Method for using a ground effect craft four-point landing system

Abstract

The present application relates to a kind of ground effect wing ship four-point landing system sliding use method, ground effect wing ship includes hull, the bottom surface of hull is sequentially arranged front sliding surface, front step, rear sliding surface, rear step from front to back, the bow middle part of the hull located in front of front sliding surface is installed front landing wheel downward, the middle landing wheel of symmetry installed in the middle of hull keel both sides above front sliding surface, the stern middle part of the hull located in rear of rear step is installed rear landing wheel downward, constitute four-point landing wheel system;Sliding launch, when the distance exists between front landing wheel and slope, the weight of hull is supported by two sides middle landing wheel and rear rear landing wheel, after the inclination of hull to front, front landing wheel and slope contact, the weight of hull is supported by two sides middle landing wheel and front front landing wheel;To effectively avoid the take-off and landing risk generated by arranging landing wheel on the hull sliding surface by the unique ground effect wing ship four-point landing wheel system, also prevent the overturning danger that can occur when ground effect wing ship ramp slides.

Description

Technical Field

[0001] The invention relates to the technical field of wing-in-ground-effect vehicles, in particular to a sliding method for a four-point landing system of a wing-in-ground-effect vehicle. Background Art

[0002] Wing-in-ground-effect craft generally adopts water take-off and landing mode, and adopts landing wheel to get on and off the water on land. The layout of existing wing-in-ground-effect craft landing wheel generally adopts tricycle type, which is the same as the landing wheel layout of modern aircraft (including seaplane).

[0003] The existing tricycle layout is both reasonable and mature. However, since the front wheels must be placed on the front planing surface of the WIG craft's hull, a complex and difficult-to-maintain front wheel retraction and deployment system and corresponding storage compartment must be designed to prevent the front landing wheels from interfering with the craft's gliding and landing during takeoff and landing on water. This significantly increases the cost of using and maintaining the WIG craft. To reduce this cost, some small WIG craft even choose not to retract the front wheels. However, placing the front wheels on the front planing surface of the hull poses significant risks to the WIG craft's takeoff and landing, especially during takeoff and landing on water, significantly affecting the performance of the front planing surface. Summary of the Invention

[0004] In response to the shortcomings of the above-mentioned existing production technology, the applicant provides a rationally structured method for sliding use of a four-point landing system for a wing-in-ground-effect vehicle. Through the unique four-point landing wheel system of the wing-in-ground-effect vehicle, the take-off and landing risks caused by arranging landing wheels on the hull sliding surface are effectively avoided, and the risk of capsizing that may occur when the wing-in-ground-effect vehicle slides down a ramp is also prevented.

[0005] The technical solutions adopted in the present invention are as follows:

[0006] A method for using a four-point landing system for a wing-in-ground-effect craft using a glide path. The wing-in-ground-effect craft includes a hull, wherein the bottom surface of the hull is provided with a front glide surface, a front step, a rear glide surface, and a rear step in sequence from front to rear. A front landing wheel is installed downwardly at the middle portion of the bow of the hull in front of the front glide surface, symmetrical middle landing wheels are installed downwardly on both sides of the midship of the hull above the front glide surface, and a rear landing wheel is installed downwardly at the middle portion of the stern of the hull behind the rear step, forming a four-point landing wheel system.

[0007] The method includes a method of sliding on flat ground, a method of sliding into water, and a method of sliding onto land. The method of sliding onto land is opposite to the method of sliding into water.

[0008] The wing-in-ground-effect vehicle is launched from flat ground via a slope, and the method for gliding into the water comprises the following steps:

[0009] When the WIG craft is on flat ground, the middle landing wheels on both sides and the rear landing wheels touch the ground, and the WIG craft slides toward the slope.

[0010] When the middle landing wheels on both sides approach and slide into the slope, the rear landing wheels are still on the flat ground, and the front landing wheels are lowered. At this time, there is a distance between the bottom surface of the front landing wheels and the slope, and the front landing wheels are suspended in the air;

[0011] The middle landing wheel slides down the slope, while the rear landing wheel remains on flat ground. As the sliding continues, the WIG vehicle tilts forward, causing the front landing wheel to contact the slope. The front wheel cylinder of the front landing wheel is compressed, and the cylinder pressure maintaining system stabilizes the front wheel cylinder at a set pressure value.

[0012] As the WIG craft continues to glide forward, the front wheel cylinder continues to be compressed, and the pressure continues to be unloaded and remains constant at the set pressure value until the front landing wheels, middle landing wheels and rear landing wheels all enter the slope glide. The front landing wheels, middle landing wheels and rear landing wheels are subjected to a stable supporting force until the WIG craft glides into the water.

