Nozzle control device of water-jet propeller

Abstract

The invention relates to the technical field of water jet propulsion and fluid control, and provides a water jet propeller nozzle control device which comprises a water jet propeller, a rotary closer, a driving device, a control device and a flow velocity sensor. The rotary closer is fixed to the outlet end of a nozzle of the water-jet propeller, and the flow velocity sensor is embedded in the rotary closer to monitor the flow velocity of the nozzle in real time. The outer ring of the rotary closer is tightly connected with the driven wheel, and blades in the rotary closer are driven to do radial opening and closing motion through gear meshing transmission. The man-machine interaction terminal is used for inputting a target nozzle flow rate or an emergency stop signal, the central controller controls the frequency converter to work according to an input instruction and feedback of the sensor, and accurate flow rate adjustment and safe emergency stop are achieved. The control performance, the safety and the reliability of the water jet propulsion system are comprehensively improved. Response is rapid, the flow field is efficient, and resistance and loss are small; the device has an active sudden stop capability, and realizes absolutely reliable rapid cut-off safety guarantee.

Description

Technical Field

[0001] This invention relates to the field of water jet propulsion and fluid control technology, and in particular to a water jet propulsion nozzle control device installed at the nozzle outlet of a water jet propulsion device, which is used to adjust the effective opening area of ​​the nozzle to achieve thrust adjustment, energy saving and emergency stop functions. Background Technology

[0002] In the field of marine waterjet propulsion systems, traditional methods of thrust or flow regulation mainly rely on variable blades, variable nozzles, throttle valves, and pump speed control. Variable blade adjustment changes the angle of the blades, thereby adjusting the interaction area and angle between the blades and the water flow, thus altering the magnitude of the thrust. Variable nozzles adjust the shape or outlet area of ​​the nozzle to regulate the speed and direction of the water flow, thereby changing the thrust. Throttle valves control the flow rate by changing the valve opening, thus regulating the thrust. Pump speed control adjusts the pump speed to change the pumping rate and pressure, thereby controlling the thrust or flow of the propulsion system.

[0003] However, these traditional adjustment methods have many problems. Variable blade and variable nozzle devices are typically complex in structure, containing numerous mechanical components, resulting in large size. Furthermore, the linkage and response between these components require time, leading to slow adjustment response that cannot meet the needs of ships under rapidly changing operating conditions. Traditional adjustment structures struggle to balance sealing and adjustment efficiency when achieving cross-section adjustment, leading to problems such as water leakage and increased energy loss during the adjustment process. Moreover, traditional mechanical structures have difficulty achieving reliable mechanical emergency stops. In emergency situations requiring immediate propulsion cessation, they cannot quickly and effectively perform emergency stops, posing a threat to the safe operation of the ship.

[0004] A search revealed that patent document CN202420160047.3 proposes a novel waterjet propulsion pump nozzle, employing a double-linkage conical sleeve nozzle adjustment structure. The annular cross-sectional area of ​​the nozzle outlet is changed by the relative axial movement of the inner and outer conical sleeves. This solution reduces the device's size and installation space requirements; however, the linear guide rail has poor sealing performance, high inertia, slow response, and lacks an emergency stop function, reducing safety. Patent document CN202311386148.9 embeds an inflatable rubber ring into the nozzle's inner wall, changing its inner diameter through inflation / deflation. Sealing relies on the rubber ring's expansion, but the rubber ring wears rapidly under high-speed, sand-laden water flow, leading to decreased sealing performance after fatigue. Furthermore, deformation of the inflatable ring can cause uneven flow channels, easily generating eddies. Patent document 202411485269.3 uses a movable plate that opens and closes radially via a sloped slider mechanism to change its diameter. However, the overlapping surfaces between the movable plates and the rotating interfaces of the multi-segment guide pipe present several sealing challenges, making leakage prone to occur under high pressure. In summary, existing adjustment schemes, due to their mechanical structure, are unable to overcome problems such as wear, jamming, high-pressure sealing, and emergency stop under harsh water conditions. Currently, the industry urgently needs a new type of water jet propulsion adjustment device that can avoid sliding friction in its structure, has excellent sealing and anti-sludge capabilities, can stop quickly, respond rapidly, and achieve a good balance between control and manufacturing costs. Summary of the Invention

