Rotor total pitch calibration device and method

Abstract

The invention belongs to the technical field of helicopter rotor calibration, and discloses a rotor total pitch calibration device and method.The rotor total pitch calibration device comprises a variable pitch pull rod, one end of the variable pitch pull rod is connected with a rotor fork lug, the other end of the variable pitch pull rod is connected with a steering engine rocker arm fork lug, and rotor blades are calibrated by adjusting the axial length of the variable pitch pull rod and the relative angle of the end faces of knuckle bearings at the two ends; the auxiliary calibration device is provided with an angle measurement mechanism and a distance measurement mechanism, the distance measurement mechanism is connected to the angle measurement mechanism and can move relatively, and the angle measurement mechanism and the distance measurement mechanism are connected with the knuckle bearings at the two ends of the variable-pitch pull rod through positioning connectors respectively; the gradienter is used for measuring the mounting angle of the rotor blade at the reference position and feeding back the mounting angle to the ground detection equipment; the ground inspection equipment converts the mounting angle into a variable pitch amount and sends the variable pitch amount to the flight control system; and the flight control system generates a control instruction according to the variable pitch quantity and sends the control instruction to a steering engine, and the steering engine manipulates a variable pitch pull rod to achieve total pitch calibration of the rotor wings. According to the method, the problem that existing helicopter rotors are difficult to calibrate is solved, and the total pitch of the rotors can be calibrated with high precision and high efficiency.

Description

Technical Field

[0001] This invention belongs to the field of helicopter rotor calibration technology, specifically relating to a rotor collective pitch calibration device and method. Background Technology

[0002] Collective pitch calibration of a helicopter rotor system is mainly achieved through the installation and adjustment of pitch control rods.

[0003] The variable pitch lever has two ends: one end is connected to the rotor fork lug, and the other end is connected to the servo rocker arm fork lug.

[0004] During rotor collective pitch calibration, the relative angle between the end faces of the joint bearings at both ends is a key control parameter, and the axial length is a key adjustment parameter.

[0005] Before calibration, the axial length of the variable pitch tie rod and the relative angle between the end faces of the spherical bearings at both ends need to be adjusted to ensure that the initial state meets the installation requirements.

[0006] During calibration, the axial length of the variable pitch tie rod needs to be adjusted under the condition that the relative angle deviation between the end faces of the two end bearings meets the requirements.

[0007] Currently, during helicopter integration and commissioning, the axial length of the pitch control rod is mainly measured using vernier calipers, and there is no corresponding device to ensure the relative angular deviation of the end faces of the joint bearings at both ends. Because there are no professional positioning clamps and measuring devices during the installation and adjustment process, only rough measurements can be achieved, and the required accuracy for collective pitch calibration cannot be reached.

[0008] In view of the above situation, the present invention proposes a rotor collective pitch calibration device and method. Summary of the Invention

[0009] Purpose of the invention: To address the difficulties in calibrating helicopter rotors, this invention provides a rotor collective pitch calibration device and method that can calibrate rotor collective pitch with high precision and efficiency.

[0010] To address the above-mentioned technical issues, the present invention provides the following technical solution: In a first aspect, the present invention provides a rotor collective pitch calibration device, comprising: The variable pitch lever connects to the rotor fork lug at one end and the servo rocker arm fork lug at the other end. The rotor blade calibration is completed by adjusting the axial length of the variable pitch lever and the relative angle between the end faces of the joint bearings at both ends. An auxiliary calibration device has an angle measuring mechanism and a distance measuring mechanism. The distance measuring mechanism is connected to the angle measuring mechanism and can move relative to it. The angle measuring mechanism and the distance measuring mechanism are respectively connected to the two end joint bearings of the variable pitch rod through positioning joints. A level is used to measure the installation angle of the rotor blades at a reference position and provide feedback to the ground inspection equipment. The ground inspection equipment converts the installation angle into a pitch value and sends it to the flight control system; The flight control system generates control commands based on the pitch change and sends them to the servos. The servos then manipulate the pitch control stick to calibrate the rotor's collective pitch.

[0011] As a further technical solution of the present invention: the variable pitch rod includes a threaded rod body and a joint bearing, and the length is changed by axially rotating the rod body.

[0012] As a further technical solution of the present invention: the angle measuring mechanism includes an angle measuring instrument panel, a vernier caliper, a vernier limiting block, and a vernier fastening screw; the angle measuring instrument panel is horizontally arranged and connected to the rod body of the variable pitch tie rod through a angle measuring instrument positioning bracket and a clamp; the vernier caliper is movably arranged on the angle measuring instrument panel, the vernier caliper end is provided with a vernier fastening screw, and both ends of the angle measuring instrument panel are provided with vernier limiting blocks.

[0013] As a further technical solution of the present invention: the ranging mechanism includes a sliding rod fastening screw, a guide tube and a sliding rod, the guide tube and the sliding rod are sleeved together, one end of the guide tube is vertically connected to the vernier of the goniometer, and the relative position of the sliding rod and the guide tube is positioned by the fastening screw, and then the scale is read.

