CN103398840A - Fan blade fatigue loading and gravity compensation device and test method thereof - Google Patents

Abstract

The invention provides a fan blade fatigue loading and gravity compensation device and a test method thereof, belonging to the field of a blade load simulation test device, and particularly relates to a fatigue loading and gravity compensation device for fan blades and a test method thereof. The fan blade fatigue loading and gravity compensation device comprises a fatigue loading device and a gravity compensation device, the fatigue loading device comprises a blade clamp (5), a power device and a fixing guide rail (1), the bottom of the power device is connected with the guide rail (1) which is fixedly arranged on the ground, the top part of the power device is hinged to the bottom of the blade clamp (5), one side of the fatigue loading device is provided with the gravity compensation device, and the external force loading end of the gravity compensation device is connected with the top part of the blade clamp (5). Firstly, the traditional installation and loading method of fixing the loading device on the surface of a blade loading point is changed, and the inherent properties of blades are maintained. Moreover, extra gravitational influence on the blades caused by a test device can be eliminated by the added gravity compensation device, thereby completely avoiding the defect of test data distortion resulting from installation of the test device.

Description

Fatigue loading and gravity compensation device and test method of fan blade

technical field

The invention relates to a fatigue loading and gravity compensation device of a fan blade and a test method thereof, belonging to the field of blade load simulation test equipment, in particular to a fatigue loading test device of a four-cylinder driven wind turbine blade.

Background technique

The wind turbine blade fatigue loading test device is mainly used for the load simulation test of the wind turbine blade. The current technical solutions mainly have the following deficiencies: First, the fatigue loading test device is currently used to fix the blade loading point, and the blade is connected to the blade through a fixture. In the integrated structural scheme, the loading device is placed on the blade, which adds a large extra weight to the blade, changes the inherent characteristics of the blade, and easily causes distortion of the fatigue test data.

Second, the current fatigue loading test device for wind turbine blades driven by hydraulic cylinders can only achieve uniaxial loading of the blades, that is, the blades are loaded in the facing and chord directions separately (the vibration at the upper and lower positions of the blade is considered as facing loading, and the vibration at the left and right positions is considered as chord direction). Loading) method, when the face-to-face loading is completed, first remove the fatigue loading device and fixture from the blade, then remove the blade from the cylindrical loading support, turn the blade 90 degrees, and then reinstall it on the fatigue loading support On the seat, and then install the blade clamp and fatigue loading device, it is very troublesome in engineering application. In addition, the fatigue loading devices are all installed on the blades, adding an extra weight to the blades. At the same time, there is no gravity compensation device, which exacerbates the inaccuracy of the experimental structure.

Therefore, the uniaxial loading method of the prior art is quite different from the actual force condition of the blade, the test period is long, the test device is not suitable, and the test results are not ideal.

Contents of the invention

The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art, to provide a fatigue loading and gravity compensation device for fan blades with short test period, no influence on the inherent characteristics of the blade, accurate test results, fatigue loading and gravity compensation at the same time and its test methods.

The technical solution adopted by the present invention to solve the technical problem is: the fatigue loading and gravity compensation device and test method of the fan blade, which is characterized in that: it includes a fatigue loading device and a gravity compensation device, and the fatigue loading device includes a blade fixture, a power device The bottom of the power unit is connected to the guide rail fixed on the ground, the top of the power unit is hinged to the bottom of the blade fixture, the side of the fatigue loading device is provided with a gravity compensation device, and the external force loading end of the gravity compensation device is connected to the top of the blade fixture. The size and size of the blade fixture can be adjusted arbitrarily, which has good versatility, and the installation of the blade fixture does not affect the inherent characteristics of the blade, and the uniaxial or biaxial fatigue loading test of the blade can be realized without changing the structure of the device, with flexibility very high.

The blade clamp is installed at 70% along the blade span.