[0013] As a further improvement of the above technical solution:

[0014] During the taxiing launch process, when there is a distance between the front landing wheels and the ramp, the weight of the hull is supported by the middle landing wheels on both sides and the rear landing wheels; after the hull tilts forward and the front landing wheels contact the ramp, the weight of the hull is supported by the middle landing wheels on both sides and the front landing wheels in front.

[0015] The front landing wheels and the rear landing wheels are located in the same longitudinal direction of the hull.

[0016] The front landing wheels are installed on the bow via a front wheel retracting and extending mechanism. The front wheel retracting and extending mechanism retracts the front landing wheels upwards or lowers them downwards. The front landing wheels are located outside the hull.

[0017] The structure of the front wheel retraction and extension mechanism is as follows: it includes a front wheel cylinder installed inside the bow of the hull via a front wheel mounting bracket, the output end of the front wheel cylinder faces downward, and a front wheel fork with a downward U-shaped structure is installed on the output end of the front wheel cylinder via a flange assembly, and a front landing wheel is rotatably installed on the lower part of the front wheel fork via the front wheel axle; the front wheel cylinder is connected to a cylinder pressure maintaining system, and a pressure value is set for the front wheel cylinder by the cylinder pressure maintaining system, and the extension state of the output end of the front wheel cylinder is passively changed by the force state of the front landing wheel.

[0018] When the front landing wheel is in a fully extended state, the front wheel oil cylinder is in a state of no stress; when the front landing wheel is in a state of stress, the front wheel oil cylinder is passively compressed, and the front wheel oil cylinder is regulated by the oil cylinder pressure maintaining system and stabilized at a set pressure value.

[0019] The middle landing wheel is installed in the middle of the ship via a middle wheel retracting and extending mechanism. The middle wheel retracting and extending mechanism retracts or lowers the middle landing wheel laterally. The middle landing wheel is located in front of the front step and the center of gravity of the hull.

[0020] The structure of the middle wheel retracting and extending mechanism is as follows: it includes an upper rod and a lower rod with one end rotatably mounted on the hull, the upper rod and the lower rod are parallel and of equal length, the other end of the upper rod and the other end of the lower rod are respectively rotatably mounted on the middle wheel pillar, a middle wheel cylinder is installed between the top surface of the middle wheel pillar and the hull, and a middle landing wheel is rotatably mounted on the outer side of the bottom end of the middle wheel pillar via the middle wheel shaft.

[0021] The rear landing wheels are installed at the stern of the ship via a rear wheel retracting and extending mechanism, and the rear wheel retracting and extending mechanism retracts the rear landing wheels backward or lowers them forward.

[0022] The structure of the rear wheel retraction and extension mechanism is as follows: it includes an upper support rod and a lower support rod whose opposite ends are rotatably installed via a rotating shaft, the other end of the upper support rod is rotatably installed on the hull, and the other end of the lower support rod is rotatably installed in the middle of the rear wheel pillar; a rear wheel cylinder is installed between the lower part of the upper support rod and the hull, the top end of the rear wheel pillar is rotatably installed with the hull, and the rear landing wheel is rotatably installed on the bottom end of the rear wheel pillar via the rear wheel axle.

[0023] The beneficial effects of the present invention are as follows:

[0024] The invention has a compact and reasonable structure and is easy to operate. The front landing wheel is arranged in front of the front sliding surface of the hull, the rear landing wheel is arranged behind the rear step of the hull, and the middle landing wheels are symmetrically arranged on both sides of the hull amidships to form a four-point landing wheel system. During the launching process of the wing-in-ground-effect craft, when there is a distance between the front landing wheel and the slope, the weight of the hull is supported by the middle landing wheels on both sides and the rear landing wheel at the rear. When the hull tilts forward and the front landing wheel contacts the slope, the weight of the hull is supported by the middle landing wheels on both sides and the front landing wheel at the front. Therefore, the unique four-point landing wheel system of the wing-in-ground-effect craft effectively avoids the take-off and landing risks caused by arranging the landing wheels on the sliding surface of the hull, and also prevents the possible capsizing risk when the wing-in-ground-effect craft slides down the ramp, thereby greatly ensuring the stability, reliability and safety of the launching or landing process of the wing-in-ground-effect craft and having good practicality.

[0025] The present invention also includes the following advantages:

[0026] Different retraction and extension mechanisms are adopted according to the different stress conditions and usage methods of the front landing wheels, middle landing wheels and rear landing wheels. In particular, a cylinder pressure maintaining system is set for the front wheel cylinders corresponding to the front landing wheels, which effectively and reliably ensures that the extension length of the front wheels meets the usage requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the state of the ground effect wing vehicle of the present invention when it is supported on flat ground before launching.