[0014] As a further technical solution of the present invention: a positioning rod is vertically provided on the angle measuring instrument panel, and a U-shaped positioning short connector is movably provided in the radial direction of the positioning rod. The U-shaped positioning short connector is inserted into the joint bearing of the variable pitch rod.

[0015] As a further technical solution of the present invention: a U-shaped positioning long joint is movably provided in the radial direction of the slide rod, and the U-shaped positioning long joint is inserted into the joint bearing of the variable pitch tie rod.

[0016] As a further technical solution of the present invention: the U-shaped positioning short connector is used to position the installation orientation of the spherical bearing and to measure the position dimension of the central axis of the spherical bearing mounting hole; The U-shaped positioning short connector is equipped with a U-shaped positioning groove, an inner positioning surface, an outer positioning surface, and a guide rod; The U-shaped positioning groove is used to connect bolts, and the outer circular surface of the bolt's smooth shank fits against the inner circular surface of the U-shaped positioning groove; The U-shaped positioning groove is located along the central axis of the variable pitch tie rod, and its groove size is the same as the outer diameter of the bolt. The inner positioning surface is in contact with the outer ring end face of the spherical bearing; The outer positioning surface is in contact with the surface of the structural fork lug on which the spherical bearing is installed; The U-shaped positioning short connector and the U-shaped positioning long connector are identical in all structural dimensions except for the corresponding guide rods and guide rod lengths.

[0017] As a further technical solution of the present invention: the goniometer positioning bracket is used to fix the goniometer panel on the variable pitch rod; The goniometer positioning bracket is equipped with a positioning surface, a fastening groove, and a mounting surface; The positioning surface is in contact with the outer cylindrical surface of the variable pitch tie rod; The fastening groove is used to limit the binding position of the clamp; The mounting surface is used to mount and fix the angle measuring instrument panel; The clamp is used to fix the goniometer positioning bracket on the variable pitch tie rod.

[0018] As a further technical solution of the present invention: the angle measuring instrument is used to measure the relative angle between the end faces of the joint bearings at both ends of the variable pitch tie rod; The angle measuring instrument panel is equipped with dial scale lines and dial guide rails; The vernier of the goniometer is used to measure the relative angle between the end faces of the joint bearings at both ends of the variable pitch tie rod; The vernier and angle measuring instrument panel of the goniometer are used together to improve measurement accuracy; The vernier of the goniometer is equipped with vernier scale lines, vernier guide grooves, and vernier fixing holes; The vernier fixing hole is used to install the vernier fastening screw; The guide tube is mounted and fixed on the vernier caliper of the goniometer; The guide tube is used to measure the length between the central axes of the mounting holes of the joint bearings at both ends of the variable pitch tie rod. The guide tube is equipped with scale lines, fixing holes and guide grooves; The scale lines are used to indicate specific length values, with each scale line representing 1 mm. The fixing hole is used to install the slide bar fastening screw; The guide groove serves as a moving guide rail for the slide bar; The guide groove can limit the range of movement of the slide bar; The slide bar is used to measure the length between the central axes of the mounting holes of the joint bearings at both ends of the variable pitch tie rod; The slide bar and guide tube are used together to improve measurement accuracy; The slide bar is equipped with scale lines, guide pins, and guide holes; The scale lines are used to indicate specific length values; since the scale lines on the slide rod and the guide tube differ by 0.02mm per division, the measurement accuracy is 0.02mm. The guide pin is installed in the guide groove and can move along the length of the guide groove. The guide hole is used to insert the guide rod, thereby ensuring that the U-shaped positioning long joint can move in the vertical direction along the central axis of the variable pitch tie rod.

[0019] Secondly, the present invention provides a rotor collective pitch calibration method, which includes the following steps: Initial adjustment of the pitch control rod: Set the length of the auxiliary calibration device to L0 and the angle to α, and tighten the slide bar fastening screw and the vernier fastening screw; install and fix the auxiliary calibration device on the pitch control rod, and adjust the pitch control rod to the initial length L0 and the initial angle α0; after the initial adjustment of the pitch control rod is completed, remove the auxiliary calibration device. Pitch control rod installation: Connect one end to the rotor fork lug with bolts, and the other end to the servo rocker arm fork lug with bolts; Variable pitch tie rod angle measurement: Install the auxiliary calibration device onto the variable pitch tie rod, install the U-shaped positioning short connector and the U-shaped positioning long connector onto the joint bearings at both ends of the variable pitch tie rod respectively, and measure the relative angle α between the end faces of the joint bearings at both ends of the variable pitch tie rod. It should satisfy α=α0±10′. Fixed pitch rod angle: Install the auxiliary calibration device onto the pitch rod, and install the U-shaped positioning short connector and U-shaped positioning long connector onto the joint bearings at both ends of the pitch rod respectively; Rotor blade installation angle measurement: Initially set the collective distance value to 0° using ground inspection equipment, and use a level to measure the installation angle θ1 of the rotor blade at the reference position at this time. Record the difference between the measured value and the theoretical value ε=θ0-θ1; Adjustment of the length of the variable pitch rod: The ground inspection equipment is set with a total pitch value of ε. According to the functional relationship L=g(θ), the axial length of the variable pitch rod is adjusted to the installation angle of the rotor blade at the reference position θ=(θ0±0.1°). Flight control system parameter adjustment: Write ε into the flight control system according to the algorithm; The collective distance is set to 0° again using ground inspection equipment. The installation angle θ of the rotor blade at the reference position is measured with a level and should satisfy θ = (θ0 ± 0.1°). Repeat the above steps to complete the calibration of the other rotor blades.

