Hydraulic retraction and extension device for ski-equipped aircraft

Abstract

A hydraulic retraction and extension device for a ski-equipped aircraft, the hydraulic retraction and extension device comprising a hydraulic oil tank, a hydraulic pump, a one-way valve, a hydraulic oil filter, a two-position three-way solenoid valve, a pressure sensor, a pressure-regulating valve, a three-position four-way solenoid valve, a front ski throttle valve, a left ski throttle valve, a right ski throttle valve, a front ski actuating cylinder, a left ski actuating cylinder and a right ski actuating cylinder. A ski can be retracted and extended. When an aircraft lands on an icy or snowy road surface, the ski is deployed, and the aircraft lands by means of the ski. When the aircraft lands on a hard road surface such as sandstone, the ski is retracted, and the aircraft lands by means of wheels and tires.

Description

A hydraulic retraction and deployment device for aircraft sleds Technical Field

[0001] This invention pertains to aircraft hydraulic system technology and relates to a hydraulic retraction and deployment device for aircraft sleds. Background Technology

[0002] Existing aircraft use fixed sled systems, lacking the capability to retract and extend the sleds. This restricts aircraft takeoff and landing on hard paved surfaces like sand and gravel, limiting their operational capabilities to icy and snowy conditions. This hydraulic sled retraction and extension system allows for the retraction and extension of the aircraft's sleds, ensuring synchronization between the left and right sleds. It enables the aircraft to switch between sled and wheel landings, allowing for takeoff and landing on both icy and snowy surfaces as well as hard paved surfaces like sand and gravel, thus expanding operational options and improving aircraft performance. Therefore, this hydraulic sled retraction and extension system can be applied to aircraft hydraulic systems. Summary of the Invention

[0003] Purpose of the invention

[0004] This invention provides a hydraulic sled deployment and retraction device for aircraft, capable of deploying and retracting the sled. When landing on icy or snowy surfaces, the sled is lowered for landing. When landing on hard surfaces such as sand or gravel, the sled is retracted for landing via the aircraft's wheels and tires.

[0005] Technical solution

[0006] A hydraulic deployment and retraction device for an aircraft sled includes a hydraulic oil tank connected to a hydraulic pump, which in turn is connected to a check valve. The check valve is connected to a hydraulic oil filter, which is connected to the pressure port P of a two-position three-way solenoid valve. The working port A of the two-position three-way solenoid valve is connected to the inlet of a pressure sensor and a pressure regulating valve. The return port O of the two-position three-way solenoid valve is connected to the return port of the hydraulic oil tank and the pressure regulating valve. The pressure sensor is connected to the pressure port P of the pressure regulating valve and a three-position four-way solenoid valve. The return port O of the three-position four-way solenoid valve is connected to the hydraulic oil tank. The working port A of the three-position four-way solenoid valve is connected to the front sled throttle valve, the left sled throttle valve, and the right sled throttle valve respectively. The working port B of the three-position four-way solenoid valve is connected to the front sled actuator, the left sled actuator, and the right sled actuator respectively. The front sled throttle valve is connected to the front sled actuator, the left sled throttle valve is connected to the left sled actuator, and the right sled throttle valve is connected to the right sled actuator.

[0007] Furthermore, pressure sensors are used to monitor the pressure of the sled deployment and take-off system, check valves are used to prevent damage to the hydraulic pump in case of overload, oil filters are used to filter impurities in the hydraulic fluid of the sled deployment and take-off system, ensuring the normal operation of the two-position two-way solenoid valve and the three-position four-way solenoid valve, and two-position three-way solenoid valves are used to control the opening and closing of the hydraulic circuit of the sled deployment and take-off system.

[0008] Furthermore, the three-position four-way solenoid valve is used to switch the corresponding pressure supply circuit to the three sled retraction / extraction actuators when the sled is raised / lowered, and the pressure regulating valve is used to adjust the pressure of the sled retraction / extraction hydraulic system.

[0009] Furthermore, the front sled throttle valve, left sled throttle valve, and right sled throttle valve are used to regulate the flow rate of the sled retraction and extension actuator supply line to ensure the timing and synchronization of the retraction and extension of the three sleds.

[0010] Furthermore, the front sled actuator is used to drive the front sled, ensuring that the front sled is retracted / lowered to the predetermined position; the left sled actuator is used to drive the left sled, ensuring that the left sled is retracted / lowered to the predetermined position; and the right sled actuator is used to drive the right sled, ensuring that the right sled is retracted / lowered to the predetermined position.

