Automatic feathering control device for propellers of double-engine aircraft

Abstract

The invention belongs to the technical field of propellers, and discloses a double-engine aircraft propeller automatic feathering control device which comprises a second engine automatic feathering electromagnetic valve and a first engine automatic feathering electromagnetic valve, and the second engine automatic feathering electromagnetic valve and the first engine automatic feathering electromagnetic valve are connected through a circuit. When one of the second engine automatic feathering electromagnetic valve and the first engine automatic feathering electromagnetic valve works, the other one is in a disconnected state. By means of the design, the automatic feathering system of the double-engine aircraft can only execute automatic feathering of one propeller at the same time, and the flight safety of the aircraft is improved; compared with an original design system, only line change is involved, no additional device is added, and it is guaranteed that the cost of the aircraft is controllable.

Description

Technical Field

[0001] The invention belongs to the technical field of propellers, and relates to a propeller control device for a twin-engine aircraft, and in particular to an automatic propeller feathering control device for a twin-engine aircraft. Background Art

[0002] The original twin-engine aircraft propeller feathering control method and logic are as follows:

[0003] Before starting, set the automatic propeller control switch 1 to the "off (II)" position. When the two power levers are pushed forward to reach the microswitch connection threshold, the No. 2 engine power microswitch 4 and the No. 1 engine power microswitch 5 are both connected. As the engine torque increases, the No. 2 engine low torque microswitch 12, the No. 1 engine low torque microswitch 13, the No. 2 engine high torque microswitch 6, and the No. 1 engine high torque microswitch 7 are successively connected.

[0004] After the dual engines are stable, the automatic propeller feathering control switch 1 is placed in the "Ready (III)" position, the No. 2 engine low torque micro switch 12, the No. 1 engine low torque micro switch 13, the No. 2 engine high torque micro switch 6, and the No. 1 engine high torque micro switch 7 are powered on, and the No. 2 engine automatic propeller feathering relay 2 and the No. 1 engine automatic propeller feathering relay 3 are powered on. At this time, the No. 2 engine automatic propeller feathering indicator light 8 and the No. 1 engine automatic propeller feathering indicator light 9 are both lit, indicating that the No. 1 engine and No. 2 engine automatic propeller feathering control systems are in the ready state.

[0005] For engine No. 1, if the torque of engine No. 1 drops to the disconnection value of engine No. 1 high torque micro switch 7 due to a fault, the automatic propeller-feathering relay 3 of engine No. 1 is de-energized and disconnected, and the negative line of the automatic propeller-feathering electromagnetic valve 11 of engine No. 1 is connected. If the torque continues to drop below the disconnection value of engine No. 1 low torque micro switch 13, the automatic propeller-feathering indicator light 9 of engine No. 1 goes out, and the positive line of the automatic propeller-feathering electromagnetic valve 11 of engine No. 1 is connected, and the propeller of engine No. 1 is feathered.

[0006] At this time, the propeller of engine No. 2 is still in standby status. If the high-torque microswitch 6 and the low-torque microswitch 12 of engine No. 2 are disconnected at the same time due to a malfunction, the automatic propeller-feathering solenoid valve 12 of engine No. 2 will be connected, causing unexpected propeller feathering of engine No. 2 and a bleed air flight disaster.

[0007] For engine No. 2, the control logic is the same as that of engine No. 1.

[0008] The above control has the following disadvantages:

[0009] 1. The original twin-engine propeller automatic feathering systems are independent of each other. When one engine propeller is automatically feathered, the other engine propeller is still in the automatic feathering preparation state. Under certain fault conditions, it may cause the engine propeller to feather unexpectedly, resulting in a bleed air flight disaster.

[0010] 2. When the torque of one engine drops below the high torque switch disconnection threshold, the propeller automatic feathering indicator lights of the two engines will still indicate the automatic feathering preparation state. The automatic feathering preparation state indication will only stop when the torque drops below the low torque switch disconnection threshold, resulting in an indication lag. Summary of the invention

[0011] In order to solve the above problems, the present invention provides a twin-engine aircraft propeller automatic feathering control device. The use of the device enables the twin-engine aircraft's automatic feathering system to perform automatic feathering of only one propeller at a time, thereby improving the safety of aircraft flight.