[0020] In summary, the beneficial effects of the present invention are as follows: 1. This invention achieves precise positioning during angle measurement.

[0021] 2. This invention achieves precise positioning during length measurement.

[0022] 3. This invention adopts an integrated design, which realizes the simultaneous measurement of length and angle.

[0023] 4. This invention enables both pre-installation and post-installation adjustment and measurement.

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the rotor collective pitch calibration device of the present invention during the installation and adjustment process.

[0026] Figure 2 This is a schematic diagram of the rotor collective pitch calibration device of the present invention.

[0027] Figure 3 This is a side view of the variable pitch tie rod joint bearing of the present invention.

[0028] Figure 4 This is a perspective view of the variable pitch tie rod joint bearing of the present invention.

[0029] Figure 5 This is a schematic diagram of the variable pitch tie rod calibration device of the present invention.

[0030] Figure 6 This is a schematic diagram of the structure of the U-shaped positioning short connector of the present invention.

[0031] Figure 7 This is a schematic diagram of the positioning bracket of the present invention.

[0032] Figure 8 This is a schematic diagram of the vernier of the goniometer of the present invention.

[0033] Figure 9 This is a schematic diagram of the positioning rod and angle measuring instrument panel of the present invention.

[0034] Figure 10 This is a schematic diagram of the guide tube of the present invention.

[0035] Figure 11 This is a schematic diagram of the slide bar of the present invention.

[0036] Explanation of reference numerals in the attached figures: 1-Variable pitch tie rod; 2-Spherical bearing; 3-Calibration device; 4-Bolt; 5-Ground inspection equipment; 6-Level; 7-Flight control system; 201-Inner ring; 202-Outer ring; 301-U-shaped positioning short connector; 302-U-shaped positioning long connector; 303-Limit ring; 304-Positioning rod; 305-Positioning bracket; 306-Clamp; 307-Angle measuring instrument panel; 308-Angle measuring instrument vernier; 309-Vernier limit block; 310-Vernier fastening screw; 311-Slide rod fastening screw; 312-Guide tube; 313-Slide rod; 3011-U-shaped positioning groove; 3012-Inner positioning surface; 3 013-Outer positioning surface; 3014-Guide rod; 3021-U-shaped positioning groove; 3022-Inner positioning surface; 3023-Outer positioning surface; 3024-Guide rod; 3041-Guide hole; 3051-Positioning surface; 3052-Fasting groove; 3053-Mounting surface; 3071-Dial scale line; 3072-Dial guide rail; 3081-Vernier scale line; 3082-Vernier guide groove; 3083-Vernier fixing hole; 3121-Scale line; 3122-Fixing hole; 3123-Guide groove; 3131-Scale line; 3132-Guide pin; 3133-Guide hole. Detailed Implementation 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 with reference to the accompanying drawings.

[0037] In the accompanying drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present invention.

[0038] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0039] The following is in conjunction with the appendix Figure 1-11 The embodiments of the present invention will be described in detail below.

[0040] Example 1 This invention discloses a variable pitch tie rod auxiliary calibration device, including a U-shaped positioning short connector 301, a U-shaped positioning long connector 302, a limiting ring 303, a positioning rod 304, a goniometer positioning bracket 305, a clamp 306, a goniometer instrument panel 307, a goniometer vernier 308, a vernier limiting block 309, a vernier fastening screw 310, a slide rod fastening screw 311, a guide tube 312, and a slide rod 313.

[0041] The U-shaped positioning short connector 301 is used to position the installation orientation of the spherical bearing 2.

[0042] The U-shaped positioning short connector 301 is also used to measure the position dimension of the center axis of the mounting hole of the spherical bearing 2.

[0043] Optionally, the U-shaped positioning short connector 301 is provided with a U-shaped positioning groove 3011, an inner positioning surface 3012, an outer positioning surface 3013, and a guide rod 3014.

[0044] The U-shaped positioning groove 3011 is used to connect the bolt 4, and the outer circular surface of the smooth rod of the bolt 4 is in contact with the inner circular surface of the U-shaped positioning groove 3011.

[0045] The U-shaped positioning groove 3011, located along the central axis of the variable pitch tie rod 1, has the same groove size as the outer diameter of the bolt 4.