[0028] Figure 2 This is a schematic diagram of the state of the middle landing wheel of the ground effect vehicle of the present invention sliding into the slope before launching.

[0029] Figure 3This is a schematic diagram of the state when the front landing wheels of the ground effect vehicle of the present invention are in contact with the slope.

[0030] Figure 4 This is a schematic diagram of the state when the four-point landing wheels of the ground effect vehicle of the present invention are all located on the slope.

[0031] Figure 5 This is a schematic diagram of the state of the ground effect wing vehicle after launching.

[0032] Figure 6 It is a front view of the ground effect wing vehicle of the present invention.

[0033] Figure 7 for Figure 6 Left view (landing wheels lowered).

[0034] Figure 8 This is a schematic diagram of the WIG craft of the present invention when its landing wheels are retracted.

[0035] Figure 9 It is a structural schematic diagram of the front wheel retracting and extending mechanism of the present invention.

[0036] Figure 10 It is a structural schematic diagram of the oil cylinder pressure maintaining system of the present invention.

[0037] Figure 11 It is a structural schematic diagram of the wheel retracting and extending mechanism of the present invention.

[0038] Figure 12 This is a schematic diagram of the wheel retracting and extending mechanism of the present invention in the retracted state.

[0039] Figure 13 It is a structural schematic diagram of the rear wheel retracting and extending mechanism of the present invention.

[0040] Figure 14 This is a schematic diagram of the rear wheel retractable mechanism of the present invention in the retracted state.

[0041] Figure 15 It is a schematic diagram of the forces acting on the wing-in-ground-effect vehicle of the present invention when it slides from flat ground to a ramp.

[0042] Figure 16 It is a schematic diagram of the forces acting on the wing-in-ground-effect vehicle of the present invention when it slides on a ramp.

[0043] Figure 17 It is a schematic diagram of the forces acting on the wing-in-ground-effect vehicle of the present invention when it slides from a ramp to flat ground.

[0044] Including: 10, hull; 20, pontoons; 30, ground effect wings; 40, power system; 50, vertical tail; 60, horizontal tail;

[0045] 11. Front sliding surface; 12. Front step; 13. Back sliding surface;

[0046] 2. Front landing wheel; 3. Middle landing wheel; 4. Rear landing wheel; 5. Front wheel retractable mechanism; 6. Middle wheel retractable mechanism; 7. Rear wheel retractable mechanism;

[0047] 51. Front wheel cylinder; 52. Front wheel mounting bracket; 53. Flange assembly; 55. Front wheel fork; 56. Front wheel axle; 510. Cylinder pressure maintaining system; 511. Relief valve; 512. Fuel tank; 513. Check valve; 514. Reversing valve; 515. Hydraulic pump;

[0048] 61. Upper rod; 62. Middle wheel cylinder; 63. Middle wheel support; 64. Lower rod; 65. Middle wheel shaft;

[0049] 71. Rear wheel support; 72. Lower support rod; 73. Rotating shaft; 74. Upper support rod; 75. Rear wheel cylinder. DETAILED DESCRIPTION

[0050] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0051] like Figure 1 As shown, a method for sliding and using a four-point landing system of a ground effect craft of the present embodiment, the ground effect craft includes a hull 10, and the bottom surface of the hull 10 is sequentially provided with a front sliding surface 11, a front step 12, a rear sliding surface 13, and a rear step from front to rear. A front landing wheel 2 is installed downwardly at the middle part of the bow of the hull 10 in front of the front sliding surface 11, symmetrical middle landing wheels 3 are installed downwardly on both sides of the midship of the hull 10 located above the front sliding surface 11, and a rear landing wheel 4 is installed downwardly at the middle part of the stern of the hull 10 located behind the rear step, forming a four-point landing wheel system;

[0052] The methods include sliding on the ground, sliding into the water and sliding landing. The sliding landing method is the opposite of the sliding into the water method.

[0053] The WIG vehicle is launched from flat ground via a slope. The method of launching into water by sliding includes the following steps:

[0054] Step 1: When the WIG craft is on flat ground, the middle landing wheels 3 on both sides and the rear landing wheels 4 touch the ground, and the WIG craft slides toward the slope. Figure 1 As shown;

[0055] Step 2: When the middle landing wheels 3 on both sides approach and slide into the slope, the rear landing wheels 4 are still on the flat ground, and the front landing wheels 2 are lowered. At this time, there is a distance between the bottom surface of the front landing wheels 2 and the slope, and the front landing wheels 2 are suspended in the air. Figure 2 As shown;

[0056] Step 3: The middle landing wheel 3 slides down the slope, and the rear landing wheel 4 is still on the flat ground. As the sliding continues, the ground effect vehicle tilts forward and the front landing wheel 2 contacts the slope. Figure 3 As shown, the front wheel cylinder 51 of the front landing wheel 2 is compressed, and the front wheel cylinder 51 is stabilized at a set pressure value by the cylinder pressure maintaining system 510;

