003] As an example of such a float dropping device, Patent Document 1 discloses an unmanned aircraft that holds a rod provided at the upper end of a rod float by a gripping portion and holds the rod float in a suspended state, and releases the holding by releasing the rod, thereby dropping the rod float.

[0004] Also, as an example of such a float dropping device, Patent Document 2 discloses a device that supports the bottom surface of a rod float from below by a bottom plate and holds it in a state where the fastener of the bottom plate is detached and the bottom plate is removed from below the bottom surface, thereby releasing the holding and dropping the rod float.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the unmanned aircraft disclosed in Patent Document 1, a rod is gripped and held in a state where a rod float is suspended. Since the center of gravity of the rod float is at the lower part of the weighted float body provided below the rod being gripped, there is a risk that the float body may come off the rod and drop at an unintended position. On the other hand, in the device disclosed in Patent Document 2, since the bottom surface of the rod float is held in a state of being supported from below, the weighted float body does not come off the rod and drop. However, the device disclosed in Patent Document 2 needs to accommodate from the upper end of the rod of the rod float to the bottom surface of the float body and support the bottom surface. As the vertical length of the rod float increases, the vertical length of the accommodating portion of the rod float increases, and there is a problem that the accommodating portion becomes heavy. For this reason, even if an attempt is made to apply the device disclosed in Patent Document 2 to an unmanned aircraft, the limit of the loadable weight at which the unmanned aircraft can fly stably is further limited by the weight of the accommodating portion, and there is a problem that the number of rod floats that can be mounted on the unmanned aircraft, that is, the number of rod floats that can be dropped during flight as a float dropping device, decreases.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to prevent a rod float from dropping at an unintended position and to make it easy to increase the number of rod floats that can be mounted.

Means for Solving the Problems

[0008] In order to achieve the above object, a float dropping device according to the present invention is a float dropping device capable of dropping a rod float from a predetermined dropping position, and includes a housing portion for housing the rod float, a holding portion for holding the rod float housed in the housing portion and capable of releasing the holding of the rod float based on a dropping command signal output by a user, an aviation portion capable of flying to the dropping position with the housing portion, the holding portion, and the rod float housed in the housing portion and held by the holding portion suspended, the rod float includes a float body with a weight and a rod whose base end is supported by the float body and whose free end extends outward from the float body, the housing portion houses the rod float by housing the float body in a state where the rod extends downward and is exposed, the holding portion is provided below the housing portion, holds the rod float by supporting the lower end of the float body housed in the housing portion from below, and releases the holding of the rod float by moving away from below the float body without contacting the rod extending below the holding portion.

Effects of the Invention

[0009] According to the present invention, since the lower end of the float body, which is the center of gravity of the rod float, is supported from below by the holding portion, the rod float does not fall at an unintended position. Further, according to the present invention, the housing portion houses the float body in a state where the rod extends downward and is exposed, and the holding portion supports the float body from below and can move away from below the float body without contacting the rod extending downward. Therefore, the float dropping device according to the present invention can reduce the size and weight of the housing portion compared to a float dropping device that does not house and hold the float body in a state where the rod extends downward and is exposed. As a result, the float dropping device according to the present invention can easily increase the number of rod floats that can be mounted while preventing the rod float from falling at an unintended position.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying out the Invention

[0011] (Regarding the float dropping device 1 according to the embodiment) Embodiments of the present invention will be described in detail with reference to the drawings. The float dropping device 1 according to the present embodiment is an unmanned aircraft that can fly to a predetermined dropping position of a river and drop a rod float 2 from the dropping position in order to observe the flow rate and flow velocity of the river. As shown in FIG. 1, the float dropping device 1 includes a housing part 3 that houses the rod float 2, a holding part 4 that holds the rod float 2 in a state of being housed in the housing part 3, and an aviation part 5 that can fly to the dropping position by an operation using an operation part (not shown) by the user. Note that the operation part is, for example, a remote controller having a function as a transmitter that can wirelessly transmit each signal to the unmanned aircraft, that is, a so-called remote control.

