Airplane center of gravity measuring device and method

Abstract

The application relates to an aircraft center of gravity measuring device and method. The aircraft center of gravity measuring device comprises a support frame, a first measuring frame and a second measuring frame arranged at two ends of the support frame, and the first measuring frame and the second measuring frame each comprise a sliding frame slidably arranged at the end of the support frame, a clamping column arranged on the sliding frame, the clamping column being used for connecting a main wheel of an aircraft, a scale arranged on the top surface of the sliding frame, and an adjusting mechanism arranged on the side wall of the support frame away from the clamping column, the adjusting mechanism being used for adjusting the support frame to a horizontal position. The aircraft center of gravity measuring device is simple in structure, convenient to use, and improves the efficiency of aircraft weight and center of gravity measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of measuring devices, in particular to an aircraft center of gravity measuring device and method. BACKGROUND

[0002] An aircraft can only fly within the allowable weight and center of gravity limit range, so as to obtain good flight performance and maneuvering, and it is also one of the necessary conditions for safe flight of the aircraft. If the aircraft is modified or equipped with equipment, the original weight and center of gravity of the aircraft will be changed, and the weight and center of gravity of the aircraft must be recalculated.

[0003] The existing center of gravity measurement method for small general aircraft is to complete the aircraft weighing and aircraft center of gravity calculation through a large ground scale and a plurality of special tooling. This method is relatively complex and time-consuming, and is not suitable for adjusting the center of gravity of the aircraft after the modification and equipment installation of the aircraft. SUMMARY

[0004] Based on the above problems, the present application provides an aircraft center of gravity measuring device and method, which can simply and efficiently measure the center of gravity of the aircraft.

[0005] One embodiment of the present application provides an aircraft center of gravity measuring device, comprising: a support frame; a first measuring frame and a second measuring frame, respectively arranged at two ends of the support frame, the first measuring frame and the second measuring frame each comprising: a sliding frame, slidably arranged at an end of the support frame; a clamping column arranged on the sliding frame, the clamping column being used for connecting a main wheel of an aircraft; a scale arranged on a top surface of the sliding frame; and an adjusting mechanism arranged on a side wall of the support frame away from the clamping column, the adjusting mechanism being used for adjusting the aircraft center of gravity measuring device to a horizontal position.

[0006] According to some embodiments of the present application, the adjusting mechanism comprises: an adjusting base arranged on the side wall of the support frame away from the clamping column; and an adjusting rod, which is arranged on the adjusting base in a liftable manner.

[0007] According to some embodiments of the present application, the aircraft center of gravity measuring device further comprises a roller, which is arranged on the support frame.

[0008] According to some embodiments of the present application, the aircraft center of gravity measuring device further comprises a roller frame, which is arranged on the support frame, and the roller is arranged on the roller frame.

[0009] According to some embodiments of the present application, the aircraft center of gravity measuring device further comprises a pad, which is arranged on a top surface of the support frame.

[0010] One embodiment of the present application provides a method for measuring the center of gravity by using the aircraft center of gravity measuring device as described above, comprising:

[0011] After placing the counterweight on the airplane, the airplane is jacked up, and the counterweight is used to simulate the weight of the pilot;

[0012] A ground scale is placed under the nose wheel, the first main wheel and the second main wheel of the airplane, and the counterweight is removed;

[0013] The airplane is adjusted to a horizontal position;

[0014] The weight G1 at the first main wheel, the weight G2 at the second main wheel and the weight G3 at the nose wheel are measured;

[0015] The first measuring frame of the airplane center of gravity measuring device is inserted into the center of the first main wheel, the second measuring frame is inserted into the center of the second main wheel, and the airplane center of gravity measuring device is adjusted to a horizontal position;