[0057] The 4th step: as the WIG craft continues to glide forward, the front wheel oil cylinder 51 continues to be compressed, and the pressure continues to unload and is constant at the set pressure value, until the front landing wheel 2, the middle landing wheel 3 and the rear landing wheel 4 all enter the slope glide, as shown in FIG. Figure 4 As shown, the front landing wheel 2, the middle landing wheel 3 and the rear landing wheel 4 are subjected to a stable supporting force until the ground effect wing craft glides into the water. After sliding into the water, the front landing wheel 2, the middle landing wheel 3 and the rear landing wheel 4 are all retracted upward relative to the hull 10, as shown in FIG. Figure 5 shown.

[0058] In this embodiment, a four-point landing wheel system is formed by arranging a front landing wheel 2 in front of the front sliding surface 11 of the hull 10, arranging a rear landing wheel 4 behind the rear step of the hull 10, and symmetrically arranging middle landing wheels 3 on both sides of the midship of the hull 10. During the gliding launching process of the wing-in-ground-effect craft, when there is a distance between the front landing wheel 2 and the slope, the weight of the hull 10 is supported by the middle landing wheels 3 on both sides and the rear landing wheel 4 at the rear. When the hull 10 tilts forward and the front landing wheel 2 contacts the slope, the weight of the hull 10 is supported by the middle landing wheels 3 on both sides and the front landing wheel 2 in front. Therefore, the unique four-point landing wheel system of the wing-in-ground-effect craft effectively avoids the take-off and landing risks caused by arranging landing wheels on the sliding surface of the hull 10, and also prevents the risk of capsizing that may occur when the wing-in-ground-effect craft slides down the ramp.

[0059] In this embodiment, the four-point landing wheel system of the ground effect vehicle is used to support the hull 10 during low-speed landing or sliding into the water. It has low requirements for dock facilities. As long as there is a cement slope, the boat can be boarded and launched, and can directly enter the hangar.

[0060] Generally speaking, the hull 10 of a ground effect wing craft extends to both sides to form ground effect wings 30, and pontoons 20 are symmetrically installed on the bottom surfaces of both ends of the ground effect wings 30. A power system 40 is also installed on the top surface of the hull 10, and the ground effect wing craft is driven forward by the operation of the power system 40. A vertical tail 50 extends upward and backward above the tail of the hull 10, and a horizontal tail 60 is installed on the top of the vertical tail 50 to form a ground effect wing craft.

[0061] When the landing wheels of the ground effect wing ship glide on flat ground, the middle landing wheel 3 and the rear landing wheel 4 touch the ground, and the front landing wheel 2 is generally in a retracted state and the wheels do not touch the ground. Of course, the front landing wheel 2 can also be in an extended force-bearing state, and the gliding state is a three-point type at this time.

[0062] During the sliding launching process, when there is a distance between the front landing wheel 2 and the slope, the weight of the hull 10 is supported by the middle landing wheels 3 on both sides and the rear landing wheel 4 at the rear; when the hull 10 tilts forward and the front landing wheel 2 contacts the slope, the weight of the hull 10 is supported by the middle landing wheels 3 on both sides and the front landing wheel 2 in front.

[0063] like Figure 6 、 Figure 7 and Figure 8 As shown, the front landing wheel 2 and the rear landing wheel 4 are located in the same longitudinal direction of the hull 10, and each has only one wheel.

[0064] In this embodiment, the front landing wheels 2 and the rear landing wheels 4 are respectively arranged on the bow and stern outside the front sliding surface 11 and the rear sliding surface 13, away from the center of gravity. During normal sliding, the two middle landing wheels 3 in the middle bear the main supporting force.

[0065] The front landing wheels 2 are mounted on the bow via a front wheel retracting and extending mechanism 5 . The front wheel retracting and extending mechanism 5 retracts the front landing wheels 2 upward or lowers the front landing wheels 2 . The front landing wheels 2 are located outside the hull 10 .

[0066] In this embodiment, since the front landing wheels 2 are arranged in front of the front gliding surface 11, they will not affect the front gliding surface 11. Therefore, during the gliding process of the ground effect vehicle, it is only necessary to retract the front landing wheels 2 upward via the front wheel retraction mechanism 5, without the need to set up an additional accommodation compartment to accommodate the front landing wheels 2 inside the hull 10. While ensuring actual use, it effectively eliminates the need for complex structural layout and saves manufacturing and use costs.