The power unit is a hydraulic power unit, and two groups are symmetrically arranged left and right, and each group includes a horizontal hydraulic cylinder installed horizontally in the guide rail and an inclined hydraulic cylinder connected to it, the left horizontal hydraulic cylinder and The left side inclined hydraulic cylinders are hinged through the left slider, and the right horizontal hydraulic cylinder and the right inclined hydraulic cylinder are hinged through the right slider; the left end of the left horizontal hydraulic cylinder and the right end of the right horizontal hydraulic cylinder Fix and connect the left and right ends of the guide rail respectively. Adjust the length of the two inclined hydraulic cylinders in real time to realize blade facing, chord or two-axis loading. During the test, if the amplitude of the blade is not enough, you can assist in adjusting the length of the two horizontal hydraulic cylinders, or adjust the length of the two horizontal hydraulic cylinders in advance. The positions of the fixed ends on both sides can be used to change the magnitude of the blade loading.

Each hydraulic cylinder of the power unit is embedded with a magnetostrictive sensor for real-time monitoring of the length of the hydraulic cylinder.

The gravity compensation device includes a fixed bracket and a plurality of pulleys installed on the fixed bracket, a slider linkage mechanism, a push-pull cylinder and a hydraulic winch. The upper end of the slider link mechanism is connected, and the lower end of the slider link mechanism is connected with a push-pull oil cylinder vertically installed on the right side of the fixed bracket.

The multiple pulleys include the first pulley installed on the lower left side of the fixed bracket, the second pulley on the upper left side of the fixed bracket, and the third pulley installed on the outer end of the support frame. The first pulley, the second pulley and the third pulley, the free end of the steel wire rope is fixedly connected to the top of the blade clamp as an external force loading end.

The slider link mechanism includes a slide rail, a longitudinal slider and a connecting rod, the slide rail is vertically installed on the right side of the fixed bracket, the slider is installed in the slide rail, the upper side of the slider is connected to the lower end of the connecting rod, The lower side is connected to the output end of the push-pull oil cylinder; the top end of the connecting rod is connected to the sliding end on the outside of the support frame.

The other side of the fatigue loading device is provided with a blade loading support at the same height as the blade clamp, and the blade loading support is a cylindrical support provided with a blade fixing hole for placing the blade root.

A test method using the fatigue loading and gravity compensation device of the fan blade as described above is characterized in that it includes the following steps,

a. First, fix the fatigue loading device of the fan blade, fix the guide rail on the ground with high-strength bolts, install the power unit in the guide rail, and hinge the blade clamp on the top of the power unit;

b. Place a cylindrical blade loading support on one side of the guide rail, fix the root of the fan blade in the blade fixing hole of the cylindrical blade loading support, and install a blade clamp along 70% of the blade span to keep the fan blade horizontal Install;

c. Stretch the wire rope from the hydraulic winch of the gravity compensation device, wind the wire rope through the first pulley, the second pulley and the third pulley in sequence, and the free end of the wire rope is fixedly connected to the top of the blade fixture as the external force loading end, and A tension sensor is connected in series on the wire rope to monitor the tension on the wire rope in real time;

d. Start the power unit, and under the action of the control system, the left inclined hydraulic cylinder and the right inclined hydraulic cylinder drive the blades to perform fatigue tests, and adjust the lengths of the left inclined hydraulic cylinder and right inclined hydraulic cylinder in real time to achieve Blade facing, chord or two-axis loading;

e. During the up and down vibration of the blade, observe the tension value displayed by the tension sensor connected in series on the wire rope in real time, and control the positive and negative rotation of the hydraulic winch according to the tension value to ensure that the force on the wire rope remains constant;

f. The magnetostrictive sensor embedded in the hydraulic cylinder monitors the length change of the corresponding hydraulic cylinder in real time and feeds back to the control system. The control system obtains the current coordinates of the blade loading point according to the feedback signal, and assists in adjusting the left horizontal hydraulic cylinder and the right The length of the horizontal hydraulic cylinder, finally to obtain accurate fatigue loading data.

The blade fixture is a rectangular body with a combined structure. The rectangular body includes a frame body surrounded by angle steel or channel steel on the upper and lower sides and splints fixedly installed on the front and rear ends of the frame body. The center of the splint is provided with a blade installation hole. The splint is composed of two rectangular plates arranged symmetrically up and down, and the inner sides of the two rectangular plates are provided with arc-shaped edges, and the two arc-shaped edges are combined to form the blade mounting holes of the splint.

