Pneumatic valve for closed-loop control of aircraft engine starting system

Abstract

A pneumatic valve for closed-loop control of an aircraft engine starting system comprises an actuating mechanism assembly, a servo assembly, a flow channel assembly, a manual control assembly, a butterfly plate, a pipeline assembly, an upstream gas probe and a valve shaft, the servo assembly is fixedly connected with the actuating mechanism assembly and connected with the flow channel assembly through the pipeline assembly, and the valve shaft is connected with the upstream gas probe. The manual control assembly is arranged at the top end of the actuating mechanism assembly, the bottom end of the actuating mechanism assembly is connected with the top end of the flow channel assembly, the butterfly plate is connected with the actuating mechanism assembly through the valve shaft, and the upstream gas probe is connected with the servo assembly and the upstream pipeline assembly. Compared with the prior art, duty ratio control is introduced, and the impact of switching air pressure on the system when open-loop starting is adopted in the prior art is eliminated; a butterfly plate position visual function and a manual locking function are added, a mechanical redundancy is added, after an electromagnetic valve fails, manual control and locking are carried out, and a starting system is maintained to work at a locking opening position in an emergency state.

Description

Technical Field

[0001] The present invention relates to the field of aircraft engine accessories, and in particular to a pneumatic valve for closed-loop control of an aircraft engine starting system. Background Art

[0002] The pneumatic valve used for aircraft engine starting control is a pneumatic butterfly valve that controls the air supply to the downstream air turbine starter. It primarily consists of a channel assembly, an actuator, a solenoid valve, and a manual control assembly. The solenoid valve is an on-off type. When energized, high-pressure gas upstream of the valve enters the actuator, overcoming spring resistance and driving the connecting rod to rotate the butterfly disc. When de-energized, the high-pressure gas upstream of the valve cannot enter the actuator, reducing the pressure in the actuator control chamber. The spring force of the actuator assembly returns the butterfly disc to its normally closed state. Current air valves present several challenges: First, they hinder fault diagnosis; the fully enclosed structure prevents intuitive identification of internal structural problems; the opening and closing of the valve exerts excessive impact on the downstream; and the product redundancy is too low, resulting in complete system failure in the event of a fault.

[0003] To address the above issues, we have made a series of improvements. Summary of the Invention

[0004] The object of the present invention is to provide a pneumatic valve for closed-loop control of an aircraft engine starting system to overcome the above-mentioned shortcomings and deficiencies of the prior art.

[0005] A pneumatic valve for closed-loop control of an aircraft engine starting system comprises: an actuating mechanism assembly, a servo assembly, a flow channel assembly, a manual control assembly, a butterfly plate, a pipeline assembly, an upstream gas probe, and a valve shaft. The servo assembly is fixedly connected to the actuating mechanism assembly, which is connected to the flow channel assembly via a pipeline assembly. The manual control assembly is provided at the top of the actuating mechanism assembly, and the bottom of the actuating mechanism assembly is connected to the top of the flow channel assembly. The butterfly plate is connected to the actuating mechanism assembly via the valve shaft. The upstream gas probe is connected to the servo assembly, which is connected to the upstream pipeline assembly.

[0006] Among them, the servo assembly includes: a servo housing, a solenoid valve assembly, a speed controller and a pressure sensor. The solenoid valve assembly and the speed controller are arranged at the front and rear ends of the servo housing, the pressure sensor is arranged at the lower end of the servo housing, and the solenoid valve assembly is connected to the upstream gas probe.

[0007] Furthermore, the actuating mechanism assembly includes: an actuator housing, a connecting rod mechanism, a closing chamber spring, a piston and an actuator cover, one end of the connecting rod mechanism is connected to the piston, and the other end of the connecting rod mechanism is connected to the butterfly plate through the valve shaft, the closing chamber spring is matched with the piston, the piston is through-connected to the actuator housing, the closing chamber spring is arranged between the actuator housing and the piston, and the actuator cover is connected to the top of the actuator housing.

[0008] Furthermore, the manual control assembly includes: a position indicator, a locking pin and a manual control base plate, the position indicator and the locking pin are connected to the top of the manual control base plate, and the manual control base plate is connected to the actuator housing.

[0009] Furthermore, the speed controller includes: a speed control valve assembly, a diaphragm box assembly, a spring and an adjusting housing, the upper end of the speed control valve assembly is connected to the diaphragm box assembly, the diaphragm box assembly is connected to the adjusting housing, the spring is arranged between the diaphragm box assembly and the adjusting housing, and the lower end of the speed control valve assembly is connected to the servo housing.