[0067] like Figure 9 As shown, the structure of the front wheel retracting and extending mechanism 5 is as follows: it includes a front wheel cylinder 51 installed inside the bow of the hull 10 via a front wheel mounting bracket 52, the output end of the front wheel cylinder 51 faces downward, and a front wheel fork 55 with a downward U-shaped structure is installed at the output end of the front wheel cylinder 51 via a flange assembly 53, and the front landing wheel 2 is rotatably installed at the lower part of the front wheel fork 55 via a front wheel shaft 56; the front wheel cylinder 51 is connected to a cylinder pressure maintaining system 510, and the cylinder pressure maintaining system 510 sets a pressure value for the front wheel cylinder 51, and the extension state of the output end of the front wheel cylinder 51 is passively changed by the force state of the front landing wheel 2.

[0068] In this embodiment, the front wheel retracting mechanism 5 utilizes a hydraulic drive mechanism, enabling remote control to drive the front landing wheels 2 in a linear motion, thereby driving the front landing wheels 2 up and down. The process of lowering and retracting the front landing wheels 2 is very simple: lowering the front wheel cylinder 51 extends outward, and retracting the front wheel cylinder 51 retracts it upward.

[0069] When the front landing wheel 2 is in a fully extended state, the front wheel cylinder 51 is in a stress-free state. When the front landing wheel 2 is in a stressed state, the front wheel cylinder 51 is passively compressed, the hydraulic system pressure increases, and the front wheel cylinder 51 is regulated by the cylinder pressure maintaining system 510 and stabilized at a set pressure value, so that the extended length of the front landing wheel 2 is also at a constant value that meets the use requirements.

[0070] like Figure 10 As shown, the hydraulic cylinder pressure-maintaining system 510 consists of a relief valve 511, a fuel tank 512, a check valve 513, a reversing valve 514, and a hydraulic pump 515. When the hydraulic system pressure exceeds a set value, the relief valve 511 automatically opens, allowing the oil to overflow and maintain a constant pressure. In the hydraulic cylinder pressure-maintaining system 510, the relief valve 511 prevents overload and ensures system safety.

[0071] When the middle landing wheel 3 of the wing-in-ground effect craft slides into the slope, the rear landing wheel 4 is still on flat ground, and the weight of the wing-in-ground effect craft is supported by the middle landing wheel 3 and the rear landing wheel 4. This moment, put down the front landing wheel 2, because there is a distance between the front landing wheel 2 and the slope surface, and the supporting force F is zero. Along with the wing-in-ground effect craft when driving into the downhill stage gradually, at a certain position, the forward moment produced by the engine thrust can make the wing-in-ground effect craft rotate forward around the center of gravity, at this moment, the rear landing wheel 4 will not be stressed, and the front landing wheel 2 begins to be stressed, and along with the wing-in-ground effect craft further drives into the downhill, the front wheel oil cylinder 51 is upwards compressed under the effect of supporting force F, and the pressure in the upper chamber of the front wheel oil cylinder 51 and the corresponding pipeline sharply rises, may cause accidents such as pipeline destruction, hydraulic pump 515 stalling, motor burning out thus; By in pipeline, relief valve 511 is set, when pressure rises, when surpassing the set pressure value, pressure oil flows back to oil tank 512 from relief valve 511, can effectively and reliably prevent accident, guarantee safety in use. When the GEV is fully engaged on the ramp, the front wheel cylinders 51 are in a compressed position, and the pressure is at a set value, indicating a stable pressure system. The extended length of the front landing wheels 2 is then constant, ensuring that the extended length of the front wheel cylinders 51 is precisely sufficient to ensure that all four landing wheels are in contact with the ramp and receive force as they descend, maintaining a stable moment balance and preventing capsizing.

[0072] The middle landing wheel 3 is installed in the middle of the ship via the middle wheel retracting and extending mechanism 6. The middle wheel retracting and extending mechanism 6 retracts or lowers the middle landing wheel 3 laterally. The middle landing wheel 3 is located in front of the front step 12 and the center of gravity of the hull 10.

[0073] like Figure 11As shown, the structure of the middle wheel retracting and extending mechanism 6 is as follows: it includes an upper rod 61 and a lower rod 64 rotatably mounted on the hull 10 at one end, the upper rod 61 and the lower rod 64 are parallel and of equal length, the other end of the upper rod 61 and the other end of the lower rod 64 are rotatably mounted on the middle wheel pillar 63 respectively, and a parallelogram connecting rod is formed by the upper rod 61, the lower rod 64, the hull 10 and the middle wheel pillar 63, and the middle wheel pillar 63 remains in a vertical state; a middle wheel cylinder 62 is installed between the top surface of the middle wheel pillar 63 and the hull 10, and a middle landing wheel 3 is rotatably mounted on the outer side of the bottom end of the middle wheel pillar 63 via a middle wheel shaft 65.