[0005] To address the above problems, this invention provides a waterjet propulsion nozzle control device that integrates a rotary closure into the nozzle of the waterjet propulsion pump and sets up a feedback and mechanical emergency stop control system. This device can achieve continuous adjustment from fully open to fully closed at the nozzle outlet, and has the advantages of fast response, reliable mechanical emergency stop, easy disassembly and maintenance, and adaptability to harsh media, so as to meet the requirements of engineering applications.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A water jet propulsion nozzle control device includes a water jet propulsion device, a rotary closure device, a drive device, a control device, and a flow rate sensor;

[0008] The rotary closure is fixedly installed at the nozzle outlet end of the water jet propulsion device by set screw A. The flow rate sensor is embedded inside the rotary closure for real-time monitoring of the nozzle flow rate.

[0009] The rotary closure includes a drive housing, pressure relief orifice blades, a drive pin, and a trajectory fixing disk. The drive housing has multiple arc-shaped drive grooves, and the trajectory fixing disk has multiple fixed curve limiting grooves. The pressure relief orifice blades are fan-shaped or fan-shaped, and multiple pressure relief orifice blades are sequentially spliced ​​and installed, arranged concentrically around the nozzle circumference. The drive pin passes through the pressure relief orifice blades, with one end embedded in the drive groove on the drive housing and the other end embedded in the limiting groove on the trajectory fixing disk. The drive groove on the drive housing is arc-shaped, and the limiting groove on the trajectory fixing disk is linear.

[0010] The drive unit includes a motor, a frequency converter, and meshing drive and driven gears. The frequency converter is used to control the forward and reverse rotation and speed of the motor. The drive gear is fixedly connected to the output shaft of the motor, and the driven gear is a sector gear fixed to the outside of the drive housing and meshes with the drive gear.

[0011] Driven by the drive device, the drive housing synchronously drives the drive pins on multiple pressure relief hole blades to move along their limiting grooves through multiple drive grooves. At the same time, the multiple pressure relief hole blades rotate synchronously around the drive pins, forming a continuous, variable diameter circular opening at the center of the nozzle during synchronous movement.

[0012] The control device includes a human-machine interface terminal and a central controller. The drive device and the flow rate sensor are both connected to the central controller. The central controller controls the operation of the drive device based on the data detected by the flow rate sensor and external control commands.

[0013] Furthermore, the trajectory of the drive groove on the drive housing satisfies the following condition:

[0014] A polar coordinate system with nozzle center O as the pole and OB as the polar axis; in the fully closed state, the polar coordinates of the hinge point between the drive pin of the pressure relief orifice blade and the drive housing are: ,in The fixed distance from the center of the drive pin to the center O of the nozzle; in the fully open state, the polar coordinates of the hinge point between the drive pin of the pressure relief orifice blade and the drive housing are: ,in The fixed distance from the center of the drive pin to the center of the nozzle O; the polar coordinates of the center of the drive pin at any position in the drive groove are: ,in The extreme diameter from the center of the drive pin to the center of the nozzle is taken as angular measurement. Let the distance from N to A be denoted as . Then, point N on the circular arc AB of the driving groove conforms to the polar radius function:

[0015] .

[0016] Furthermore, the limiting groove of the trajectory fixing disk is linear. Let A be the hinge point between the driving pin of the pressure relief hole blade and the trajectory fixing disk when it is fully closed, and C be the hinge point between the driving pin of the pressure relief hole blade and the trajectory fixing disk when it is fully open. Then the chord AB corresponding to the arc AB of the limiting groove AC and the driving groove is symmetrical with respect to the OA axis.

[0017] Furthermore, the external tooth distribution area of ​​the driven gear occupies only one-quarter of the circumference.

[0018] Furthermore, the pressure relief hole blade is provided with pressure relief holes distributed in a gradient. The shape of the pressure relief holes can be circular, teardrop-shaped, Venturi-shaped, or inclined elliptical. The spacing between adjacent pressure relief holes on the pressure relief hole blade increases from the center to the edge, and the diameter of the pressure relief holes also increases from the center to the edge. The pressure relief holes are distributed from the root of the blade to the tip in a manner that changes from dense to sparse and from small to large.

[0019] Furthermore, the pressure relief hole blade is a core functional component for adjusting the cross-sectional area of ​​the flow channel. It adopts a plano-convex airfoil design, with the pressure surface of the blade being a convex arc shape, in order to optimize the fluid pressure distribution, improve streamline characteristics, and reduce hydrodynamic losses.