[0046] The inner positioning surface 3012 is in contact with the end face of the outer ring 202 of the spherical bearing 2.

[0047] The outer positioning surface 3013 is in contact with the surface of the structural fork lug on which the spherical bearing 2 is installed.

[0048] The guide rod 3014 can adjust the position and size of the U-shaped positioning short joint 301 in the vertical direction of the central axis of the variable pitch tie rod 1 to ensure that the inner circle of the U-shaped positioning groove 3011 is fully in contact with the outer circle of the smooth rod of the bolt 4.

[0049] The U-shaped positioning long connector 302 and the U-shaped positioning short connector 301 have the same function. Except for the different lengths of the corresponding guide rods 3014 and 3024, the other structural dimensions are the same.

[0050] The limiting ring 303 is installed on the U-shaped positioning short connector 301 to limit the displacement of the guide rod 3014 of the U-shaped positioning short connector 301 and ensure that it will not separate from the positioning rod 304.

[0051] The limiting ring 303 is installed on the U-shaped positioning long connector 302 to limit the displacement of the guide rod 3024 of the U-shaped positioning long connector 302 and ensure that it will not separate from the slide rod 313.

[0052] The positioning rod 304 is used to position the U-shaped positioning short connector 301 circumferentially along the axis of the variable pitch tie rod 1.

[0053] Optionally, the positioning rod 304 is provided with a guide hole 3041.

[0054] The guide hole 3041 is used to insert the guide rod 3014, thereby ensuring that the U-shaped positioning short joint 301 can move in the vertical direction along the central axis of the variable pitch tie rod 1.

[0055] The angle measuring instrument positioning bracket 305 is used to fix the angle measuring instrument panel 307 on the variable pitch rod 1.

[0056] Optionally, the goniometer positioning bracket 305 is provided with a positioning surface 3051, a fastening groove 3052, and a mounting surface 3053.

[0057] The positioning surface 3051 is in contact with the outer cylindrical surface of the variable pitch tie rod 1.

[0058] The fastening groove 3052 is used to restrict the binding position of the clamp 306.

[0059] The mounting surface 3053 is used to mount and fix the angle measuring instrument panel 307.

[0060] The clamp 306 is used to fix the angle measuring instrument positioning bracket 305 on the variable pitch tie rod 1.

[0061] The angle measuring instrument panel 307 is used to measure the relative angle between the end faces of the joint bearings 2 at both ends of the variable pitch rod 1.

[0062] Optionally, the angle measuring instrument panel 307 is provided with dial scale lines 3071 and dial guide rail 3072.

[0063] The dial scale lines 3071 are used to indicate specific angle values, with each scale line representing 1°.

[0064] The dial guide rail 3072 is used as the moving guide rail for the vernier 308 of the goniometer.

[0065] The vernier 308 of the goniometer is used to measure the relative angle between the end faces of the joint bearings 2 at both ends of the variable pitch rod 1.

[0066] The vernier 308 of the goniometer is used in conjunction with the goniometer panel 307 to improve measurement accuracy.

[0067] Optionally, the vernier 308 of the goniometer is provided with vernier scale lines 3081, vernier guide groove 3082 and vernier fixing hole 3083.

[0068] The vernier scale line 3081 is used to mark specific angle values, with each scale line representing (29 / 30)°.

[0069] The vernier scale line 3081 has a total of 30 equally divided graduations and a total radian of 29°.

[0070] The vernier scale line 3081 has a measurement accuracy of 2′ because the difference between each division of the vernier scale line 308 and the scale line of the angle measuring instrument panel 307 is (1 / 30)°, or 2′.

[0071] The vernier guide groove 3082 is installed on the dial guide rail 3072 and can move along the arc direction of the dial guide rail 3072.

[0072] The vernier fixing hole 3083 is used to install the vernier fastening screw 310.

[0073] The vernier limiting block 309 is installed on both ends of the dial guide rail 3072 to limit the movement range of the vernier 308 of the goniometer.

[0074] The vernier fastening screw 310 is installed on the vernier fixing hole 3083. Tightening the vernier fastening screw 310 can fix the relative position of the vernier 308 of the goniometer on the dial guide rail 3072.

[0075] The slide bar fastening screw 311 is installed on the fixing hole 3122. Tightening the slide bar fastening screw 311 can fix the relative position of the slide bar 313 on the guide tube 312.

[0076] The guide tube 312 is installed and fixed on the vernier 308 of the goniometer.

[0077] The guide tube 312 is used to measure the length between the central axes of the mounting holes of the joint bearings 2 at both ends of the variable pitch tie rod 1.

[0078] Optionally, the guide tube 312 is provided with scale lines 3121, fixing holes 3122 and guide grooves 3123.

[0079] The scale line 3121 is used to mark specific length values, with each scale line being 1mm.

[0080] The fixing hole 3122 is used to install the slide rod fastening screw 311.

