Amphibious vehicle
11198343 · 2021-12-14
Assignee
Inventors
- Shinichi Sato (Tokyo, JP)
- Tetsuya Miyamoto (Tokyo, JP)
- Takashi Matsunaga (Tokyo, JP)
- Katsuhiko Nakajo (Tokyo, JP)
- Taichi Omura (Tokyo, JP)
- Yuta SHIMIZU (Tokyo, JP)
- Takenori Kawana (Tokyo, JP)
- Takashi Mizumoto (Tokyo, JP)
Cpc classification
International classification
Abstract
To enlarge a collapsible flap and store the collapsible flap appropriately. In an amphibious vehicle (1) in which a flap (13) which receives lift from water in water navigation is provided to be deployable and storable at a front side in a travel direction of a vehicle body (11), the flap (13) includes a lower flap (21) which is stored to come close to a front surface (11a) of the vehicle body (11) and an upper flap (22) which is stored to come close to an upper surface (11b) of the vehicle body (11), and at least one of the lower flap (21) and the upper flap (22) includes a first flap member (31) and a second flap member (32) and is configured such that a flap length (L.sub.13) in a direction orthogonal to a vehicle width direction is variable.
Claims
1. An amphibious vehicle in which a flap that receives lift from water in water navigation is provided to be deployable and storable at a front side in a travel direction of a vehicle body, wherein the flap includes a lower flap which is stored to come close to a front surface of the vehicle body and an upper flap which is stored to come close to an upper surface of the vehicle body, at least one of the lower flap and the upper flap includes a first flap member and a second flap member and is configured such that a flap length in a direction orthogonal to a vehicle width direction is variable, the first flap member and the second flap member are connected to be slidable with respect to each other, the flap is configured such that the flap length is variable by a sliding operation of the first flap member and the second flap member, a driving unit which deploys and stores the flap, a navigation state detecting unit which can detect a navigation state in moving on water; and a control unit which controls driving of the driving unit based on a detection result of the navigation state detecting unit, wherein the control unit operates the driving unit such that the flap length is longer when the navigation state detecting unit detects that the navigation state is a floating state, and the control unit operates the driving unit such that the flap length is shorter when the navigation state detecting unit detects that the navigation state is a sliding state.
2. An amphibious vehicle in which a flap that receives lift from water in water navigation is provided to be deployable and storable at a front side in a travel direction of a vehicle body, wherein the flap includes a lower flap which is stored to come close to a front surface of the vehicle body and an upper flap which is stored to come close to an upper surface of the vehicle body, and at least one of the lower flap and the upper flap includes a first flap member and a second flap member and is configured such that a flap length in a direction orthogonal to a vehicle width direction is variable, the amphibious vehicle comprising: a driving unit which deploys and stores the flap; a navigation state detecting unit which can detect a navigation state in moving on water; and a control unit which controls driving of the driving unit based on a detection result of the navigation state detecting unit, wherein the control unit operates the driving unit such that the flap length is longer when the navigation state detecting unit detects that the navigation state is a floating state, and the control unit operates the driving unit such that the flap length is shorter when the navigation state detecting unit detects that the navigation state is a sliding state.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DESCRIPTION OF EMBODIMENTS
(12) Hereinafter, examples of an amphibious vehicle according to the present invention will be explained in detail with reference to attached drawings. Of course, the present invention is not limited to the following examples, and various modifications can be executed in the scope not departing from the gist of the present invention.
First Example
(13) A structure of an amphibious vehicle according to a first example of the present invention will be explained with reference to
(14) As shown in
(15) As shown in
(16) As shown in
(17) As shown in
(18) As shown in
(19) The first upper flap 31 is a plate-like member which is substantially rectangular-shaped and whose lower end 31a is connected to an upper end 21b having a broad width in the lower flap 21 via a hinge 24. Also, the first upper flap 31 is mechanically connected to a second flap driving unit 42 (see
(20) The second upper flap 32 is a plate-like member which is substantially rectangular-shaped and whose rear surface 32a contacts to a front surface 31b of the first upper flap 31 to be slidably connected to the first upper flap 31. Also, the second upper flap 32 is mechanically connected to a third flap driving unit 43 (see
(21) Thus, in a short length state that the second upper flap 32 is stored to be overlapped with the first upper flap 31 (in
(22) As shown in
(23) Here, as the first flap driving unit 41, the second flap driving unit 42 and the third flap driving unit 43, various driving sources and mechanisms etc. can be adopted. For example, by providing a hydraulic cylinder (an expansion member) as a driving source between members (between the vehicle body 11 and the lower flap 21, between the lower flap 21 and the first upper flap 31, and between the first upper flap 31 and the second upper flap 32), a rotating operation and a sliding operation between the members can be executed using an expanding operation of the hydraulic cylinder. Also, for example, by providing a motor (a power generator) and a gear mechanism (or a wire mechanism) as a driving source between the members (between the vehicle body 11 and the lower flap 21, between the lower flap 21 and the first upper flap 31, and between the first upper flap 31 and the second upper flap 32), the rotating operation and the sliding operation between the members can be executed using a rotating operation of the motor.
