Adjustable cabin door stop block structure for civil aircraft

Abstract

This invention discloses an adjustable stop block structure for a civil aircraft cabin door, comprising a stop body on which a steel friction plate, a stop pin, a fixing plate, and a nut are sequentially fitted. By adjusting the tightness of the nut, the stress level on the stop pin can be increased or decreased. The fixing plate further prevents the stop pin from loosening. The stop pin and the stop body are clearance-fitted, allowing rotation between them. The stop pin can be quickly replaced by rotating the nut. The adjustable stop block structure for a civil aircraft cabin door provided by this invention avoids severe local wear of the stop block caused by over-positioning of the cabin door, and features accurate positioning, adjustable position, and good assembly performance.

Description

Technical Field

[0001] This invention belongs to the field of mechanical design technology, specifically relating to an adjustable stop block structure for a civil aircraft cabin door. Background Technology

[0002] Currently, most civil aircraft cabin doors employ a blocking or semi-blocking door structure. Under pressurized cabin conditions, multiple sets of stop blocks are designed on both sides of the door and door frame to ensure reliable door locking. Structurally, three sets of stop blocks are usually sufficient for complete door positioning. However, to prevent accidental stop block failure, six or more sets are typically used. This creates an over-constrained state, resulting in uneven force distribution on the stop blocks. Secondly, due to the large size of the cabin door and significant manufacturing errors (approximately on the order of 0.1mm), the installation position errors of each set of stop blocks are substantial, leading to interference or collisions among some blocks. Theoretically, only three sets of stop blocks actually make contact, while the remaining stops are non-contact. Theoretically, full contact among multiple sets of stop blocks can only be achieved if the design and assembly precision of all stop blocks are sufficient. However, this is practically difficult to achieve. Furthermore, stop blocks are wear-prone parts and require regular inspection and replacement. Because existing stop blocks are used in pairs, replacing one stop block requires replacing both, resulting in unnecessary waste. Therefore, maximizing the contact of the stop blocks is the most important aspect of stop block design. Currently, most existing stop blocks are integral rigid components, lacking adjustability and partial interchangeability in assembly. Specifically, due to the inherent deviations in the mounting holes of the hatch or door frame, point or line contact between the hatch stop block and the door frame stop block is unavoidable. This will cause or exacerbate wear on the stop blocks, affecting the hatch assembly quality and generating friction noise.

[0003] Currently, research on stop blocks for civil aircraft boarding doors mainly focuses on static strength verification, fatigue verification, methods for calculating contact plane tolerances, and reliability analysis of contact gaps and offsets. Existing stop block strength and reliability analyses have formed a relatively complete system, and related optimization design research has been widely applied. However, the stop blocks still use integral rigid components, lacking adjustability and interchangeability. In summary, the existing civil aircraft cabin door stop block structure lacks adjustability and interchangeability. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems and provide a civil aircraft cabin door stop block structure that is accurate in positioning, adjustable in position, and has good assembly performance.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: an adjustable civil aircraft cabin door stop block structure, including a stop body, on which a steel friction plate, a stop pin, a fixing plate and a nut are sequentially sleeved. By adjusting the tightness of the nut, the force level of the stop pin can be increased or decreased. The fixing plate can further prevent the stop pin from loosening. The stop pin and the stop body are clearance-fitted, and the two can rotate in the middle. The stop pin can be quickly replaced by rotating the nut.

[0006] Preferably, the stop body includes a stop body base plate, a stop body body, and a stop body connecting post fixedly connected as one piece. The stop body base plate is provided with a stop body base plate through hole, which is located at the four corners of the stop body base plate. The stop body body is located between the stop body base plate and the stop body connecting post. The stop body connecting post has a cylindrical structure, and the end of the stop body connecting post has an external thread structure. The stop body connecting post is connected to a steel friction plate, a stop pin, a fixing plate, and a nut.

[0007] Preferably, the main body of the stop is a cylindrical structure, and the two ends of the main body of the stop are circular; the diameter of the end of the main body of the stop that contacts the bottom plate of the stop is larger than the diameter of the other end, and the cross-sectional circles at the two ends of the main body of the stop are not coaxial.

[0008] Preferably, the steel friction plate has a ring-shaped sheet structure, and the contact surface of the steel friction plate is rough to increase the coefficient of friction.

[0009] Preferably, the stop pin includes a stop pin block, a stop pin connecting block, and a stop pin post that are fixed together as a whole. The stop pin block has a cuboid structure; the stop pin connecting block has a cylindrical structure with an annular cross-section and is sleeved on the stop pin connecting post; the stop pin post has a stepped cylindrical structure.

[0010] Preferably, the edge of the fixing piece protrudes outward and is bent to form a fixing piece end plate, and the cross-section of the fixing piece is a circular ring structure; the fixing piece is sleeved on the stop body connecting column, and the fixing piece end plate is in contact with the stop nail block.