[0081] The guide groove 3123 serves as a moving guide rail for the slide bar 313.

[0082] The guide groove 3123 can limit the range of movement of the slide bar 313.

[0083] The slide bar 313 is used to measure the length between the central axes of the mounting holes of the joint bearings 2 at both ends of the variable pitch tie rod 1.

[0084] The slide bar 313 is used in conjunction with the guide tube 312 to improve measurement accuracy.

[0085] Optionally, the slide bar 313 is provided with scale lines 3131, guide pins 3132 and guide holes 3133.

[0086] The scale line 3131 is used to mark specific length values, and each scale line is (49 / 50) mm.

[0087] The scale line 3131 has a total of 50 equal divisions and a total length of 49mm.

[0088] The scale line 3131 has a measurement accuracy of 0.02mm because the difference between each division of the scale line of the slide rod 313 and the guide tube 312 is 0.02mm.

[0089] The guide pin 3132 is installed in the guide groove 3123 and can move along the length of the guide groove 3123.

[0090] The guide hole 3133 is used to insert the guide rod 3024, thereby ensuring that the U-shaped positioning long connector 302 can move in the vertical direction along the central axis of the variable pitch tie rod 1.

[0091] The variable pitch tie rod 1 to which this invention is applied has a joint bearing 2 connected to each end.

[0092] The spherical bearing 2 is connected to the structural fork lug by bolts 4.

[0093] Optionally, the spherical plain bearing 2 includes an inner ring 201 and an outer ring 202.

[0094] The inner ring 201 is used to install bolt 4.

[0095] The inner ring 201 has an end face that is parallel to the end face of the outer ring 202, and there is a height difference between them.

[0096] When the length of the variable pitch tie rod 1 is adjusted, the end face of the outer ring 202 and the structural fork lug must always maintain a safe distance.

[0097] The functions of the rotor collective pitch calibration device provided by the present invention during use will be described below with reference to the accompanying drawings.

[0098] The U-shaped positioning short connector 301 has a movement trajectory that intersects with and is perpendicular to the central axis of the variable pitch rod 1.

[0099] The U-shaped positioning short connector 301 has its U-shaped positioning groove 3011 having a central axis perpendicular to the central axis of the variable pitch tie rod 1.

[0100] The U-shaped positioning short connector 301 has its guide rod 3014 central axis intersecting with the central axis of the inner ring 201.

[0101] The U-shaped positioning long connector 302 has a movement trajectory that intersects with and is perpendicular to the central axis of the variable pitch rod 1.

[0102] The U-shaped positioning short connector 302 has its U-shaped positioning groove 3021 having a central axis perpendicular to the central axis of the variable pitch tie rod 1.

[0103] The U-shaped positioning short connector 302 has its guide rod 3024's central axis intersecting with the central axis of the inner ring 201.

[0104] The central axis of the positioning rod 304 is parallel to the central axis of the variable pitch rod 1.

[0105] The center axis of the mounting surface 3053 of the angle measuring instrument positioning bracket 305 coincides with the center axis of the variable pitch rod 1.

[0106] The central axis of the dial guide rail 3072 of the angle measuring instrument panel 307 coincides with the central axis of the variable pitch rod 1.

[0107] The center point of the dial scale line 3071 of the angle measuring instrument panel 307 coincides with the central axis of the variable pitch lever 1.

[0108] The center point of the motion trajectory of the vernier 308 of the goniometer coincides with the central axis of the variable pitch lever 1.

[0109] The vernier 308 of the goniometer has its vernier scale line 3081 coinciding with the central axis of the variable pitch rod 1.

[0110] The vernier 308 of the goniometer has its central axis of the vernier guide groove 3082 coinciding with the central axis of the variable pitch rod 1.

[0111] The guide tube 312 has its central axis parallel to the central axis of the variable pitch tie rod 1.

[0112] The central axis of the slide bar 313 is parallel to the central axis of the variable pitch tie rod 1.

[0113] The sliding rod 313 has a movement trajectory parallel to the central axis of the variable pitch rod 1.

[0114] During the use of the calibration device, there is relative movement between the U-shaped positioning short connector 301 and the positioning rod 304.

[0115] During the use of the calibration device, there is relative movement between the U-shaped positioning long connector 302 and the slide bar 313.

[0116] During the use of the calibration device, there is relative movement between the angle measuring instrument panel 307 and the angle measuring vernier 308.

[0117] During the use of the calibration device, there is relative movement between the vernier fastening screw 310 and the vernier 308 of the goniometer.

[0118] During the use of the calibration device, there is relative movement between the slide rod fastening screw 311 and the guide tube 312.

[0119] During the use of the calibration device, the relative movement of the angle measuring instrument panel 307 and the angle measuring vernier 308 can measure the relative angle value of the end faces of the joint bearings 2 at both ends of the variable pitch rod 1.

[0120] During the use of the calibration device, the relative movement of the guide tube 312 and the slide rod 313 can measure the length between the central axes of the mounting holes of the joint bearings 2 at both ends of the variable pitch tie rod 1.

