Propeller pitch angle adjustment device and adjustment method

Abstract

The invention discloses a propeller pitch angle adjustment device and adjustment method, comprising: an outer circular ring, which is vertically arranged and has angle marks arranged along its outer edge; an inner circular ring, which is coaxially arranged with the outer circular ring and is located in the inner cavity of the outer circular ring and can rotate with its center in the outer circular ring; two fixed tubes, which are symmetrically arranged and respectively fixed on the two side edges of the inner circular ring, the connecting line of the two tube body axes passes through the center of the inner circular ring; two Y-shaped members, which are located in the inner cavity of the inner circular ring and have springs sleeved on their aggregated ends so that the aggregated ends can extend into the corresponding fixed tubes and can move along the fixed tubes; the springs are fixedly connected to the inner ends of the corresponding fixed tubes; the inner circular ring is used to clamp the blades and drive the blades to rotate a predetermined angle, thereby adjusting the angle between the blade chord and the rotating plane of the propeller disk; the invention improves the efficiency of the experiment and reduces the cost, can accurately find the positions of the front and rear edges at the 75% spanwise section, and realizes the adjustment of the pitch angle through the angle between the blade chord and the rotating plane of the propeller disk.

Description

Technical Field

[0001] The invention belongs to the field of propeller test equipment, and in particular relates to a propeller pitch angle adjustment device and an adjustment method. Background Art

[0002] General aviation refers to civil aviation activities other than public air transport carried out by civil aircraft, including: operational flights in industry, agriculture, forestry, fishery, construction, as well as flight activities in the fields of medical care, disaster relief, scientific experiments, ocean monitoring, culture and education, etc. General aircraft usually use propellers as the device for generating thrust (thrust). In the design stage of general aircraft, it is very necessary to accurately measure the performance parameters of the propellers.

[0003] The pitch angle is generally defined as the angle between the chord line of the airfoil section at the spanwise position of 70% or 75% of the propeller from the center of the propeller disc and the propeller disc rotation plane. In the experimental process, in order to obtain more comprehensive data, the propeller pitch angle is usually adjusted multiple times. The existing experimental methods for adjusting the pitch angle mainly include two methods: using height difference calculation (hereinafter referred to as the height difference method) and using angle block adjustment (hereinafter referred to as the angle block method).

[0004] The height difference method is to use a height gauge to measure the height difference between the leading edge and the trailing edge of the blade after the experimental blade is fixed, and then calculate the pitch angle of the propeller based on trigonometric functions. The angle block method is to process the shape change module of the local blade under different pitch angles, and match the blade surface through different modules to achieve the purpose of pitch condition.

[0005] Both of the above methods have their own shortcomings:

[0006] Height difference method: Under small pitch angle conditions, the height difference between the leading and trailing edges of the blade is actually very small, and the result measured and calculated using a height gauge is not accurate; under large pitch angle conditions, it is difficult to find the leading edge point of the local section using a height gauge, which also causes inaccurate measurement; during the adjustment process, it is necessary to adjust the pitch angle to a specific angle and then measure the height difference between the leading and trailing edges. If it is not enough, repeat the above steps, which is cumbersome and inefficient.

[0007] Angle blocks: There is no way to continuously change the angle, you can only make angle blocks with a series of angles, which increases the cost of the experiment. Summary of the invention

[0008] The purpose of the present invention is to provide a propeller pitch angle adjustment device and adjustment method, which can quickly and accurately adjust the required pitch angle parameters.

[0009] The present invention adopts the following technical solution: a propeller pitch angle adjustment device, comprising:

[0010] The outer ring is vertically arranged with angle marks along its outer edge.

[0011] The inner ring is coaxially arranged with the outer ring and is located in the inner cavity of the outer ring, and can rotate with its center in the outer ring.

[0012] Two fixed tubes are symmetrically arranged and fixed on the two side edges of the inner ring respectively. The connecting line of the two tube axes passes through the center of the inner ring.