[0012] The technical solution of the present invention is as follows:

[0013] A twin-engine aircraft propeller automatic feathering control device comprises a No. 2 engine automatic feathering electromagnetic valve and a No. 1 engine automatic feathering electromagnetic valve. The No. 2 engine automatic feathering electromagnetic valve and the No. 1 engine automatic feathering electromagnetic valve are connected by a circuit so that when one of the No. 2 engine automatic feathering electromagnetic valve and the No. 1 engine automatic feathering electromagnetic valve is in operation, the other is in a disconnected state.

[0014] Furthermore, it includes an automatic propeller-feathering switch, an automatic propeller-feathering relay for engine No. 2, an automatic propeller-feathering relay for engine No. 1, a low-torque microswitch for engine No. 2 and an automatic propeller-feathering indicator light for engine No. 2; after the automatic propeller-feathering switch is turned on, when the automatic propeller-feathering relay for engine No. 1 is turned on, the power supply is connected to the low-torque microswitch for engine No. 2 through the contact connected when the automatic propeller-feathering relay for engine No. 1 is turned on, the low-torque microswitch for engine No. 2 selects the automatic propeller-feathering indicator light for engine No. 2 and the automatic propeller-feathering electromagnetic valve for engine No. 2, the other side of the automatic propeller-feathering electromagnetic valve for engine No. 2 is connected to the negative pole through the contact connected when the automatic propeller-feathering relay for engine No. 2 is disconnected; the other end of the automatic propeller-feathering indicator light for engine No. 2 is connected to the negative pole.

[0015] Furthermore, the No. 2 engine low torque micro switch is a switch that is opened and closed according to the torque of the No. 2 engine. When the torque of the No. 2 engine is lower than the set value, the No. 2 engine low torque micro switch turns on the No. 2 engine automatic propeller feathering solenoid valve; when the torque of the No. 2 engine is higher than the set value, the No. 2 engine low torque micro switch turns on the No. 2 engine automatic propeller feathering indicator light.

[0016] Furthermore, it also includes a high-torque microswitch for engine No. 1, which controls whether the automatic propeller-feathering relay of engine No. 1 is connected. Specifically, when the torque of engine No. 1 is higher than the set value, the high-torque microswitch of engine No. 1 controls the automatic propeller-feathering relay of engine No. 1 to be in the connected state; when the torque of engine No. 1 is lower than the set value, the high-torque microswitch of engine No. 1 controls the automatic propeller-feathering relay of engine No. 1 to be in the disconnected state.

[0017] Furthermore, it includes a low torque micro switch for engine No. 1 and an automatic propeller-feathering indicator light for engine No. 1; after the automatic propeller-feathering switch is turned on, when the automatic propeller-feathering relay for engine No. 2 is turned on, the power supply is connected to the low torque micro switch for engine No. 1 through the contact connected when the automatic propeller-feathering relay for engine No. 2 is turned on, the low torque micro switch for engine No. 1 selects the automatic propeller-feathering indicator light for engine No. 1 and the automatic propeller-feathering electromagnetic valve for engine No. 1, and the other side of the automatic propeller-feathering electromagnetic valve for engine No. 1 is connected to the negative pole through the contact connected when the automatic propeller-feathering relay for engine No. 1 is disconnected; the other end of the automatic propeller-feathering indicator light for engine No. 1 is connected to the negative pole.

[0018] Furthermore, the No. 1 engine low torque micro switch is a switch that is opened and closed according to the torque of the No. 1 engine. When the torque of the No. 1 engine is lower than the set value, the No. 1 engine low torque micro switch turns on the No. 1 engine automatic propeller feathering solenoid valve; when the torque of the No. 1 engine is higher than the set value, the No. 1 engine low torque micro switch turns on the No. 1 engine automatic propeller feathering indicator light.