(24) Also, as shown in
(25) Here, as the moving state detecting unit 45 and the navigation state detecting unit 46, various sensors etc. can be adopted. For example, as the moving state detecting unit 45, a switch operated by an occupant and a water pressure sensor which detects that the amphibious vehicle 1 is launched etc. can be adopted, and as the navigation state detecting unit 46, a speed sensor which detects a moving speed in water navigation etc. can be adopted. Additionally, in a case where the speed sensor is adopted as the navigation state detecting unit 46, the control unit 44 determines that the amphibious vehicle 1 is in a floating state when a moving speed of the amphibious vehicle 1 in water navigation is less than a predetermined value, while it determines that the amphibious vehicle 1 is in a sliding state when a moving speed of the amphibious vehicle 1 in water navigation is the predetermined value or more.
(26) An operation of the amphibious vehicle according to the first example of the present invention will be explained with reference to
(27) First, when the amphibious vehicle 1 drives the wheel 12 by the not shown driving source and moves on land, the flap 13 is in a completely stored state (see
(28) The flap 13 in the completely stored state is in a state that the lower flap 21 is stored to come close to the front surface 11a of the vehicle body 11 and the upper flap 22 is stored to come close to the upper surface 11b of the vehicle body 11 in the short length state.
(29) Following this, for example, when the amphibious vehicle 1 is launched and navigates water by driving the not shown propeller by the not shown driving source, the moving state detecting unit 45 detects that a moving state of the amphibious vehicle 1 is moved from a land driving state to a water navigation state (see
(30) Also, immediately after the amphibious vehicle 1 is moved from the land driving state to the water navigation state, the amphibious vehicle 1 is in a floating state with a deep draft, so that the navigation state detecting unit 46 detects that a navigation state of the amphibious vehicle 1 is the floating state.
(31) Thus, the control unit 44 respectively drives the first flap driving unit 41, the second flap driving unit 42 and the third flap driving unit 43 based on a detection result of the moving state detecting unit 45 and the navigation state detecting unit 46, and transforms the flap 13 from the completely stored state to a completely deployed state.
(32) The flap 13 in the completely deployed state is in a state that the lower flap 21 is deployed to be separated from the front surface 11a of the vehicle body 11 and the upper flap 22 is deployed to be separated from the upper surface 11b of the vehicle body 11 in the long length state.
(33) In other words, when the amphibious vehicle 1 is moved from the land driving state to the water navigation state (the floating state), the lower flap 21 is deployed to be separated from the front surface 11a of the vehicle body 11 by the first flap driving unit 41 and the first upper flap 31 is deployed to be separated from the upper surface 11b of the vehicle body 11 by the second flap driving unit 42, and the second upper flap 32 is deployed to be shifted from the first upper flap 31 by the third flap driving unit 43.
(34) Following this, when the amphibious vehicle 1 increases speed in water navigation and is moved from the floating state to the sliding state, the navigation state detecting unit 46 detects that the navigation state of the amphibious vehicle 1 is moved from the floating state to the sliding state (see
(35) Thus, the control unit 44 drives only the third flap driving unit 43 based on a detection result of the navigation state detecting unit 46 and transforms the flap 13 from the completely deployed state to a partially deployed state (a partially stored state.)
(36) The flap 13 in the partially deployed state (the partially stored state) is in a state that the lower flap 21 is deployed to be separated from the front surface 11a of the vehicle body 11 and the upper flap 22 is deployed to be separated from the upper surface 11b of the vehicle body 11 in the short length state.
(37) In other words, when the amphibious vehicle 1 is moved from the floating state to the sliding state in the water navigation state, in a state that the lower flap 21 and the first upper flap 31 are remained as deployed, the second upper flap 32 is stored to be overlapped with the first upper flap 31 by the third flap driving unit 43.