Compared with prior art, the beneficial effect that the present invention has is:

1. Change the installation and fixing method of the fatigue loading device to maintain the inherent characteristics of the blade: the fatigue loading and gravity compensation device of the fan blade and its test method are directly fixed on the ground through the guide rail, completely changing the previous loading device fixed on the surface of the blade loading point The installation and loading method ensures that the installation of the test device does not change the inherent properties of the blade, thereby completely eliminating the disadvantages of the distortion of the test data caused by the installation of the test device.

2. Reduce the error to the greatest extent and ensure the accuracy and reliability of the test data: a gravity compensation device is installed on the fatigue loading side at the same time, and at the same time of fatigue loading, it can overcome the gravity effect caused by the self-weight of the blade fixture and other test devices on the blade in real time , to the greatest extent restored the force situation of the blade in the actual stress process, reduced the force error, fully guaranteed the reliability, authenticity and accuracy of the fatigue loading data, eliminated the error existing in the test process to the greatest extent, and guaranteed the test results .

3. The structure is simple, the design is reasonable, and multi-directional loading is realized: four hydraulic cylinders arranged symmetrically are used for dynamic fatigue loading of the fan blades, and the fatigue loading of the blades in the face, chord direction or two axes is realized on the same device at the same time, shortening The test cycle is shortened, and the tediousness of repeatedly disassembling and installing the blade fixture is eliminated. As long as different control methods are used, the test requirements can be met, and the disadvantages of the existing loading schemes that can only achieve single-axis or double-axis are eliminated.

4. It can achieve a large range of blade movement. By adjusting the length of the four hydraulic drive cylinders or changing the fixed end position of the horizontal hydraulic cylinder and the length of the horizontal hydraulic cylinder, the blade can be loaded in a large range and the test cycle can be shortened.

Description of drawings

Figure 1 is a schematic diagram of an axonometric view of a four-cylinder driven fan blade fatigue loading device.

Fig. 2 is a front view schematic diagram of a four-cylinder driven fan blade fatigue loading device.

Fig. 3 is a schematic diagram of the motion process of the four-cylinder driven fan blade fatigue loading device.

Fig. 4 is a schematic diagram of an axonometric view of a four-cylinder-driven fan blade gravity compensation device.

Fig. 5 is a front view schematic diagram of a gravity compensation device for fan blades driven by four cylinders.

Among them: 1. Guide rail 2. Left slider 3. Left horizontal hydraulic cylinder 4. Left inclined hydraulic cylinder 5. Blade fixture 6. Right inclined hydraulic cylinder 7. Right slider 8. Right horizontal hydraulic cylinder 9 , sensor 10, splint 11, blade installation hole 12, frame body 13, fixed bracket 14, push-pull cylinder 15, hydraulic winch 16, running wheel 17, support frame 18, first pulley 19, second pulley 20, third pulley 21 , slide rail 22, slider 23, connecting rod 24, blade loading support 25, blade fixing hole.

Detailed ways

Fig. 1～3 is preferred embodiment of the present invention, below in conjunction with accompanying drawing 1～3 the present invention is described further.

Referring to accompanying drawings 1-3: Fatigue loading and gravity compensation device for fan blades, including fatigue loading device and gravity compensation device, fatigue loading device includes blade fixture 5, power device and guide rail 1 for fixing, guide rail 1 passes through uniformly distributed multiple A fixed screw is fixedly installed on the ground, the bottom of the power unit is connected with the guide rail 1 fixed on the ground, the top of the power unit is hinged to the bottom of the blade clamp 5, and the blade clamp 5 is installed at 70% of the span direction of the blade, in the fatigue loading device A gravity compensation device is arranged on one side, and the external force loading end of the gravity compensation device is connected to the top of the blade fixture 5 . The other side of the fatigue loading device is provided with a blade loading support 24 at the same height as the blade fixture 5, and the blade loading support 24 is a cylindrical support provided with a blade fixing hole 25 for placing the blade root.