[0012] (Regarding the rod float 2 according to the embodiment) The rod float 2 is, for example, a rod float (pole float) used for measuring the flow rate and flow velocity of a river, which is commercially available under product names such as pulp float, float for flow rate observation, and float for flow velocity measurement. As shown in FIG. 2, the rod float 2 includes a float body 21 that is the main body of the rod float 2 and a rod 22 of the rod float 2. Note that when the rod float 2 is flowing in the dropped river, the float body 21 is arranged on the lower side and the rod 22 is arranged on the upper side. Therefore, unless otherwise specified, the rod float 2 is assumed to be provided with the rod 22 at the upper part and the float body 21 at the lower part as shown in FIG. 2.

[0013] The float body 21 includes a cylindrical member 23 extending in the vertical direction, a weight (not shown) housed inside the cylindrical member 23, a bottom plate 24 fixed to the lower end of the cylindrical member 23 to support the weight, and a lid 25 fixed in a state of covering an opening provided at the upper end of the cylindrical member 23. At the center of the lid 25, a joint 26 for fixing the lower end, which is the base end of the rod 22 extending in the vertical direction, is formed. In this embodiment, the total weight of the rod float 2 is preset to about 250 g.

[0014] (Details of the float dropping device 1 according to the embodiment) Returning to FIG. 1, the housing portion 3 is, for example, a box-shaped housing box, and a plurality of such housing boxes may be connected in a state where a plurality of rod floats 2 can be housed. For example, as shown in FIG. 3(A), the housing portion 3 includes a first housing box 31, a second housing box 32, a third housing box 33, a fourth housing box 34, a fifth housing box 35, and a sixth housing box 36 that are integrally formed in a state of being connected in the front-rear direction. Further, as shown in FIGS. 1 and 3(A), a connection portion 37 with the aviation portion 5 is fixedly supported at the center of the upper end of the housing portion 3. Also, on the outside of the lower right end of the housing portion 3, a roof-shaped housing case 38 that protrudes rightward and extends in the front-rear direction from the front end of the first housing box 31 to the rear end of the sixth housing box 36 is integrally formed.

[0015] Note that the configurations of the housing boxes 31 to 36 are the same. Therefore, in order to reduce redundant explanations, the following provides a detailed description of the first housing box 31 using FIG. 3(B), and detailed descriptions of the remaining second housing box 32 to sixth housing box 36 are omitted. As shown in FIGS. 3(A) and 3(B), first through holes 315 and second through holes 316 that extend in the vertical direction with an interval are formed at the central portions of the front side wall 311, rear side wall 312, left side wall 313, and right side wall 314 of the first housing box 31. Also, as shown in FIGS. 3(A) to 3(C), an opening 317 is formed at the lower end of the first housing box 31. Thus, the housing portion 3 can house the rod float 2 inside each of the housing boxes 31 to 36 by moving the rod float 2 provided below upward.

[0016] Here, the vertical length inside the accommodating portion 3 is preset to be the vertical length of the float body 21. Therefore, even if the accommodating portion 3 attempts to accommodate the rod float 2 shown in FIG. 2 inside each of the accommodating boxes 31 to 36 with the rod 22 provided at the upper part and the float body 21 provided at the lower part, the lower end portion of the float body 21 will be exposed below each of the accommodating boxes 31 to 36. Thus, as shown in FIGS. 1 and 3(A), if the accommodating portion 3 reverses the rod float 2 shown in FIG. 2 so that the float body 21 is provided at the upper part and the rod 22 is provided at the lower part, the entire float body 21 can be accommodated inside each of the accommodating boxes 31 to 36 with the rod 22 exposed downward.

[0017] The holding portion 4 is, for example, an electric opening and closing lever that can operate based on a signal output by the user using the operation portion. As shown in FIGS. 3(A) to 3(C), the holding portion 4 includes a receiving portion 40 and a driving portion 41 that are fixedly supported outside the accommodating portion 3 while being accommodated inside the accommodating case 38, a rotating shaft 42 rotatably supported by the driving portion 41, and an extension portion 43 fixed to the rotating shaft 42. The receiving portion 40 is attached to the outside of the lower end portion of the right side wall 314 of the fifth accommodating box 35. The receiving portion 40 is a receiver that receives a signal output by the user using the operation portion.

