Stern door device suitable for retracting and releasing stern chute of large boat equipment and design method

Abstract

The invention discloses a stern door device suitable for retracting and releasing a stern chute of large boat equipment and a design method. The stern door device comprises a larboard door body structure and a starboard door body structure, and multi-connecting-rod locking bolts in the larboard door body structure and the starboard door body structure are matched with bolt seats on the ship body structure; the port door body structure and the starboard door body structure are provided with an inter-door-body sealing structure and an inter-door-body sealing groove respectively, and when the stern door device is closed, the inter-door-body sealing structure abuts against an inter-door-body sealing strip in the inter-door-body sealing groove. The design method comprises the following steps: determining the type of the stern door device; determining load input of the stern door device in various operation scenes; the push-pull force in the opening and closing process of the stern door device is calculated based on kinematics and dynamics simulation, and model selection is conducted on an executing mechanism; finite element numerical simulation is carried out based on the preliminary scheme of the stern door device, and optimization design is carried out on the stern door device. According to the invention, a large access space can be provided for large boat equipment in the stern chute retracting and releasing process, and the stern cabin section can be shielded and is weather-tight.

Description

Technical Field

[0001] The invention relates to a stern door device suitable for retracting and deploying a stern slideway of a large boat and a design method thereof, belonging to the technical field of ship engineering. Background Art

[0002] Large ships generally need to be equipped with high-speed boats for performing tasks in shallow or narrow waters, among which high-speed boats can be retracted and deployed through the swing-down stern slide. Accordingly, in order to prevent the large cabin of the boat from being exposed and hit by waves when the stern slide is stored, a stern door device needs to be installed on the stern cover of large ships. First, when the stern door device is opened, an opening for the boat to be retracted and deployed is formed, which guarantees the normal entry and exit of the boat on the stern slide in terms of space. Second, when the stern door device is closed, it shields the space inside the stern cabin of the large ship and provides wind and rainproof protection, preventing seawater from entering the stern cabin section and affecting the equipment and personnel operations in the cabin.

[0003] On the one hand, ro-ro ships and mixed-cargo ships are often equipped with stern gates on the stern boards for loading and unloading of goods and entry and exit of personnel, but this type of stern gate is arranged above the water surface and only involves the locking and sealing between the stern gate and the fixed hull, which is not suitable for the process of retracting and lowering the boat stern slide; on the other hand, for the process of retracting and lowering the boat by swinging the stern slide up and down, a multi-link flip-up stern gate device is generally configured on the stern sealing plate. This solution uses a multi-link hydraulic drive to open and close the stern gate, which occupies a large space, limits the size of the boat and has a risk of collision. In addition, this solution is only suitable for the retraction and release of the stern slide of small boats, and the relevant locking and sealing design does not fully consider the complex force and large load conditions. For the retraction and release of the stern slide of large boats, there is an urgent need for a large stern gate device that is suitable for the swing-down stern slide device, occupies a small space and can withstand a large load.

[0004] At the same time, the operating scenarios of the stern gate device include the closed state, the open state, the opening process and the closing process. There are many operating scenarios and the forces are complex. There is an urgent need for a systematic stern gate device design method to support the stern gate device structure and actuator design.

[0005] Among the publicly available stern gate devices, there is no stern gate device suitable for retracting and deploying the stern slide of large boats and vessels, and a system design method for the stern gate device. Therefore, it is necessary to seek a large stern gate device and a design method that occupies a small space, is adaptable to complex operating sea conditions, can withstand a large load and has good reliability, so as to ensure that large boats and vessels can safely retract and deploy the stern slide and perform operations in the cabin under complex sea conditions, thereby reducing operating risks. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a stern door device and a design method suitable for retracting and deploying the stern slide of large boats and ships.