[0019] Furthermore, it also includes a high-torque microswitch for engine No. 2, which controls whether the automatic propeller-feathering relay of engine No. 2 is connected. Specifically, when the torque of engine No. 2 is higher than the set value, the high-torque microswitch of engine No. 2 controls the automatic propeller-feathering relay of engine No. 2 to be in the connected state; when the torque of engine No. 2 is lower than the set value, the high-torque microswitch of engine No. 2 controls the automatic propeller-feathering relay of engine No. 1 to be in the disconnected state.

[0020] Furthermore, it also includes a No. 2 engine power micro switch and a No. 1 engine power micro switch, and the No. 2 engine power micro switch and the No. 1 engine power micro switch are arranged between the automatic propeller feathering switch and the subsequent circuit.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The design of the present invention enables the automatic propeller feathering system of a twin-engine aircraft to perform automatic propeller feathering of only one propeller at a time, thereby improving the safety of aircraft flight.

[0023] 2. Compared with the original design system, the present invention only involves changes in the circuits without adding any additional components, thus ensuring that the cost of the aircraft is controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the implementation method of the patent of the present invention, the following is a brief introduction to the drawings required for use in the implementation method. It should be understood that the following drawings only show certain embodiments of the patent of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the automatic feathering control of the present invention;

[0026] Figure 2 It is the original automatic feathering control principle diagram in the background technology;

[0027] Among them, 1—automatic propeller feathering switch, 2—automatic propeller feathering relay of engine No. 2, 3—automatic propeller feathering relay of engine No. 1, 4—power microswitch of engine No. 2, 5—power microswitch of engine No. 1, 6—high torque microswitch of engine No. 2, 7—high torque microswitch of engine No. 1, 8—automatic propeller feathering indicator light of engine No. 2, 9—automatic propeller feathering indicator light of engine No. 1, 10—automatic propeller feathering solenoid valve of engine No. 2, 11—automatic propeller feathering solenoid valve of engine No. 1, 12—low torque microswitch 12 of engine No. 2, 13—low torque microswitch of engine No. 1. DETAILED DESCRIPTION

[0028] This section is an embodiment of the present invention, which is used to explain and illustrate the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships as given in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or case referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be interpreted in a broad sense, for example, it can be a fixed connection, a detachable connection or an integrated connection; it can be a mechanical connection or a point connection; it can be a direct connection or a connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0031] Embodiment 1:

[0032] A twin-engine aircraft propeller automatic feathering control device comprises a No. 2 engine automatic feathering electromagnetic valve 10 and a No. 1 engine automatic feathering electromagnetic valve 11. The No. 2 engine automatic feathering electromagnetic valve 10 and the No. 1 engine automatic feathering electromagnetic valve 11 are connected by a circuit so that when one of the No. 2 engine automatic feathering electromagnetic valve 10 and the No. 1 engine automatic feathering electromagnetic valve 11 is in operation, the other is in a disconnected state.

[0033] It includes an automatic propeller-feathering switch 1, an automatic propeller-feathering relay 2 for engine No. 2, an automatic propeller-feathering relay 3 for engine No. 1, a low-torque microswitch 12 for engine No. 2 and an automatic propeller-feathering indicator light 8 for engine No. 2; after the automatic propeller-feathering switch 1 is turned on, when the automatic propeller-feathering relay 3 for engine No. 1 is turned on, the power supply is connected to the low-torque microswitch 12 for engine No. 2 through the contact connected when the automatic propeller-feathering relay 3 for engine No. 1 is turned on, the low-torque microswitch 12 for engine No. 2 selectively connects the automatic propeller-feathering indicator light 8 for engine No. 2 and the automatic propeller-feathering electromagnetic valve 10 for engine No. 2, the other side of the automatic propeller-feathering electromagnetic valve 10 for engine No. 2 is connected to the negative pole through the contact connected when the automatic propeller-feathering relay 2 for engine No. 2 is disconnected; the other end of the automatic propeller-feathering indicator light 8 for engine No. 2 is connected to the negative pole.

