Undercarriage folding and discharging actuator cylinder with emergency stretching function

Abstract

The utility model belongs to the field of aircraft actuating cylinders, and relates to an undercarriage folding and discharging actuating cylinder with an emergency stretching function. The actuator cylinder comprises an internal link rod, an external link rod, an elastic piece, a small ball, a sliding sleeve, a valve and a high-pressure gas cylinder. The external connecting rod is divided into a large section and a small section, the internal connecting rod is sleeved with the large section, the end, close to the small section, of the internal connecting rod is sleeved with the sliding sleeve, the sliding sleeve is of a step type rotary metal structure and is divided into a large end and a small end through a step, the small end right faces the small section, and the small ball is installed between the large end and the external connecting rod. An avoiding structure for avoiding the small ball is arranged on the internal connecting rod; in a structural cavity formed by the internal connecting rod, the external connecting rod and the sliding sleeve, the internal connecting rod and the external connecting rod are integrated; a large-end port of the sliding sleeve is connected with one end of the elastic piece, the other end of the elastic piece is fixedly connected with the internal link rod, a small-end port of the sliding sleeve and the external link rod form a fluid medium cavity, and the fluid medium cavity is connected with the valve and the high-pressure gas cylinder.

Description

Technical Field

[0001] The invention belongs to the field of aircraft actuators, and relates to a landing gear retraction and discharge actuator with an emergency extension function. Background Art

[0002] To reduce drag during flight, the landing gear should be stowed inside the cabin and lowered when the aircraft lands. Currently, the mainstream landing gear retraction and extension method uses a hydraulic actuator to extend or retract the gear. However, hydraulic pressure has disadvantages such as leakage, complex pipeline structures, and high maintenance workload. There is also some research on replacing hydraulic actuators with electric actuators to drive landing gear retraction and extension, but this is only used on some small UAVs. This is because in the event of a failure, the hydraulic actuator can bypass the actuator hydraulic pipeline and rely on the gravity, inertia, and aerodynamic forces of the landing gear to cause emergency landing. Electric actuators, on the other hand, have a failure mode of leadscrew jamming, which is a single point of failure for electric actuators and can cause the landing gear to fail to extend (in the most serious case, if the electric actuator fails during the extension process and cannot continue to work, the landing gear will not be fully extended and cannot be retracted). This seriously affects the safety of the aircraft. These shortcomings have led to the current use of electric landing gear actuators on only some small UAVs. Summary of the Invention

[0003] The present invention provides an electric actuator for driving the retraction and extension of a landing gear, which can be released in an emergency in the event of a fault to control the lowering of the landing gear and ensure the safe landing of an aircraft.

[0004] Technical solution:

[0005] Provided is a landing gear retraction and discharge actuator with an emergency extension function, comprising: an internal connecting rod, an external connecting rod, an elastic member, a small ball, a sliding sleeve, a valve, and a high-pressure gas cylinder;

[0006] The external connecting rod is divided into a large section and a small section, the large section is covered with an internal connecting rod, and the end of the internal connecting rod close to the small section is covered with a sliding sleeve. The sliding sleeve is a stepped rotating metal structure, and the sliding sleeve is divided into a large end and a small end by a step. The small end is opposite to the small section, and a small ball is installed between the large end and the external connecting rod; a avoidance structure for avoiding the small ball is provided on the internal connecting rod; in the structural chamber composed of the internal connecting rod, the external connecting rod and the sliding sleeve, the internal connecting rod and the external connecting rod are integrated into one body; the large end port of the sliding sleeve is connected to one end of the elastic part, and the other end of the elastic part is fixedly connected to the internal connecting rod, and the small end port of the sliding sleeve and the external connecting rod form a fluid medium cavity, and the fluid medium cavity is connected to the valve and the high-pressure gas cylinder.

[0007] Furthermore, the elastic member is a spring.

[0008] Furthermore, the small ball is a steel ball.

[0009] Furthermore, the valve is opened and closed by a cable.

[0010] Furthermore, the valve is opened and closed by a steel cable.

[0011] Furthermore, when the landing gear is normally retracted and extended, the internal connecting rod and the external connecting rod combination of the electric actuator normally complete the extension and retraction action. At this time, the valve is locked and there is no air in the flow medium cavity.

[0012] When the landing gear is stuck in retraction and extension, the valve opens after receiving the signal and releases the medium in the high-pressure gas cylinder into the flow medium chamber. The rapid increase of high-pressure medium compresses the spring and drives the sleeve to move axially. The steel ball is released as the sleeve moves, and the connection between the internal connecting rod and the external connecting rod is released. The internal connecting rod is released in an emergency under the thrust of the continuous filling of high-pressure medium.

[0013] Beneficial effects:

[0014] A landing gear retraction and retraction actuator with an emergency release function is provided. During normal operation, the electric mechanism is energized to release and retract to control the landing gear. In the event of a fault or power failure, the electric mechanism can be released in an emergency to lower the landing gear and ensure the safe landing of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure is a structural schematic diagram of a landing gear retraction and discharge actuator cylinder with an emergency extension function according to the present invention.

[0016] Among them, 1—internal connecting rod; 2—external connecting rod; 3—spring; 4—steel ball; 5—sleeve; 6—cable (or steel rope); 7—valve; 8—high-pressure gas cylinder.