(38) Following this, when the amphibious vehicle 1 decreases speed in water navigation and is moved from the sliding state to the floating state, the navigation state detecting unit 46 detects that the navigation state of the amphibious vehicle 1 is moved from the sliding state to the floating state (see
(39) Thus, the control unit 44 drives only the third flap driving unit 43 based on a detection result of the navigation state detecting unit 46 and transforms the flap 13 from the partially deployed state (the partially stored state) to the completely deployed state.
(40) In other words, when the amphibious vehicle 1 is moved from the sliding state to the floating state in the water navigation state, in a state that the lower flap 21 and the first upper flap 31 are remained as deployed, the second upper flap 32 is stored to be shifted from the first upper flap 31 by the third flap driving unit 43.
(41) Following this, for example, when the amphibious vehicle 1 makes a landing and drives the wheel 12 by the not shown driving source to move on land, the moving state detecting unit 45 detects that the moving state of the amphibious vehicle 1 is moved from the water navigation state to the land driving state (see
(42) Thus, the control unit 44 respectively drives the first flap driving unit 41, the second flap driving unit 42 and the third flap driving unit 43 based on a detection result of the moving state detecting unit 45, and transforms the flap 13 from the completely deployed state to the completely stored state.
(43) In other words, when the amphibious vehicle 1 is moved from the water navigation state (the floating state) to the land driving state, the second upper flap 32 is stored to be overlapped with the first upper flap 31 by the third flap driving unit 43, and the lower flap 21 is stored to come close to the front surface 11a of the vehicle body 11 by the first flap driving unit 41 and the first upper flap 31 (the upper flap 22) is stored to come close to the upper surface 11b of the vehicle body 11 by the second flap driving unit 42.
(44) According to the amphibious vehicle 1 according to this example, since the upper flap 22 (the flap 13) is configured such that its flap length is variable, the flap length L.sub.22B of the upper flap 22 in the long length state can be set to be longer than that of the conventional flap, and the flap length L.sub.13 of the flap 13 in the completely deployed state can be set to be longer than that of the conventional flap (see
(45) Also, according to the amphibious vehicle 1 according to this example, since the large flap 13 is provided, a contact angle θ.sub.1 of the flap 13 with a water surface (a draft line) 100 can be set to be smaller than the conventional contact angle (see
(46) Moreover, according to the amphibious vehicle 1 according to this example, since the upper flap 22 is configured such that its flap length is variable, the flap length L.sub.22A of the upper flap 22 in the short length state can be set to be substantially the same as that of the conventional flap (see
(47) In addition, according to the amphibious vehicle 1 according to this example, the upper flap 22 in the short length state (the first upper flap 31 and the second upper flap 32) can be stored to come close to the upper surface 11b of the vehicle body 11, so that the lower flap 21 can be stored to come close to the front surface 11a of the vehicle body 11 (see
(48) Also, according to the amphibious vehicle 1 of this example, since the upper flap 22 (the flap 13) is configured such that its flap length is variable, when the navigation state of the amphibious vehicle 1 is moved to the sliding state, by allowing the upper flap 22 (the flap 13) to be in the short length state, an amount of protrusion D.sub.1 of the flap 13 from the water surface (the draft line) 100 can be inhibited (see
(49) Moreover, according to the amphibious vehicle 1 of this example, even when a front portion of the vehicle body 11 is inclined upward (an upper side in the vertical direction) in the sliding state, by inhibiting the amount of protrusion D.sub.1 of the flap 13 from the water surface 100, vision in a horizontal direction from the wheel window 14a of the driver's seat 14 can be well secured (see
(50) In this example, the upper flap 22 is schematically constituted by the first upper flap 31 and the second upper flap 32 which are slidable with respect to each other, and is configured such that the flap length of the upper flap 22 (the flap 13) is variable by a sliding operation of the first upper flap 31 and the second upper flap 32. Of course, the present invention is not limited to the configuration of this example.
(51) For example, as shown in
(52) Also, in this example, to avoid interference of the lower flap 21 (the lower flap 121) with the wheel 12, the lower flap 21 is formed to be substantially T-letter-shaped and a notch 21c (a notch 121c) is provided to the lower flap 21. Of course, the present invention is not limited to the configuration of this example. For example, the lower flap may be formed as the shape which is similar to a rectangle to the extent that interference with the wheel can be avoided, or such a configuration is accepted that the notch of the lower flap formed to be substantially T-letter-shaped can be closed in water navigation.