[0016] A reference plane is taken as a vertical plane passing through the design center of the airplane, a plumb bob is placed at a first preset position on the airplane, the reading of the scale of the first measuring frame pointed by the plumb bob is A1, a plumb bob is placed at a second preset position on the airplane, the reading of the scale of the second measuring frame pointed by the plumb bob is A2, the first preset position and the second preset position are symmetrically arranged with respect to the axis of the airplane, and the distance from the first preset position and the second preset position to the reference plane is B1,

[0017] X1=A1+B1, X2=A2+B1,

[0018] Wherein, X1 is the distance from the axis of the first main wheel to the reference plane, and X2 is the distance from the center of the second main wheel to the reference plane;

[0019] The distance A3 from the axis of the nose wheel to a third preset position on the support frame and the distance A4 from the axis of the nose wheel to a fourth preset position on the support frame are measured, the third preset position and the fourth preset position are symmetrically arranged with respect to the axis of the support frame, and the distance from the third preset position and the fourth preset position to the axis of the clamping column is B2,

[0020] X3=(A1+A2) / 2+B1-(A3+A4) / 2-B2,

[0021] Wherein, X3 is the distance from the axis of the nose wheel to the reference plane;

[0022] According to the formula M=(G1×X1)+(G2×X2)+(G3×X3),

[0023] X4=M / (G1+G2+G3), the position of the airplane empty center of gravity is determined.

[0024] According to some embodiments of the present application, the method further comprises: placing a tire slide plate between the first main wheel and the ground balance and between the second main wheel and the ground balance.

[0025] According to some embodiments of the present application, the method further comprises: measuring the inclination angle of the first main wheel and the inclination angle of the second main wheel by a level.

[0026] According to some embodiments of the present application, the method further comprises: measuring the track angle of the first main wheel with the first measuring frame as a reference to the surface of the first main wheel; and measuring the track angle of the second main wheel with the second measuring frame as a reference to the surface of the second main wheel.

[0027] According to some embodiments of the present application, the method further comprises: measuring the distance between the first main wheel and the second main wheel.

[0028] The aircraft center of gravity measuring device of the present application has simple structure and is convenient to use, improves the efficiency of aircraft weight and center of gravity measurement, and is beneficial to ensuring the safety of the aircraft. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art according to these drawings without departing from the scope of the present application.

[0030] Figure 1 is a schematic diagram of the aircraft center of gravity measuring device of the embodiment of the present application;

[0031] Figure 2 is a top view of the aircraft center of gravity measuring device of the embodiment of the present application;

[0032] Figure 3 is a schematic diagram of the measuring support of the embodiment of the present application;

[0033] Figure 4 is a schematic diagram of the adjusting mechanism of the embodiment of the present application;

[0034] Figure 5 is a schematic diagram of the cushion block of the embodiment of the present application;

[0035] Figure 6 is a schematic diagram of the measuring of the distance from the main wheel to the reference surface of the embodiment of the present application;

[0036] Figure 7 is a schematic diagram of the measuring of the distance from the front shaft axis to the reference surface of the embodiment of the present application;

[0037] Figure 8This is an envelope diagram of the aircraft weight and center of gravity according to an embodiment of this application. Detailed Implementation

[0038] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0039] If the aircraft is modified, its weight and center of gravity will change, requiring a specialized workshop and multiple specialized tools to measure the aircraft's weight and center of gravity.

[0040] like Figure 1 and Figure 2 As shown, an embodiment of this application provides an aircraft center of gravity measuring device (hereinafter referred to as the measuring device) 100 for measuring the center of gravity of an aircraft. The measuring device 100 includes a support frame 1, a first measuring frame 2, a second measuring frame 3, and an adjustment mechanism 4.