[0013] Two Y-shaped pieces are located in the inner cavity of the inner ring, and a spring is sleeved on the aggregated end thereof so that the aggregated end can extend into the corresponding fixed tube and can move along the fixed tube. The spring is fixedly connected to the inner end of the corresponding fixed tube. The openings of the bifurcated ends of the two Y-shaped pieces face the inner cavity of the inner ring. The openings of the two Y-shaped pieces are used to cooperate with each other to clamp the leading edge and the trailing edge of the rotating blade of the propeller respectively. The center lines of the two Y-shaped pieces coincide with the center lines of the two fixed tubes, and the center lines of the two Y-shaped pieces are also the chord lines of the blades.

[0014] Among them, the inner ring is used to clamp the blade and drive the blade to rotate to a predetermined angle, thereby adjusting the angle between the blade chord and the rotating plane of the propeller disc.

[0015] Furthermore, it also includes a fixed ring fixed by a bracket and arranged vertically, the fixed ring is located at the rear side of the inner ring and the outer ring, and is arranged coaxially with the inner ring and the outer ring, and is used to fix the inner ring and the outer ring.

[0016] Furthermore, the upper and lower sides of the fixed ring are fixedly connected with U-shaped support grooves, and the two support grooves extend into the inner cavity of the inner ring from back to front. The grooves of the two support grooves are used for the inner edges of the inner ring to extend into, so that the two support grooves clamp the inner ring.

[0017] Furthermore, a fixing hole is provided on the outer ring, and the fixing hole is used for bolts to extend into and fix the outer ring on the fixing ring.

[0018] Furthermore, the fixing hole is arc-shaped, the arc center of the arc-shaped fixing hole coincides with the center of the outer ring and the inner ring, and the arc-shaped fixing hole is used to adjust the horizontal state of the outer ring.

[0019] Furthermore, the outer edge of the inner ring fits with the inner edge of the outer ring.

[0020] Furthermore, a pointer is fixedly connected to the outer end of any fixed tube, and the center line of the pointer passes through the center of the inner ring. One end of the pointer is fixedly connected to the outer end of the fixed tube, and the other end is close to the angle mark of the outer ring. The pointer is used to indicate the rotation angle of the inner ring relative to the outer ring.

[0021] Furthermore, the bracket consists of two vertical poles, a flat plate and multiple adjusting bolts. The two vertical poles are vertically arranged and symmetrical to each other. The lower ends of the two vertical poles are fixedly connected to the flat plate. The flat plate is supported by adjusting bolts on all sides. The multiple adjusting bolts are used to adjust the flat plate to make it horizontal.

[0022] Furthermore, levels are installed on the flat plate and the outer ring.

[0023] A propeller pitch angle adjustment method comprises the following steps:

[0024] Adjust the flat plate and the outer ring to a horizontal state;

[0025] Place the propeller disk together with the blades horizontally on the operating platform, and adjust the height of the operating platform so that the rotating plane of the disk is horizontally set and the center of the inner ring is on the rotating plane of the disk;

[0026] The leading edge and the trailing edge of the 75% cross section of the rotating blade of the propeller are clamped by two Y-shaped pieces so that the center line of the two Y-shaped pieces after clamping the blade is the blade chord line;

[0027] Use the pointer to rotate the inner ring to a predetermined angle;

[0028] Tighten the bolts at the hub to complete the adjustment of the pitch angle of the blade, and so on, until the pitch angles of all blades are adjusted to the same angle.

[0029] The beneficial effects of the present invention are as follows: the present invention improves the efficiency of the experiment and reduces the cost, can accurately find the positions of the front and rear edges at the 75% spanwise section, and adjust the pitch angle through the angle between the blade chord and the propeller disk rotation plane; the pitch angle can be found quickly, directly and accurately, and quickly adjusted; the device can adjust the angle of any propeller, reducing the processing cost; the inner ring of the present invention can change the angle continuously and arbitrarily many times as needed, which not only improves the experimental efficiency but also broadens the angle selection surface; the present invention is suitable for angle adjustment on propellers of any shape and any section, reducing the experimental cost; the adjustment is more precise and durable, and the model installation accuracy is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is an axial view of the present invention;

[0031] Figure 2 It is a schematic structural diagram of the Y-shaped member of the present invention;

[0032] Figure 3 It is a rear view of the present invention.