(53) Moreover, in this example, when the moving state of the amphibious vehicle 1 is moved to the water navigation state or the land driving state, the moving state detecting unit 45 detects the moving state, and the control unit 44 respectively controls driving of the first flap driving unit 41, the second flap driving unit 42 and the third flap driving unit 43 based on a detection result of the moving state detecting unit 45. Of course, the present invention is not limited to the operation of this example. For example, the control unit may respectively control driving of the first flap driving unit, the second flap driving unit and the third flap driving unit based on an operation of a switch which is a moving state detecting unit, or assuming that the moving state detecting unit can predict transition of the moving state of the amphibious vehicle, the control unit may respectively control driving of the first flap driving unit, the second flap driving unit and the third flap driving unit before the transition (immediately before) of the moving state of the amphibious vehicle. Due to these operations, for example, the amphibious vehicle can store the flap in a state of floating on water.
Second Example
(54) A structure of an amphibious vehicle according to a second example of the present invention will be explained with reference to
(55) The amphibious vehicle according to this example has the same structure as the amphibious vehicle according to the first example of the present invention excluding a configuration of a flap. Accordingly, a duplicated explanation about the same structure as in the first example in the amphibious vehicle according to this example is appropriately omitted.
(56) As shown in
(57) As shown in
(58) The first lower flap 231 is a plate-like member which is substantially rectangular-shaped with a narrow width and whose lower end 231a is connected to a lower end 211c of the vehicle body 211 at a front side in a travel direction via a hinge 223. Also, the first lower flap 231 is mechanically connected to a first flap driving unit 241 (see
(59) The second lower flap 232 is a plate-like member which is substantially rectangular-shaped with a broad width and whose rear surface 232a contacts to a front surface 231b of the first lower flap 231 to be slidably connected to the first lower flap 231. Also, the second lower flap 232 is mechanically connected to a second flap driving unit 242 (see
(60) Thus, in a short length state that the second lower flap 232 is stored to be overlapped with the first lower flap 231 (in
(61) As shown in
(62) As shown in
(63) Also, as shown in
(64) An operation of the amphibious vehicle according to the second example of the present invention will be explained with reference to
(65) First, when the amphibious vehicle 201 drives a wheel (or a track) 212 by a not shown driving source and moves on land, the flap 213 is in a completely stored state (see
(66) The flap 213 in the completely stored state is in a state that the lower flap 221 is stored to come close to the front surface 211a of the vehicle body 211 in the short length state and the upper flap 222 is stored to come close to the upper surface 211b of the vehicle body 211.
(67) Following this, for example, when the amphibious vehicle 201 is launched and navigates water by driving a not shown propeller by a not shown driving source, the moving state detecting unit 245 detects that a moving state of the amphibious vehicle 201 is moved from a land driving state to a water navigation state (see
(68) Also, immediately after the amphibious vehicle 201 is moved from the land driving state to the water navigation state, the amphibious vehicle 201 is in a floating state with a deep draft, so that the navigation state detecting unit 246 detects that a navigation state of the amphibious vehicle 201 is the floating state.
(69) Thus, the control unit 244 respectively drives the first flap driving unit 241, the second flap driving unit 242 and the third flap driving unit 243 based on a detection result of the moving state detecting unit 245 and the navigation state detecting unit 246, and transforms the flap 213 from the completely stored state to a completely deployed state.
(70) The flap 213 in the completely deployed state is in a state that the lower flap 221 is deployed to be separated from the front surface 211a of the vehicle body 211 in the long length state and the upper flap 222 is deployed to be separated from the upper surface 211b of the vehicle body 11.
(71) In other words, when the amphibious vehicle 201 is moved from the land driving state to the water navigation state (the floating state), the lower flap 221 (the first lower flap 231) is deployed to be separated from the front surface 211a of the vehicle body 211 by the first flap driving unit 241 and the second lower flap 232 is deployed to be shifted from the first lower flap 231 by the second flap driving unit 242, and the upper flap 222 is deployed to be separated from the upper surface 211b of the vehicle body 211 by the third flap driving unit 243.
(72) Following this, when the amphibious vehicle 201 increases speed in water navigation and is moved from the floating state to the sliding state, the navigation state detecting unit 246 detects that the navigation state of the amphibious vehicle 201 is moved from the floating state to the sliding state (see
(73) Thus, the control unit 244 drives only the second flap driving unit 242 based on a detection result of the navigation state detecting unit 246 and transforms the flap 213 from the completely deployed state to a partially deployed state (a partially stored state.)