[0041] The support frame 1 is made of square tubing. A first measuring frame 2 and a second measuring frame 3 are respectively positioned at both ends of the support frame 1. Both the first measuring frame 2 and the second measuring frame 3 are slidably connected to the support frame 1, allowing the measuring device 100 to be applicable to different aircraft models. The first measuring frame 2 is used to assist in measuring the lever arm from the first main wheel of the aircraft to the reference plane, and the second measuring frame 3 is used to assist in measuring the lever arm from the second main wheel of the aircraft to the reference plane. The reference plane is the vertical plane where the aircraft's design center point is located, and the reference plane is perpendicular to the aircraft's horizontal axis.

[0042] like Figure 3 As shown, both the first measuring frame 2 and the second measuring frame 3 include a sliding frame 21, a locking post 22, and a scale 23. The first measuring frame 2 and the second measuring frame 3 are arranged symmetrically with respect to the axis of the support frame 1.

[0043] A sliding hole is provided on the end face of the support frame 1, and one end of the sliding frame 21 can be slidably inserted into the sliding hole of the support frame 1. Optionally, the sliding frame 21 includes a sliding part 211, a retaining post support part 212, and a reinforcing rib 213. The sliding part 211 is arranged parallel to the support frame 1, and its end can be slidably inserted into the sliding hole of the support frame 1. The retaining post support part 212 is perpendicular to the sliding part 211. One end of the reinforcing rib 213 is connected to the sliding part 211, and the other end is connected to the retaining post support part 212 to improve the strength of the sliding frame 21.

[0044] The clamping post 22 is arranged on the clamping post supporting portion 212 of the sliding frame 21 and is located on the side wall of the supporting frame 1 close to the clamping post supporting portion 212. The structure of the clamping post 22 is matched with the structure at the center of the main wheel to play a positioning role. Optionally, the clamping post 22 is detachably connected with the clamping post supporting portion 212, for example, through threaded connection, so as to replace the clamping post 22 according to different aircraft models.

[0045] The scale 23 is located on the distal end of the sliding frame 21, and the scale 23 is arranged on the top surface of the sliding frame 21. In this embodiment, the scale 23 is located on the top surface of the sliding portion 211. After the measuring device 100 is connected with the aircraft, the scale 23 is located substantially below the wing. The scale 23 is used to measure the distance from the axis of the main wheel to the preset position of the aircraft. The sum of the distance from the axis of the main wheel to the preset position of the aircraft and the distance from the preset position of the aircraft to the reference surface is the distance from the main wheel to the reference surface, which is used as the force arm from the main wheel to the reference surface.

[0046] The adjusting mechanism 4 is arranged on the side wall of the supporting frame 1 away from the clamping post 22. When the measuring device 100 is used, the measuring device 100 and the aircraft should be located in a horizontal position, and the adjusting mechanism 4 can be used to adjust the measuring device 100 as a whole to the horizontal position.

[0047] The supporting frame 1 is also provided with a preset position, so as to measure the distance from the front wheel of the aircraft to the reference surface, which is used as the force arm from the front wheel to the reference surface.

[0048] The measuring device 100 of this embodiment has a simple structure, and the force arm from the front wheel to the reference surface, the force arm from the first main wheel to the reference surface, and the force arm from the second main wheel to the reference surface can be quickly measured by the measuring device 100. The measurement does not need to be performed in a professional factory, and the work efficiency is improved.

[0049] As shown in FIG. 1, Figure 4 In some embodiments, the adjusting mechanism 4 includes an adjusting base 41 and an adjusting rod 42. The adjusting base 41 is arranged on the side wall of the supporting frame 1 away from the clamping post 22. The adjusting rod 42 is threadedly connected with the adjusting base 41, and the axis of the adjusting rod 42 is substantially located in the vertical direction. After the bottom end of the adjusting rod 42 is in contact with the ground, the adjusting rod 42 is rotated to drive the adjusting base 41 to ascend or descend, so as to adjust the measuring device 100 to the horizontal position. When leveling, a level is placed on the supporting frame 1 to detect whether the measuring device 100 is adjusted to the horizontal position.