[0034] The No. 2 engine low torque micro switch 12 is a switch that is opened and closed according to the torque of the No. 2 engine. When the torque of the No. 2 engine is lower than the set value, the No. 2 engine low torque micro switch 12 connects the No. 2 engine automatic propeller-feathering electromagnetic valve 10; when the torque of the No. 2 engine is higher than the set value, the No. 2 engine low torque micro switch 12 connects the No. 2 engine automatic propeller-feathering indicator light 8.

[0035] It also includes a No. 1 engine high torque micro switch 7, which controls whether the No. 1 engine automatic propeller-feathering relay 3 is connected. Specifically, when the torque of the No. 1 engine is higher than the set value, the No. 1 engine high torque micro switch 7 controls the No. 1 engine automatic propeller-feathering relay 3 to be in the connected state; when the torque of the No. 1 engine is lower than the set value, the No. 1 engine high torque micro switch 7 controls the No. 1 engine automatic propeller-feathering relay 3 to be in the disconnected state.

[0036] It includes a No. 1 engine low torque micro switch 13 and a No. 1 engine automatic propeller-feathering indicator light 9; after the automatic propeller-feathering switch 1 is turned on, when the No. 2 engine automatic propeller-feathering relay 2 is turned on, the power supply is connected to the No. 1 engine low torque micro switch 13 through the contact connected when the No. 2 engine automatic propeller-feathering relay 2 is turned on, and the No. 1 engine low torque micro switch 13 selectively connects the No. 1 engine automatic propeller-feathering indicator light 9 and the No. 1 engine automatic propeller-feathering electromagnetic valve 11, and the other side of the No. 1 engine automatic propeller-feathering electromagnetic valve 11 is connected to the negative pole through the contact connected when the No. 1 engine automatic propeller-feathering relay 3 is disconnected; the other end of the No. 1 engine automatic propeller-feathering indicator light 9 is connected to the negative pole.

[0037] The No. 1 engine low torque micro switch 13 is a switch that is opened and closed according to the torque of the No. 1 engine. When the torque of the No. 1 engine is lower than the set value, the No. 1 engine low torque micro switch 13 connects the No. 1 engine automatic propeller-feathering electromagnetic valve 11; when the torque of the No. 1 engine is higher than the set value, the No. 1 engine low torque micro switch 13 connects the No. 1 engine automatic propeller-feathering indicator light 9.

[0038] It also includes a high-torque microswitch 6 for engine No. 2, which controls whether the automatic propeller-feathering relay 2 for engine No. 2 is connected. Specifically, when the torque of engine No. 2 is higher than the set value, the high-torque microswitch 6 for engine No. 2 controls the automatic propeller-feathering relay 2 for engine No. 2 to be in the connected state; when the torque of engine No. 2 is lower than the set value, the high-torque microswitch 6 for engine No. 2 controls the automatic propeller-feathering relay 2 for engine No. 1 to be in the disconnected state.

[0039] It also includes a No. 2 engine power micro switch 4 and a No. 1 engine power micro switch 5, and the No. 2 engine power micro switch 4 and the No. 1 engine power micro switch 5 are arranged between the automatic propeller feathering switch 1 and the subsequent circuit.

[0040] Embodiment 2:

[0041] An automatic propeller feathering control circuit, the control circuit comprising an automatic propeller feathering switch 1, an automatic propeller feathering relay 2 for engine No. 2, an automatic propeller feathering relay 3 for engine No. 1, a power microswitch 4 for engine No. 2, a power microswitch 5 for engine No. 1, a high torque microswitch 6 for engine No. 2, a high torque microswitch 7 for engine No. 1, an automatic propeller feathering electromagnetic valve 10 for engine No. 2, an automatic propeller feathering electromagnetic valve 11 for engine No. 1, an automatic propeller feathering indicator light 8 for engine No. 2, an automatic propeller feathering indicator light 9 for engine No. 1, a low torque microswitch 12 for engine No. 2, and a low torque microswitch 13 for engine No. 1. The invention is characterized in that the power line of the automatic propeller-feathering electromagnetic valve 11 of the No. 1 engine is connected to the automatic propeller-feathering relay 2 of the No. 2 engine, and the power line of the automatic propeller-feathering electromagnetic valve 10 of the No. 2 engine is connected to the automatic propeller-feathering relay 3 of the No. 1 engine, so that when the automatic propeller-feathering electromagnetic valve 11 of the No. 1 engine is powered on, the power line of the automatic propeller-feathering electromagnetic valve 10 of the No. 2 engine is disconnected, and when the automatic propeller-feathering electromagnetic valve 10 of the No. 2 engine is powered on, the power line of the automatic propeller-feathering electromagnetic valve 11 of the No. 1 engine is disconnected, so that the automatic propeller-feathering system of the twin-engine aircraft can only perform the automatic propeller-feathering of one propeller at a time, thereby improving safety.

[0042] Embodiment 3:

[0043] In the specific implementation case, the automatic feathering electrical control system is composed of automatic feathering switch 1, automatic feathering relay 2 of engine No. 2, automatic feathering relay 3 of engine No. 1, power micro switch 4 of engine No. 2, power micro switch 5 of engine No. 1, high torque micro switch 6 of engine No. 2, high torque micro switch 7 of engine No. 1, automatic feathering electromagnetic valve 10 of engine No. 2, automatic feathering electromagnetic valve 11 of engine No. 1, automatic feathering indicator light 8 of engine No. 2, automatic feathering indicator light 9 of engine No. 1, low torque micro switch 12 of engine No. 2, low torque micro switch 13 of engine No. 1 and electrical circuits. It is mainly used to automatically feather the propeller of one engine to reduce resistance when it stops due to failure during takeoff.

[0044] The main functions of each component are:

[0045] Automatic feathering switch 1 is used to control the working state of automatic feathering. By flipping the switch, the working mode of the automatic feathering control system can be switched between "ready (III)", "disconnect (II)" and "test (I)";

[0046] The high torque pressure switch 6 / 7 senses the change in engine torque pressure and connects or disconnects the automatic propeller feathering control circuit of the high torque pressure switch 6 / 7;

[0047] The low torque pressure switch 12 / 13 senses the change in engine torque pressure and connects or disconnects the automatic propeller feathering control circuit of the low torque pressure switch 12 / 13;

[0048] The function of the engine power micro switch 4 / 5 is to connect the automatic propeller feathering circuit when the power levers of the two engines are above 90% Ng;

[0049] The function of the engine automatic propeller feathering solenoid valve 11 / 12 is to open and release the lubricating oil in the propeller cylinder after power is turned on, so as to feather the propeller;

[0050] The function of the engine automatic propeller feathering indicator light 8 / 9 is to indicate the working status of the engine automatic propeller feathering system;

[0051] The function of the engine automatic propeller-feathering relay 2 / 3 is to control the connection of the engine automatic propeller-feathering solenoid valve 11 / 12 and the lighting of the engine automatic propeller-feathering indicator light 8 / 9 according to the high torque pressure switch 6 / 7, the low torque pressure switch 12 / 13 and the engine power micro switch 4 / 5.

[0052] The system works as described:

[0053] When the automatic propeller feathering control switch is in the "Ready (III)" position, the two power levers are pushed forward to reach the microswitch connection threshold, the No. 2 engine power microswitch 4 and the No. 1 engine power microswitch 5 are both connected, and as the engine torque increases, the No. 2 engine low torque microswitch 12, the No. 1 engine low torque microswitch 13, the No. 2 engine high torque microswitch 6, and the No. 1 engine high torque microswitch 7 are successively connected, the No. 2 engine high torque microswitch 6 and the No. 1 engine high torque microswitch 7 are powered on, and the No. 2 engine automatic propeller feathering relay 2 and the No. 1 engine automatic propeller feathering relay 3 are powered on. At the same time, the low torque pressure switch is powered on, and the automatic propeller feathering electromagnetic valve is powered off. At this time, the No. 2 engine automatic propeller feathering indicator light 8 and the No. 1 engine automatic propeller feathering indicator light 9 are both lit to show that the No. 1 engine and No. 2 engine automatic propeller feathering control systems are in the ready state.