[0020] Furthermore, the pressure relief hole has a gradually expanding diameter.

[0021] Furthermore, a polyurethane flap valve is vulcanized on the backwater side of the pressure relief hole.

[0022] Furthermore, the trajectory fixing disk is attached and fixed to the nozzle outlet end by a set screw, and the side connected to the nozzle is designed as a continuous "S"-shaped guide surface.

[0023] Furthermore, the human-computer interaction terminal can input emergency stop commands, and the central controller prioritizes executing the emergency stop commands.

[0024] The core innovation of this invention lies in the integration of a rotary closure device at the nozzle's outlet end, used for continuous and precise adjustment of the effective flow area of ​​the nozzle. Compared with the prior art, the advantages of this invention are as follows:

[0025] This invention comprehensively improves the control performance and safety reliability of the waterjet propulsion system. Specifically, it is manifested in: (1) Fast response speed, using rotary drive and sector gear transmission, with small inertia of moving parts, achieving millisecond-level nozzle adjustment speed. (2) High efficiency of flow field, low resistance and loss, the pressure relief hole blades are in a centrally symmetrical concentric opening and closing manner, forming a streamlined and optimal circular flow channel, fundamentally avoiding eddy current and flow separation, significantly reducing flow resistance and hydrodynamic loss, and achieving high propulsion efficiency. (3) Possesses active emergency stop capability, the control system has a highest priority emergency stop logic, which can drive the nozzle to close instantly and trigger mechanical locking, achieving absolutely reliable rapid flow interruption safety guarantee. Attached Figure Description

[0026] Figure 1 This is a three-dimensional assembly diagram of the water jet propulsion nozzle control device of the present invention.

[0027] Figure 2 This is a cross-sectional schematic diagram of the nozzle control device for the water jet propulsion device described in this invention.

[0028] Figure 3 This is a part drawing of the rotary closure device described in this invention.

[0029] Figure 4 This is a diagram of the drive housing of the rotary closure described in this invention.

[0030] Figure 5 This is a diagram of the trajectory fixing plate for the rotary closure device described in this invention.

[0031] Figure 6 This is a geometric schematic diagram of the limiting hole described in this invention.

[0032] Figure 7 This is a blade diagram of the rotary closure device described in this invention.

[0033] Figure 8 This is a schematic diagram of the open and closed states of the rotary closure device described in this invention.

[0034] Figure 9 This is a schematic diagram of the drive mechanism for the nozzle control device of the water jet propulsion unit described in this invention.

[0035] Figure 10 This is a schematic diagram of the control device for the water jet propulsion nozzle of the present invention.

[0036] Explanation of reference numerals in the attached diagram: 1. Rotary closure device; 2. Flow rate sensor; 3. Drive gear; 4. Motor; 5. Frequency converter; 6. Central controller; 7. Terminal; 8. Water jet propulsion device; 9. Driven wheel; 10. Drive wheel; 11. Set screw A; 12. Nozzle; 13. Hub; 14. Set screw B; 15. Set screw C; 16. Shaft end retaining ring; 17. Guide vane; 18. Impeller housing; 19. Bearing housing; 20. Skeleton oil seal A; 2 1. Impeller, 22. Housing, 23. Impeller shaft, 24. Inlet pipe, 25. Inlet, 26. Shaft tube, 27. Oil seal B, 28. Push bearing, 29. Drive flange, 30. Set screw D, 31. Sealing ring, 1-1. Drive housing, 1-2. Pressure relief hole blade, 1-3. Drive pin coarse end, 1-4. Circular clamping nut A, 1-5. Drive pin fine end, 1-6. Circular clamping nut B, 1-7. Track fixing plate. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0038] like Figure 1 , Figure 2 As shown, the water jet propulsion unit 8 mainly consists of an inlet 25, an impeller 21, guide vanes 17, nozzles 12, and a drive shaft system. The drive flange 29 receives external power, driving the impeller shaft 23 to rotate at high speed. This causes water to enter through the inlet 25, where it is accelerated by the impeller 21 to gain kinetic and pressure energy. The water is then rectified by the guide vanes 17, converting the rotational kinetic energy into axial kinetic energy, which is finally ejected at high speed through the converging nozzles 12 to generate propulsive thrust. The water jet propulsion unit 8 also includes an impeller housing 18, a housing 22, a bearing seat 19, a shaft tube 26, a drive bearing 28, a hub 13, a skeleton oil seal A20, and a skeleton oil seal B27. Stable assembly of the shaft system is achieved through set screws B14 and C15, and a shaft end retaining ring 16.

