Water traction joint for helicopter and assembly method thereof

Abstract

The invention provides a water traction joint for a helicopter and an assembly method thereof, and belongs to the technical field of helicopter structural design, the water traction joint is symmetrically mounted on the left side and the right side of a nose skin, the axial direction of a traction ring is along the course, the mounting height is above the water level, and the traction ring in the water traction joint adopts a circular ring belt double-lug structural form; the cylindrical area of the single-lug threaded connecting piece is provided with threads; a single-lug joint of the single-lug threaded connecting piece is connected with a double-lug joint of the traction ring; a round hole is formed in the vertical edge of the front end of the groove-shaped corner box; vertical edges on three surfaces of the groove-shaped corner box are provided with turned edges; the bushing nut is a variable-section cylinder, and the inner ring of the bushing nut is provided with threads; the cylindrical area of the outer ring is attached to the circular hole wall of the groove-shaped corner box, and the cylindrical area of the outer ring of the bush nut is in small clearance fit with the circular hole wall of the groove-shaped corner box. The cylinder of the large ring of the bushing nut transmits traction load by extruding the inner wall of the groove-shaped angle box; the position above the water level can be selected, the structural form is simple, and 360-degree free rotation can be achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of helicopter structure design, and particularly relates to a water towing joint for a helicopter and an assembly method thereof. Background Art

[0002] When a helicopter performs tasks in water environments such as the ocean and rivers, it has the ability of water ditching and water emergency floating. Therefore, the helicopter needs to have the function of water towing to ensure the safety of the aircraft, equipment and personnel.

[0003] Traditional ground towing joints are generally arranged at the bottom of the fuselage, such as at the nose landing gear or at the strong support structure of the bottom frame beam. When the aircraft performs tasks such as water ditching, the towing joint is below the water surface, which is not suitable for rapid towing on water. Summary of the Invention

[0004] To solve the technical problem that in the prior art, when the aircraft performs tasks such as water ditching, the towing joint is below the water surface and is not suitable for rapid towing on water, the present invention provides a water towing joint for a helicopter and an assembly method thereof. The helicopter towing joint assembly is symmetrically installed on both sides of the nose. The specific position can be selected above the water level according to the different structures and weights of the helicopter to ensure a rapid towing function on water; the structure form of the towing joint is simple, and it can realize 360-degree free rotation; the structure weight of the towing joint is light, and the load transfer is direct and efficient. The technical solutions are as follows:

[0005] In the first aspect, a water towing joint for a helicopter is provided, which is symmetrically installed on the left and right sides of the nose skin. The axial direction of the towing ring is along the course, and the installation height is above the water level. The water towing joint 16 includes: a towing ring 1, a single-ear threaded connector 2, a channel-shaped angle box 3, a bushing nut 4, a wire retaining ring 5.

[0006] The towing ring 1 adopts a circular ring with double-ear structure, and the circular ring is used to connect the towing rod or towing rope.

[0007] The cylindrical area of the single-ear threaded connector 2 has threads and is used to connect the bushing nut 4; the single-ear joint of the single-ear threaded connector 2 connects the double-ear joint of the towing ring 1.

[0008] A round hole is opened at the vertical edge of the front end of the channel-shaped angle box 3, and the inner wall of the round hole is provided with a chamfer, which fits the bushing nut 4; the three vertical edges of the channel-shaped angle box 3 are all provided with flanges, and the flanges are connected to the fuselage skin.

[0009] The bushing nut 4 is a cylindrical shape with a variable cross-section, having internal threads on the inner ring, and is used to connect the single-ear threaded connector 2; the cylindrical area of the outer ring fits against the inner wall of the circular hole of the channel-shaped angle box 3, and the small clearance fit between the cylindrical area of the outer ring of the bushing nut 4 and the inner wall of the circular hole of the channel-shaped angle box 3 is used to ensure the free rotation of the towing ring 1; the cylinder of the large ring of the bushing nut 4 transmits the towing load by pressing against the inner wall of the channel-shaped angle box 3; a narrow groove is provided between the cylinders of the large ring and the small ring, and a small circular hole is opened on the groove surface of the narrow groove for fixing the wire snap ring 5.

[0010] Optionally, the water towing joint for the helicopter is provided with two upper and lower longerons 15 arranged along the course at the position inside the nose skin 14, in order to transmit the towing load and also provide a certain lateral stiffness support.

[0011] Optionally, the water towing joint further includes: a reinforcing backing plate 6, the outer shape of the reinforcing backing plate 6 fits against the fuselage skin 14, and the reinforcing backing plate 6 is connected to the fuselage longeron and the skin with rivets, which is used to improve the anti-extrusion ability of the structure and disperse the towing load.