[0007] In order to solve the above problems, the present invention provides a stern door device suitable for retracting and deploying a stern slide equipped with a large boat, which includes a port door body structure and a starboard door body structure, wherein the port door body structure and the starboard door body structure are respectively provided with a locking latch and a plug hole that cooperate with each other between the door bodies; a multi-link locking latch is respectively provided in the port door body structure and the starboard door body structure, and the multi-link locking latch cooperates with a latch seat on the hull structure;

[0008] The port door body structure and the starboard door body structure are connected to the hydraulic rotating cylinder through the port rotating arm and the starboard rotating arm respectively, and the port door body structure and the starboard door body structure are also connected to the upper part of the stern sealing plate through the port auxiliary rotating arm and the starboard auxiliary rotating arm respectively; the port door body structure and the starboard door body structure are respectively provided with an inter-door body sealing structure and an inter-door body sealing groove, and an inter-door body sealing strip is provided in the inter-door body sealing groove; when the stern door device is closed, the inter-door body sealing structure abuts against the inter-door body sealing strip.

[0009] Preferably, the backs of the port door body mechanism and the starboard door body structure are respectively provided with supporting structures.

[0010] Preferably, the inter-door body sealing structure is fixed on the starboard door body structure, and the inter-door body sealing groove is fixed on the port door body structure.

[0011] Preferably, the sealing strip between the door bodies is fixed in the sealing groove between the door bodies by an adhesive.

[0012] Preferably, a port sealing groove is provided at the upper, left and lower edges of the port door body structure, a port sealing strip is provided in the port sealing groove, a starboard sealing groove is provided at the upper, right and lower edges of the starboard door body structure, a starboard sealing strip is provided in the starboard sealing groove; a hatch coaming attachment is provided on the stern sealing plate on the upper part of the hull structure, and a gangway sealing strip is provided on the slideway gangway at the bottom of the hull structure; when the stern door device is closed, the hatch coaming attachment and the gangway sealing strip abut against the port sealing strip or the starboard sealing strip at the corresponding position.

[0013] More preferably, the port side sealing strip is fixed in the port side sealing groove by an adhesive.

[0014] More preferably, the starboard side sealing strip is fixed in the starboard side sealing groove by an adhesive.

[0015] More preferably, the upper portions of the port side sealing strip and the starboard side sealing strip that contact the hatch coaming attachment are inverted U-shaped sealing strips, and the lower portions that contact the ramp sealing strip are U-shaped sealing strips.

[0016] Preferably, a limiting seat for limiting the stern door device is provided on the upper part of the opening of the stern sealing plate on the hull structure, on the left and right sides of the opening of the stern sealing plate and on the slideway ramp.

[0017] More preferably, the upper opening portion of the stern cover plate on the hull structure and the limit seat on the slideway ramp are L-shaped structures for closing the guide and transferring the load during storage.

[0018] The present invention also provides a design method for a stern door device suitable for retracting and deploying a stern slideway of a large boat, comprising the following steps:

[0019] Step 1: Determine the type of stern door device;

[0020] Step 2: Determine the load input of the stern door device under various operating scenarios;

[0021] Step 3: Calculate the push and pull forces of the stern door device during the opening and closing process based on kinematics and dynamics simulation, and select the actuator;

[0022] Step 4: Perform finite element numerical simulation based on the preliminary plan of the stern door device and optimize the design of the stern door device.

[0023] Preferably, step 1 comprises the following steps:

[0024] Step 1.1: Based on the motion posture of the boat stern slide during the retraction and deployment process and the opening constraint of the hull stern cover plate, determine the overall dimensions of the stern door device and the channel dimensions when the stern door device is open;

[0025] Step 1.2: Determine the watertightness level of the stern door device based on the cabin operation requirements;

[0026] Step 1.3: Based on the channel size and overall ship resources determined in step 1.1, determine the opening and closing mode, locking type and actuator type of the stern door device through multi-scheme comparison and analysis;

[0027] Step 1.4: Based on the interface and watertightness level between the stern slide and the stern door device, determine the sealing type between the stern door device, the hull and the stern slide.