[0018] The driving portion 41 includes a first driving portion 411, a second driving portion 412, a third driving portion 413, a fourth driving portion 414, and a sixth driving portion 416 attached to the outside of the lower end portion of the right side wall 314 of the first accommodating box 31, the second accommodating box 32, the third accommodating box 33, the fourth accommodating box 34, and the sixth accommodating box 36. Each of the driving portions 411 to 414, 416 is, for example, a motor that drives based on a signal received by the receiver.

[0019] The rotating shaft 42 includes a first rotating shaft 421, a second rotating shaft 422, a third rotating shaft 423, a fourth rotating shaft 424, and a sixth rotating shaft 426. The upper end, which is the base end of the first drive unit 411, the second drive unit 412, the third drive unit 413, the fourth drive unit 414, and the sixth drive unit 416, is supported in a rotatable state, and the lower end, which is the free end, extends downward. Each of the rotating shafts 421 to 424, 426 is, for example, the rotating shaft of the motor if each of the drive units 411 to 414, 416 is a motor.

[0020] The extension part 43 includes a first extension part 431, a second extension part 432, a third extension part 433, a fourth extension part 434, and a sixth extension part 436 in a rod shape. The base end is fixedly supported at the lower end, which is the free end of the first rotating shaft 421, the second rotating shaft 422, the third rotating shaft 423, the fourth rotating shaft 424, and the sixth rotating shaft 426, and the free end extends in the radial direction of each of the rotating shafts 421 to 424, 426.

[0021] As shown by the solid line in FIG. 3(C), the holding part 4 enables the free ends of the extension parts 431 to 434, 436 to be provided at contact positions below the openings 317 of the respective storage boxes 31 to 34, 36. In this case, the holding part 4 supports the float body 21 by contacting the lid 25 of the float body 21 in which the extension parts 431 to 434, 436 are accommodated from below, so that the rod float 2 can be held without damage to the extension parts 431 to 434, 436. Therefore, the holding part 4 can hold up to five rod floats 2 accommodated in the respective storage boxes 31 to 34, 36. At this time, as shown in FIG. 3(A), the holding part 4 holds the float body 21 accommodated inside the respective storage boxes 31 to 36 with the rod 22 exposed downward.

[0022] Also, as shown by the dotted line in Fig. 3(C), when the receiver receives the dropping command signal output from the operation unit, the holding unit 4 can rotate each of the rotating shafts 421 to 424, 426 based on the dropping command signal. In this case, the holding unit 4 can release the holding of the rod float 2 by moving the free ends of the respective extension parts 431 to 434, 436 to a separated position away from below the opening 317 of each of the storage boxes 31 to 34, 36 with each of the rotating shafts 421 to 424, 426 as the rotation center. At this time, as shown in Fig. 3(C), the holding unit 4 moves from the contact position to the separated position so that the free ends of the respective extension parts 431 to 434, 436 do not contact the rod 22 exposed downward, and releases the holding of the float body 21 accommodated inside each of the storage boxes 31 to 36.

[0023] In addition, in the present embodiment, the dropping command signal is a signal capable of specifying which of the rotating shafts 421 to 424, 426 is to be rotated. Therefore, the holding unit 4 can release the holding of each of the maximum five rod floats 2 accommodated and held in each of the storage boxes 31 to 34, 36 one by one and drop them into the river.

[0024] Returning to Fig. 1, the aviation unit 5 is a drone capable of flying based on an operation using an operation unit by a user, for example. The aviation unit 5 includes a frame 51. The frame 51 is formed with a frame body 510, a first arm 511, a second arm 512, a third arm 513, and a fourth arm 514 that radially extend from the frame body 510 on a horizontal plane. Further, a connected part 515 to which the connecting part 37 is connected is provided at the lower end of the frame body 510. At the free ends of the respective arms 511 to 514, a first motor 521, a second motor 522, a third motor 523, and a fourth motor 524 are fixedly supported. Below each of the motors 521 to 524, a first propeller 531, a second propeller 532, a third propeller 533, and a fourth propeller 534 are rotatably supported with the rotation shafts of the respective motors 521 to 524 as the rotation center.