[0039] The water jet propulsion nozzle control device of the present invention is characterized in that it includes a water jet propulsion unit 8, a rotary closure unit 1, a drive device, a control device, and a flow rate sensor 2. The rotary closure unit 1 is fixedly installed at the nozzle 12 outlet end of the water jet propulsion unit 8 by a set screw A11. The flow rate sensor 2 is embedded inside the rotary closure unit 1 for real-time monitoring of the nozzle flow rate. The rotary closure unit 1 includes a drive housing 1-1, a pressure relief hole blade 1-2, a drive pin, and a trajectory fixing disc 1-4.

[0040] The drive housing 1-1 serves as a sealed housing and pressure-bearing body, connected to an external drive unit to house and drive the internal moving parts. For example... Figure 3 As shown, the drive housing 1-1 has multiple arc-shaped drive grooves, and the trajectory fixing disk 1-7 has multiple fixed curve limiting grooves. The pressure relief hole blades 1-2 are fan-shaped or fan-shaped rings. The center of the inner edge contour of the multiple pressure relief hole blades 1-2 coincides with the nozzle axis, and the outer edges are arranged sequentially along the circumference to form a circular edge. After the multiple pressure relief hole blades 1-2 are sequentially spliced ​​and installed, they can be arranged closely around the nozzle in a concentric circle manner. Each blade is equipped with a drive pin, which penetrates the pressure relief hole blade 1-2. The thick end of the drive pin is embedded in the drive groove on the drive housing 1-1, and the thin end of the drive pin is embedded in the limiting groove of the trajectory fixing disk 1-7 to realize power transmission and motion guidance. The drive groove on the drive housing 1-1 is arc-shaped, and the limiting groove of the trajectory fixing disk 1-7 is linear. Figure 4 , Figure 5The trajectory fixing disk 1-4 is installed tightly against the nozzle using set screw B. A sealing ring is installed at the connection between the trajectory fixing disk 1-4 and the nozzle to ensure high-pressure sealing. The inner surface of the trajectory fixing disk 1-4 is designed as an "S"-shaped curved surface, forming a smooth geometric transition with the inner wall of the nozzle and the external flow channel, effectively eliminating fluid separation and significantly reducing eddy energy loss. This guiding curved surface can guide the water flow to accelerate and change direction smoothly, significantly reducing local resistance and turbulence intensity, thereby improving propulsion efficiency.

[0041] like Figure 9 As shown, the drive device includes a motor 4, a frequency converter 5, and a meshing drive gear and a driven gear 9. The frequency converter 5 is used to control the forward and reverse rotation and speed of the motor 4. The drive gear is fixedly connected to the output shaft of the motor 4. The driven gear 9 is a sector gear fixed to the outside of the drive housing 1-1 and meshes with the drive gear.

[0042] Driven by the drive device, the drive housing 1-1 synchronously drives the drive pins on multiple pressure relief orifice blades 1-2 to move along their limiting grooves via multiple drive grooves. Simultaneously, the multiple pressure relief orifice blades 1-2 rotate synchronously around the drive pins, forming a continuous, variable-diameter circular opening at the nozzle center during synchronous movement, achieving symmetrical adjustment of the nozzle diameter. During this process, adjacent blades remain in close contact. The contact section between adjacent pressure relief orifice blades 1-2 is either planar contact or an overlapping interface.

[0043] The control device includes a human-machine interface terminal 7 and a central controller 6. The drive device and the flow rate sensor 2 are both connected to the central controller 6. The central controller 6 controls the operation of the drive device based on the data detected by the flow rate sensor and external control commands.

[0044] The combination and control device of the water jet propulsion pump and rotary closure 1 of the present invention mainly includes a water jet propulsion pump body 8, a rotary closure 1 in the mechanical action layer, a flow rate sensor 2 in the signal feedback layer, a drive execution layer including a motor 4, a frequency converter 5 and a drive gear 3, a central controller 6 in the core control layer, and a human-machine interface terminal 7 in the user command layer. The impeller 21 of the water jet propulsion pump rotates at high speed under power drive, drawing water in from the inlet 25 and into the pump body through the inlet pipe 24. After gaining kinetic and pressure energy inside the pump, the water flows through the guide vanes 17 for rectification and is finally ejected at high speed through the nozzle 12, generating propulsive thrust based on the principle of reaction force.