[0121] Example 2 This invention discloses a rotor collective pitch calibration method, the operation process of which is as follows. Wherein, L is the axial length of the pitch control rod, α is the relative angle between the end faces of the joint bearings at both ends of the pitch control rod, θ is the rotor blade installation angle at the reference position, the functional relationship between the axial length of the pitch control rod and the rotor blade installation angle at the reference position is L=g(θ), L0 is the initial length of the pitch control rod, α0 is the theoretical angle of the pitch control rod, and θ0 is the theoretical value of the rotor blade installation angle at the reference position when the collective pitch is 0°. ① Initial adjustment of the variable pitch rod 1: Set the length of the auxiliary calibration device 3 to L0 and the angle to α, and tighten the slide rod fastening screw 311 and the vernier fastening screw 310. Install and fix the auxiliary calibration device 3 on the variable pitch rod 1, and adjust the variable pitch rod 1 until the initial length is L0 and the initial angle is α0. After the initial adjustment of the variable pitch rod 1 is completed, remove the auxiliary calibration device 3.

[0122] ② Installation of variable pitch tie rod 1: Connect one end to the rotor fork lug with bolts, and connect the other end to the servo rocker arm fork lug with bolts.

[0123] ③ Angle measurement of variable pitch tie rod 1: Install auxiliary calibration device 3 onto variable pitch tie rod 1, install U-shaped positioning short connector 301 and U-shaped positioning long connector 302 onto the joint bearings 2 at both ends of variable pitch tie rod 1 respectively, and measure the relative angle α between the end faces of the joint bearings at both ends of variable pitch tie rod 1. It should satisfy α=α0±10′.

[0124] ④ Fixing the angle of the variable pitch rod 1: Install the auxiliary calibration device 3 onto the variable pitch rod 1, and install the U-shaped positioning short connector 301 and the U-shaped positioning long connector 302 onto the joint bearings 2 at both ends of the variable pitch rod 1 respectively.

[0125] ⑤ Rotor blade installation angle measurement: Initially set the collective distance value to 0° using ground inspection equipment 5, and measure the installation angle θ1 of the rotor blade at the reference position using level 6. Record the difference between the measured value and the theoretical value ε=θ0-θ1.

[0126] ⑥ Adjustment of the length of the variable pitch rod 1: The ground inspection equipment is set with a total pitch value of ε. Based on the functional relationship L=g(θ), the axial length of the variable pitch rod and the installation angle θ of the rotor blade at the reference position are adjusted to (θ0±0.1°).

[0127] ⑦ Flight control system 7 parameter adjustment: Write ε into flight control system 7 according to the algorithm.

[0128] ⑧ Set the collective distance to 0° again using ground inspection equipment 5, and measure the installation angle θ of the rotor blade at the reference position using level 6. It should satisfy θ = (θ0 ± 0.1°).

[0129] The present invention has the following effects: ① It achieves precise positioning during angle measurement.

[0130] Analysis of the spherical plain bearing 2 shows that the end faces of the inner ring 201 and the outer ring 202 are parallel, but there is a height difference.

[0131] In previous measurements, the influence of the aforementioned height difference was ignored, resulting in a discrepancy between the reference surface and the actual spherical bearing 2 during measurement, thus causing positioning errors. In this invention, based on the structural characteristics of the spherical bearing 2, a U-shaped positioning short connector 301 and a U-shaped positioning long connector 302 were designed to ensure the consistency between the reference surface and the actual spherical bearing 2 during measurement, eliminating positioning errors.

[0132] ② It achieves precise positioning during length measurement.

[0133] The length of the variable pitch tie rod 1 is measured by measuring the distance between the center axes of the mounting holes of the two end spherical bearings 2 when both center axes are perpendicular to the center axis of the variable pitch tie rod 1.

[0134] In previous measurements, the distance between the outer surfaces of the mounting bolts 4 at both ends was mainly measured. However, this method could not guarantee that the central axis of the mounting holes of the spherical bearings 2 at both ends was perpendicular to the central axis of the variable pitch rod 1, which led to positioning and measurement errors.

[0135] In this invention, the U-shaped positioning grooves 3011 and 3021 on the U-shaped positioning short connector 301 and U-shaped positioning long connector 302 ensure that the central axes of the mounting holes of the spherical bearings 2 at both ends are perpendicular to the central axis of the variable pitch tie rod 1; the distance between the central axes of the guide rods 3014 and 3024 is the same as the distance between the central axes of the mounting holes of the spherical bearings 2 at both ends. This measurement method ensures the conformity of the measurement and positioning references with the actual object, eliminating reference errors and positioning errors during the length measurement process.

[0136] ③ An integrated design was adopted, enabling simultaneous measurement of length and angle.

[0137] The adjustment of the variable pitch rod 1 needs to meet both length and angle requirements.