[0050] In some embodiments, the measuring device 100 further includes a plurality of rollers 51 arranged on the supporting frame 1. The rollers 51 are arranged below the supporting frame 1, and the number of the rollers 51 can be multiple, so as to facilitate the movement of the measuring device 100.

[0051] In some embodiments, the measuring device 100 further comprises a roller frame 52, which is arranged on the support frame 1 and is perpendicular to the support frame 1. Rollers 51 are arranged at both ends of the roller frame 52. Optionally, the number of roller frames 52 is two, and the two roller frames 52 are symmetrically arranged relative to the axis of the support frame 1 to provide stable support for the support frame 1.

[0052] As shown in Figure 5 some embodiments, the measuring device 100 further comprises a pad 61 arranged on the top surface of the support frame 1. For example, a support plate 62 is arranged on the top surface of the support frame 1, and the pad 61 is arranged on the support plate 62. When leveling the support frame 1, the level is placed on the pad 61, which facilitates the level to detect whether the measuring device 100 is adjusted to the horizontal position. Optionally, the support plate 62 is arranged close to the adjustment base 41.

[0053] The embodiments of the present application also provide a method for measuring the center of gravity of an airplane by using the above measuring device 100, which comprises the following steps:

[0054] 1. A counterweight is placed on the airplane, which is used to simulate the weight of the pilot to balance the airplane. Optionally, the counterweight is 250 kg; and a jack is used to lift the airplane.

[0055] 2. As shown in Figure 6 , three ground scales 210 are placed under the front wheel, the first main wheel and the second main wheel of the airplane respectively, the counterweight is removed, the jack is removed, and the airplane is placed on the ground scales; the ground scales 210 can be lifted, and the existing ground scales are selected.

[0056] 3. The horizontal measuring device is used to adjust the airplane to the horizontal position by lifting the three ground scales 210.

[0057] 4. The values of the three ground scales 210 are read to measure the weight G1 at the first main wheel, the weight G2 at the second main wheel and the weight G3 at the front wheel. The sum of G1, G2 and G3 is the weight of the airplane in the empty state.

[0058] 5. The measuring device 100 is moved, the clamping column of the first measuring frame 2 is inserted into the center of the first main wheel, the clamping column of the second measuring frame 3 is inserted into the center of the second main wheel, and the measuring device 100 is adjusted to the horizontal position by the adjustment mechanism 4.

[0059] 6. As shown in Figure 6As shown, the vertical plane containing the aircraft's design center point is used as the reference plane, which is perpendicular to the aircraft's horizontal axis. A plumb bob is placed at a first preset position on the aircraft, and the reading on the scale of the first measuring frame pointed to by the plumb bob is A1, where A1 is the horizontal distance from the axis of the first main wheel to the first preset position. A plumb bob is placed at a second preset position on the aircraft, and the reading on the scale of the second measuring frame pointed to by the plumb bob is A2, where A2 is the horizontal distance from the axis of the second main wheel to the second preset position. The first and second preset positions are symmetrically set with respect to the aircraft's horizontal axis, and the distances from both the first and second preset positions to the reference plane are B1, where B1 is a known quantity.

[0060] X1 = A1 + B1, X2 = A2 + B1,

[0061] Where X1 is the distance from the axis of the first main wheel to the reference surface, and X2 is the distance from the center of the second main wheel to the reference surface.

[0062] For example, the first preset position is the intersection of the upper and lower wing surfaces at the wing root at the leading edge of the left wing, and the second preset position is the intersection of the upper and lower wing surfaces at the wing root at the leading edge of the right wing. Figure 6 The dashed line represents a plumb bob.

[0063] 7. For example Figure 7 As shown, a third preset position 11 and a fourth preset position 12 are provided on the support frame 1. For example, the third preset position 11 and the fourth preset position 12 are both located on the side wall of the support frame 1 away from the locking post, and the third preset position 11 and the fourth preset position 12 are symmetrically arranged with respect to the axis of the support frame 1. The distance from the third preset position 11 and the fourth preset position 12 to the axis of the locking post is B2, where B2 is a known quantity.