[0033] Among them: 1. Inner ring; 2. Fixed tube; 3. Spring; 4. Y-shaped piece; 5. Outer ring; 6. Converging end; 7. Forked end; 8. Angle mark; 9. Fixed ring; 10. Support groove; 11. Fixed hole; 12. Pointer; 13. Vertical pole; 14. Plate; 15. Adjustment bolt. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] The present invention discloses a propeller pitch angle adjustment device, such as Figure 1-3 As shown, it includes: an inner ring 1, two fixed tubes 2, two springs 3, two Y-shaped parts 4, and an outer ring 5. The outer ring 5 and the inner ring 1 are both arranged vertically, the outer ring 5 and the inner ring 1 are arranged coaxially, and the outer ring 5 is located on the outside of the inner ring 1. An angle mark 8 is arranged around the outer edge of the outer ring 5. The inner ring 1 can rotate with its center in the outer ring 5. The inner ring 1 is used to clamp the blade and then drive the blade to rotate a predetermined angle, thereby adjusting the angle between the blade chord and the rotating plane of the propeller disk. In this way, after the two Y-shaped parts 4 of the inner ring 1 clamp the leading edge and the trailing edge of the blade, the inner ring 1 can be rotated to adjust the angle between the blade chord and the rotating plane of the propeller disk.

[0036] The two fixed tubes 2 are respectively fixed on the two side edges of the inner ring 1. The two fixed tubes 2 are symmetrically arranged. The connecting line of the axes of the two fixed tubes 2 passes through the center of the inner ring 1, so as to ensure that the center lines of the two fixed tubes 2 coincide with each other and ensure that the center lines of the two fixed tubes 2 are the chord lines of the blades.

[0037] The two Y-shaped members 4 are located in the inner cavity of the inner ring 1. A spring 3 is sleeved on the aggregated end 6 of the two Y-shaped members 4, so that the aggregated end 6 can extend into the corresponding fixed tube 2 and can move along the fixed tube 2. The spring 3 is fixedly connected to the inner end of the corresponding fixed tube 2. The openings of the two forked ends 7 of the two Y-shaped members 4 face the inner cavity of the inner ring 1. The openings of the two Y-shaped members 4 are used to cooperate with each other to clamp the leading edge and the trailing edge of the rotating blade of the propeller respectively. The center lines of the two Y-shaped members 4 coincide with the center lines of the two fixed tubes 2, and the center lines of the two Y-shaped members 4 are also the blade chord lines.

[0038] The opening angles of the two Y-shaped parts 4 can be set according to the angles of the leading edge and the trailing edge of the blade, as long as the center line of the two Y-shaped parts 4 is the chord line of the blade, because the purpose of the two Y-shaped parts 4 is to ensure that the blade is fully clamped and the chord line of the blade coincides with the center line of the two Y-shaped parts 4.

[0039] A spring 3 is sleeved on the aggregated end 6 of the two Y-shaped members 4. Since the blade needs to be fully clamped, the spring 3 needs to be compressed back and forth to meet the clamping requirement. Therefore, the closer the free ends of the aggregated ends 6 of the two Y-shaped members 4 are arranged to the fixed tube 2, the easier it is to control the movement of the Y-shaped member 4. Otherwise, if the aggregated end 6 is too far away from the fixed tube 2, the spring 3 may be easily twisted after being compressed, resulting in the inability of the aggregated end 6 to enter the inner cavity of the fixed tube 2, making it impossible for the blade chord line to coincide with the center line of the two Y-shaped members 4, affecting the adjustment effect.