[0011] Preferably, the connecting end face of the nut is rough to prevent the stop pin from rotating.

[0012] The beneficial effects of this invention are:

[0013] 1. The adjustable civil aircraft cabin door stop block structure provided by the present invention can avoid severe local wear of the stop block caused by over-positioning of the cabin door, and has the characteristics of accurate positioning, adjustable position, and good assembly performance.

[0014] 2. The stop block structure proposed in this invention can adjust the axial assembly length and contact surface, so that the door stop block and the door frame stop block form a better surface contact, reducing wear and noise.

[0015] 3. When the stop block wears out during use, only the stop pin needs to be replaced, without replacing the entire stop block, thus providing good interchangeability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an adjustable civil aircraft cabin door stop block structure according to the present invention;

[0017] Figure 2 This is a schematic diagram of the stop body structure of the present invention;

[0018] Figure 3 This is a schematic diagram of the steel friction plate structure of the present invention;

[0019] Figure 4 This is a schematic diagram of the stop pin structure of the present invention;

[0020] Figure 5 This is a schematic diagram of the fixing plate structure of the present invention;

[0021] Figure 6 This is a schematic diagram of the nut structure of the present invention.

[0022] Explanation of reference numerals in the attached drawings: 1. Stop body; 2. Steel friction plate; 3. Stop pin; 4. Fixing plate; 5. Nut; 11. Stop body base plate; 12. Stop body main body; 13. Stop body connecting column; 31. Stop pin block; 32. Stop pin connecting block; 33. Stop pin column; 41. Fixing plate end plate; 111. Through hole in the stop body base plate. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0024] like Figures 1 to 6 As shown, the present invention provides an adjustable civil aircraft cabin door stop block structure, including a stop body 1. A steel friction plate 2, a stop pin 3, a fixing plate 4, and a nut 5 are sequentially fitted onto the stop body 1. By adjusting the tightness of the nut 5, the force level on the stop pin 3 can be increased or decreased. The fixing plate 4 further prevents the stop pin 3 from loosening. The stop pin 3 and the stop body 1 are in a clearance fit, allowing rotation between them. The stop pin 3 can be quickly replaced by rotating the nut 5.

[0025] In this embodiment, the steel friction plate 2 effectively enhances the connection strength between the stop pin 3 and the stop body 1, ensuring sufficient force. In actual use, the stop pin 3 and steel friction plate 2 can be designed in a series according to actual conditions to allow for adjustment of the assembly gap and maximize the contact area of ​​the stop block. During hatch assembly, based on the actual fit between the existing door frame stop block and the hatch stop block, the most suitable stop pin 3 can be selected. After adjusting the contact surfaces of the hatch stop pin and the door frame stop pin, the nut 5 is tightened to form the final stop block assembly. Furthermore, since the stop pin 3 is a component prone to wear, loosening the nut 5 allows for quick removal of the worn stop pin 3 and replacement with a new one, facilitating convenient maintenance.

[0026] In practical use, stop blocks are typically fixedly installed on the hatch and door frame respectively, and are referred to as hatch stop blocks and door frame stop blocks, used in pairs. To improve the interchangeability of parts, the stop block structure proposed in this invention is used for both hatch stop blocks and door frame stop blocks. During fixed installation, first, a stop block is installed on the door frame, called a door frame stop block. Then, a stop block is installed on the hatch, called a hatch stop block, which is exactly the same as the door frame stop block. The hatch stop block and the door frame stop block are installed opposite each other, that is, the end faces of the stop pins on the hatch stop block and the end faces of the stop pins on the door frame stop block are in contact. To meet the installation clearance requirements of the hatch, the number or thickness of the steel friction plates 2 on the two stop blocks, as well as the rotation angle of the stop pins 3, are selected or adjusted respectively. The aim is to ensure that the stop pins 3 on the two stop blocks fit tightly, forming complete and sufficient surface contact, to avoid end face wear caused by local contact, and to improve the stress state of the hatch.

[0027] The stop body 1 includes a stop body base plate 11, a stop body body 12, and a stop body connecting post 13, all fixed together. The stop body base plate 11 has stop body base plate through holes 111 located at its four corners. The stop body body 12 is located between the stop body base plate 11 and the stop body connecting post 13. The stop body connecting post 13 is a cylindrical structure with externally threaded ends. The stop body connecting post 13 is connected to the steel friction plate 2, the stop pin 3, the fixing plate 4, and the nut 5.

[0028] The main body 12 of the stop body is a cylindrical structure, and the cross-sections at both ends of the main body 12 of the stop body are circular. The diameter of the end of the main body 12 of the stop body that contacts the bottom plate 11 of the stop body is larger than the diameter of the other end, and the cross-sectional circles at both ends of the main body 12 of the stop body are not coaxial.