[0074] When the middle wheel retracting mechanism 6 switches the middle landing wheel 3 from the lowered state to the retracted state, the middle wheel cylinder 62 works and pushes the middle wheel pillar 63 outward. The middle wheel cylinder 62 rotates upward at the hinge point between the middle wheel cylinder 62 and the hull 10, and at the same time, the middle wheel pillar 63 moves upward, and the parallelogram connecting rod is deformed and compressed upward until it is as shown in FIG. Figure 12 As shown, the middle landing wheel 3 reaches a state of being stowed upwards.

[0075] In this embodiment, the middle landing wheel 3 is supported by a parallelogram connecting rod, which on the one hand effectively ensures the longitudinal strength and rigidity of the middle landing wheel 3; on the other hand, during the folding and lowering process, the vertical state of the middle wheel support 63 is maintained to effectively ensure that the middle landing wheel 3 always remains in a vertical state, so that the middle landing wheel 3 can be close to the outer wall of the hull 10 when folded, and can remain perpendicular to the ground when lowered, effectively ensuring the normal, stable and reliable rotation of the middle landing wheel 3.

[0076] The rear landing wheels 4 are mounted on the stern of the ship via a rear wheel retracting and extending mechanism 7 , which retracts the rear landing wheels 4 backward or extends them forward.

[0077] like Figure 13 As shown, the structure of the rear wheel retracting and extending mechanism 7 is as follows: it includes an upper support rod 74 and a lower support rod 72 whose opposite ends are rotatably mounted via a rotating shaft 73, the other end of the upper support rod 74 is rotatably mounted on the hull 10, and the other end of the lower support rod 72 is rotatably mounted on the middle part of the rear wheel pillar 71; a rear wheel cylinder 75 is installed between the lower part of the upper support rod 74 and the hull 10, the top end of the rear wheel pillar 71 is rotatably mounted on the hull 10, and the rear landing wheel 4 is rotatably mounted on the bottom end of the rear wheel pillar 71 via the rear wheel axle.

[0078] In this embodiment, the rear wheel cylinder 75 is a hydraulic drive device that can remotely control the drive device to perform linear motion to drive the upper support rod 74, the lower support rod 72 and the rear wheel support 71 to rotate or move, ultimately achieving the retraction and extension of the rear landing wheel 4.

[0079] When the rear landing wheel 4 needs to be lowered, the rear wheel cylinder 75 is extended first, and the upper support rod 74 is rotated downward counterclockwise with the upper end of the upper support rod 74 as the center of the circle through the push of the rear wheel cylinder 75. The upper support rod 74 then drives the lower support rod 72 to move downward through the rotating shaft 73; the downward moving lower support rod 72 pushes the upper end of the rear wheel support 71 to swing downward clockwise, thereby completing the task of lowering the landing wheel 4. Figure 13 shown.

[0080] When the rear landing wheel 4 needs to be folded up, the rear wheel cylinder 75 retracts first, and the rear wheel cylinder 75 pulls the upper support rod 74 to rotate upward clockwise with the upper end as the center of the circle, and the upper support rod 74 then drives the lower support rod 72 to move upward through the rotating shaft 73; the upward moving lower support rod 72 drives the upper end of the rear wheel support 71 to rotate upward counterclockwise, thereby completing the folding task of the landing wheel 4. Figure 14 shown.

[0081] In this embodiment, the four-point landing wheel system avoids arranging landing wheels on the sliding surface of the ground effect vehicle hull 10, and prevents the danger of tipping forward on the downhill slope caused by the rear three-point landing wheel arrangement. The specific working principle is as follows:

[0082] Whether the WIG craft will capsize on the ramp depends mainly on the equilibrium state of the relevant moments. When the forward capsizing moment generated by the front engine thrust T around the center of gravity is greater than the reverse support moment generated by the support force Fz of the middle landing wheel 3 around the center of gravity, the craft will capsize if there is no support from the front landing wheel 2.

[0083] from Figure 15 and Figure 16 As shown in FIG, when the wing-in-force ship slides down from the flat ground to the ramp, the arm value of the support force Fz of the middle landing wheel 3 from the center of gravity gradually decreases. On the contrary, when the wing-in-force ship slides up from the water to the ramp, the arm value of the support force Fz of the middle landing wheel 3 from the center of gravity gradually increases. The above reason is that the middle landing wheel 3 is located in front of the center of gravity. Figure 17 shown.