[0064] Using measuring tools, such as a tape measure, measure the distance A3 from the front wheel axle to the third preset position 11 on the support frame and the distance A4 from the front wheel axle to the fourth preset position 12 on the support frame.

[0065] X3 = (A1 + A2) / 2 + B1 - (A3 + A4) / 2 - B2, where X3 is the distance from the front wheel axis to the reference plane.

[0066] 8. According to the formula M=(G1×X1)+(G2×X2)+(G3×X3), M is the aircraft's weight torque.

[0067] X4 = M / (G1+G2+G3) determines the position of the aircraft's unloaded center of gravity, where X4 is the distance from the aircraft's unloaded center of gravity to the reference plane.

[0068] like Figure 8 As shown, the aircraft's weight and center of gravity should be located at... Figure 8For example, if the weight of the aircraft is 1450kg, the center of gravity X4 of the aircraft should be between 2350cm and 2455cm to ensure the safety of the aircraft.

[0069] As shown in some embodiments, the method further comprises placing a tire slide plate 220 between the first main wheel and the corresponding ground scale and between the second main wheel and the corresponding ground scale after the aircraft is jacked up. The tire slide plate 220 is arranged between the main wheel and the ground scale to reduce the friction between the main wheel and the ground scale, thereby improving the accuracy of the center of gravity detection. Figure 6

[0070] Optionally, the tire slide plate 220 comprises two parallel steel plates, and lubricating oil is applied between the two steel plates to reduce the friction between the two steel plates.

[0071] In some embodiments, the method further comprises measuring the inclination angles of the first main wheel and the second main wheel by using a level to determine whether the inclination angles of the main wheels are within the allowed range. Optionally, the inward inclination is negative and the outward inclination is positive.

[0072] As shown in some embodiments, the method further comprises measuring the track angles of the main wheels. With the first measuring frame away from the surface 2a of the first main wheel as the reference, the distance from the leading edge and the trailing edge of the first main wheel to the surface 2a of the first measuring frame away from the first main wheel is measured by using a measuring tool, such as a vernier caliper, to determine the track angle of the first main wheel. With the second measuring frame away from the surface 3a of the second main wheel as the reference, the distance from the leading edge and the trailing edge of the second main wheel to the surface 2a of the second measuring frame away from the second main wheel is measured by using a measuring tool, such as a vernier caliper, to determine the track angle of the second main wheel. Figure 7 In some embodiments, the method further comprises measuring the distance S between the first main wheel and the second main wheel.

[0073] Optionally, the method further comprises measuring the center of gravity of the aircraft after loading:

[0074] The moment of the weight of the aircraft M = (G1 x X1) + (G2 x X2) + (G3 x X3) + (G5 x X5) + (G6 x X6) …,

[0075] X4 = M / G, G = G1 + G2 + G3 + G5 + G6,

[0076] wherein G5 is the weight of the main fuel tank, G6 is the weight of the auxiliary fuel tank, X5 is the distance from the center of gravity of the main fuel tank to the reference surface, X6 is the distance from the auxiliary fuel tank to the reference surface, G is the total weight of the aircraft after loading, and G5, G6, X5 and X6 are known quantities. According to the requirements, other loads can also be added to determine the center of gravity of the aircraft after loading.

[0077]

[0078] ​​The above has carried out the detailed introduction to the embodiment of the application. The principle and implementation mode of the application are described by applying specific examples in this paper, and the above embodiment is only used to help understand the technical scheme of the application and its core idea. Therefore, the changes or deformations made by the person skilled in the art on the basis of the specific implementation mode and the application range of the application all belong to the protection range of the application. In summary, the content of the specification should not be understood as a limitation of the application.