[0029] In this embodiment, in order to reduce weight, the main body 12 of the stop body is a hollow structure, and the through hole 111 of the bottom plate of the stop body enables connection with the existing hatch or door frame.

[0030] The steel friction plate 2 has a circular, sheet-like structure. The contact surface of the steel friction plate 2 is rough, which increases the coefficient of friction and prevents the stop pin from rotating under force. By replacing the steel friction plates 2 with steel plates of different thicknesses, the optimal fit of the stop pin 3 is achieved.

[0031] The stop pin 3 includes a stop pin block 31, a stop pin connecting block 32, and a stop pin post 33, which are fixed together as a single unit. The stop pin block 31 has a cuboid structure. The stop pin connecting block 32 has a cylindrical structure with an annular cross-section and is fitted onto the stop pin connecting post 13. The stop pin post 33 has a stepped cylindrical structure.

[0032] In this embodiment, the stop pin connecting block 32 and the stop body connecting post 13 form a clearance fit. This ensures optimal fit between the door frame stop pin and the hatch stop pin, resulting in optimal surface contact, avoiding uneven contact surfaces, and allowing multiple sets of stop blocks to bear force evenly, delaying local wear and effectively reducing wear phenomena. The stop pin block 31 further prevents rotation by engaging with the end face of the fixing plate 4.

[0033] The edge of the fixing piece 4 protrudes outward and is bent to form the fixing piece end plate 41. The cross-section of the fixing piece 4 is a circular ring structure. The fixing piece 4 is sleeved on the stop body connecting post 13, and the fixing piece end plate 41 is in contact with the stop nail block 31.

[0034] The purpose of setting the fixing plate 4 is to further prevent the rotation of the stop pin and to adjust the assembly clearance. The center hole of the fixing plate 4 forms a clearance fit with the stop body connecting post 13. During installation, the end plate 41 of the fixing plate forms a contact fit with the stop pin block 31.

[0035] The connecting end face of nut 5 is rough to prevent the stop pin from rotating. A standard nut can be used depending on the actual application.

[0036] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. An adjustable stop block structure for a civil aircraft cabin door, characterized in that: The device includes a stop body (1), on which a steel friction plate (2), a stop pin (3), a fixing plate (4), and a nut (5) are sequentially fitted. By adjusting the tightness of the nut (5), the force level of the stop pin (3) can be increased or decreased. The fixing plate (4) can further prevent the stop pin (3) from loosening. The stop pin (3) and the stop body (1) are in clearance fit, and they can rotate in the middle. By rotating the nut (5), the stop pin (3) can be quickly replaced.

2. The adjustable civil aircraft cabin door stop block structure according to claim 1, characterized in that: The stop body (1) includes a stop body base plate (11), a stop body body (12) and a stop body connecting column (13) that are fixed together. The stop body base plate (11) is provided with a stop body base plate through hole (111), which is located at the four corners of the stop body base plate (11). The stop body body (12) is located between the stop body base plate (11) and the stop body connecting column (13). The stop body connecting column (13) is a cylindrical structure, and the end of the stop body connecting column (13) is an external thread structure. The stop body connecting column (13) is connected to the steel friction plate (2), the stop pin (3), the fixing plate (4) and the nut (5).

3. The adjustable civil aircraft cabin door stop block structure according to claim 2, characterized in that: The main body (12) of the stop body is a column structure, and the two ends of the main body (12) of the stop body are circular. The diameter of the end of the main body (12) that contacts the bottom plate (11) of the stop body is larger than the diameter of the other end. The cross-sectional circles at both ends of the main body (12) are not coaxial.

4. The adjustable civil aircraft cabin door stop block structure according to claim 1, characterized in that: The steel friction plate (2) has a ring-shaped sheet structure and the contact surface of the steel friction plate (2) is rough, which increases the coefficient of friction.

5. The adjustable civil aircraft cabin door stop block structure according to claim 2, characterized in that: The stop pin (3) includes a stop pin block (31), a stop pin connecting block (32), and a stop pin post (33) that are fixed together. The stop pin block (31) is a cuboid structure. The stop pin connecting block (32) is a cylindrical structure with a circular cross-section. The stop pin connecting block (32) is fitted onto the stop pin connecting post (13). The stop pin post (33) is a stepped cylindrical structure.

6. The adjustable civil aircraft cabin door stop block structure according to claim 5, characterized in that: The edge of the fixing piece (4) protrudes outward and is bent to form a fixing piece end plate (41). The cross section of the fixing piece (4) is a circular structure. The fixing piece (4) is sleeved on the stop body connecting column (13), and the fixing piece end plate (41) contacts the stop nail block (31).

7. The adjustable civil aircraft cabin door stop block structure according to claim 1, characterized in that: The connecting end face of the nut (5) is rough to prevent the stop pin from rotating.

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