[0010] Beneficial effects of the present invention:

[0011] Compared with traditional technology, the present invention introduces duty cycle control to achieve closed-loop regulation of the downstream starter inlet gas pressure, so as to eliminate the impact of the switch gas pressure on the system when the traditional technology adopts open-loop starting; compared with traditional technology, the present invention adds a butterfly plate position visual function and a manual locking function on the basis of the traditional structure, and adds a mechanical redundancy. After the solenoid valve fails, it can be manually controlled and locked, and the starting system can be maintained in the locked opening position under emergency conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural schematic diagram of the present invention.

[0013] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0014] Figure 3 Schematic diagram of the structure of the actuator assembly.

[0015] Figure 4 This is a connection diagram for use in the present invention.

[0016] Reference numerals:

[0017] The actuator assembly 100 includes an actuator housing 110 , a linkage 120 , a closing chamber spring 130 , a piston 140 and an actuator cover 150 .

[0018] The servo assembly 200 , the servo housing 210 , the solenoid valve assembly 220 , the speed controller 230 , the speed regulating valve assembly 231 , the diaphragm assembly 232 , the spring 233 , the regulating housing 234 and the pressure sensor 240 .

[0019] The flow channel assembly 300 , the manual operation assembly 400 , the position indicator 410 , the locking pin 420 and the manual operation base plate 430 .

[0020] Butterfly plate 500 , pipe assembly 600 , upstream gas probe 700 , valve shaft 800 and upstream pipe assembly 900 . DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to specific examples. It should be understood that the following examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0022] Example 1

[0023] Figure 1 It is a structural schematic diagram of the present invention. Figure 2 It is a schematic diagram of the internal structure of the present invention. Figure 3 Schematic diagram of the structure of the actuator assembly. Figure 4 This is a connection diagram for use in the present invention.

[0024] like Figure 1-4 As shown, a pneumatic valve for closed-loop control of an aircraft engine starting system includes: an actuator assembly 100, a servo assembly 200, a flow channel assembly 300, a manual control assembly 400, a butterfly plate 500, a pipeline assembly 600, an upstream gas probe 700, and a valve shaft 800. The servo assembly 200 is fixedly connected to the actuator assembly 100, and the servo assembly 200 is connected to the flow channel assembly 300 via the pipeline assembly 600. The manual control assembly 400 is provided at the top of the actuator assembly 100, and the bottom end of the actuator assembly 100 is connected to the top of the flow channel assembly 300. The butterfly plate 500 is connected to the actuator assembly 100 via the valve shaft 800. The upstream gas probe 700 is connected to the servo assembly 200, and the upstream gas probe 700 is connected to the upstream pipeline assembly 900.

[0025] Among them, the servo assembly 200 includes: a servo housing 210, a solenoid valve assembly 220, a speed controller 230 and a pressure sensor 240. The solenoid valve assembly 220 and the speed controller 230 are arranged at the front and rear ends of the servo housing 210, the pressure sensor 240 is arranged at the lower end of the servo housing 210, and the solenoid valve assembly 220 is connected to the upstream gas probe 700.

[0026] The actuator mechanism assembly 100 includes: an actuator housing 110, a connecting rod mechanism 120, a closing chamber spring 130, a piston 140 and an actuator cover 150. One end of the connecting rod mechanism 120 is connected to the piston 140, and the other end of the connecting rod mechanism 120 is connected to the butterfly plate 500 through the valve shaft 800. The closing chamber spring 130 is matched with the piston 140, and the piston 140 is through-connected to the actuator housing 110. The closing chamber spring 130 is arranged between the actuator housing 110 and the piston 140, and the actuator cover 150 is connected to the top of the actuator housing 110.

[0027] The manual control assembly 400 includes a position indicator 410 , a locking pin 420 and a manual control base plate 430 . The position indicator 410 and the locking pin 420 are connected to the top of the manual control base plate 430 , and the manual control base plate 430 is connected to the actuator housing 110 .

[0028] The speed controller 230 includes: a speed control valve assembly 231, a diaphragm box assembly 232, a spring 233 and an adjusting housing 234. The upper end of the speed control valve assembly 231 is connected to the diaphragm box assembly 232, the diaphragm box assembly 232 is connected to the adjusting housing 234, the spring 233 is arranged between the diaphragm box assembly 232 and the adjusting housing 234, and the lower end of the speed control valve assembly 231 is connected to the servo housing 210.