[0012] Optionally, the channel-shaped angle box 3 is made of a high-strength aluminum alloy machining part, and a circular hole Φ16H8 is opened at the vertical edge of the front end, and a chamfer of 1×45° is provided on the inner wall of the circular hole.

[0013] Optionally, the single-ear threaded connector 2 is provided with external threads. After the wire snap ring 5 is clamped into the narrow groove of the bushing nut 4, the wire snap ring 5 is bent at the small circular hole on the groove surface of the narrow groove to form an elbow, and the elbow of the wire snap ring 5 is clamped into the thread groove of the external threads of the single-ear threaded connector 2, which plays a role in limiting, adjusting the clearance and preventing loosening.

[0014] Optionally, the wire snap ring 5 is made of 70# carbon structural steel with a diameter of 1mm, and has good strength and elasticity.

[0015] Optionally, the towing ring 1 is designed by using a die forging process of alloy structural steel.

[0016] Optionally, both the single-ear threaded connector 2 and the bushing nut 4 are made of alloy structural steel materials, which have high strength and wear resistance and are suitable for parts with threaded processing;

[0017] The reinforcing backing plate 6 is made of a high-strength aluminum alloy sheet metal part, which can ensure high strength performance while having excellent machining performance and is lighter in weight than steel materials.

[0018] In a second aspect, there is provided an assembly method for the water towing joint for a helicopter according to any one of the first aspect, including:

[0019] Connect the single-ear joint of the single-ear threaded connector 2 to the double-ear joint of the towing ring 1;

[0020] Insert the bushing nut 4 into the inner wall of the round hole of the grooved angle box 3 until the end face of the bushing nut 4 contacts the end face of the grooved angle box 3;

[0021] Screw the threaded cylindrical area of the single-ear threaded connector 2 into the inner ring of the bushing nut 4 and screw it in for a certain distance so that the gap between the single-ear threaded connector 2 and the grooved angle box 3 is not greater than 0.5 mm, ensuring that the towing ring 1 can rotate freely;

[0022] Snap the wire retaining ring 5 into the narrow groove of the bushing nut 4.

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

[0024] (1) The towing joint assembly can be arranged at a position above the water level line to achieve rapid towing;

[0025] (2) The towing ring of the towing joint can achieve 360-degree free rotation and has good limiting and anti-loosening properties;

[0026] (3) The towing joint assembly mainly transmits the towing force through the skin shear, with a direct force transmission path and a small weight cost;

[0027] (4) All helicopters that require water towing can use this design method, with a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the installation position of the towing joint of the present invention;

[0029] Figure 2 is a schematic diagram of the structure of the towing joint of the present invention;

[0030] Figure 3 is a schematic diagram of the connection of the towing joint of the present invention

[0031] Figure 4 is a schematic diagram of the structure of the grooved angle box of the present invention;

[0032] Figure 5 is a schematic diagram of the structure of the single-ear threaded connector of the present invention;

[0033] Figure 6 is a schematic diagram of the structure of the towing ring of the present invention;

[0034] Figure 7 is a schematic diagram of the structure of the bushing nut of the present invention;

[0035] Figure 8 is a schematic diagram of the assembly of the bushing nut of the present invention;

[0036] Among them, 1 - towing ring, 2 - single-ear threaded connector, 3 - channel-shaped angle box, 4 - bushing nut, 5 - wire snap ring, 6 - reinforcing backing plate, 7 - M10 bolt, 8 - gasket, 9 - M10 nut, 10 - split pin, 11 - rivet, 12 - M6 bolt, 13 - M6 clevis nut, 14 - skin, 15 - stringer, 16 - towing joint assembly. Specific embodiments

[0037] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those of ordinary skill in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention. The present invention is in no way limited to any specific arrangement and method set forth below, but covers any improvement, substitution and modification of structures, methods, and devices without departing from the spirit of the present invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the present invention.

[0039] It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other, and the various embodiments may refer to and cite each other.

[0040] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] As Figure 1 shown, an embodiment of the present invention provides a water towing joint assembly for a helicopter, which is symmetrically installed on the left and right sides of the nose skin. The axial direction of the towing ring is along the course, and the installation height is above the water level line.

[0042] As Figure 2 , Figure 3 shown, the water towing joint 16 includes: a towing ring 1, a single-ear threaded connector 2, a channel-shaped angle box 3, a bushing nut 4, and a wire snap ring 5.

[0043] The towing ring 1 adopts a circular ring with double ears structure. The circular ring is used to connect the towing rod or towing rope; the cylindrical area of the single-ear threaded connector 2 has threads and is used to connect the bushing nut 4; the single-ear joint of the single-ear threaded connector 2 is connected to the double-ear joint of the towing ring 1.