[0025] Although illustration is omitted, the frame body 510 houses a receiver that receives signals output by the user using the operation unit, a controller that controls the attitude, speed, etc. during flight, a battery that supplies power to electronic devices, and the like. In the present embodiment, the battery of the flight unit 5 is not only electrically connected to electronic devices such as the receiver, controller, and each motor 521 to 524 included in the flight unit 5, but also electrically connected to the receiving unit 40 and the driving unit 41 included in the holding unit 4.

[0026] When the receiver of the flight unit 5 receives an aviation command signal output from the operation unit, the controller transmits an instruction from the receiver to each motor 521 to 524 to control the rotation of each motor 521 to 524, so that the entire float dropping device 1 can be lifted by the rotation of each propeller 531 to 534 and flown to the dropping position. In the present embodiment, the maximum load weight that can be safely flown by the flight unit 5 is preset to 2700 g, and the total weight of the storage unit 3, the holding unit 4, and the five rod floats 2 is preset to 2420 g. Therefore, when the connecting portion 37 is connected to the connected portion 515 of the flight unit 5, the flight unit 5 can safely fly to the dropping position while suspending the storage unit 3, the holding unit 4, and the five rod floats 2 with the five rod floats 2 stored and held in the respective storage boxes 31 to 34, 36.

[0027] As described above, according to the float dropping device 1 according to the present embodiment, the storage unit 3 stores the rod floats 2, the holding unit 4 holds the rod floats 2 stored in the storage unit 3, and can release the holding of the rod floats 2 based on the dropping command signal output by the user. Further, the flight unit 5 can fly to the dropping position while suspending the storage unit 3, the holding unit 4, and the rod floats 2 stored in the storage unit 3 and held by the holding unit 4.

[0028] Here, the rod float 2 includes a float body 21 with a weight and a rod 22 whose base end is supported by the float body 21 and whose free end extends outward from the float body. Therefore, when holding the rod float 2 in a state where the rod 22 is gripped and suspended, like the unmanned aircraft disclosed in Patent Document 1, since the center of gravity of the rod float 2 is in the float body 21 below the rod 22 being gripped, there is a risk that the rod 22 comes off from the joint 26 and the float body 21 including the lid 25 drops at an unintended position different from the dropping position, or the lid 25 comes off from the float body 21 and the float body 21 drops at an unintended position different from the dropping position together with the weight.

[0029] In contrast, in the float dropping device 1 according to the present embodiment, the housing portion 3 houses the rod float 2 by housing the float body 21 in a state where the rod 22 extends downward and is exposed. And the holding portion 4 is provided below the housing portion 3, holds the rod float 2 by supporting the lid 25 at the lower end of the float body 21 housed in the housing portion 3 from below, and releases the holding of the rod float 2 by moving away from below the float body 21 without contacting the rod 22 extending downward from the holding portion 4.

[0030] By doing so, in the float dropping device 1 according to the present embodiment, the rod float 2 is not dropped at an unintended position because the lower end of the float body 21 where the center of gravity of the rod float 2 is located is supported from below by the holding portion 4. Also, by doing so, the housing portion 3 of the float dropping device 1 according to the present embodiment can be made smaller and lighter than a float dropping device that does not house and hold the float body in a state where the rod extends downward and is exposed. As a result, the float dropping device 1 according to the present embodiment can easily increase the number of rod floats 2 that can be mounted while preventing the rod float 2 from dropping at an unintended position.

[0031] Further, according to the float dropping device 1 according to the present embodiment, the holding portion 4 includes a receiving portion 40 and a driving portion 41 supported outside the housing portion 3, a rotating shaft 42 extending downward from the driving portion 41, and an extension portion 43 extending in the radial direction of the rotating shaft 42 from the lower end portion which is the free end portion of the rotating shaft 42. Then, the free end portion of the extension portion 43 rotates from a contact position where it can contact the lid 25 at the lower end of the float body 21 accommodated in the housing portion 3 around the rotating shaft 42 as the rotation center to a separation position away from the lower end of the float body 21 by driving the driving portion 41 according to an instruction from the receiving portion 40 that has received a dropping command signal and rotating the rotating shaft 42.