[0138] The calibration device provided by the present invention includes an angle measuring instrument panel 307 and an angle measuring vernier 308 that can realize angle adjustment and measurement, and a guide tube 312 and a slide rod 313 that can realize length adjustment and measurement. The whole device adopts an integrated design and can realize synchronous adjustment and measurement of length and angle.

[0139] ④ It enables pre-installation adjustment and measurement while also meeting the requirements for post-installation adjustment and measurement.

[0140] The difference between adjusting and measuring the variable pitch tie rod 1 before and after installation is that: before installation, there is no absolute position requirement for the end face of the outer ring 202 of the spherical bearing 2; after installation, there is an absolute position requirement for the end face of the outer ring 202 of the spherical bearing 2, that is, it must always maintain a safe distance and absolute position with the structural fork lug.

[0141] In this invention, the outer positioning surface 3013 of the U-shaped positioning short connector 301 and the outer positioning surface 3023 of the U-shaped positioning long connector 302 are both positioned in contact with the surface of the structural fork lug on which the spherical bearing 2 is installed, thus ensuring the safe distance and absolute position between the end face of the outer ring 202 of the spherical bearing 2 and the structural fork lug.

[0142] ⑤ Improved the accuracy of length and angle adjustment measurements.

[0143] For angle measurement, a vernier angle measurement method combining the angle measuring instrument panel 307 and the vernier 308 is adopted, and the measurement accuracy reaches 2′.

[0144] For length measurement, a vernier length measurement method combining guide tube 312 and slide bar 313 is adopted, and the measurement accuracy reaches 0.02m.

[0145] ⑥ Easy to operate.

[0146] The U-shaped positioning short connector 301 and the U-shaped positioning long connector 302 adopt a fork-ear structure, which makes it convenient and quick to install and position on the spherical bearing 2.

[0147] The calibration device is installed on the variable pitch tie rod 1 by fitting and positioning the mounting surface 3053 and tightening the clamp 306, which ensures accurate positioning and simple operation.

[0148] Both length and angle adjustments are made using a vernier-type structure, which ensures efficient operation and accurate measurement.

[0149] Thus, the objective of this invention has been achieved.

[0150] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rotor collective pitch calibration device, characterized in that, include: The variable pitch lever connects to the rotor fork lug at one end and the servo rocker arm fork lug at the other end. The rotor blade calibration is completed by adjusting the axial length of the variable pitch lever and the relative angle between the end faces of the joint bearings at both ends. An auxiliary calibration device has an angle measuring mechanism and a distance measuring mechanism. The distance measuring mechanism is connected to the angle measuring mechanism and can move relative to it. The angle measuring mechanism and the distance measuring mechanism are respectively connected to the two end joint bearings of the variable pitch rod through positioning joints. A level is used to measure the installation angle of the rotor blades at a reference position and provide feedback to the ground inspection equipment. The ground inspection equipment converts the installation angle into a pitch value and sends it to the flight control system; The flight control system generates control commands based on the pitch change and sends them to the servos. The servos then manipulate the pitch control stick to calibrate the rotor's collective pitch.

2. The rotor collective pitch calibration device according to claim 1, characterized in that, The variable pitch rod includes a threaded rod body and a joint bearing, and the length is changed by axially rotating the rod body.

3. The rotor collective pitch calibration device according to claim 1, characterized in that, The angle measuring mechanism includes an angle measuring instrument panel, a vernier caliper, a vernier limit block, and a vernier fastening screw; the angle measuring instrument panel is horizontally set and connected to the rod body of the variable pitch tie rod through a angle measuring instrument positioning bracket and a clamp; the vernier caliper is movably set on the angle measuring instrument panel, and a vernier fastening screw is provided at the end of the vernier caliper; both ends of the angle measuring instrument panel are provided with vernier limit blocks.

4. The rotor collective pitch calibration device according to claim 3, characterized in that, The ranging mechanism includes a sliding rod fastening screw, a guide tube, and a sliding rod. The guide tube and the sliding rod are sleeved together. One end of the guide tube is vertically connected to the vernier of the goniometer. The relative position of the sliding rod and the guide tube is positioned by the fastening screw, and then the scale is read.

5. The rotor collective pitch calibration device according to claim 4, characterized in that, A positioning rod is vertically mounted on the angle measuring instrument panel, and a U-shaped positioning short connector is movably mounted radially on the positioning rod. The U-shaped positioning short connector is inserted into the joint bearing of the pitch-changing tie rod.

6. The rotor collective pitch calibration device according to claim 5, characterized in that, A U-shaped positioning long connector is provided in the radial direction of the slide rod, and the U-shaped positioning long connector is inserted into the joint bearing of the variable pitch tie rod.