[0054] For engine No. 1, if the torque of engine No. 1 drops to the disconnection value of engine No. 1 high torque micro switch 7 due to a fault, the automatic propeller-feathering relay 3 of engine No. 1 is de-energized and disconnected, the circuit of engine No. 2 low torque micro switch 12 is disconnected, and the automatic propeller-feathering indicator light 8 of engine No. 2 goes out. If the torque continues to drop below the disconnection value of engine No. 1 low torque micro switch 13, the automatic propeller-feathering indicator light 9 of engine No. 1 also goes out, and the automatic propeller-feathering electromagnetic valve 11 of engine No. 1 is turned on, and the propeller of engine No. 1 is feathered.

[0055] Put the automatic propeller feathering control switch in the "Ready (III)" position. If the No. 1 engine fails for some reason during takeoff and the torque drops to a certain value, the No. 1 engine high torque micro switch 7 is disconnected, and the automatic propeller feathering system automatically feathers the corresponding propeller. At the same time, the automatic propeller feathering circuit of the other engine is disconnected to ensure that only one engine can automatically feather.

[0056] For engine No. 2, if the torque of engine No. 2 drops to the disconnection value of engine No. 2 high torque micro switch 6 due to a fault, the automatic propeller-feathering relay 2 of engine No. 2 is de-energized and disconnected, the circuit of engine No. 1 low torque micro switch 11 is disconnected, and the automatic propeller-feathering indicator light 9 of engine No. 1 goes out. If the torque continues to drop below the disconnection value of engine No. 2 low torque micro switch 12, the automatic propeller-feathering indicator light 8 of engine No. 2 also goes out, and the automatic propeller-feathering electromagnetic valve 12 of engine No. 2 is turned on, and the propeller of engine No. 2 is feathered.

[0057] Put the automatic propeller feathering control switch in the "Ready (III)" position. If the No. 2 engine fails for some reason during takeoff and the torque drops to a certain value, the No. 2 engine high torque micro switch 6 is disconnected, and the automatic propeller feathering system automatically feathers the corresponding propeller. At the same time, the automatic propeller feathering circuit of the other engine is disconnected to ensure that only one engine can automatically feather.

Claims

1. A twin-engine aircraft propeller automatic feathering control device, characterized in that: The invention comprises a No. 2 engine automatic propeller-feathering electromagnetic valve (10) and a No. 1 engine automatic propeller-feathering electromagnetic valve (11). The No. 2 engine automatic propeller-feathering electromagnetic valve (10) and the No. 1 engine automatic propeller-feathering electromagnetic valve (11) are connected by a circuit, so that when one of the No. 2 engine automatic propeller-feathering electromagnetic valve (10) and the No. 1 engine automatic propeller-feathering electromagnetic valve (11) is in operation, the other is in a disconnected state.

2. The automatic propeller feathering control device for a twin-engine aircraft according to claim 1, characterized in that: The invention comprises an automatic propeller-feathering switch (1), an automatic propeller-feathering relay (2) for a No. 2 engine, an automatic propeller-feathering relay (3) for a No. 1 engine, a low-torque microswitch (12) for a No. 2 engine and an automatic propeller-feathering indicator light (8) for a No. 2 engine. After the automatic propeller-feathering switch (1) is turned on, when the automatic propeller-feathering relay (3) for the No. 1 engine is turned on, the power source is connected to the low-torque microswitch (12) for the No. 2 engine through the contact connected when the automatic propeller-feathering relay (3) for the No. 1 engine is turned on, the low-torque microswitch (12) for the No. 2 engine is selectively connected to the automatic propeller-feathering indicator light (8) for the No. 2 engine and the automatic propeller-feathering electromagnetic valve (10) for the No. 2 engine, the other side of the automatic propeller-feathering electromagnetic valve (10) for the No. 2 engine is connected to the negative pole through the contact connected when the automatic propeller-feathering relay (2) for the No. 2 engine is turned off; the other end of the automatic propeller-feathering indicator light (8) for the No. 2 engine is connected to the negative pole.