The power unit is a hydraulic power unit, and two groups are symmetrically arranged left and right, and each group includes a horizontal hydraulic cylinder installed horizontally in the guide rail 1 and an inclined hydraulic cylinder connected to it, and each hydraulic cylinder is embedded with There is a magnetostrictive sensor 9 for monitoring the length of the hydraulic cylinder in real time. The left horizontal hydraulic cylinder 3 installed on the left side and the left inclined hydraulic cylinder 4 are hinged through the left slide block 2, and the right horizontal hydraulic cylinder 8 installed on the right side and the right inclined hydraulic cylinder 6 are hinged through The right slider 7 is hinged, and the left slider 2 and the right slider 7 can slide linearly in the inner groove of the guide rail 1; the left end of the left horizontal hydraulic cylinder 3 and the right end of the right horizontal hydraulic cylinder 8 are respectively fixedly connected to the left and right sides Both ends are fixed inside the guide rail 1 by a fixed block and a screw rod, so as to be convenient to adjust the positions of the left end of the left horizontal hydraulic cylinder 3 and the fixed end of the right horizontal hydraulic cylinder 8 at any time. The upper ends of the left inclined hydraulic cylinder 4 and the right inclined hydraulic cylinder 6 jointly hinge the center of the bottom of the blade clamp 5 through a hinge.

The blade fixture 5 is a rectangular body with a combined structure. The rectangular body includes a frame body 12 surrounded by angle steel or channel steel on the upper and lower sides and splints 10 fixedly installed on the front and rear ends of the frame body 12. The center of the splint 10 is provided with blades. The mounting hole 11, the size and size of the blade mounting hole 11 are adjusted according to the size of the blade to be tested. The splint 10 is composed of two rectangular plates symmetrically arranged up and down, and the inner sides of the two rectangular plates are provided with arc-shaped sides, and the combination of the two arc-shaped sides forms the blade installation hole 11 of the splint 10 .

The gravity compensation device includes a fixed bracket 13 and a plurality of pulleys installed on the fixed bracket 13, a slider linkage mechanism, a push-pull oil cylinder 14 and a hydraulic winch 15. The bottom of the fixed bracket 13 is provided with a running wheel 16, and the upper right side hinged support frame 17 , the support frame 17 below is connected to the upper end of the slider linkage mechanism, and the lower end of the slider linkage mechanism is connected to the push-pull oil cylinder 14 that is vertically installed on the right side of the fixed bracket 13 . A plurality of pulleys comprise the first pulley 18 installed on the lower left side of the fixed bracket 13, the second pulley 19 on the upper left side of the fixed bracket 13 and the third pulley 20 installed at the outer end of the support frame 17, stretched out from the hydraulic winch 15 The steel wire rope passes through the first pulley 18 , the second pulley 19 and the third pulley 20 in sequence, and the free end of the steel wire rope is used as an external force loading end to be fixedly connected to the top of the blade clamp 5 .

Slider link mechanism comprises slide rail 21, longitudinal slide block 22 and connecting rod 23, and slide rail 21 is vertically installed on the right side of fixed support 13, and slide block 22 is installed in slide rail 21, and slide block 22 upper side The lower end of the connecting rod 23 is connected, and the lower side is connected with the output end of the push-pull oil cylinder 14; the top end of the connecting rod 23 is connected with the sliding end of the support frame 17 outside.

Using the test method of the fatigue loading and gravity compensation device of the above-mentioned fan blade, the experimental steps are as follows:

a. First fix the fatigue loading device of the fan blade, fix the guide rail 1 on the ground through high-strength bolts, install the power unit in the guide rail 1, and hinge the blade clamp 5 on the top of the power unit;

b. Place a cylindrical blade loading support 24 on one side of the guide rail, fix the root of the fan blade on the blade fixing hole 25 of the cylindrical blade loading support 24, and install the blade clamp 5 along the 70% of the blade span direction, Keep the fan blades installed horizontally;

c. Stretch the wire rope from the hydraulic winch 15 of the gravity compensation device, wind the wire rope sequentially through the first pulley 18, the second pulley 19 and the third pulley 20, and the free end of the wire rope is fixedly connected to the blade clamp 5 as the external force loading end above, and a tension sensor is connected in series on the wire rope to monitor the tension on the wire rope in real time;

