A method of installing a fuel tank for a light helicopter

Abstract

The present application relates to the technical field of helicopter parts installation, in particular to a light helicopter fuel tank installation method, comprising the following steps: determining the center of gravity position A of the fuel tank in the full oil state and the center of gravity position B of the fuel tank in the empty state; measuring the offset distance a of the center of gravity position A and the center of gravity position B in the same vertical plane, and measuring the offset distance b of the center of gravity position A and the center of gravity position B in the same horizontal plane, so that the offset distance a is less than the offset distance b; determining the center of gravity limit space, installing the fuel tank into the truss, and making the center of gravity position A and the center of gravity position B located in the conical space measured in step 3. The light helicopter fuel tank installation method is used to improve the control of the overall fuselage center of gravity and the fuel tank center of gravity position when the fuel tank is combined and installed with the truss, reduce the influence of the center of gravity change of the fuel tank in the full oil or empty state on the fuselage center of gravity, and improve the stability of the helicopter in the flight state.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of helicopter parts installation, in particular to a light helicopter fuel tank installation method. BACKGROUND

[0002] The fuel tank is a container for storing liquid fuel (gasoline, kerosene, diesel) on a helicopter, which directly receives energy from a liquid fuel internal combustion engine. Generally, the fuel tank is installed on the side of the helicopter and is composed of a sealed tank body, which has a fuel inlet and a fuel inlet cover. In addition, if necessary, an opening can be provided on the tank body for introducing a sensor for monitoring the fuel level and its pressure.

[0003] Currently, in light engine aircraft with piston engines, high-octane gasoline is used, and the fuel tank is usually located in the area with the least deformation outside the passenger cabin in emergency situations, and the fuel tank must be able to withstand vibrations, inertial forces, fluid effects, structural and temperature loads that may be affected by operating conditions. The existing light helicopter fuel tank is placed on one side of the fuselage using a traditional installation structure. During the flight of the helicopter, it is often accompanied by shaking and collision, which is not convenient for the stability of the center of gravity of the fuselage, and there is a certain safety hazard. In view of this, we propose a light helicopter fuel tank installation method. SUMMARY

[0004] The purpose of the present application is to provide a light helicopter fuel tank installation method to solve the problems raised in the background art.

[0005] To achieve the above purpose, the present application provides the following technical solutions:

[0006] A light helicopter fuel tank installation method, comprising the following steps:

[0007] Step 1: Center of gravity determination

[0008] Determine the center of gravity position A of the fuel tank in the full fuel state and the center of gravity position B of the fuel tank in the empty state;

[0009] Step 2: Center of gravity offset determination

[0010] Measure the offset a of the center of gravity position A and the center of gravity position B in the same vertical plane, and measure the offset b of the center of gravity position A and the center of gravity position B in the same horizontal plane, so that the offset a is less than the offset b;

[0011] Step 3: Center of gravity limit space determination

[0012] The center of the circle formed by the main rotor of the helicopter is taken as the vertex C, a vertical axis D is made along the vertex C to the bottom edge of the truss, a generatrix E is made along the vertex C to the bottom edge of the truss, and a reference line F is connected between the bottom end of the vertical axis D and the generatrix E, so that the vertical axis D, the generatrix E and the reference line F form a triangular area, and the triangular area is rotated along the vertical axis D to form a conical space;

[0013] Step 4: installation

[0014] The fuel tank is installed into the truss, and the center of gravity position A and the center of gravity position B are located in the conical space measured in step 3.

[0015] Preferably, in step 2, the offset a is not greater than 8 cm, and the offset b is not greater than 14.5 cm.

[0016] Preferably, in step 3, when the generatrix E is made along the vertex C to the bottom edge of the truss, the included angle between the generatrix E and the vertical axis D is not greater than 2.8°.

[0017] Compared with the prior art, the light helicopter fuel tank installation method of the present application has the beneficial effects that the fuel tank is installed in the fuselage support truss of the helicopter, the truss can play a certain protective role for the fuel tank, and the center of gravity position A and the center of gravity position B of the fuel tank in the full tank and empty states always do not deviate from the center of gravity limit space of the overall truss, so as to improve the control of the overall fuselage center of gravity and the center of gravity position of the fuel tank during the combination and installation of the fuel tank and the truss, reduce the influence of the center of gravity change of the fuel tank in the full tank or empty state on the fuselage center of gravity, and improve the stability of the helicopter in the flight state. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the overall structure of the present application;

[0019] Figure 2 The figure is a curve graph showing the relationship between the included angle between the generatrix E and the vertical axis D and the fuselage swing intensity. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0022] A method for installing a fuel tank of a light helicopter, as shown in Figure 1 The method comprises the following steps:

[0023] Step 1: determination of the center of gravity

[0024] Determine the center of gravity position A of the fuel tank in the full fuel state, and the center of gravity position B of the fuel tank in the empty state;

[0025] Step 2: determination of the center of gravity offset

[0026] Measure the offset a of the center of gravity position A and the center of gravity position B in the same vertical plane, and measure the offset b of the center of gravity position A and the center of gravity position B in the same horizontal plane, so that the offset a is less than the offset b, and the offset a is not greater than 8 cm, and the offset b is not greater than 14.5 cm, and in the embodiment, the offset a is preferably 8 cm, and the offset b is preferably 14.5 cm, so as to maximize the volume of the fuel tank, improve the fuel capacity, and improve the endurance of the helicopter;

[0027] Step 3: determination of the center of gravity limit space

[0028] Take the center of the circle formed by the main rotor of the helicopter during rotation as a vertex C, draw a vertical axis D from the vertex C to the bottom edge of the truss, draw a generatrix E from the vertex C to the bottom edge of the truss, and the included angle between the generatrix E and the vertical axis D is not greater than 2.8°, and connect the bottom end of the vertical axis D and the generatrix E to draw a reference line F, so that the vertical axis D, the generatrix E and the reference line F form a triangular area, and the triangular area is rotated along the vertical axis D to form a conical space, and the conical space is used as the limit displacement space of the center of gravity of the fuel tank during the shaking process;

[0029] Step 4: installation in place

[0030] The fuel tank is installed into the truss, and the gravity center position A and the gravity center position B are located in the conical space measured in step 3, so that the overshoot of the helicopter body in a certain range is shaken, the gravity center position A and the gravity center position B are always deviated from the gravity center limit space, so that the control of the overall body gravity center and the fuel tank gravity center position is improved when the fuel tank is combined and installed with the truss, the influence of the gravity center change of the fuel tank in the full oil or empty state on the body gravity center is reduced, and the stability of the helicopter in the flight state is improved.

[0031] It is worth noting that, as shown in Figure 2 The figure shows the relationship curve between the included angle between the bus E and the vertical axis D and the body shaking intensity, which is used to measure the relationship between the included angle degree and the body stability in the simulation state, and it can be known from the figure that the body shaking intensity is the smallest when the included angle is about 2.6°, but the angle must be reduced in the actual practical process to reduce the volume of the fuel tank, therefore, in order to ensure the body stability and meet the sufficient endurance of the fuel tank, the included angle is preferably between 2.8° and 3°, and the included angle of 2.8° is taken as an example in the embodiment.

[0032] The above-mentioned installation method is completed, the fuel tank is installed in the body support truss of the helicopter, the truss can play a certain protection role for the fuel tank, at the same time, the gravity center position A and the gravity center position B of the fuel tank in the full oil and empty state are always deviated from the gravity center limit space of the overall truss, so that the control of the overall body gravity center and the fuel tank gravity center position is improved when the fuel tank is combined and installed with the truss, the influence of the gravity center change of the fuel tank in the full oil or empty state on the body gravity center is reduced, and the stability of the helicopter in the flight state is improved.

[0033] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above-mentioned embodiments, the above-mentioned embodiments and descriptions in the specification are only preferred examples of the present application, and are not used to limit the present application, various changes and improvements of the present application can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for installing a fuel tank on a lightweight helicopter, characterized in that, Includes the following steps: Step 1: Determine the center of gravity Determine the position of the center of gravity, A, when the fuel tank is full, and the position of the center of gravity, B, when the fuel tank is empty. Step 2: Measurement of center of gravity offset Measure the offset a between the center of gravity positions A and B in the same vertical plane, and measure the offset b between the center of gravity positions A and B in the same horizontal plane, so that the offset a is less than the offset b. Step 3: Determining the Limit Space of the Center of Gravity Take the center of the circle traced by the helicopter's main rotor as vertex C, draw a vertical axis D along vertex C to the bottom edge of the truss, draw a generatrix E along vertex C to the bottom edge of the truss, and connect the bottom of the vertical axis D and the generatrix E to draw a reference line F, so that the vertical axis D, the generatrix E and the reference line F form a triangular region, and rotate the triangular region along the vertical axis D to form a cone-shaped space. Step 4: Installation in place Install the fuel tank into the truss, ensuring that the center of gravity A and center of gravity B are located within the conical space measured in step 3.

2. The method for installing a light helicopter fuel tank according to claim 1, characterized in that: In step 2, the offset a is no greater than 8cm and the offset b is no greater than 14.5cm.

3. The method for installing a light helicopter fuel tank according to claim 1, characterized in that: In step 3, when drawing a generatrix E along vertex C to the bottom edge of the truss, the angle between generatrix E and the vertical axis D is no greater than 2.8°.

Images