[0032] By doing so, in the float dropping device 1 according to the present embodiment, the free end portion of the extension portion 43 rotates from the contact position to the separation position, so that it can be detached from below the float body 21 without contacting the rod 22 extending downward, and the float body 21 accommodated in the housing portion 3 can be dropped. Also, by doing so, the float dropping device 1 according to the present embodiment can make the holding portion 4 smaller and lighter than a float dropping device in which the holding portion does not include a driving portion, a rotating shaft, and an extension portion, and it is easier to increase the number of rod floats 2 that can be mounted.

[0033] Further, according to the float dropping device 1 according to the present embodiment, the holding portion 4 is supplied with power from the battery of the aviation portion 5 and shares the aviation portion 5 and the battery. By doing so, the float dropping device 1 according to the present embodiment can make the holding portion 4 smaller and lighter than a float dropping device in which the holding portion has a separate battery without sharing the aviation portion and the battery, and it is easier to increase the number of rod floats 2 that can be mounted.

[0034] Further, according to the float dropping device 1 according to the present embodiment, in the housing portion 3, first through holes 315 and second through holes 316 are formed in the side walls 311 to 314 of the respective housing boxes 31 to 36, and the respective housing boxes 31 to 36 are so-called skeletonized. By doing so, the float dropping device 1 according to the present embodiment can reduce the weight of the storage unit 3 compared to a float dropping device in which each storage box of the storage unit is not skeletonized, and it is easier to increase the number of rod floats 2 that can be mounted.

[0035] (Modification example) In addition, although it is preferable that the holding unit 4 shares the aircraft unit 5 and the battery as in the present embodiment, the holding unit 4 may be provided with its own battery without sharing the aircraft unit 5 and the battery.

[0036] In addition, in the present embodiment, the holding unit 4 includes a drive unit 41 in which a drive mechanism is housed, a rotating shaft 42, and an extension unit 43. However, the configuration, size, shape, material, etc. can be arbitrarily changed so that these can be miniaturized and weight-reduced. Even in this case, the holding unit 4 needs to be able to hold or release the float body 21 housed inside each of the storage boxes 31 to 36 by moving between the contact position and the separated position without the respective extension parts 431 to 434, 436 contacting the rod 22.

[0037] In addition, in the present embodiment, the storage unit 3 is weight-reduced by two through holes 315 and 316 extending in the vertical direction formed at the central portions of the respective side walls 311 to 314 of each of the storage boxes 31 to 36. However, the shape, position, size, and number of the through holes can be arbitrarily changed. For example, the storage unit 3 may be formed with one elliptical through hole larger than the through holes 315 and 316 at the central portions of the side walls 311 to 314 of each of the storage boxes 31 to 36. In this case, each of the storage boxes 31 to 34, 36 needs to have sufficient strength to store the rod float 2 and prevent the stored rod float 2 from falling from other than the opening 317.

[0038] Incidentally, as in the present embodiment, it is preferable that the vertical length inside the housing portion 3 is the same as the vertical length of the float body 21, but it is not limited thereto. For example, the vertical length inside the housing portion 3 is set to be equal to or greater than the vertical length of the float body 21 and less than the vertical length of the entire rod float 2 including the rod 22 so that the entire float body 21 cannot be housed inside each of the housing boxes 31 to 36 in a state where the rod 22 is exposed downward. It can be set to any length.

[0039] Incidentally, in the present embodiment, the housing portion 3 is lightened by the through holes 315 and 316 formed in the side walls 311 to 314 of each of the housing boxes 31 to 36. However, as long as each of the housing boxes 31 to 34 and 36 has sufficient strength to house the rod float 2, it may be lightened by means different from the through holes. For example, the housing portion 3 may be lightened by changing the material of each of the housing boxes 31 to 36 and the housing case 38, or by reducing the thickness of each of the side walls 311 to 314 and the upper end wall.