[0011] Furthermore, when the sled retraction action is performed, the two-position three-way solenoid valve connects the hydraulic pump to the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "retract" position. The hydraulic pump draws oil from the hydraulic oil tank. The pressurized oil passes through the check valve, hydraulic oil filter, two-position three-way solenoid valve, pressure sensor, pressure regulating valve, three-position four-way solenoid valve, front sled throttle valve, left sled throttle valve, and right sled throttle valve, and supplies the front sled actuator, left sled actuator, and right sled actuator to the front sled actuator, left sled actuator, and right sled actuator. The front, left, and right sled actuators simultaneously drive the front, left, and right sleds to retract to the predetermined position and lock. After the three sleds are locked, the two-position three-way solenoid valve disconnects the hydraulic pump from the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "neutral" position and connected to the hydraulic oil tank.

[0012] Furthermore, when the sled is lowered, the two-position three-way solenoid valve connects the hydraulic pump to the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "release" position. The hydraulic pump draws oil from the hydraulic oil tank. The pressurized oil passes through the check valve, hydraulic oil filter, two-position three-way solenoid valve, pressure sensor, pressure regulating valve, three-position four-way solenoid valve, front sled throttle valve, left sled throttle valve, and right sled throttle valve, and supplies the front sled actuator, left sled actuator, and right sled actuator to the front sled actuator, left sled actuator, and right sled actuator. The front sled actuator, left sled actuator, and right sled actuator simultaneously drive the front, left, and right sleds to retract to the predetermined position and lock. After the three sleds are locked, the two-position three-way solenoid valve disconnects the hydraulic pump from the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "neutral" position and connected to the hydraulic oil tank.

[0013] Furthermore, a simulation model of the sled deployment and take-off system is established in the simulation software. Based on the load under different flight conditions, the displacement versus time curves are obtained to determine the flow range of the adjustable throttle valve. The flow area range of the throttle valve is calculated according to the orifice throttling formula, and the flow area range is used as the flow regulation requirement of the adjustable throttle valve.

[0014] Furthermore, the formula for orifice throttling is:

[0015]

[0016] In the formula: —Area of ​​the small hole, mm 2 ;

[0017] —Flow rate through the orifice, L / min;

[0018] —The flow coefficient is usually taken as 0.6 to 0.61 in approximate calculations;

[0019] —Pressure difference across the orifice, MPa;

[0020] —Fluid density, kg / m³ 3 .

[0021] The beneficial effects of this application are as follows:

[0022] By applying this sled hydraulic retraction and deployment device, the aircraft sled device can be retracted and deployed, and the synchronization of the retraction and deployment of the left and right sleds can be ensured. This enables the aircraft to switch between sled and wheel landing, allowing it to take off and land on icy and snowy roads as well as on hard paved surfaces such as sand and gravel. This expands the mission configuration and improves the aircraft's performance. Attached Figure Description

[0023] Figure 1 is a schematic diagram of the structure of this device.

[0024] The system includes: hydraulic oil tank 1, hydraulic pump 2, check valve 3, hydraulic oil filter 4, two-position three-way solenoid valve 5, pressure sensor 6, pressure regulating valve 7, three-position four-way solenoid valve 8, front sled throttle valve 9, left sled throttle valve 10, right sled throttle valve 11, and supplies power to the front sled actuator 12, left sled actuator 13, and right sled actuator 14. Embodiments of the present invention

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be described in more detail below. In the examples, the same or similar reference numerals denote the same or similar components or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this invention. The embodiments described below with reference to reference are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below.

[0026] Hydraulic oil tank 1 is connected to hydraulic pump 2. Hydraulic pump 2 is connected to check valve 3. Check valve 3 is connected to hydraulic oil filter 4. Hydraulic oil filter 4 is connected to the pressure port P of two-position three-way solenoid valve 5. The working port A of two-position three-way solenoid valve 5 is connected to the inlet port of pressure sensor 6 and pressure regulating valve 7. The return port O of two-position three-way solenoid valve 5 is connected to hydraulic oil tank 1 and the return port of pressure regulating valve 7. Pressure sensor 6 is connected to the pressure port P of pressure regulating valve 7 and three-position four-way solenoid valve 8. Pressure regulating valve 7 is connected to hydraulic oil tank 1. The return port O of the three-position four-way solenoid valve 8 is connected to the hydraulic oil tank 1. The working port A of the three-position four-way solenoid valve 8 is connected to the front sled throttle valve 9, the left sled throttle valve 10, and the right sled throttle valve 11. The working port B of the three-position four-way solenoid valve 8 is connected to the front sled actuator 12, the left sled actuator 13, and the right sled actuator 14. The front sled throttle valve 9 is connected to the front sled actuator 12, the left sled throttle valve 10 is connected to the left sled actuator 13, and the right sled throttle valve 11 is connected to the right sled actuator 14.