d. Start the power unit. Under the action of the control system, the left inclined hydraulic cylinder 4 and the right inclined hydraulic cylinder 6 drive the blades to perform fatigue tests, and adjust the left inclined hydraulic cylinder 4 and the right inclined hydraulic cylinder in real time. The length of 6 realizes blade facing, chord or two-axis loading;

e. During the up and down vibration of the blade, observe the tension value displayed by the tension sensor connected in series on the wire rope in real time, and control the positive and negative rotation of the hydraulic winch 15 according to the tension value, so as to ensure that the force on the wire rope remains constant;

f. The magnetostrictive sensor 9 embedded in the hydraulic cylinder monitors the length change of the corresponding hydraulic cylinder in real time and feeds back to the control system. The control system obtains the current coordinates of the blade loading point according to the feedback signal, and assists in adjusting the left horizontal hydraulic cylinder 3 and The length of the horizontal hydraulic cylinder 8 on the right side finally obtains accurate fatigue loading data.

The magnetostrictive sensor 9 embedded in the hydraulic cylinder monitors the length change of the hydraulic cylinder in real time and feeds back to the control system. The control system obtains the current coordinates of the blade loading point according to the feedback signal, and adjusts the left inclined hydraulic cylinder 4 and the right side in real time. The length of the inclined hydraulic cylinder 6 realizes blade-facing, chord-wise or two-axis loading. During the test, if the amplitude of the blade is not enough, you can assist in adjusting the lengths of the left horizontal hydraulic cylinder 3 and the right horizontal hydraulic cylinder 8, and you can also adjust the lengths of the left end of the left horizontal hydraulic cylinder 3 and the right horizontal hydraulic cylinder 8 in advance. The position of the fixed end is used to change the amplitude of the blade loading, which fully guarantees the accuracy of the experimental data. If larger blade vibration amplitude is required, the left side inclined hydraulic cylinder 4 and the left side horizontal hydraulic cylinder 3 can be stretched or the positions of the left slider 2 and the right slider 7 can be adjusted.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention to other forms. Any skilled person who is familiar with this profession may use the technical content disclosed above to change or modify the equivalent of equivalent changes. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims (10)