[0045] At the user command level, operators input target nozzle flow rate commands via the human-machine interface terminal 7. This level also receives the highest priority emergency stop signal, which can immediately interrupt the normal control process.

[0046] The core control layer, with the central controller 6 as its brain, continuously receives target commands from the user command layer and actual nozzle velocity data from the signal feedback layer. Internally, the controller runs closed-loop control algorithms such as PID, calculating and outputting control commands like "increase opening" or "decrease opening" in real time by comparing target and actual values. In the signal feedback layer, the velocity sensor 2 monitors the actual nozzle velocity in real time and feeds this data back to the central controller 6, forming the basis of closed-loop control. In the drive execution layer, the frequency converter 5 receives control commands from the central controller 6 and precisely controls the rotation direction, angle, and speed of the drive motor 4 accordingly.

[0047] Mechanical Action Layer: The rotation of motor 4, through the drive gear 3, ultimately drives the rotary closure 1 to actuate, changing the effective cross-sectional area of ​​the flow channel and thus affecting the flow velocity, bringing it closer to the target value. Emergency Stop and Safety Logic: When the system receives an emergency stop signal, the central controller 6 will ignore any other instructions and immediately drive the rotary closure 1 to the fully closed position in the shortest possible time via the frequency converter 5 and motor 4. To further ensure safety, the system will simultaneously trigger a physical locking mechanism (not shown in the diagram), such as an electromagnetic pin, to mechanically lock the blades in the closed state, ensuring absolutely reliable flow interruption safety.

[0048] Reference Figure 10 The drive actuator layer is powered by a pair of meshing gears. The output shaft of the motor 4 is connected to the drive gear 10. Meshing with the drive gear 10 is the driven gear 9, which is designed as a sector gear with only 1 / 4 of its circumference. This design allows its limited rotation angle to precisely match the required travel of the drive pin 1-3 inside the rotary closure 1, achieving compact and efficient power transmission. The driven gear 9 is fixedly connected to the drive housing 1-1. When the motor 4 drives the drive gear 10 to rotate under the control of the frequency converter 5, it drives the driven gear 9 to perform a sector reciprocating motion, thereby causing the drive housing 1-1 to move accordingly. The drive pin 1-3 is fixed to the drive housing 1-1. The rotational motion of the drive housing 1-1 is converted into a synchronous and precise radial opening and closing motion of multiple pressure relief hole blades 1-2 through the engagement of the drive pin 1-3 with the precision curved limiting groove on the fixed track fixing plate 1-4. Figure 8 , Figure 9 This allows for stepless adjustment of the nozzle diameter.

[0049] The pressure relief orifice blades 1-2 are core functional components for adjusting the cross-sectional area of ​​the flow channel. The blades have gradient-distributed pressure relief orifices with shapes including circular, teardrop, Venturi, or inclined elliptical orifices—all optimized for fluid dynamics. These orifices are distributed from the blade root to the tip, following a pattern of increasing density and size to accommodate the pressure and velocity gradients in the flow channel, suppress eddy currents, reduce flow resistance, and balance the pressure difference across the blade. The blade sides employ a plano-convex airfoil design, such as... Figure 7 As shown, the pressure surfaces of the pressure relief orifice blades 1-2 are convex arc-shaped to optimize fluid pressure distribution, improve streamline characteristics, and reduce hydrodynamic losses. The inner wall of the side channel of the pressure relief orifice is gradually expanding to guide the fluid to expand smoothly, prevent fluid separation and cavitation, and improve durability. On the backwater side of the orifice, i.e., the side that is subjected to water flow impact during normal propulsion, a valve made of polyurethane material is vulcanized. During forward propulsion, the valve automatically closes under water pressure, sealing the orifice and ensuring effective establishment of the main thrust; during reverse water flow or pressure fluctuations, the valve opens to achieve pressure relief, buffering, and pressure balance, improving the dynamic stability of the system.