[0017] Figure 2 It is a schematic diagram of the movement of the present invention in an emergency state. DETAILED DESCRIPTION

[0018] The following structural diagram ( Figure 1 ) and motion diagram ( Figure 2 ) A landing gear retraction and discharge actuator with an emergency extension function is described in detail, including:

[0019] Internal connecting rod 1, external connecting rod 2, spring 3, steel ball 4, sliding sleeve 5, valve 7, high-pressure gas cylinder 8;

[0020] The external connecting rod 2 is divided into a large section and a small section. The internal connecting rod 1 is sleeved in the large section. The end of the internal connecting rod 1 close to the small section is sleeved with a sliding sleeve 5. The sliding sleeve 5 is a stepped rotating metal structure. The sliding sleeve 5 is divided into a large end and a small end by a step. The small end is opposite to the small section, and a steel ball 4 is installed between the large end and the external connecting rod 2; a avoidance structure for avoiding the steel ball 4 is provided on the internal connecting rod 1; in the structural chamber composed of the internal connecting rod 1, the external connecting rod 2 and the sliding sleeve 5, the internal connecting rod 1 and the external connecting rod 2 are integrated; the large end port of the sliding sleeve 5 is connected to one end of the spring 3, and the other end of the spring 3 is fixedly connected to the internal connecting rod, and the small end port of the sliding sleeve and the external connecting rod 2 form a fluid medium cavity, and the fluid medium cavity is connected to the valve 7 and the high-pressure gas cylinder 8.

[0021] The valve 7 is switched on and off via a cable or a steel rope 6 .

[0022] The steel ball 4 is installed in the structural chamber composed of the internal connecting rod 1, the external connecting rod 2 and the sliding sleeve 5, fixing the internal connecting rod 1 and the external connecting rod 2 into a whole; the sliding sleeve 5 is a stepped rotating metal structure, the left end face of which is connected to the spring 3, the other end of the spring 3 is fixedly connected to the internal connecting rod, and the right end face and the external connecting rod 2 form a fluid medium chamber, and the cavity is connected to the valve 7 and the high-pressure gas cylinder 8.

[0023] When the landing gear is normally retracted and extended, the combination of the inner link 1 and the outer link 2 of the electric actuator completes the extension and retraction action normally. At this time, the valve is locked and there is no air in the flow medium cavity.

[0024] When the landing gear is stuck in retraction and extension (the electric actuator is the screw stuck), the valve 7 opens after receiving the signal and releases the medium in the high-pressure gas cylinder 8 to fill the flow medium cavity. The rapid increase of the high-pressure medium compresses the spring 3 and drives the sleeve 5 to move axially. The steel ball 4 is released as the sleeve 5 moves, and the connection between the internal connecting rod 1 and the external connecting rod 2 is released. The internal connecting rod is released in an emergency under the thrust of the continuous filling of the high-pressure medium.

[0025] The present invention provides a landing gear retraction and retraction actuator with an emergency release function. During normal operation, the electric mechanism is energized to release and retract to control the lowering and retraction of the landing gear. In the event of a fault or power failure, the electric mechanism can be released in an emergency to lower the landing gear, thereby ensuring the safe landing of the aircraft.

Claims

1. A landing gear retraction and discharge actuator with emergency extension function, characterized in that: include: Internal connecting rod (1), external connecting rod (2), elastic member, small ball, sliding sleeve (5), valve (7), high-pressure gas cylinder (8); The external connecting rod (2) is divided into a large section and a small section. The internal connecting rod (1) is sleeved in the large section. The end of the internal connecting rod (1) close to the small section is sleeved with a sliding sleeve (5). The sliding sleeve (5) is a stepped rotating body metal structure. The sliding sleeve (5) is divided into a large end and a small end by a step. The small end faces the small section. A small ball is installed between the large end and the external connecting rod (2). A avoidance structure for avoiding the small ball is provided on the internal connecting rod (1). In a structural chamber composed of the internal connecting rod (1), the external connecting rod (2) and the sliding sleeve (5), the internal connecting rod (1) and the external connecting rod (2) are integrated. The large end of the sliding sleeve (5) is connected to one end of an elastic member, and the other end of the elastic member is fixedly connected to the internal connecting rod. The small end of the sliding sleeve and the external connecting rod (2) form a fluid medium chamber, and the fluid medium chamber is connected to a valve (7) and a high-pressure gas cylinder (8).

2. The electric actuator according to claim 1, characterized in that: The elastic member is a spring (3).

3. The electric actuator according to claim 1, characterized in that: The small ball is a steel ball (4).

4. The electric actuator according to claim 1, characterized in that: The valve (7) is switched on and off via a cable.

5. The electric actuator according to claim 1, characterized in that: The valve (7) is opened and closed by a steel cable.

6. The electric actuator according to claim 2, characterized in that: When the landing gear is normally retracted and extended, the internal and external connecting rods of the electric actuator complete the extension and retraction actions normally. At this time, the valve is locked and there is no air in the flow medium cavity. When the landing gear is stuck in retraction and extension, the valve opens after receiving the signal and releases the medium in the high-pressure gas cylinder into the flow medium chamber. The rapid increase of high-pressure medium compresses the spring and drives the sleeve to move axially. The steel ball is released as the sleeve moves, and the connection between the internal connecting rod and the external connecting rod is released. The internal connecting rod is released in an emergency under the thrust of the continuous filling of high-pressure medium.

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