[0040] The two ends of the blade are the leading edge and the trailing edge, respectively. Since the leading edge is blunt-shaped, when the Y-shaped piece 4 contacts the leading edge, it is similar to making an inscribed circle at the opening of the Y-shaped piece 4. Therefore, the vertex of the Y-shaped piece 4 and the leading edge of the airfoil are in the same chord direction, thus achieving the capture of the leading edge point. Since the trailing edge is a sharp trailing edge, it is easy to find the trailing edge point using the Y-shaped piece 4.

[0041] The present invention further includes a fixing ring 9 fixed by a bracket and arranged vertically, the fixing ring 9 is located at the rear side of the inner ring 1 and the outer ring 5, and is arranged coaxially with the inner ring 1, and the fixing ring 9 is used to fix the inner ring 1 and the outer ring 5. In order to facilitate the fixing of the inner ring 1 and the outer ring 5, the fixing ring 9 is arranged to fix the inner ring 1 and the outer ring 5, so that the inner ring 1 can rotate while the outer ring 5 does not rotate, and then the angle of rotation of the blade driven by the inner ring 1 is measured to ensure the accuracy of adjustment.

[0042] The upper and lower sides of the fixed circular ring 9 are fixedly connected with U-shaped support grooves 10. The two support grooves 10 extend from the back to the front into the inner cavity of the inner circular ring 1. The grooves of the two support grooves 10 are used for the inner edges of the inner circular ring 1 to extend into, so that the two support grooves 10 clamp the inner circular ring 1. Because the inner circular ring 1 needs to rotate, the best fixing method is to fix the inner circular ring 1 on the fixed circular ring 9 through the support grooves 10, which can not only ensure that the rotation of the inner circular ring 1 is not affected, but also ensure that the center of the inner circular ring 1 does not change during the rotation process, so as to avoid affecting the accuracy of the measurement. After the two support grooves 10 are set, the inner edge of the inner circular ring 1 extends into the support grooves 10, making the inner circular ring 1 more stable and easy to operate.

[0043] The outer ring 5 is provided with a fixing hole 11, and the fixing hole 11 is used for bolts to extend into and fix the outer ring 5 to the fixing ring 9. After the inner ring 1 is fixed, the outer ring 5 needs to be fixed, and the outer ring 5 does not need to be rotated during the adjustment process, so the outer ring 5 can be directly fixed to the fixing ring 9 by bolts.

[0044] The fixing hole 11 is arc-shaped, and the arc center of the arc-shaped fixing hole 11 coincides with the center of the outer ring 5 and the inner ring 1. The arc-shaped fixing hole 11 is used to adjust the horizontal state of the outer ring 5. Although the outer ring 5 does not need to be rotated during the process of adjusting the blade pitch angle, when adjusting the horizontal state of the outer ring 5, it is necessary to fine-tune the outer ring 5 so that the outer ring 5 is in a horizontal state, that is, the line connecting the 0-degree mark and the 180-degree mark of the outer ring 5 is parallel to the horizontal plane, so as to ensure the accuracy of the subsequent adjustment of the blade pitch angle. By setting the fixing hole 11 to be arc-shaped, the horizontal state of the outer ring 5 can be adjusted by fine-tuning the fixing position of the bolt.

[0045] The outer edge of the inner ring 1 and the inner edge of the outer ring 5 are fitted together. In order to make the device compact and easy to use, the outer edge of the inner ring 1 and the inner edge of the outer ring 5 are fitted together, so that the scale markings on the outer ring 5 can be closest to the inner ring 1. In this way, the rotation angle of the inner ring 1 can be well observed, and the inner ring 1 can be accurately rotated to accurately adjust the pitch angle.

[0046] A pointer 12 is also fixedly connected to the outside of any fixed tube 2, and the center line of the pointer 12 passes through the center of the inner ring 1. One end of the pointer 12 is fixedly connected to the outer end of the fixed tube 2, and the other end is close to the angle mark 8 of the outer ring 5. The pointer 12 is used to mark the rotation angle of the inner ring 1 relative to the outer ring 5. By setting the pointer 12, the slender feature of the free end of the pointer 12 is used to accurately rotate the required pitch angle. If it is not set, the error will be greater if it is judged by the extension line of the fixed tube 2. With the pointer 12, it is more accurate and the error is smaller.