[0050] The drive unit uses motor 4 as a power source, and frequency converter 5 is electrically connected to motor 4, receiving command signals from central controller 6 to precisely control the rotation direction, angle, and speed of motor 4. The drive wheel is driven by motor 4, and the drive gear is directly or via a coupling connected to the output shaft of motor 4. The driven gear is designed as a sector gear occupying only 1 / 4 of the circumference, continuously meshing with the drive gear. The outer ring of the rotary closure 1 is fixedly connected to the driven gear 9. When the motor drives the drive gear to rotate, the driven gear reciprocates in a sector motion, driving the drive housing 1-1 to rotate. The limited rotation angle of the sector gear matches the geometric length of the limiting groove of the drive pin, ensuring that its limited rotation range precisely matches the required stroke of the drive pin, achieving a compact and complete movement of the blade from fully open to fully closed, and enabling continuous adjustment of the effective flow area of ​​the nozzle. Figure 8 The diagram shows three typical operating states, from fully open to fully closed.

[0051] The human-machine interface terminal 7 of the control device can input the target nozzle flow rate index or the highest priority emergency stop signal. The central controller 6, as the intelligent control hub of the entire system, is responsible for realizing closed-loop flow control and safe emergency stop functions. When an emergency stop signal is received, the controller immediately interrupts the normal control process, drives the rotary closure 1 to quickly move to the fully closed position, and triggers the physical locking mechanism to ensure absolute flow interruption safety. The flow rate sensor 2 is embedded inside the drive housing 1-1, collecting nozzle flow rate data in real time and transmitting the signal to the central controller 6. Based on the real-time data fed back by the flow rate sensor 2, the controller uses a closed-loop control algorithm such as PID to dynamically adjust the output command.

[0052] The principle of synchronous opening and closing of the rotary closure is as follows:

[0053] The rotary closure 1 consists of a drive housing 1-1, several pressure relief blades 1-2, a drive pin, and a track fixing disk 1-7. The drive groove on the drive housing 1-1 and the limiting groove on the track fixing disk 1-7 are distributed circumferentially and correspond to the kinematics of the blades. The thick end 1-3 of the drive pin is inserted into the drive groove of the drive housing 1-1, and the thin end 1-5 of the drive pin is inserted into the limiting groove of the track fixing disk 1-7. Both the limiting groove and the drive groove are designed as bosses. The two ends of the drive pin are axially clamped by circular clamping nuts A1-4 and B1-6 to ensure that it does not come out axially but maintains a sliding fit in the radial / circumferential direction. When the drive housing 1-1 rotates angularly, the thick end 1-3 of the drive pin, embedded in the drive housing 1-1, undergoes angular displacement in the circumferential direction with the housing; however, the thin end 1-5 of the drive pin is constrained by the fixed curved limiting groove on the track fixing disk 1-7. Therefore, the circumferential motion of the drive pin is geometrically constrained into a composite motion along the groove (angular + radial component). The radial component of the drive pin is converted into the angular change of the blade around the hinge point through its rigid connection with blade 1-2, thereby realizing the radial opening and closing of the blade. To ensure interference-free and smooth movement, the limiting groove is a single-valued extreme radius function r(θ) in polar coordinates, and the geometry, starting and ending angles, and end limits of each limiting groove are the same in manufacturing and assembly or arranged symmetrically. The drive pin adopts the same installation radius and the same guiding relationship at all blades. Therefore, under the same angular drive of the drive housing 1-1, each drive pin will slide synchronously along its respective limiting groove, causing all blades to open and close synchronously and concentrically. The end limiting holes correspond to the limit positions of the drive pin in the angular and radial directions, and are used to achieve mechanical positioning and locking when in place, preventing overtravel and ensuring closing stability.

[0054] Specifically, the drive groove and the upper limit groove of the track fixing disk on the drive housing 1-1 are circles with the outer diameter d of the thick end of the drive pin and the outer diameter d' of the thin end of the drive pin as their diameters, respectively. The center of the circle moves along a certain curve, and the area traversed by the circle is determined by the curve.

[0055] To determine the trajectory of the drive groove, as shown in Figure 6, a polar coordinate system is used, with the nozzle center O as the pole and OB as the polar axis. In the fully closed state, the polar coordinates of the blade hinge point are assumed to be... ,in Let O be the fixed distance from the center of the drive pin to the center of the nozzle. In the fully open state, let the polar coordinates of the blade hinge point be... ,in This is the fixed distance from the center of the drive pin to the center of the nozzle O. The polar coordinates of the center of the drive pin at any position in the limiting groove are: ,in The extreme diameter from the center of the drive pin to the center of the nozzle is taken as angular measurement. . The distance to A is set as Then there are constraints:

[0056]

[0057] Solving this equation yields the extreme diameter function of the limiting groove (taking the physical solution that satisfies the boundary conditions):

[0058] .