(74) The flap 213 in the partially deployed state (the partially stored state) is in a state that the lower flap 221 is deployed to be separated from the front surface 211a of the vehicle body 211 in the short length state and the upper flap 222 is deployed to be separated from the upper surface 211b of the vehicle body 211.
(75) In other words, when the amphibious vehicle 201 is moved from the floating state to the sliding state in the water navigation state, in a state that the lower flap 221 (the first lower flap 231) and the upper flap 222 are remained as deployed, the second lower flap 232 is stored to be overlapped with the first lower flap 231 by the second flap driving unit 242.
(76) Following this, when the amphibious vehicle 201 decreases speed in water navigation and is moved from the sliding state to the floating state, the navigation state detecting unit 246 detects that the navigation state of the amphibious vehicle 201 is moved from the sliding state to the floating state (see
(77) Thus, the control unit 244 drives only the second flap driving unit 242 based on a detection result of the navigation state detecting unit 246 and transforms the flap 213 from the partially deployed state (the partially stored state) to the completely deployed state.
(78) In other words, when the amphibious vehicle 201 is moved from the sliding state to the floating state in the water navigation state, in a state that the lower flap 221 (the first lower flap 231) is remained as deployed, the second lower flap 232 is stored to be shifted from the first lower flap 231 by the second flap driving unit 242.
(79) Following this, for example, when the amphibious vehicle 201 makes a landing and drives the wheel 212 by the not shown driving source to move on land, the moving state detecting unit 245 detects that the moving state of the amphibious vehicle 201 is moved from the water navigation state to the land driving state (see
(80) Thus, the control unit 244 respectively drives the first flap driving unit 241, the second flap driving unit 242 and the third flap driving unit 243 based on a detection result of the moving state detecting unit 245, and transforms the flap 213 from the completely deployed state to the completely stored state.
(81) In other words, when the amphibious vehicle 201 is moved from the water navigation state (the floating state) to the land driving state, the second lower flap 232 is stored to be overlapped with the first lower flap 231 by the second flap driving unit 242, and the lower flap 221 (the first lower flap 231) is stored to come close to the front surface 211a of the vehicle body 211 by the first flap driving unit 241 and the upper flap 222 is stored to come close to the upper surface 211b of the vehicle body 211 by the third flap driving unit 243.
(82) According to the amphibious vehicle 201 according to this example, since the lower flap 221 (the flap 213) is configured such that its flap length is variable, the flap length L.sub.221B of the lower flap 221 (the long length state) can be set to be longer than that of the conventional flap, and the flap length L.sub.213 of the flap 213 (the completely deployed state) can be set to be longer than that of the conventional flap (see
(83) Also, according to the amphibious vehicle 201 according to this example, since the large flap 213 is provided, a contact angle θ.sub.201 of the flap 213 with the water surface (the draft line) 100 can be set to be smaller than the conventional contact angle (see
(84) Moreover, according to the amphibious vehicle 201 according to this example, since the lower flap 221 is configured such that its flap length is variable, the flap length L.sub.221A of the lower flap 221 in the short length state can be set to be substantially the same as that of the conventional flap (see
(85) In addition, according to the amphibious vehicle 201 according to this example, the lower flap 221 can be stored to come close to the front surface 211a of the vehicle body 211, so that the amphibious vehicle 201 can move on land (irregular ground or a stepped portion etc.) without any contact of the flap 213 (the lower flap 221) with the stepped portion etc. in land driving.
(86) Also, according to the amphibious vehicle 201 of this example, since the lower flap 221 (the flap 213) is configured such that its flap length is variable, when the navigation state of the amphibious vehicle 201 is moved to the sliding state, by allowing the lower flap 221 (the flap 213) to be in the short length state, an amount of protrusion D.sub.201 of the flap 213 from the air surface (the draft line) 100 can be inhibited (see
(87) Moreover, according to the amphibious vehicle 201 of this example, even when a front portion of the vehicle body 211 is inclined upward (an upper side in the vertical direction) in the sliding state, by inhibiting the amount of protrusion D.sub.201 of the flap 213 from the water surface 100, vision in a horizontal direction from the wheel window 214a of the driver's seat 214 can be well secured (see
(88) In this example, the lower flap 221 is schematically constituted by the first lower flap 231 and the second lower flap 232 which are slidable with respect to each other, and is configured such that the flap length of the lower flap 221 (the flap 213) is variable by a sliding operation of the first lower flap 231 and the second lower flap 232. Of course, the present invention is not limited to the configuration of this example. For example, the lower flap may be constituted by a plurality of (for example, three) flaps (a plate-like member) which are rotatable with respect to each other, and may be configured such that the flap length of the lower flap (the flap) is variable by a rotating operation of the plurality of flaps.