[0084] like Figure 15 As shown in FIG. 2 , at the same time, the lever arm between engine thrust T and the center of gravity then remains unchanged, and generally must implement brakes to middle landing wheel 3 when sliding downward on ramp in addition, and this also can increase overturning moment.When overturning moment is greater than the opposing torque that middle landing wheel 3 supporting forces Fz produce, will cause the wing-in-ground effect craft to overturn when sliding down ramp, at this moment the front landing wheel 2 that is arranged on the bow will play a decisive role.Because front landing wheel 2 is very far away from the center of gravity, the supporting force Fq of namely front landing wheel 2 is very large apart from the lever arm value of the center of gravity, less supporting force Fq just can produce larger opposing torque, makes the relevant moment of wing-in-ground effect craft when sliding down ramp be in equilibrium state.

[0085] like Figure 17 As shown, when the WIG craft slides on the ramp, the arm value of the support force Fz of the middle landing wheel 3 from the center of gravity gradually increases, which ensures that when the WIG craft slides on the ramp, the original related torque will be in a more balanced and stable state.

[0086] The function of the front landing wheel 2 oil cylinder pressure-maintaining system 510 is that when the extended front landing wheel 2 is subjected to an upward supporting force Fq and transmitted to the front wheel oil cylinder 51, the front wheel oil cylinder 51 is compressed and moved upward and retracted under the action of the supporting force Fq. As the pressure in the upper chamber of the front wheel oil cylinder 51 and the corresponding pipeline increases sharply, when it exceeds a certain set pressure value, the relief valve 511 is unloaded, and the pressure system is also in a stable state. At this time, the extended length of the front wheel oil cylinder 51 can be kept stable. For the ground effect vehicle landing wheel system, the pressure value set by the relief valve 511 is to ensure that the extended length of the front wheel oil cylinder 51 is exactly the same as that of the four landing wheels when sliding down the ramp. It is stressed, so that the entire torque is in a stable equilibrium state and there is no risk of overturning.

[0087] Different retraction and extension mechanisms are adopted according to the different stress conditions and usage modes of the front landing wheels 2, the middle landing wheels 3, and the rear landing wheels 4. In particular, a cylinder pressure maintaining system 510 is provided for the front wheel cylinder 51 corresponding to the front landing wheel 2, which effectively and reliably ensures that the extension length of the front wheel meets the usage requirements.

[0088] The present invention effectively avoids the take-off and landing risks caused by arranging landing wheels on the sliding surface of the hull through a unique four-point landing wheel system of the ground effect wing vehicle, and also prevents the risk of capsizing that may occur when the ground effect wing vehicle slides down the ramp, thereby greatly ensuring the stability, reliability and safety of the ground effect wing vehicle during the launching or landing process, and having good practicality.

[0089] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any modifications may be made within the scope of protection of the present invention.

Claims

1. A method for using a four-point landing system of a ground effect wing craft for sliding, the ground effect wing craft comprising a hull (10), the bottom surface of the hull (10) being provided with a front sliding surface (11), a front step (12), a rear sliding surface (13), and a rear step in sequence from front to rear, characterized in that: A front landing wheel (2) is installed downwardly at the middle of the bow of the hull (10) located in front of the front sliding surface (11), symmetrical middle landing wheels (3) are installed downwardly on both sides of the midship of the hull (10) located above the front sliding surface (11), and a rear landing wheel (4) is installed downwardly at the middle of the stern of the hull (10) located behind the rear step, forming a four-point landing wheel system; The method includes a method of sliding on flat ground, a method of sliding into water, and a method of sliding onto land. The method of sliding onto land is opposite to the method of sliding into water. The wing-in-ground-effect vehicle is launched from flat ground via a slope, and the method for gliding into the water comprises the following steps: When the WIG craft is on flat ground, the middle landing wheels (3) on both sides and the rear landing wheels (4) touch the ground, and the WIG craft slides toward the slope. When the middle landing wheels (3) on both sides approach and slide into the slope, the rear landing wheels (4) are still on the flat ground, and the front landing wheels (2) are lowered. At this time, there is a distance between the bottom surface of the front landing wheels (2) and the slope, and the front landing wheels (2) are suspended in the air; The middle landing wheel (3) slides downward along the slope, and the rear landing wheel (4) is still located on the flat ground. As the sliding continues, the ground effect vehicle tilts forward so that the front landing wheel (2) contacts the slope, and the front wheel oil cylinder (51) of the front landing wheel (2) is compressed. The front wheel oil cylinder (51) is stabilized at a set pressure value by the oil cylinder pressure maintaining system (510); As the wing-in-ground-effect craft continues to glide forward, the front wheel oil cylinder (51) continues to be compressed, and the pressure continues to be unloaded and remains constant at the set pressure value until the front landing wheel (2), the middle landing wheel (3) and the rear landing wheel (4) all enter the slope glide, and the front landing wheel (2), the middle landing wheel (3) and the rear landing wheel (4) are subjected to a stable supporting force until the wing-in-ground-effect craft glides into the water.