[0029] The weight of the present invention is no more than 4.8 kg, and its outer dimensions (length x width x height) are no more than 248 mm x 220 mm x 330 mm. The manual control assembly 400 allows the valve to be manually locked in the fully open, half-open, and fully closed positions when the solenoid valve is not powered. The actuator assembly 100 is a pneumatic actuator that converts the linear motion of the piston 140 into rotation of the butterfly plate 500 via the connecting rod mechanism 120. The solenoid valve assembly is a key control component of the starting air valve, receiving control signals from the EEC to control the opening and closing of the starting air valve. The servo assembly 200 is used to house control components such as the speed controller 230 and the solenoid valve assembly 220, and is connected to the control air circuit through the internal channels of the servo housing 210. Various bleed air flow channels are also provided within the invention, and the butterfly plate 500 controls the gas flow through the starting air valve. The duct assembly 600 provides bleed air upstream of the butterfly plate, feedback bleed air downstream of the butterfly plate, and bleed air to the pressure sensor. The main materials of the starting air valve parts are 321 stainless steel and 6061-T651, which not only meet the functional performance requirements but also ensure the stability of the starting air valve under high temperature operation.

[0030] The working principle of the present invention is that when the solenoid valve assembly 220 is energized, the high-pressure air in the flow channel is released into the actuator chamber by the solenoid valve assembly 220. The piston surface in the actuating chamber generates a force under the action of air pressure (pressure * area = force). When the force is greater than the preloaded spring force, the piston 140 is pushed to the other side, thereby opening the butterfly plate 500 through the conversion of the connecting rod mechanism 120 and the rotating shaft. Similarly, when the solenoid valve assembly 220 is de-energized, the control air circuit is cut off, and the piston 140 is stationary in the starting position under the action of the preload force of the closing chamber spring 130, thereby closing the butterfly plate 500. It can be seen that the on and off of the solenoid valve can control the opening and closing of the butterfly plate 500 in the flow channel. When the butterfly plate 500 opens and closes, the flow area of ​​the airflow in the flow channel also changes. By controlling the PWM duty cycle of solenoid valve assembly 220 and accurately calculating the air path load, we can achieve a positive relationship (close to proportionality) between the output pressure of solenoid valve assembly 220 and its duty cycle within a certain frequency range, with both the repetition rate and control accuracy meeting operational requirements. This feature allows precise control of the angle of butterfly disc 500 via the solenoid valve's output pressure. Combined with downstream pressure sensor 240, we can achieve closed-loop control: target pressure—duty cycle output—disc rotation—downstream pressure feedback—duty cycle adjustment.

[0031] The innovation of this invention lies in the introduction of duty cycle control, which linearly adjusts the actuating chamber air pressure within the system's set frequency and gain range. Furthermore, a pressure acquisition point is provided downstream of the butterfly valve 500. Pressure sensor 240 feeds this pressure signal back to the system controller, achieving closed-loop control of the post-valve gas pressure. In conventional startup mode, this valve is an on-off valve. When de-energized, the valve is normally closed. Upon power-up, the butterfly valve 500 immediately opens, a process that takes less than one second. During this time, products in the downstream gas path experience a significant pressure shock, which not only impacts the product's service life but can also cause gas path oscillations and control failure. In the process of the present invention, the pneumatic valve is located downstream of the turbine starter. Airflow flowing through the starter turbine blades drives the starter to rotate, thereby converting potential energy into kinetic energy. Because the acceleration of the starter and its load (including the accessory gearbox connected to the starter, the engine main shaft, etc.) requires time, when the butterfly valve is fully opened, the pressure rises too quickly, causing axial and normal impacts on the starter turbine blades at the moment of starting, and generating a large torque load impact. Air path oscillation is caused by pressure shocks in the pipeline. Due to the transmission characteristics of compressed air, repeated impacts in the pipeline form oscillations. To effectively overcome the above-mentioned impact and oscillation problems, the valve structure and control logic have been innovatively improved. The improved valve adopts duty cycle closed-loop control instead of traditional on-off control, allowing the valve to gradually increase the valve pressure (i.e., the starter inlet pressure) in a set pressure step, avoiding the occurrence of impact and oscillation. Therefore, the present invention is a significant improvement in solving air pressure shocks and air path oscillation.

[0032] Secondly, based on the traditional valve structure, a disc position visualization function and a manual locking function are added. The visual position of the disc 500 can significantly save troubleshooting time. For example, when an electrical signal is given, the disc 500 should be in the open position, allowing direct visual inspection to determine whether the valve is functioning properly. The manual locking function increases the product's operational redundancy. In the event of a partial valve failure, such as a solenoid valve failure, manual control and locking can be performed. In an emergency, the starting system can be maintained in the locked open position.