[0047] The bracket is composed of two vertical poles 13, a flat plate 14 and a plurality of adjusting bolts 15. The two vertical poles 13 are vertically arranged and symmetrical to each other. The lower ends of the two vertical poles 13 are fixedly connected to the flat plate 14. The flat plate 14 is supported by the adjusting bolts 15 on all sides. The plurality of adjusting bolts 15 are used to adjust the flat plate 14 to make it in a horizontal state.

[0048] The inner ring 1 and the outer ring 5 of the present invention need to be in a horizontal state during use, but the inner ring 1 and the outer ring 5 are both circular and cannot be placed accurately. Therefore, the inner ring 1 and the outer ring 5 can be well fixed on the vertical pole 13 through the flat plate 14, the vertical pole 13 and the adjusting bolt 15, and the horizontal state can be found through the adjusting bolt 15, which is convenient and quick.

[0049] Levels are installed on the flat plate 14 and the outer ring 5. In order to ensure the horizontal state of the entire device, levels are set on the flat plate 14 and the outer ring 5, which can ensure that the flat plate 14 and the outer ring 5 are quickly aligned, thereby increasing the speed of adjusting the pitch angle.

[0050] The method for adjusting the pitch angle of the present invention is as follows:

[0051] The present invention is placed on a platform and adjusted to a horizontal state, so that the flat plate 14 and the outer ring 5 are in a horizontal state, that is, the horizontal directions through the centers of the inner ring 1 and the outer ring 5 are 0° and 180°, and the propeller disk together with the blades are placed horizontally on the operating platform, and the height of the operating platform is adjusted so that the rotation plane of the disk is horizontally set and the center of the inner ring 1 is on the rotation plane of the disk.

[0052] Extend any blade horizontally into the inner ring 1, and 75% of the span-wise section is clamped by two Y-shaped parts 4. At this time, the connecting line direction of the two Y-shaped parts 4 is the blade chord; rotate the inner ring 1 to a predetermined angle, and the inner ring 1 drives the Y-shaped part 4 and the blade to rotate together and adjust to the required angle; tighten the screws at the hub to complete the angle adjustment of one blade; and so on, until the pitch angles of all blades are adjusted to the same angle.

[0053] The present invention also discloses a propeller pitch angle adjustment method, which comprises the following steps:

[0054] Step 1: Adjust the flat plate 14 and the outer ring 5 to a horizontal state.

[0055] Step 2: Place the propeller disk together with the blades horizontally on the operating platform, and adjust the height of the operating platform so that the rotation plane of the disk is set horizontally and the center of the inner ring 1 is on the rotation plane of the disk.

[0056] Step 3: The leading edge and the trailing edge of the 75% cross section of the propeller rotating blade are clamped by two Y-shaped pieces 4, so that the center line of the two Y-shaped pieces 4 after clamping the blade is the blade chord line.

[0057] Step 4: Using the pointer 12 to mark, rotate the inner ring 1 to a predetermined angle.

[0058] Step 5: Tighten the bolts on the propeller hub to complete the adjustment of the pitch angle of the blade. Repeat this process until the pitch angles of all the blades are adjusted to the same angle.