[0028] Preferably, step 2 comprises the following steps:

[0029] Step 2.1: Determine the strength calculation standard of the stern door device according to the reference standard specification of the stern door device design;

[0030] Step 2.2: Based on the actuator type and opening and closing method of the tailgate device, theoretically calculate the load applied by the actuator to the tailgate body structure during the opening and closing process of the tailgate device;

[0031] Step 2.3: Based on the ship's seakeeping calculation, obtain the additional load caused by waves under the operating sea conditions.

[0032] Preferably, step 3 comprises the following steps:

[0033] Step 3.1: Construct a three-dimensional model and kinematic pair of the stern door device, perform kinematic simulation, and eliminate the dead point in the opening and closing process of the stern door device;

[0034] Step 3.2: Based on the opening and closing push-pull force calculated in step 2.2, the driving force of the actuator of the stern door device is verified through dynamic simulation;

[0035] Step 3.3: Based on the simulation results of step 3.2, consider the safety factor comprehensively and select the actuator.

[0036] Preferably, step 4 comprises the following steps:

[0037] Step 4.1: Construct a finite element model of the stern door device, and perform finite element simulation calculation of the stern door device based on the load input of the closed state, open state, closing process and opening process of the stern door device;

[0038] Step 4.2: Analyze the stress concentration areas in the simulation calculation results of the finite element method and perform structural optimization design;

[0039] Step 4.3: Perform finite element simulation calculation on the folding stern door device to determine the optimal solution for the stern door device.

[0040] The present invention adopts a double-opening form of a rotary cylinder to realize the opening and closing of the stern door device; adopts a continuous split sealing mechanism to realize the overall wind and rain tightness between the stern door device and the ship and the slideway ramp; reduces the number of action actuators through a multi-link locking latch mechanism to enhance the reliability of the stern door device; realizes the closing guide limit and load transfer of the stern door device through upper and lower L-shaped limit seats to improve the bearing capacity of the stern door device; by arranging limit seats around, the large local load applied by the door structure of the stern door device to the sealing mechanism during the closing process is reduced, and the force is more uniform. In the above manner, the present invention can provide a larger entry and exit space for large boat equipment during the stern slideway retraction and deployment process, as well as the stern cabin section shielding and wind and rain tightness.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. A stern door device suitable for the stern slideway of large boats and ships of the present invention adopts a double horizontal opening form of a rotary cylinder. Firstly, it does not occupy the upper space of the stern sealing plate opening. Secondly, the width space occupied by the stern door device can be reduced by driving the door to swing outward through the hydraulic rotary cylinder, thereby increasing the storage space of large boats and ships and reducing the risk of collision.

[0043] 2. A stern door device for retracting and deploying a stern slideway of a large boat and ship of the present invention adopts a continuous split sealing form to achieve the overall sealing of the stern door device, the ship and the slideway ramp in view of the up and down swinging characteristics of the stern slideway. First, a continuous rubber sealing strip is arranged around the stern door device. When the stern door device is closed, the upper inverted U-shaped sealing strip is pressed and sealed with the upper hatch coaming attachment of the ship. Second, the lower U-shaped sealing strip is pressed and sealed with the U-shaped sealing strip of the stern slideway, thereby achieving the overall wind sealing of the stern slideway and the stern door device.

[0044] 3. A stern door device suitable for the retracting and unfolding of the stern slideway of a large boat and a boat of the present invention is provided with L-shaped limit seats at the upper and lower parts, which play a guiding and limiting role in the closing process, and can play a load transfer role after being closed in place, thereby improving the bearing capacity of the stern door device and the adaptability to complex wave environments; at the same time, limit seats are provided at the upper part and left and right sides of the stern sealing plate opening to limit the closing position of the stern door device, reduce the load on the sealing mechanism during the closing process of the large stern door device, and the stern door device is evenly stressed as a whole, and no local concentrated stress will occur;