[0044] The water towing joint for helicopters is provided with two upper and lower longerons 15 arranged along the course inside the nose skin 14. In order to transmit the towing load and also provide a certain lateral stiffness support; the shape of the reinforcing backing plate 6 fits the fuselage skin 14. The reinforcing backing plate 6 is connected to the fuselage longerons and skin with rivets to improve the anti-extrusion ability of the structure and disperse the towing load.

[0045] The towing joint 16 does not damage the fuselage structure. The towing force on the water can be converted into the shear dispersion of the skin 14 and its longerons 15 by using the extrusion of the channel angle box 3, and a reinforcing backing plate 6 is added at the skin fitting surface to improve the anti-extrusion ability and effectively and evenly disperse the load; the towing ring 1 can rotate freely by 360 degrees, ensuring that there will be no jamming due to the change of the towing direction during water towing.

[0046] As Figure 4 shown, the channel angle box 3 is made of high-strength aluminum alloy machining parts. Round holes Φ16H8 are opened at the front vertical edge. The inner wall of the round hole is countersunk to facilitate the fitting of the bushing nut 4, and a chamfer of 1×45° is provided to facilitate the installation of the bushing nut; the upper and lower vertical surfaces of the angle box adopt a variable cross-section design according to the loading form, which can effectively reduce the weight. All three vertical edges have flanges. A total of 7 groups of bolts are provided on the flanges to connect the reinforcing backing plate 6, the fuselage skin 14, and the reinforcing longeron 15 through the plate nuts 13, making the water towing joint 16 convenient for disassembly, as Figure 3 shown.

[0047] As Figure 5 shown, the single-ear threaded connectors 2 are all made of alloy structural steel materials; the cylindrical area of the single-ear threaded connectors 2 has threads (M12×1.5) and is used to connect the bushing nuts; the single-ear joints are connected to the double-ear joints of the towing ring through shear bolts (HB 1-105-10×40×4) and channel nuts (HB 1-402M10), and split pins (GB 91-2.5×20 -1Cr18Ni9Ti) are used for anti-loosening.

[0048] As Figure 6 shown, the towing ring 1 is made of alloy structural steel materials; among them, the towing ring 1 adopts a forging processing technology, with more excellent mechanical properties and lighter weight under the same mechanical property indexes. The towing ring 1 adopts a circular ring with double ears structure. The circular ring is used to fix the towing rod or towing rope; the double-ear structure is used to connect with the single-ear structure of the single-ear threaded connector 2.

[0049] As Figure 7 、 Figure 8As shown in the figure, the bushing nut 4 is made of alloy structural steel, and is a cylindrical shape with variable cross-section. It has a thread (M12×1.5) on the inner ring and is used to connect the single-ear threaded connector 2. The cylindrical area of the outer ring fits against the inner wall of the circular hole of the channel-shaped angle box 3. The small clearance fit (Φ16h8 / Φ16H8) between the cylindrical area of the outer ring of the bushing nut 4 and the inner wall of the circular hole of the channel-shaped angle box 3 is used to ensure the free rotation of the towing ring 1. The diameter of the large ring of the bushing nut 4 is Φ26, and its cylinder transmits the towing load by pressing against the inner wall of the channel-shaped angle box 3. There is a narrow groove with a width of 1.5 mm and a depth of 2 mm in total between the cylinders of the large ring Φ26 and the small ring Φ22. A small circular hole with a diameter of 2 mm is opened on the groove surface for fixing the wire snap ring 5. The design of the small ring Φ22 facilitates the installation and maintenance of the wire snap ring 5. The wire snap ring 5 is made of 70# carbon structural steel with a diameter of 1 mm, and has good strength and elasticity.

[0050] The bushing nut 4 is inserted into and fits against the inner wall of the circular hole of the channel-shaped angle box 3. The threaded cylinder of the single-ear threaded connector 2 is connected to the inner ring of the bushing nut 4 and screwed in for a certain distance so that there is a slight clearance (not more than 0.5 mm) from the channel-shaped angle box 3. After ensuring the free rotation of the towing ring 1, the wire snap ring 5 is installed at the circular hole on the groove surface of the bushing nut 4, so that the elbow of the wire snap ring 5 is stuck into the thread teeth of the single-ear threaded connector 2, playing the roles of limiting, adjusting the clearance and preventing loosening.