[0040] Incidentally, in the present embodiment, the aviation unit 5 is configured to be able to mount a maximum of five rod floats 2 in a state where the housing portion 3 and the holding portion 4 are suspended. However, the number of rod floats 2 that can be mounted is not limited thereto. For example, it may be six or more at maximum. In this case, it is necessary to change the aviation unit 5 to increase the maximum load capacity, or to further lighten the housing portion 3 and the holding portion 4.

[0041] Incidentally, in the present embodiment, the housing portion 3 includes the fifth housing box 35 that supports the receiving unit 40. However, the fifth housing box 35 may be omitted and the fourth housing box 34 and the sixth housing box 36 may be connected. In this case, the housing portion 3 can be further lightened. In this case, it is necessary to support the receiving unit 40 by any one of the other housing boxes 31 to 34 and 36 of the housing portion 3.

[0042] The present invention can be implemented in various embodiments and variations without departing from the broad spirit and scope of the present invention. Further, the above-described embodiments are for explaining the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is indicated by the claims rather than the embodiments. And various modifications made within the scope of the claims and within the scope of the meaning of equivalent inventions are considered to be within the scope of the present invention.

Explanation of Reference Numerals

[0043] 1... Float dropping device, 2... Rod float, 3... Accommodating portion, 4... Holding portion, 5... Aerial portion, 21... Float body, 22... Rod, 23... Cylindrical member, 24... Bottom plate, 25... Lid, 26... Joint, 31... First accommodating box, 32... Second accommodating box, 33... Third accommodating box, 34... Fourth accommodating box, 35... Fifth accommodating box, 36... Sixth accommodating box, 37... Connecting portion, 38... Accommodating case, 40... Receiving portion, 41... Driving portion, 42... Rotating shaft, 43... Extension portion, 51... Frame, 311... Front side wall, 312... Rear side wall, 313... Left side wall, 314... Right side wall, 315... First through hole, 316... Second through hole, 317... Opening, 411... First driving portion, 412... Second driving portion, 413... Third driving portion, 414... Fourth driving portion, 416... Sixth driving portion, 421... First rotating shaft, 422... Second rotating shaft, 423... Third rotating shaft, 424... Fourth rotating shaft, 426... Sixth rotating shaft, 431... First extension portion, 432... Second extension portion, 433... Third extension portion, 434... Fourth extension portion, 436... Sixth extension portion, 510... Frame body, 511... First arm, 512... Second arm, 513... Third arm, 514... Fourth arm, 515... Connected portion, 521... First motor, 522... Second motor, 523... Third motor, 524... Fourth motor, 531... First propeller, 532... Second propeller, 533... Third propeller, 534... Fourth propeller.

Claims

1. A float dropping device capable of dropping a rod float from a predetermined dropping position, comprising: a housing part for housing the rod float; a holding part for holding the rod float housed in the housing part and capable of releasing the holding of the rod float based on a dropping command signal output by a user; an aviation part capable of flying to the dropping position with the housing part, the holding part, and the rod float housed in the housing part and held by the holding part being suspended; and the rod float includes a weighted float body and a rod having a base end supported by the float body and a free end extending outward from the float body; the housing part houses the rod float by housing the float body with the rod extending downward and exposed; the holding part is provided below the housing part, holds the rod float by supporting the lower end of the float body housed in the housing part from below, and releases the holding of the rod float by moving away from below the float body without contacting the rod extending below the holding part; a float dropping device.

2. The holding part includes a receiving part for receiving the dropping command signal, a driving part supported outside the housing part and driven by an instruction from the receiving part that has received the dropping command signal, a rotating shaft extending downward from the driving part, and an extension part extending in the radial direction of the rotating shaft from the lower end part of the rotating shaft; the free end of the extension part is capable of rotatingly moving from a contact position where it can contact the lower end of the float body housed in the housing part from below with the rotating shaft as the center of rotation to a separated position away from the lower end of the float body housed in the housing part; The float dropping device according to Claim 1.

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