[0033] The principle of the present invention is how the solenoid valve assembly 220 controls airflow. Currently, commercially available solenoid valves consist of a housing, a coil, a coil bobbin, an armature, a connecting rod, and a preload spring. The present invention is based on an existing product, so the specific structural components are not detailed here. The solenoid coil generates an electromagnetic field through current excitation. The magnetic field acts on the armature, causing it to move downward. When the magnetic field reaches a certain intensity, the downward thrust of the armature overcomes the preload spring force, pushing the connecting rod downward. The air path control valve, primarily composed of a valve body, a valve core, and a preload spring, functions to switch the air path. When the solenoid valve is de-energized, the preload spring forces the valve core in the air path control valve to its upper limit position, blocking the air inlet and connecting the port to the solenoid valve vent. When the solenoid valve is energized, the magnetic field generated by the solenoid coil overcomes the spring force of the preload spring, causing the valve core in the air path control valve to its lower limit position, blocking the solenoid valve vent and connecting the air inlet to the port. Duty cycle control: connect the solenoid valve air inlet to the air source, the port to the actuating chamber, and the vent port to the atmosphere. The movement of the secondary valve core is controlled by a fixed-frequency duty cycle signal, so that the actuating chamber connection port is alternately connected between the air source port and the atmosphere port. The purpose of controlling the pressure in the actuating chamber can be achieved by controlling the duty cycle.

[0034] Principle of Closed-Loop Control: According to design principles, the pressure within the actuating chamber increases as the duty cycle increases. In this invention, the solenoid valve assembly 220 is the actuator, and a pressure sensor is installed after the valve. When the sensor receives the pressure signal and transmits it to the controller (in this embodiment, the controller refers to an external device), the controller makes a decision, such as increasing / decreasing / maintaining the duty cycle. This forms a closed-loop control loop. The closed-loop control process follows the following steps: target pressure - duty cycle output - butterfly valve rotation - downstream pressure feedback - duty cycle adjustment.

[0035] The above describes the specific embodiments of the present invention, but the present invention is not limited thereto. The present invention can be modified in various ways without departing from the spirit of the present invention.

Claims

1. A pneumatic valve for closed-loop control of an aircraft engine starting system, characterized in that: include: An actuating mechanism assembly (100), a servo assembly (200), a flow channel assembly (300), a manual control assembly (400), a butterfly plate (500), a pipeline assembly (600), an upstream gas probe (700) and a valve shaft (800); the servo assembly (200) is fixedly connected to the actuating mechanism assembly (100); the servo assembly (200) is connected to the flow channel assembly (300) via the pipeline assembly (600); the top end of the actuating mechanism assembly (100) is provided with a manual control assembly (400); the bottom end of the actuating mechanism assembly (100) is connected to the top end of the flow channel assembly (300); the butterfly plate (500) is connected to the actuating mechanism assembly (100) via the valve shaft (800); the upstream gas probe (700) is connected to the servo assembly (200); and the upstream gas probe (700) is connected to the upstream pipeline assembly (900); The servo assembly (200) comprises a servo housing (210), a solenoid valve assembly (220), a speed controller (230) and a pressure sensor (240). The solenoid valve assembly (220) and the speed controller (230) are arranged at the front and rear ends of the servo housing (210). The pressure sensor (240) is arranged at the lower end of the servo housing (210). The solenoid valve assembly (220) is connected to an upstream gas probe (700).

2. A pneumatic valve for closed-loop control of an aircraft engine starting system according to claim 1, characterized in that: The actuating mechanism assembly (100) comprises: an actuator housing (110), a connecting rod mechanism (120), a closing chamber spring (130), a piston (140) and an actuator cover (150); one end of the connecting rod mechanism (120) is connected to the piston (140); the other end of the connecting rod mechanism (120) is connected to the butterfly plate (500) via a valve shaft (800); the closing chamber spring (130) is matched with the piston (140); the piston (140) is connected to the actuator housing (110); the closing chamber spring (130) is arranged between the actuator housing (110) and the piston (140); and the actuator cover (150) is connected to the top end of the actuator housing (110).

3. A pneumatic valve for closed-loop control of an aircraft engine starting system according to claim 2, characterized in that: The manual control assembly (400) comprises a position indicator (410), a locking pin (420) and a manual control base plate (430). The position indicator (410) and the locking pin (420) are connected to the top of the manual control base plate (430), and the manual control base plate (430) is connected to the actuator housing (110).

4. A pneumatic valve for closed-loop control of an aircraft engine starting system according to claim 1, characterized in that: The speed controller (230) comprises: a speed regulating valve assembly (231), a diaphragm assembly (232), a spring (233) and an adjusting housing (234); the upper end of the speed regulating valve assembly (231) is connected to the diaphragm assembly (232), the diaphragm assembly (232) is connected to the adjusting housing (234), the spring (233) is arranged between the diaphragm assembly (232) and the adjusting housing (234), and the lower end of the speed regulating valve assembly (231) is connected to the servo housing (210).

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