[0059] Fully open hour, .

[0060] Fully closed state hour, .

[0061] parameter satisfy .

[0062] The limiting groove on the track fixing plate ensures that the drive pin is at any drive angle. All components are positioned within the limiting grooves of the track fixing disk. Let A be the hinge point between the drive pin of the pressure relief hole blade 1-2 and the track fixing disk 1-7 in the fully closed state, and C be the hinge point in the fully open state. The chord AB corresponding to the arc AB of the limiting groove AC and the drive groove is symmetrical about the OA axis, ensuring that the sliding of the pin within the limiting groove accurately controls the rotation of the blade. Each limiting groove has end-limiting bosses at both ends for mechanical travel and positioning.

[0063] However, it's important to note that synchronized blade opening and closing is not the only method. Other methods are equally feasible, such as using limiting grooves of different shapes or adjusting the angle and length of the grooves to achieve synchronized blade opening and closing. Specific design and implementation methods can be appropriately adjusted and optimized according to actual needs.

[0064] This invention is implemented through the following steps:

[0065] Step 1: After the system is powered on, the central controller 6 enters standby mode, and the flow rate sensor 2 begins to collect nozzle flow rate data in real time and transmit it to the central controller 6.

[0066] Step 2: The operator inputs the target nozzle flow rate command through terminal 7. The central controller 6 compares the target value with the real-time flow rate feedback value and starts the closed-loop control algorithm to generate control commands.

[0067] Step 3: The central controller 6 sends control commands to the frequency converter 5, which then adjusts the rotation direction, speed, and angle of the motor 4 accordingly.

[0068] Step 4: The output shaft of motor 4 drives the drive gear 9 to rotate. The drive gear 9 drives the sector driven gear 10 that meshes with it to perform reciprocating motion at a limited angle, thereby driving the drive housing 1-1 to rotate around the axis of nozzle 12.

[0069] Step 5: During the rotation of the drive housing 1-1, the drive pin moves in the circumferential direction and generates radial displacement under the geometric constraint of the curve limiting groove of the trajectory fixing disk 1-7. The drive pin transmits this composite motion to the pressure relief hole blades 1-2, so that all blades open and close synchronously, forming a continuously variable diameter circular flow section at the center of the nozzle.

[0070] Step 6: When the nozzle velocity reaches the target value, the central controller 6 maintains the current control output, so that the rotary closure 1 is stabilized at the corresponding opening position, thus achieving stable propulsion.

[0071] Step 7: When the system receives the highest priority emergency stop signal, the central controller 6 immediately interrupts the normal adjustment process, drives the motor 4 to run in reverse quickly, so that the rotary closure 1 moves to the fully closed position in the shortest time, and at the same time triggers the mechanical locking mechanism to lock the blades 1-2 in the closed state, so as to achieve absolute safety flow interruption.

[0072] The present invention integrates a rotary closure 1 at the outlet end of the nozzle 12, which can continuously and precisely adjust the effective flow area of ​​the nozzle, thereby realizing stepless adjustment of the nozzle diameter.