[0027] In one embodiment of the present invention, pressure sensor 6 is used to monitor the pressure of the sled retraction and deployment system; check valve 3 is used to prevent damage to the hydraulic pump in case of overload; oil filter 4 is used to filter impurities in the hydraulic fluid of the sled retraction and deployment system, ensuring the normal operation of the two-position two-way solenoid valve 5 and the three-position four-way solenoid valve 8; two-position three-way solenoid valve 5 is used to control the on / off of the hydraulic circuit of the sled retraction and deployment system; three-position four-way solenoid valve 8 is used to switch the corresponding pressure supply circuit to the three sled retraction and deployment actuators when the sled is raised / lowered; and pressure regulating valve 7 is used to adjust the hydraulic fluid of the sled retraction and deployment system. The system pressure is controlled to prevent overpressure and provide protection. The front sled throttle valve 9, left sled throttle valve 10, and right sled throttle valve 11 are used to regulate the flow rate of the pressure supply line of the sled retraction and extension actuator to ensure the timing and synchronization of the retraction and extension of the three sleds. The front sled actuator 12 is used to drive the front sled to ensure that the front sled retraction / extension / lowering reaches the predetermined position. The left sled actuator 13 is used to drive the left sled to ensure that the left sled retraction / extension / lowering reaches the predetermined position. The right sled actuator 14 is used to drive the right sled to ensure that the right sled retraction / extension / lowering reaches the predetermined position.

[0028] In one embodiment of the present invention, when the sled retraction action is performed, the two-position three-way solenoid valve 5 connects the hydraulic pump 2 to the oil circuit of the three-position four-way solenoid valve 8. The three-position four-way solenoid valve 8 is in the "retract" position. The hydraulic pump 2 draws oil from the hydraulic oil tank 1. The pressurized oil passes through the check valve 3, hydraulic oil filter 4, two-position three-way solenoid valve 5, pressure sensor 6, pressure regulating valve 7, three-position four-way solenoid valve 8, front sled throttle valve 9, left sled throttle valve 10, and right sled throttle valve 11, and supplies the front sled actuator 12, left sled actuator 13, and right sled actuator 14. The front, left, and right sled actuators simultaneously drive the front, left, and right sleds to retract and reach the predetermined position and lock. After the three sleds are locked, the two-position three-way solenoid valve 5 disconnects the hydraulic pump 2 from the oil circuit of the three-position four-way solenoid valve 8. The three-position four-way solenoid valve 8 is in the "neutral" position and connected to the hydraulic oil tank 1.

[0029] In one embodiment of the present invention, when the sled is lowered, the two-position three-way solenoid valve 5 connects the hydraulic pump 2 to the three-position four-way solenoid valve 8. The three-position four-way solenoid valve 8 is in the "release" position. The hydraulic pump 2 draws oil from the hydraulic oil tank 1. The pressurized oil passes through the check valve 3, hydraulic oil filter 4, two-position three-way solenoid valve 5, pressure sensor 6, pressure regulating valve 7, three-position four-way solenoid valve 8, front sled throttle valve 9, left sled throttle valve 10, and right sled throttle valve 11, and supplies the front sled actuator 12, left sled actuator 13, and right sled actuator 14. The front sled actuator 12, left sled actuator 13, and right sled actuator 14 simultaneously drive the front, left, and right sleds to retract to the predetermined position and lock. After the three sleds are locked, the two-position three-way solenoid valve 5 disconnects the hydraulic pump 2 from the hydraulic pump 2 to the three-position four-way solenoid valve 8. The three-position four-way solenoid valve 8 is in the "neutral" position and connected to the hydraulic oil tank 1.

[0030] In one embodiment of the present invention, a simulation model of the sled deployment and take-off system is established in simulation software. Based on the load under different flight conditions, the displacement versus time curves are obtained to determine the flow range of the adjustable throttle valve. The flow area range of the throttle valve is calculated according to the orifice throttling formula, and the flow area range is used as the flow regulation requirement of the adjustable throttle valve.

[0031] In one embodiment of the present invention, the orifice throttling formula is as follows:

[0032]

[0033] In the formula: —Area of ​​the small hole, mm 2 ;

[0034] —Flow rate through the orifice, L / min;

[0035] —The flow coefficient is usually taken as 0.6 to 0.61 in approximate calculations;

[0036] —Pressure difference across the orifice, MPa;

[0037] —Fluid density, kg / m³ 3 .

[0038] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Within the spirit and principles of the present invention, any person skilled in the art may use the disclosed technical content to make changes or modifications to create equivalent embodiments applicable to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, any modifications, equivalent substitutions, improvements, etc., should be included within the protection scope of the present invention.