[0045] 4. The stern gate device of the present invention, which is suitable for retracting and deploying the stern slide of large boats and ships, adopts a multi-link locking latch mechanism in view of the fact that it has multiple locking positions. It can realize the simultaneous locking of three latch mechanisms through one oil cylinder, thereby reducing the number of oil cylinder structures, improving the locking synchronization of the stern gate device, and having higher reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A side view of the stern door device provided by the present invention;

[0047] Figure 2 for Figure 1 Schematic diagram of the A direction;

[0048] Figure 3 for Figure 2 Sectional view of the AA plane;

[0049] Figure 4 , 5 for Figure 2 Sectional views of the middle BB plane in different directions;

[0050] Figure 6 , 7 for Figure 2 Sectional views of the CC plane in different directions;

[0051] Figure 8 for Figure 2 Sectional view of the middle DD plane;

[0052] Fig. 9 for Figure 2 Sectional view of the middle EE plane;

[0053] Fig.10 for Figure 2 Sectional view of the FF plane;

[0054] Fig.11 for Figure 2 Sectional view of the middle GG plane;

[0055] Fig.12 It is a schematic diagram of a continuous split sealing structure;

[0056] Fig.13 A top view of the stern door device provided by the present invention in a closed state;

[0057] Fig.14 This is a top view of the stern door device provided by the present invention in the open state. DETAILED DESCRIPTION

[0058] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0059] Example

[0060] A design method for a stern door device suitable for retracting and deploying a stern slideway of a large boat and ship, comprising the following steps:

[0061] Step 1: Determine the type of stern door device, as follows:

[0062] Step 1.1: Based on the motion posture of the boat stern slide during the retraction and deployment process and the opening constraint of the hull stern cover plate, determine the overall dimensions of the stern door device and the channel dimensions when the stern door device is open;

[0063] Step 1.2: Determine the watertightness level of the stern door device based on the cabin operation requirements;

[0064] Step 1.3: Based on the channel size and overall ship resources determined in step 1.1, determine the opening and closing mode, locking type and actuator type of the stern door device through multi-scheme comparison and analysis;

[0065] Step 1.4: Based on the interface and watertightness level between the stern slide and the stern door device, the sealing type between the stern door device and the hull and stern slide is determined;

[0066] Step 2: Determine the load input for the stern door device in various operating scenarios, as follows:

[0067] Step 2.1: Determine the strength calculation standard of the stern door device according to the reference standard specification of the stern door device design;

[0068] Step 2.2: Based on the actuator type and opening and closing method of the tailgate device, theoretically calculate the load applied by the actuator to the tailgate body structure during the opening and closing process of the tailgate device;

[0069] Step 2.3: Based on the calculation of the ship's seakeeping performance, obtain the additional load caused by waves under the operating sea conditions;

[0070] Step 3: Based on kinematics and dynamics simulation, calculate the push and pull forces of the stern door device during the opening and closing process, and select the actuator, as follows:

[0071] Step 3.1: Construct a three-dimensional model and kinematic pair of the stern door device, perform kinematic simulation, and eliminate the dead point in the opening and closing process of the stern door device;

[0072] Step 3.2: Based on the opening and closing push-pull force calculated in step 2.2, the driving force of the actuator of the stern door device is verified through dynamic simulation;

[0073] Step 3.3: Based on the simulation results of step 3.2, consider the safety factor comprehensively and select the actuator;

[0074] Step 4: Based on the preliminary scheme of the stern door device, finite element numerical simulation is performed to optimize the design of the stern door device, as follows:

[0075] Step 4.1: Construct a finite element model of the stern door device, and perform finite element simulation calculation of the stern door device based on the load input of the closed state, open state, closing process and opening process of the stern door device;

[0076] Step 4.2: Analyze the stress concentration areas in the simulation calculation results of the finite element method and perform structural optimization design;

[0077] Step 4.3: Perform finite element simulation calculation on the folding stern door device to determine the optimal solution for the stern door device.