Claims

1. An aircraft center of gravity measuring device, characterized in that, The application relates to an aircraft center of gravity measuring device. The device comprises a support frame, a first measuring frame and a second measuring frame arranged at two ends of the support frame, wherein the first measuring frame and the second measuring frame each comprise a sliding frame arranged at the end of the support frame, a clamping column arranged on the sliding frame and used for connecting a main wheel of an aircraft, a scale arranged on the top surface of the sliding frame, and an adjusting mechanism arranged on the side wall of the support frame away from the clamping column and used for adjusting the aircraft center of gravity measuring device to a horizontal position. The adjusting mechanism comprises an adjusting base arranged on the side wall of the support frame away from the clamping column and an adjusting rod arranged on the adjusting base in a liftable manner. The device further comprises a roller arranged on the support frame. The device further comprises a roller frame arranged on the support frame, wherein the roller is arranged on the roller frame. The device further comprises a pad arranged on the top surface of the support frame. The device is used in the following way.

2. The aircraft center of gravity measurement apparatus of claim 1, wherein, After placing a counterweight on the aircraft, the aircraft is lifted, wherein the counterweight is used for simulating the weight of a pilot. A ground scale is placed under the front wheel, the first main wheel and the second main wheel of the aircraft, and the counterweight is removed. The aircraft is adjusted to a horizontal position.

3. The aircraft center of gravity measurement apparatus of claim 1, wherein, The weight G1 at the first main wheel, the weight G2 at the second main wheel and the weight G3 at the front wheel are measured.

4. The aircraft center of gravity measurement apparatus of claim 3, wherein The first measuring frame of the aircraft center of gravity measuring device is inserted into the center of the first main wheel, the second measuring frame is inserted into the center of the second main wheel, and the aircraft center of gravity measuring device is adjusted to a horizontal position.

5. The aircraft center of gravity measurement apparatus of claim 1, wherein, A vertical plane in which the design center of the aircraft is located is taken as a reference plane, a plumb line is placed at a first preset position on the aircraft, the reading of the scale of the first measuring frame pointed by the plumb line is A1, a plumb line is placed at a second preset position on the aircraft, the reading of the scale of the second measuring frame pointed by the plumb line is A2, the first preset position and the second preset position are symmetrically arranged relative to the axis of the aircraft, and the distance from the first preset position and the second preset position to the reference plane is B1.

6. A method of measuring the center of gravity of an aircraft using the center of gravity measuring device according to any one of claims 1 to 5, characterized by, X1=A1+B1 and X2=A2+B1, wherein X1 is the distance from the axis of the first main wheel to the reference plane, and X2 is the distance from the center of the second main wheel to the reference plane. The distance A3 from the axis of the front wheel to a third preset position on the support frame and the distance A4 from the axis of the front wheel to a fourth preset position on the support frame are measured, the third preset position and the fourth preset position are symmetrically arranged relative to the axis of the support frame, the distance from the third preset position and the fourth preset position to the axis of the clamping column is B2, and X3=(A1+A2) / 2+B1-(A3+A4) / 2-B2, wherein X3 is the distance from the axis of the front wheel to the reference plane. According to the formula M=(G1*X1)+(G2*X2)+(G3*X3), the position of the aircraft empty center of gravity is determined. The device further comprises a tire sliding plate arranged between the first main wheel and the ground scale and between the second main wheel and the ground scale. The device further comprises a level used for measuring the inclination angles of the first main wheel and the second main wheel. The device further comprises ​ ​ ​ ​ ​ ​ ​ ​ 7. The method of claim 6, wherein, ​ ​ 8. The method of claim 6, wherein, ​ ​ 9. The method of claim 6, wherein, ​ measuring a track angle of the first main wheel with reference to a surface of the first main wheel away from the first measuring frame; measuring a track angle of the second main wheel with reference to a surface of the second main wheel away from the second measuring frame.

10. The method of claim 6, wherein, Further comprising: measuring a distance between the first main wheel and the second main wheel.

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