[0051] The key points of the present invention are as follows:

[0052] (1) This towing joint assembly can be installed at a position above the water level line on the left and right side skins of the aircraft nose, and can achieve rapid towing on water;

[0053] (2) This towing joint assembly is designed with good limiting and anti-loosening measures, and can achieve 360-degree free rotation of the joint;

[0054] (3) This towing joint transmits load directly and efficiently, and mainly transmits load through skin shear, without the need to strengthen the airframe structure;

[0055] (4) This towing joint has a reasonable structural configuration, a low weight cost, only 0.73 kg on one side, and is convenient for disassembly.

[0056] The above only expresses the implementation modes of the present invention, and the description is relatively specific and detailed. However, it should not be construed as a limitation of the patent scope. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional technologies.

Claims

1. A water towing joint for a helicopter, characterized in that, Symmetrically installed on both the left and right sides of the nose skin, the axial direction of the towing ring is along the course, and the installation height is above the water level line. The water towing joint (16) includes: a towing ring (1), a single-ear threaded connector (2), a channel-shaped angle box (3), a bushing nut (4), and a wire retaining ring (5). The towing ring (1) adopts a circular ring with double-ear structure. The circular ring is used to connect the towing rod or towing rope. The cylindrical area of the single-ear threaded connector (2) has threads for connecting the bushing nut (4). The single-ear joint of the single-ear threaded connector (2) connects to the double-ear joint of the towing ring (1). A round hole is opened at the vertical edge of the front end of the channel-shaped angle box (3), and the inner wall of the round hole is provided with a chamfer, which fits the bushing nut (4). Flanges are provided on the three vertical edges of the channel-shaped angle box (3), and the flanges are connected to the fuselage skin. The bushing nut (4) is a cylindrical shape with a variable cross-section, and the inner ring has threads for connecting the single-ear threaded connector (2). The cylindrical area of the outer ring fits the inner wall of the round hole of the channel-shaped angle box (3). A small clearance fit between the cylindrical area of the outer ring of the bushing nut (4) and the inner wall of the round hole of the channel-shaped angle box (3) ensures the free rotation of the towing ring (1). The cylindrical body of the large ring of the bushing nut (4) transmits the towing load by extruding the inner wall of the channel-shaped angle box (3). A narrow groove is provided between the cylindrical bodies of the large ring and the small ring, and a small round hole is opened on the groove surface of the narrow groove for fixing the wire retaining ring (5).

2. The water towing joint for a helicopter according to claim 1, characterized in that, Two longitudinal stringers (15) arranged longitudinally are provided at the position inside the nose skin (14) of the water towing joint for helicopters.

3. The water towing joint for a helicopter according to claim 1, characterized in that, The water towing joint further includes: a reinforcing backing plate (6). The shape of the reinforcing backing plate (6) fits the fuselage skin (14), and the reinforcing backing plate (6) is connected to the fuselage longitudinal stringer and skin with rivets.

4. The water towing joint for a helicopter according to claim 1, characterized in that, The channel-shaped angle box (3) is a machined part made of high-strength aluminum alloy. A round hole of Φ16H8 is opened at the vertical edge of the front end, and the inner wall of the round hole is provided with a 1×45° chamfer.

5. The water towing joint for a helicopter according to claim 1, wherein, The single-ear threaded connector (2) is provided with external threads. After the wire retaining ring (5) is snapped into the narrow groove of the bushing nut (4), the wire retaining ring (5) is bent at the small round hole on the groove surface of the narrow groove to form an elbow, and the elbow of the wire retaining ring (5) is snapped into the thread groove of the external threads of the single-ear threaded connector (2).

6. The water towing joint for a helicopter according to claim 1, characterized in that, The wire retaining ring (5) is made of 70# carbon structural steel with a diameter of 1mm.

7. The water towing joint for a helicopter according to claim 1, characterized in that The towing ring (1) is designed by the forging process of alloy structural steel.

8. The water towing joint for a helicopter according to claim 1, characterized in that, Both the single-ear threaded connector (2) and the bushing nut (4) are made of alloy structural steel; the reinforcing backing plate (6) is made of high-strength aluminum alloy sheet metal.

9. An assembly method for a water towing joint for a helicopter according to any one of claims 1 to 8, characterized in that, Including: Connect the single-ear joint of the single-ear threaded connector (2) to the double-ear joint of the towing ring (1). Insert the bushing nut (4) into the inner wall of the round hole of the channel-shaped angle box (3) until the end face of the bushing nut (4) contacts the end face of the channel-shaped angle box (3). Screw the threaded cylindrical area of the single-ear threaded connector (2) into the inner ring of the bushing nut (4) and screw it in for a certain distance so that the clearance between the single-ear threaded connector (2) and the channel-shaped angle box (3) is not greater than the preset value to ensure the free rotation of the towing ring (1). Snap the wire retaining ring (5) into the narrow groove of the bushing nut (4).

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