[0078] The stern door device designed by the above design method is suitable for retracting and deploying the stern slide of a large boat. Figure 1-12 As shown, it includes a port door structure 1 and a starboard door structure 2. The port door structure 1 is provided with a door-to-door locking pin 19, and the starboard door structure 2 is provided with a socket that matches the door-to-door locking pin 19. The port door structure 1 and the starboard door structure 2 are respectively provided with two multi-link locking pins 18, and the multi-link locking pins 18 match the pin seat 20 on the hull structure I.

[0079] The port door structure 1 and the starboard door structure 2 are connected to the hydraulic rotary cylinder 4 on the hull structure I through a pair of port rotating arms 5 and starboard rotating arms 6, respectively. The port door structure 1 and the starboard door structure 2 are also connected to the upper part of the stern sealing plate through the port auxiliary rotating arm 7 and the starboard auxiliary rotating arm 8, respectively. The port door structure 1 and the starboard door structure 2 are respectively provided with a door-to-door sealing structure 10 and a door-to-door sealing groove 11. The door-to-door sealing structure 10 is fixed to the starboard door structure 2, and the door-to-door sealing groove 11 is fixed to the port door structure 1. The door-to-door sealing groove 11 is provided with a door-to-door sealing strip 12, and the door-to-door sealing strip 12 is fixed to the door-to-door sealing groove 11 by an adhesive; when the stern door device is closed, the door-to-door sealing structure 10 abuts against the door-to-door sealing strip 12.

[0080] The backs of the port door body structure 1 and the starboard door body structure 2 are respectively provided with supporting structures 3 .

[0081] The upper, left and lower edges of the port door structure 1 are provided with a port sealing groove 13, and a port sealing strip 15 is provided in the port sealing groove 13; the upper, right and lower edges of the starboard door structure 2 are provided with a starboard sealing groove 14, and a starboard sealing strip 16 is provided in the starboard sealing groove 14; a hatch coaming attachment 9 is provided on the stern sealing plate on the upper part of the hull structure I, and a ramp sealing strip 23 is provided on the slide ramp 22 at the bottom of the hull structure I; when the stern door device is closed, the hatch coaming attachment 9 and the ramp sealing strip 23 abut against the port sealing strip 15 or the starboard sealing strip 16 at the corresponding position. The port sealing strip 15 is fixed in the port sealing groove 13 by an adhesive. The starboard sealing strip 16 is fixed in the starboard sealing groove 14 by an adhesive. The upper part of the port sealing strip 15 and the starboard sealing strip 16 that contacts the hatch coaming attachment 9 is an inverted U-shaped sealing strip, and the lower part that contacts the ramp sealing strip 23 is a U-shaped sealing strip.

[0082] A limiting seat 21 for limiting the stern door device is provided on the upper opening of the stern sealing plate on the hull structure I, the left and right sides of the opening of the stern sealing plate, and the slideway ramp 22. The limiting seat 21 on the upper opening of the stern sealing plate on the hull structure I and the slideway ramp 22 is an L-shaped structure, which is used to close the guide and transfer the load when storing.

[0083] Working principle: A stern door device suitable for retracting and retracting the stern slide of large boats and ships provides the stern door opening and closing power through the hydraulic rotating cylinder in the transmission mechanism, and drives the door structure to open or close through the rotating arm and the auxiliary rotating arm. During the process of opening and closing the stern door device, the limit seat limits the stop position of the door body. After closing, the multi-link locking pin is inserted into the pin seat, and the locking pin between the door bodies is inserted into the starboard door body structure to achieve locking; at the same time, the left and right door structures of the stern door device are sealed by the compression between the sealing structure between the door bodies and the sealing strip between the door bodies, the upper inverted U-shaped sealing strip of the stern door device is compressed and sealed with the hatch coaming accessories, and the lower U-shaped sealing strip is compressed and sealed with the U-shaped sealing strip of the stern slide, thereby achieving the overall sealing of the stern door device. The following is the process of opening and closing the stern door device:

[0084] 1. Opening process of stern door device

[0085] 1) All latches in the stern door device are retracted

[0086] 2) The starboard door structure is pushed open horizontally by the hydraulic rotary cylinder. After fully opened, the support structure on the back of the door structure is close to the stern sealing plate, and the hydraulic rotary cylinder stops moving;

[0087] 3) The port door structure is pushed open horizontally by the hydraulic rotary cylinder. After fully opened, the support structure on the back of the door structure is close to the stern sealing plate, and the hydraulic rotary cylinder stops moving;

[0088] 4) The slideway springboard is lowered to the specified angle and locked. Fig.13 shown.

[0089] 2. Closing process of stern door device

[0090] 1) The slideway springboard is recovered to the storage state;

[0091] 2) The port door structure is closed under the action of the hydraulic rotating arm and is closed in place under the guiding and limiting action of the limiting seat;

[0092] 3) Insert the port multi-link locking pin into the pin seat to complete the locking;

[0093] 4) The starboard door structure is closed under the action of the hydraulic rotating arm and is closed in place under the guiding and limiting action of the limiting seat;

[0094] 5) The starboard multi-link locking pin is inserted into the pin seat, and the door body locking pin is inserted into the starboard door body structure to complete the locking. Fig.14 shown.

Claims

1. A stern door device suitable for retracting and deploying a stern slideway of a large boat, characterized in that: The invention comprises a port door structure (1) and a starboard door structure (2), wherein the port door structure (1) and the starboard door structure (2) are respectively provided with a door locking latch (19) and a plug hole which cooperate with each other; a multi-link locking latch (18) is respectively provided in the port door structure (1) and the starboard door structure (2), and the multi-link locking latch (18) cooperates with a latch seat (20) on the hull structure (I); The port door structure (1) and the starboard door structure (2) are connected to the hydraulic rotary cylinder (4) through the port rotating arm (5) and the starboard rotating arm (6), respectively. The port door structure (1) and the starboard door structure (2) are also connected to the upper part of the stern sealing plate through the port auxiliary rotating arm (7) and the starboard auxiliary rotating arm (8), respectively. The port door structure (1) and the starboard door structure (2) are respectively provided with an inter-door sealing structure (10) and an inter-door sealing groove (11), and an inter-door sealing strip (12) is provided in the inter-door sealing groove (11); when the stern door device is closed, the inter-door sealing structure (10) abuts against the inter-door sealing strip (12).

2. The stern door device suitable for retracting and deploying the stern slideway of a large boat as claimed in claim 1, characterized in that: The port door structure (1) and the starboard door structure (2) are respectively provided with a support structure (3) on their backs; the door-to-door sealing structure (10) is fixed on the starboard door structure (2), and the door-to-door sealing groove (11) is fixed on the port door structure (1); and the door-to-door sealing strip (12) is fixed in the door-to-door sealing groove (11) by means of an adhesive.

3. The stern door device suitable for retracting and deploying the stern slideway of a large boat as claimed in claim 1, characterized in that: The upper, left and lower edges of the port door structure (1) are provided with a port sealing groove (13), and a port sealing strip (15) is arranged in the port sealing groove (13); the upper, right and lower edges of the starboard door structure (2) are provided with a starboard sealing groove (14), and a starboard sealing strip (16) is arranged in the starboard sealing groove (14); a hatch coaming attachment (9) is arranged on the stern sealing plate on the upper part of the hull structure (I), and a ramp sealing strip (23) is arranged on the slideway ramp (22) at the bottom of the hull structure (I); when the stern door device is closed, the hatch coaming attachment (9) and the ramp sealing strip (23) abut against the port sealing strip (15) or the starboard sealing strip (16) at the corresponding position.