3. The automatic propeller feathering control device for a twin-engine aircraft according to claim 2, characterized in that: The No. 2 engine low torque micro switch (12) is a switch that is turned on and off according to the torque of the No. 2 engine. When the torque of the No. 2 engine is lower than a set value, the No. 2 engine low torque micro switch (12) turns on the No. 2 engine automatic propeller-feathering electromagnetic valve (10); when the torque of the No. 2 engine is higher than a set value, the No. 2 engine low torque micro switch (12) turns on the No. 2 engine automatic propeller-feathering indicator light (8).

4. The automatic propeller feathering control device for a twin-engine aircraft according to claim 3, characterized in that: The invention also includes a No. 1 engine high torque micro switch (7), which controls whether the No. 1 engine automatic propeller-feathering relay (3) is connected. Specifically, when the torque of the No. 1 engine is higher than a set value, the No. 1 engine high torque micro switch (7) controls the No. 1 engine automatic propeller-feathering relay (3) to be in an on state; when the torque of the No. 1 engine is lower than a set value, the No. 1 engine high torque micro switch (7) controls the No. 1 engine automatic propeller-feathering relay (3) to be in an off state.

5. The automatic propeller feathering control device for a twin-engine aircraft according to claim 2, characterized in that: The invention comprises a No. 1 engine low torque micro switch (13) and a No. 1 engine automatic propeller-feathering indicator light (9); after the automatic propeller-feathering switch (1) is turned on, when the No. 2 engine automatic propeller-feathering relay (2) is turned on, the power source is connected to the No. 1 engine low torque micro switch (13) through the contact connected when the No. 2 engine automatic propeller-feathering relay (2) is turned on, the No. 1 engine low torque micro switch (13) is selectively connected to the No. 1 engine automatic propeller-feathering indicator light (9) and the No. 1 engine automatic propeller-feathering electromagnetic valve (11), and the other side of the No. 1 engine automatic propeller-feathering electromagnetic valve (11) is connected to the negative pole through the contact connected when the No. 1 engine automatic propeller-feathering relay (3) is turned off; the other end of the No. 1 engine automatic propeller-feathering indicator light (9) is connected to the negative pole.

6. The automatic propeller feathering control device for a twin-engine aircraft according to claim 5, characterized in that: The No. 1 engine low torque micro switch (13) is a switch that is turned on and off according to the torque of the No. 1 engine. When the torque of the No. 1 engine is lower than a set value, the No. 1 engine low torque micro switch (13) turns on the No. 1 engine automatic propeller-feathering electromagnetic valve (11); when the torque of the No. 1 engine is higher than a set value, the No. 1 engine low torque micro switch (13) turns on the No. 1 engine automatic propeller-feathering indicator light (9).

7. The automatic propeller feathering control device for a twin-engine aircraft according to claim 6, characterized in that: The invention also includes a No. 2 engine high torque micro switch (6), which controls whether the No. 2 engine automatic propeller-feathering relay (2) is connected. Specifically, when the torque of the No. 2 engine is higher than a set value, the No. 2 engine high torque micro switch (6) controls the No. 2 engine automatic propeller-feathering relay (2) to be in an on state; when the torque of the No. 2 engine is lower than a set value, the No. 2 engine high torque micro switch (6) controls the No. 1 engine automatic propeller-feathering relay (2) to be in an off state.

8. The automatic propeller feathering control device for a twin-engine aircraft according to claim 1, characterized in that: It also includes a No. 2 engine power micro switch (4) and a No. 1 engine power micro switch (5), wherein the No. 2 engine power micro switch (4) and the No. 1 engine power micro switch (5) are arranged between the automatic propeller feathering switch (1) and the subsequent circuit.

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