[0073] The embodiments described above are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A waterjet propulsion nozzle control device, characterized in that, Includes a water jet propulsion unit (8), a rotary closure unit (1), a drive unit, a control unit, and a flow rate sensor (2); The rotary closure (1) is fixedly installed at the nozzle (12) outlet end of the water jet propulsion unit (8) by a set screw A (11). The flow rate sensor (2) is embedded inside the rotary closure (1) for real-time monitoring of the nozzle flow rate. The rotary closure (1) includes a drive housing (1-1), a pressure relief hole blade (1-2), a drive pin, and a trajectory fixing disk (1-4). The drive housing (1-1) is provided with multiple arc-shaped drive grooves, and the trajectory fixing disk (1-4) is provided with... Multiple fixed curve limiting grooves are provided. The pressure relief hole blades (1-2) are fan-shaped or fan-shaped. After multiple pressure relief hole blades (1-2) are spliced ​​and installed in sequence, they are arranged closely around the nozzle in a concentric circle manner. The driving pin passes through the pressure relief hole blades (1-2), with one end embedded in the driving groove on the driving housing (1-1) and the other end embedded in the limiting groove of the trajectory fixing disk 1-7. The driving groove on the driving housing (1-1) is arc-shaped, and the limiting groove of the trajectory fixing disk 1-7 is straight. The drive unit includes a motor (4), a frequency converter (5), and a meshing drive gear (10) and a driven gear (9). The frequency converter (5) is used to control the forward and reverse rotation and speed of the motor (4). The drive gear (10) is fixedly connected to the output shaft of the motor (4). The driven gear (9) is a sector gear fixed to the outside of the drive housing (1-1) and meshes with the drive gear (10). Driven by the drive device, the drive housing (1-1) drives the drive pins on the multiple pressure relief hole blades (1-2) to move along their limiting grooves through multiple drive grooves. At the same time, the multiple pressure relief hole blades (1-2) rotate around the drive pins in sync, forming a continuous, variable diameter circular opening at the center of the nozzle during synchronous movement. The control device includes a human-machine interface terminal (7) and a central controller (6). The drive device and the flow rate sensor (2) are both connected to the central controller (6). The central controller (6) controls the operation of the drive device according to the data detected by the flow rate sensor and external control commands.

2. The waterjet propulsion nozzle control device according to claim 1, characterized in that, The trajectory of the drive groove on the drive housing (1-1) satisfies the following conditions: A polar coordinate system with nozzle center O as the pole and OB as the polar axis; in the fully closed state, the polar coordinates of the hinge point between the drive pin of the pressure relief orifice blade (1-2) and the drive housing (1-1) are A(a,θ), where The fixed distance from the center of the drive pin to the center of the nozzle O; in the fully open state, the polar coordinates of the hinge point between the drive pin of the pressure relief orifice blade (1-2) and the drive housing (1-1) are B(b,θ), where Let N(r,α) be the fixed distance from the center of the drive pin to the center of the nozzle O; let N(r,α) be the polar coordinate of the center of the drive pin at any position in the drive groove, where Let α be the extreme diameter from the center of the drive pin to the center of the nozzle, and let α be the angle. Let the distance from N to A be denoted as α. Then, point N on the circular arc AB of the driving groove conforms to the polar radius function: 。 3. The waterjet propulsion nozzle control device according to claim 2, characterized in that, The limiting grooves of the trajectory fixing discs 1-7 are linear. Assume: When fully closed, the hinge point between the drive pin of the pressure relief hole blade (1-2) and the track fixing disk (1-7) is A. When fully open, the hinge point between the drive pin of the pressure relief hole blade (1-2) and the track fixing disk (1-7) is C. Then, the chord AB corresponding to the arc AB of the limiting groove AC and the drive groove is symmetrical about the OA axis.

4. The waterjet propulsion nozzle control device according to claim 1, characterized in that, The external tooth distribution area of ​​the driven gear (9) occupies only one-quarter of the circumference.

5. The waterjet propulsion nozzle control device according to claim 1, characterized in that, The pressure relief hole blade (1-2) is provided with pressure relief holes distributed in a gradient. The spacing between adjacent pressure relief holes on the pressure relief hole blade (1-2) increases from the center to the edge, and the diameter of the pressure relief holes also increases from the center to the edge. The shape of the pressure relief holes can be circular, teardrop-shaped, Venturi-shaped, or inclined elliptical.

6. The waterjet propulsion nozzle control device according to claim 1, characterized in that, The pressure relief hole blade adopts a flat-convex airfoil design, and the pressure surface of the blade is a convex arc shape.

7. The waterjet propulsion nozzle control device according to claim 1, characterized in that, The pressure relief hole has a gradually expanding diameter.

8. The waterjet propulsion nozzle control device according to claim 1, characterized in that, A polyurethane flap valve is vulcanized on the backwater side of the pressure relief hole.

9. The waterjet propulsion nozzle control device according to claim 1, characterized in that, The trajectory fixing plate is attached and fixed to the nozzle outlet end by a set screw, and the side connected to the nozzle is designed as a continuous "S"-shaped guide surface.

10. The waterjet propulsion nozzle control device according to claim 1, characterized in that, The human-computer interaction terminal (7) can input emergency stop commands, and the central controller prioritizes executing emergency stop commands.

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