4. The stern door device suitable for retracting and deploying the stern slideway of a large boat as claimed in claim 3, characterized in that: The port side sealing strip (15) is fixed in the port side sealing groove (13) by means of an adhesive; the starboard side sealing strip (16) is fixed in the starboard side sealing groove (14) by means of an adhesive; the upper portions of the port side sealing strip (15) and the starboard side sealing strip (16) that contact the hatch coaming attachment (9) are inverted U-shaped sealing strips, and the lower portions that contact the gangway sealing strip (23) are U-shaped sealing strips.

5. The stern door device suitable for retracting and deploying the stern slideway of a large boat as claimed in claim 1, characterized in that: A limiting seat (21) for limiting the stern door device is provided on the upper opening of the stern sealing plate on the hull structure (Ⅰ), the left and right sides of the opening of the stern sealing plate and the slideway gangway (22); the limiting seat (21) on the upper opening of the stern sealing plate on the hull structure (Ⅰ) and the slideway gangway (22) is an L-shaped structure, which is used for closing the guide and transferring the load when storing.

6. A design method for a stern door device suitable for retracting and deploying a stern slideway of a large boat, characterized in that: The following steps are involved: Step 1: Determine the type of stern door device; Step 2: Determine the load input of the stern door device under various operating scenarios; Step 3: Calculate the push and pull forces of the stern door device during the opening and closing process based on kinematics and dynamics simulation, and select the actuator; Step 4: Perform finite element numerical simulation based on the preliminary plan of the stern door device and optimize the design of the stern door device.

7. The design method of a stern door device suitable for retracting and deploying a stern slideway of a large boat as claimed in claim 5, characterized in that: Step 1 includes the following steps: Step 1.1: Based on the motion posture of the boat stern slide during the retraction and deployment process and the opening constraint of the hull stern cover plate, determine the overall dimensions of the stern door device and the channel dimensions when the stern door device is open; Step 1.2: Determine the watertightness level of the stern door device based on the cabin operation requirements; Step 1.3: Based on the channel size and overall ship resources determined in step 1.1, determine the opening and closing mode, locking type and actuator type of the stern door device through multi-scheme comparison and analysis; Step 1.4: Based on the interface and watertightness level between the stern slide and the stern door device, determine the sealing type between the stern door device, the hull and the stern slide.

8. The design method of a stern door device suitable for retracting and deploying a stern slideway of a large boat as claimed in claim 5, characterized in that: Step 2 includes the following steps: Step 2.1: Determine the strength calculation standard of the stern door device according to the reference standard specification of the stern door device design; Step 2.2: Based on the actuator type and opening and closing method of the tailgate device, theoretically calculate the load applied by the actuator to the tailgate body structure during the opening and closing process of the tailgate device; Step 2.3: Based on the ship's seakeeping calculation, obtain the additional load caused by waves under the operating sea conditions.

9. The design method of a stern door device suitable for retracting and deploying a stern slideway of a large boat as claimed in claim 5, characterized in that: Step 3 includes the following steps: Step 3.1: Construct a three-dimensional model and kinematic pair of the stern door device, perform kinematic simulation, and eliminate the dead point in the opening and closing process of the stern door device; Step 3.2: Based on the opening and closing push-pull force calculated in step 2.2, the driving force of the actuator of the stern door device is verified through dynamic simulation; Step 3.3: Based on the simulation results of step 3.2, consider the safety factor comprehensively and select the actuator.

10. The design method of a stern door device suitable for retracting and deploying a stern slideway of a large boat as claimed in claim 5, characterized in that: Step 4 includes the following steps: Step 4.1: Construct a finite element model of the stern door device, and perform finite element simulation calculation of the stern door device based on the load input of the closed state, open state, closing process and opening process of the stern door device; Step 4.2: Analyze the stress concentration areas in the finite element simulation calculation results and perform structural optimization design; Step 4.3: Perform finite element simulation calculation on the folding stern door device to determine the optimal solution for the stern door device.

Images