7. The rotor collective pitch calibration device according to claim 6, characterized in that, The U-shaped positioning short connector is used to position the installation orientation of the spherical plain bearing and to measure the position and dimensions of the center axis of the mounting hole of the spherical plain bearing. The U-shaped positioning short connector is equipped with a U-shaped positioning groove, an inner positioning surface, an outer positioning surface, and a guide rod; The U-shaped positioning groove is used to connect bolts, and the outer circular surface of the bolt's smooth shank fits against the inner circular surface of the U-shaped positioning groove; The U-shaped positioning groove is located along the central axis of the variable pitch tie rod, and its groove size is the same as the outer diameter of the bolt. The inner positioning surface is in contact with the outer ring end face of the spherical bearing; The outer positioning surface is in contact with the surface of the structural fork lug on which the spherical bearing is installed; The U-shaped positioning short connector and the U-shaped positioning long connector are identical in all structural dimensions except for the corresponding guide rods and guide rod lengths.

8. The rotor collective pitch calibration device according to claim 7, characterized in that, The goniometer positioning bracket is used to fix the goniometer panel on the variable pitch tie rod; The goniometer positioning bracket is equipped with a positioning surface, a fastening groove, and a mounting surface; The positioning surface is in contact with the outer cylindrical surface of the variable pitch tie rod; The fastening groove is used to limit the binding position of the clamp; The mounting surface is used to mount and fix the angle measuring instrument panel; The clamp is used to fix the goniometer positioning bracket on the variable pitch tie rod.

9. The rotor collective pitch calibration device according to claim 8, characterized in that, The angle measuring instrument panel is used to measure the relative angle between the end faces of the joint bearings at both ends of the pitch-changing tie rod; The angle measuring instrument panel is equipped with dial scale lines and dial guide rails; The vernier of the goniometer is used to measure the relative angle between the end faces of the joint bearings at both ends of the variable pitch tie rod; The vernier and angle measuring instrument panel of the goniometer are used together to improve measurement accuracy; The vernier of the goniometer is equipped with vernier scale lines, vernier guide grooves, and vernier fixing holes; The vernier fixing hole is used to install the vernier fastening screw; The guide tube is mounted and fixed on the vernier caliper of the goniometer; The guide tube is used to measure the length between the central axes of the mounting holes of the joint bearings at both ends of the variable pitch tie rod. The guide tube is equipped with scale lines, fixing holes and guide grooves; The scale lines are used to indicate specific length values, with each scale line representing 1 mm. The fixing hole is used to install the slide bar fastening screw; The guide groove serves as a moving guide rail for the slide bar; The guide groove can limit the range of movement of the slide bar; The slide bar is used to measure the length between the central axes of the mounting holes of the joint bearings at both ends of the variable pitch tie rod; The slide bar and guide tube are used together to improve measurement accuracy; The slide bar is equipped with scale lines, guide pins, and guide holes; The scale lines are used to indicate specific length values; since the scale lines on the slide rod and the guide tube differ by 0.02mm per division, the measurement accuracy is 0.02mm. The guide pin is installed in the guide groove and can move along the length of the guide groove. The guide hole is used to insert the guide rod, thereby ensuring that the U-shaped positioning long joint can move in the vertical direction along the central axis of the variable pitch tie rod.

10. A method for calibrating rotor collective pitch, characterized in that, Includes the following steps: Initial adjustment of the pitch control rod: Set the length of the auxiliary calibration device to L0 and the angle to α, and tighten the slide bar fastening screw and the vernier fastening screw; install and fix the auxiliary calibration device on the pitch control rod, and adjust the pitch control rod to the initial length L0 and the initial angle α0; after the initial adjustment of the pitch control rod is completed, remove the auxiliary calibration device. Pitch control rod installation: Connect one end to the rotor fork lug with bolts, and the other end to the servo rocker arm fork lug with bolts; Variable pitch tie rod angle measurement: Install the auxiliary calibration device onto the variable pitch tie rod, install the U-shaped positioning short connector and the U-shaped positioning long connector onto the joint bearings at both ends of the variable pitch tie rod respectively, and measure the relative angle α between the end faces of the joint bearings at both ends of the variable pitch tie rod. It should satisfy α=α0±10′. Fixed pitch rod angle: Install the auxiliary calibration device onto the pitch rod, and install the U-shaped positioning short connector and U-shaped positioning long connector onto the joint bearings at both ends of the pitch rod respectively; Rotor blade installation angle measurement: Initially set the collective distance value to 0° using ground inspection equipment, and use a level to measure the installation angle θ1 of the rotor blade at the reference position at this time. Record the difference between the measured value and the theoretical value ε=θ0-θ1; Adjustment of the length of the variable pitch rod: The ground inspection equipment is set with a total pitch value of ε. According to the functional relationship L=g(θ), the axial length of the variable pitch rod is adjusted to the installation angle of the rotor blade at the reference position θ=(θ0±0.1°). Flight control system parameter adjustment: Write ε into the flight control system according to the algorithm; The collective distance is set to 0° again using the ground inspection equipment. The installation angle θ of the rotor blade at the reference position is measured with a level and should satisfy θ = (θ0 ± 0.1°). Repeat the above steps to complete the calibration of the other rotor blades.

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