(89) Also, in this example, to avoid interference of the lower flap 221 with the wheel 212, lengths in the vehicle width direction of the first lower flap 231 and the second lower flap 232 are formed as different, and the lower flap 221 is formed to be substantially T-letter-shaped and a notch 221c is provided to the lower flap 221. Of course, the present invention is not limited to the configuration of this example. For example, the lengths in the vehicle width direction of the first lower flap and the second lower flap may be formed to be substantially the same to the extent that interference with the wheel can be avoided, or such a configuration is accepted that the notch of the lower flap formed to be substantially T-letter-shaped (the lengths in the vehicle width direction are different) can be closed in water navigation.
(90) Moreover, in this example, when the moving state of the amphibious vehicle 201 is moved to the water navigation state or the land driving state, the moving state detecting unit 245 detects the moving state, and the control unit 244 respectively controls driving of the first flap driving unit 241, the second flap driving unit 242 and the third flap driving unit 243 based on a detection result of the moving state detecting unit 245. Of course, the present invention is not limited to the operation of this example. For example, the control unit may respectively control driving of the first flap driving unit, the second flap driving unit and the third flap driving unit based on an operation of a switch which is a moving state detecting unit, or assuming that the moving state detecting unit can predict transition of the moving state of the amphibious vehicle, the control unit may respectively control driving of the first flap driving unit, the second flap driving unit and the third flap driving unit before the transition (immediately before) of the moving state of the amphibious vehicle. Due to these configurations, for example, the amphibious vehicle can store the flap in a state of floating on water.
(91) Also, for example, by combining the first example and the second example, the flap lengths of the lower flap and the upper flap may be configured as variable. Needless to say, the amphibious vehicle including the collapsible flap having such configuration provides the same operational effect as in the amphibious vehicle 1 according to the first example and the second example.
REFERENCE SIGNS LIST
(92) 1 Amphibious vehicle 11 Vehicle body 11a Front surface of a vehicle body 11b Upper surface of the vehicle body 11c Lower end at a front side in a travel direction of the vehicle body 12 Wheel 13 Flap 14 Driver's seat 14a Wheel window of the driver's seat 21 Lower flap 21a Lower end of the lower flap 21b Upper end of the lower flap 21c Notch of the lower flap 22 Upper flap 23 First hinge 24 Second hinge 31 First upper flap (first flap member) 31a Lower end of the first upper flap 31b Front surface of the first upper flap 32 Second upper flap (second flap member) 32a Rear surface of the second upper flap 41 First flap driving unit (driving unit) 42 Second flap driving unit (driving unit) 43 Third flap driving unit (driving unit) 44 Control unit 45 Moving state detecting unit 46 Navigation state detecting unit 100 Water surface (draft line) D.sub.1 Amount of protrusion of a flap L.sub.13 Flap length of the flap L.sub.22A Flap length of an upper flap (a short length state) L.sub.22B Flap length of the upper flap (a long length state) θ.sub.1 Contact angle of the flap 201 Amphibious vehicle 211 Vehicle body 211a Front surface of the vehicle body 211b Upper surface of the vehicle body 211c Lower end at the front side in the travel direction of the vehicle body 212 Wheel 213 Flap 214 Driver's seat 214a Wheel window of the driver's seat 221 Lower flap 221c Notch of the lower flap 222 Upper flap 222a Lower end of the upper flap 223 First hinge 224 Second hinge 231 First lower flap (first flap member) 231a Lower end of the first lower flap 231b Front surface of the first lower flap 232 Second lower flap (second flap member) 232a Rear surface of the second lower flap 232b Upper end of the second lower flap 241 First flap driving unit (driving unit) 242 Second flap driving unit (driving unit) 243 Third flap driving unit (driving unit) 244 Control unit 245 Moving state detecting unit 246 Navigation state detecting unit D.sub.201 Amount of protrusion of the flap L.sub.213 Flap length of the flap L.sub.221A Flap length of the lower flap (a short length state) L.sub.221B Flap length of the lower flap (a long length state) θ.sub.201 Contact angle of the flap