Claims

1. A propeller pitch angle adjustment device, characterized in that: include: The outer ring (5) is arranged vertically and has angle marks (8) arranged along its outer edge. The inner ring (1) is coaxially arranged with the outer ring (5) and is located in the inner cavity of the outer ring (5), and can rotate with its center inside the outer ring (5). The two fixed tubes (2) are symmetrically arranged and respectively fixed on the two side edges of the inner ring (1). The connecting line of the two tube body axes passes through the center of the inner ring (1). Two Y-shaped members (4) are located in the inner cavity of the inner ring (1), and a spring (3) is sleeved on the aggregated end (6) thereof so that the aggregated end (6) can extend into the corresponding fixed tube (2) and can move along the fixed tube (2). The spring (3) is fixedly connected to the inner end of the corresponding fixed tube (2). The openings of the bifurcated ends (7) of the two Y-shaped members (4) face the inner cavity of the inner ring (1). The openings of the two Y-shaped members (4) are used to cooperate with each other to clamp the leading edge and the trailing edge of the rotating blade of the propeller respectively. The center lines of the two Y-shaped members (4) coincide with the center lines of the two fixed tubes (2). The center lines of the two Y-shaped members (4) are also the chord lines of the blades. The inner ring (1) is used to clamp the blade and drive the blade to rotate at a predetermined angle, thereby adjusting the angle between the blade chord and the rotating plane of the propeller disc; It also includes a fixing ring (9) fixed by a bracket and arranged vertically, the fixing ring (9) being located at the rear side of the inner ring (1) and the outer ring (5) and being arranged coaxially with the inner ring (1) and the outer ring (5), and the fixing ring (9) being used to fix the inner ring (1) and the outer ring (5); The upper and lower sides of the fixed circular ring (9) are both fixedly connected with U-shaped support grooves (10), and the two support grooves (10) extend from the back to the front into the inner cavity of the inner circular ring (1), and the grooves of the two support grooves (10) are used for the inner edges of the inner circular ring (1) to extend into, so that the two support grooves (10) clamp the inner circular ring (1); The bracket is composed of two vertical poles (13), a flat plate (14) and a plurality of adjusting bolts (15); the two vertical poles (13) are arranged vertically and symmetrically; the lower ends of the two vertical poles (13) are fixedly connected to the flat plate (14); the flat plate (14) is supported by adjusting bolts (15) on all sides; the plurality of adjusting bolts (15) are used to adjust the flat plate (14) to be in a horizontal state; The leading edge of the propeller rotating blade is blunt-nosed; A pointer (12) is also fixedly connected to the outer end of any of the fixed tubes (2), the center line of the pointer (12) passes through the center of the inner ring (1), one end of the pointer (12) is fixedly connected to the outer end of the fixed tube (2), and the other end is close to the angle mark (8) of the outer ring (5), and the pointer (12) is used to indicate the rotation angle of the inner ring (1) relative to the outer ring (5).

2. A propeller pitch angle adjustment device according to claim 1, characterized in that: The outer ring (5) is provided with a fixing hole (11), and the fixing hole (11) is used for bolts to extend into and fix the outer ring (5) to the fixing ring (9).

3. A propeller pitch angle adjustment device according to claim 2, characterized in that: The fixing hole (11) is arc-shaped, the arc center of the arc-shaped fixing hole (11) coincides with the center of the outer ring (5) and the inner ring (1), and the arc-shaped fixing hole (11) is used to adjust the horizontal state of the outer ring (5).

4. A propeller pitch angle adjustment device according to claim 3, characterized in that: The outer edge of the inner ring (1) and the inner edge of the outer ring (5) are in contact with each other.

5. A propeller pitch angle adjustment device according to claim 4, characterized in that: Level gauges are installed on the flat plate (14) and the outer ring (5).

6. A method for adjusting a propeller pitch angle adjustment device according to any one of claims 1 to 5, characterized in that: It consists of the following steps: Adjust the plate (14) and the outer ring (5) to a horizontal state; Placing the propeller disk together with the propeller blades horizontally on an operating platform, and adjusting the height of the operating platform so that the propeller disk rotation plane is arranged horizontally and the center of the inner ring (1) is on the propeller disk rotation plane; The leading edge and the trailing edge of the 75% cross section of the propeller rotating blade are clamped by two Y-shaped members (4), so that after the blade is clamped, the center line of the two Y-shaped members (4) is the blade chord line; Using the pointer (12) to mark, rotate the inner ring (1) to a predetermined angle; Tighten the bolts at the hub to complete the adjustment of the pitch angle of the blade, and so on, until the pitch angles of all blades are adjusted to the same angle.

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