Claims

1. A hydraulic retraction and deployment device for aircraft sleds, characterized in that, The hydraulic oil tank is connected to the hydraulic pump, the hydraulic pump is connected to the check valve, the check valve is connected to the hydraulic oil filter, the hydraulic oil filter is connected to the pressure port P of the two-position three-way solenoid valve, the working port A of the two-position three-way solenoid valve is connected to the pressure sensor and the inlet of the pressure regulating valve, and the return port O of the two-position three-way solenoid valve is connected to the hydraulic oil tank and the return port of the pressure regulating valve. The pressure sensor is connected to the pressure port P of the pressure regulating valve and the three-position four-way solenoid valve, the pressure regulating valve is connected to the hydraulic oil tank, the return port O of the three-position four-way solenoid valve is connected to the hydraulic oil tank, the working port A of the three-position four-way solenoid valve is connected to the front sled throttle valve, the left sled throttle valve, and the right sled throttle valve respectively, the working port B of the three-position four-way solenoid valve is connected to the front sled actuator, the left sled actuator, and the right sled actuator respectively, the front sled throttle valve is connected to the front sled actuator, the left sled throttle valve is connected to the left sled actuator, and the right sled throttle valve is connected to the right sled actuator.

2. The apparatus as claimed in claim 1, characterized in that, Pressure sensors are used to monitor the pressure of the sled deployment and take-off system. Check valves are used to prevent damage to the hydraulic pump in case of overload. Oil filters are used to filter impurities in the hydraulic fluid of the sled deployment and take-off system, ensuring the normal operation of the two-position two-way solenoid valve and the three-position four-way solenoid valve. Two-position three-way solenoid valves are used to control the opening and closing of the hydraulic circuit of the sled deployment and take-off system.

3. The apparatus as described in claim 1, characterized in that, The three-position four-way solenoid valve is used to switch the corresponding pressure supply circuit to the three sled retraction and extension actuators when the sled is raised / lowered. The pressure regulating valve is used to adjust the pressure of the sled retraction and extension hydraulic system.

4. The apparatus as claimed in claim 1, characterized in that, The front sled throttle valve, left sled throttle valve, and right sled throttle valve are used to regulate the flow rate of the pressure supply line of the sled retraction and extension actuator cylinder to ensure the timing and synchronization of the retraction and extension of the three sleds.

5. The apparatus as claimed in claim 1, characterized in that, The front sled actuator is used to drive the front sled, ensuring that the front sled is retracted / lowered to the predetermined position. The left sled actuator is used to drive the left sled, ensuring that the left sled is retracted / lowered to the predetermined position. The right sled actuator is used to drive the right sled, ensuring that the right sled is retracted / lowered to the predetermined position.

6. The apparatus as claimed in claim 1, characterized in that, When the sled retraction action is performed, the two-position three-way solenoid valve connects the hydraulic pump to the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "retract" position. The hydraulic pump draws oil from the hydraulic oil tank. The pressurized oil passes through the check valve, hydraulic oil filter, two-position three-way solenoid valve, pressure sensor, pressure regulating valve, three-position four-way solenoid valve, front sled throttle valve, left sled throttle valve, and right sled throttle valve, and supplies the front sled actuator, left sled actuator, and right sled actuator to the front sled actuator, left sled actuator, and right sled actuator. The front, left, and right sled actuators simultaneously drive the front, left, and right sleds to retract to the predetermined position and lock. After the three sleds are locked, the two-position three-way solenoid valve disconnects the hydraulic pump from the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "neutral" position and connected to the hydraulic oil tank.

7. The apparatus as claimed in claim 1, characterized in that, When the sled is lowered, the two-position three-way solenoid valve connects the hydraulic pump to the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "release" position. The hydraulic pump draws oil from the hydraulic oil tank. The pressurized oil passes through the check valve, hydraulic oil filter, two-position three-way solenoid valve, pressure sensor, pressure regulating valve, three-position four-way solenoid valve, front sled throttle valve, left sled throttle valve, and right sled throttle valve, and supplies the front sled actuator, left sled actuator, and right sled actuator to the front sled actuator, left sled actuator, and right sled actuator. The front sled actuator, left sled actuator, and right sled actuator simultaneously drive the front, left, and right sleds to retract to the predetermined position and lock. After the three sleds are locked, the two-position three-way solenoid valve disconnects the hydraulic pump from the three-position four-way solenoid valve. The three-position four-way solenoid valve is in the "neutral" position and connected to the hydraulic oil tank.

8. The apparatus as claimed in claim 1, characterized in that, A simulation model of the sled deployment and take-off system is established in simulation software. Based on the load under different flight conditions, the displacement versus time curves are obtained to determine the flow range of the adjustable throttle valve. The flow area range of the throttle valve is calculated according to the orifice throttling formula, and the flow area range is used as the flow regulation requirement of the adjustable throttle valve.

9. The apparatus as claimed in claim 8, characterized in that, The formula for orifice throttling is: In the formula: —Area of ​​the small hole, mm 2 ; —Flow rate through the orifice, L / min; —The flow coefficient is usually taken as 0.6 to 0.61 in approximate calculations; —Pressure difference across the orifice, MPa; —Fluid density, kg / m³ 3 .

Images