1. Fatigue loading and gravity compensation device for fan blades, characterized in that it includes a fatigue loading device and a gravity compensation device, the fatigue loading device includes a blade clamp (5), a power device and a guide rail (1) for fixing, the bottom of the power device and The guide rails (1) fixed on the ground are connected, the top of the power unit is hinged to the bottom of the blade clamp (5), and a gravity compensation device is installed on one side of the fatigue loading device, and the external force loading end of the gravity compensation device is connected to the top of the blade clamp (5). 2. The device for fatigue loading and gravity compensation of fan blades according to claim 1, characterized in that: the blade clamp (5) is installed at 70% along the blade span direction. 3. The device for fatigue loading and gravity compensation of fan blades according to claim 1, characterized in that: the power device is a hydraulic power device, and two groups are symmetrically arranged on the left and right, and each group includes a horizontally installed on the guide rail (1 ) in the horizontal hydraulic cylinder and an oblique hydraulic cylinder connected with it, the left horizontal hydraulic cylinder (3) and the left oblique hydraulic cylinder (4) are hinged through the left slider (2), and the right The side horizontal hydraulic cylinder (8) and the right inclined hydraulic cylinder (6) are hinged through the right slider (7); the left end of the left horizontal hydraulic cylinder (3) and the right end of the right horizontal hydraulic cylinder (8) Fix and connect the left and right ends of the guide rail (1) respectively. 4. The fatigue loading and gravity compensation device for fan blades according to claim 3, characterized in that: each hydraulic cylinder of the power unit is embedded with a magnetostrictive sensor (9 ). 5. The device for fatigue loading and gravity compensation of fan blades according to claim 1, characterized in that: the gravity compensation device includes a fixed bracket (13) and a plurality of pulleys, pulleys and pulleys installed on the fixed bracket (13). block linkage mechanism, push-pull cylinder (14) and hydraulic winch (15), the bottom of the fixed bracket (13) is provided with running wheels (16), the upper right hinged support frame (17), and the slide block is connected under the support frame (17) The upper end of the linkage mechanism and the lower end of the slider linkage mechanism are connected to the push-pull oil cylinder (14) vertically installed on the right side of the fixed support (13). 6. The device for fatigue loading and gravity compensation of fan blades according to claim 5, characterized in that: the plurality of pulleys include the first pulley (18) installed on the lower left side of the fixed bracket (13), the fixed bracket (13) The second pulley (19) on the upper left side and the third pulley (20) installed on the outer end of the support frame (17), the wire rope protruding from the hydraulic winch (15) winds around the first pulley (18) in sequence , the second pulley (19) and the third pulley (20), the free end of the wire rope is used as an external force loading end to be fixedly connected to the top of the blade clamp (5). 7. The device for fatigue loading and gravity compensation of fan blades according to claim 5, characterized in that: the slider linkage mechanism includes a slide rail (21), a longitudinal slider (22) and a connecting rod (23) , the slide rail (21) is installed vertically on the right side of the fixed bracket (13), the slide block (22) is installed inside the slide rail (21), the upper side of the slide block (22) is connected to the lower end of the connecting rod (23), The lower side is connected to the output end of the push-pull oil cylinder (14); the top end of the connecting rod (23) is connected to the sliding end on the outside of the support frame (17). 8. The fatigue loading and gravity compensation device for fan blades according to claim 1, characterized in that: the other side of the fatigue loading device is provided with a blade loading support (24) at the same height as the blade clamp (5) ), the blade loading support (24) is a cylindrical bracket provided with a blade fixing hole (25) for placing the blade root. 9. A test method utilizing the fatigue loading and gravity compensation device of the fan blade according to any one of claims 1 to 8, characterized in that: comprising the following steps, a. First fix the fatigue loading device of the fan blade, fix the guide rail (1) on the ground with high-strength bolts, install the power unit in the guide rail (1), and hinge the blade clamp (5) on the top of the power unit; b. Place a cylindrical blade loading support (24) on one side of the guide rail, fix the root of the fan blade in the blade fixing hole (25) of the cylindrical blade loading support (24), at 70% along the blade span Install the blade clamp (5) to keep the fan blades installed horizontally; c. Stretch the wire rope from the hydraulic winch (15) of the gravity compensation device, wind the wire rope through the first pulley (18), the second pulley (19) and the third pulley (20) in sequence, and the free end of the wire rope acts as an external force The loading end is fixedly connected to the top of the blade clamp (5), and a tension sensor is connected in series on the wire rope to monitor the tension on the wire rope in real time; d. Start the power unit, the left inclined hydraulic cylinder (4) and the right inclined hydraulic cylinder (6) are under the action of the control system, drive the blades for fatigue test, and adjust the left inclined hydraulic cylinder (4) and the right inclined hydraulic cylinder (6) in real time The length of the right inclined hydraulic cylinder (6) realizes blade facing, chord or two-axis loading; e. During the up and down vibration of the blade, observe the tension value displayed by the tension sensor connected in series on the wire rope in real time, and control the positive and negative rotation of the hydraulic winch (15) according to the tension value, so as to ensure that the force on the wire rope remains constant; f. The magnetostrictive sensor (9) embedded in the hydraulic cylinder monitors the length change of the corresponding hydraulic cylinder in real time and feeds back to the control system. The control system obtains the current coordinates of the blade loading point according to the feedback signal, and assists in adjusting the left horizontal hydraulic cylinder (3) and the length of the right horizontal hydraulic cylinder (8) to finally obtain accurate fatigue loading data. 10. The fatigue loading and gravity compensation device and test method for fan blades according to claim 1 or 2, characterized in that: the blade fixture (5) is a rectangular body with a combined structure, and the rectangular body includes upper and lower sides The frame body (12) surrounded by angle steel or channel steel side by side and the splint (10) fixedly installed on the front and rear ends of the frame body (12), the center of the splint (10) is provided with a blade installation hole (11); The splint (10) is composed of two rectangular plates symmetrically arranged up and down, and the inner sides of the two rectangular plates are provided with arc edges, and the combination of the two arc edges forms the blade mounting holes (11) of the splint (10).

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