2. The method for sliding a four-point landing system for a wing-in-ground-effect vehicle according to claim 1, wherein: During the sliding launching process, when there is a distance between the front landing wheel (2) and the slope, the weight of the hull (10) is supported by the middle landing wheels (3) on both sides and the rear landing wheel (4) at the rear; after the hull (10) tilts forward and the front landing wheel (2) contacts the slope, the weight of the hull (10) is supported by the middle landing wheels (3) on both sides and the front landing wheel (2) at the front.

3. The method for sliding and using a four-point landing system of a wing-in-ground-effect vehicle according to claim 1, wherein: The front landing wheels (2) and the rear landing wheels (4) are located in the same longitudinal direction of the hull (10).

4. The method for sliding and using a four-point landing system of a wing-in-ground-effect vehicle according to claim 1, wherein: The front landing wheel (2) is installed on the bow via a front wheel retracting and extending mechanism (5). The front wheel retracting and extending mechanism (5) retracts the front landing wheel (2) upward or lowers it downward. The front landing wheel (2) is located outside the hull (10).

5. The method for sliding and using a four-point landing system of a wing-in-ground-effect vehicle according to claim 4, characterized in that: The structure of the front wheel retracting and extending mechanism (5) is as follows: it comprises a front wheel oil cylinder (51) mounted inside the bow of the hull (10) via a front wheel mounting support (52); the output end of the front wheel oil cylinder (51) faces downward; a front wheel fork (55) with a downward U-shaped structure is mounted on the output end of the front wheel oil cylinder (51) via a flange assembly (53); the lower part of the front wheel fork (55) is rotatably mounted with a front landing wheel (2) via a front wheel shaft (56); the front wheel oil cylinder (51) is connected to a cylinder pressure maintaining system (510); the cylinder pressure maintaining system (510) sets a pressure value for the front wheel oil cylinder (51); and the extension state of the output end of the front wheel oil cylinder (51) is passively changed by the force state of the front landing wheel (2).

6. A method for sliding a four-point landing system for a wing-in-ground-effect vehicle according to claim 1 or 5, characterized in that: When the front landing wheel (2) is in a fully extended state, the front wheel oil cylinder (51) is in a non-stressed state; when the front landing wheel (2) is in a stressed state, the front wheel oil cylinder (51) is passively compressed, and the front wheel oil cylinder (51) is regulated by the oil cylinder pressure maintaining system (510) and stabilized at a set pressure value.

7. The method for sliding and using a four-point landing system of a wing-in-ground-effect vehicle according to claim 1, wherein: The middle landing wheel (3) is installed in the middle of the ship via a middle wheel retracting and extending mechanism (6). The middle wheel retracting and extending mechanism (6) retracts or lowers the middle landing wheel (3) laterally. The middle landing wheel (3) is located in front of the front step (12) and the center of gravity of the hull (10).

8. A method for sliding and using a four-point landing system for a wing-in-ground-effect vehicle according to claim 7, characterized in that: The structure of the middle wheel retracting and extending mechanism (6) is as follows: it comprises an upper rod (61) and a lower rod (64) rotatably mounted on the hull (10) at one end, the upper rod (61) and the lower rod (64) are parallel and of equal length, the other ends of the upper rod (61) and the other ends of the lower rod (64) are rotatably mounted on the middle wheel pillar (63), a middle wheel oil cylinder (62) is installed between the top surface of the middle wheel pillar (63) and the hull (10), and a middle landing wheel (3) is rotatably mounted on the outer side of the bottom end of the middle wheel pillar (63) via a middle wheel shaft (65).

9. The method for using a four-point landing system for a wing-in-ground-effect vehicle according to claim 1, wherein: The rear landing wheel (4) is mounted on the stern of the ship via a rear wheel retracting and extending mechanism (7), and the rear wheel retracting and extending mechanism (7) retracts the rear landing wheel (4) backward or lowers it forward.

10. A method for sliding and using a four-point landing system for a wing-in-ground-effect vehicle according to claim 9, characterized in that: The rear wheel retracting and extending mechanism (7) comprises an upper support rod (74) and a lower support rod (72) whose opposite ends are rotatably mounted via a rotating shaft (73), the other end of the upper support rod (74) being rotatably mounted on the hull (10), and the other end of the lower support rod (72) being rotatably mounted on the middle of the rear wheel support column (71); a rear wheel oil cylinder (75) being mounted between the lower part of the upper support rod (74) and the hull (10), the top end of the rear wheel support column (71) being rotatably mounted on the hull (10), and the bottom end of the rear wheel support column (71) being rotatably mounted with the rear landing wheel (4) via a rear wheel axle.

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