Automatic bolt fastening system and calculation method

Abstract

This invention discloses an automatic bolt tightening system and calculation method, including auxiliary tooling and a tightening mechanism. The auxiliary tooling includes a mounting bracket, a rotating arm, and a servo motor. The mounting bracket is detachably connected to the workpiece, and the servo motor is mounted on the mounting bracket and can drive the rotating arm to rotate on the mounting bracket. Tightening mechanisms are provided at both ends of the rotating arm. Each tightening mechanism includes a tightening shaft and a lifting cylinder. The lifting cylinder is located at the end of the rotating arm and connected to the tightening shaft. A tightening sleeve is provided at the end of the tightening shaft. Using the above-mentioned automatic bolt tightening system and calculation method, by fixing the device to the workpiece with the auxiliary tooling, the positioning of the tightening mechanism and the bolt can be quickly completed with high accuracy. If there is an error between the device and the workpiece, the actual center coordinates of the auxiliary tooling can be calculated using the tightening reference bolt, eliminating the need for extensive device calibration and significantly improving work efficiency.

Description

Technical Field

[0001] This invention relates to the field of wind turbine installation technology, specifically to an automatic bolt tightening system and calculation method. Background Technology

[0002] The trend towards larger wind turbine units is evident in the wind power market. Currently, the largest single-unit capacity of wind turbines in the industry exceeds 20MW. With the increasing size and weight of turbine components, as well as the greater number of parts, the yaw bearing and pitch bearing are among the components with the most bolts used in wind turbine assembly workshops. Each component has nearly a hundred bolts. If workers were to tighten these bolts one by one using traditional methods, not only would the bolt tightening work be inefficient and labor-intensive, but it would also pose significant safety hazards.

[0003] Currently, although there are specialized devices for automatically tightening bolts, these devices are separate from the workpiece. They require the device to be aligned with the bolts on the workpiece for tightening, and the centering accuracy needs to be adjusted each time, resulting in low work efficiency. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes an automatic bolt tightening system that can be fixed to a workpiece and tighten bolts.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an automatic bolt tightening system, comprising auxiliary tooling and a tightening mechanism;

[0006] The auxiliary tooling includes a mounting bracket, a rotating arm, and a servo motor. The mounting bracket is detachably connected to the workpiece, and the servo motor is mounted on the mounting bracket and can drive the rotating arm to rotate on the mounting bracket.

[0007] Both ends of the rotating arm are provided with tightening mechanisms. The tightening mechanism includes a tightening shaft and a lifting cylinder. The lifting cylinder is located at the end of the rotating arm and is connected to the tightening shaft. The end of the tightening shaft is provided with a tightening sleeve.

[0008] The auxiliary tooling is fixed on the workpiece by the mounting bracket. The rotating arm is driven by the servo motor to rotate on the mounting bracket, which in turn drives the tightening mechanism to rotate. The tightening mechanism is aligned with each bolt point on the workpiece in sequence. The lifting cylinder drives the tightening shaft and tightening sleeve to move, thereby tightening the bolt and completing the bolt fastening.

[0009] The advantages of the above-mentioned automatic bolt tightening system are: by fixing the auxiliary tooling on the workpiece, the positioning of the tightening mechanism and the bolt can be completed quickly and with high precision, thus improving work efficiency.

[0010] Furthermore, the mounting bracket is a triangular mounting bracket with three reference arms evenly spaced around the circumference. The reference arms are detachably connected to quick-change arms by bolts, and the quick-change arms are detachably connected to the workpiece by bolts.

[0011] By connecting the three reference arms of the triangular bracket to the workpiece via quick-change arms, a stable triangular structure can be formed, ensuring that the device is securely installed on the workpiece. Depending on the type of workpiece, quick-change arms of different lengths can be replaced, making it highly adaptable.

[0012] Furthermore, the rotating support arm is equipped with a lead screw, a telescopic arm, and an offset cylinder. Both ends of the rotating support arm are rotatably connected to lead screws, which can drive the telescopic arm to move axially. The offset cylinder is mounted on the telescopic arm and connected to the tightening mechanism.

[0013] After the auxiliary tooling is fixed to the workpiece, if there is a deviation between the center and the center of the workpiece, the position of the tightening mechanism can be adjusted by moving the telescopic arm with the lead screw and moving the tightening mechanism with the offset cylinder, thereby compensating for the error. This eliminates the need to spend a long time adjusting the centering accuracy and greatly improves work efficiency.

[0014] A calculation method for an automatic bolt tightening system, using the aforementioned automatic bolt tightening system, includes the following calculation steps:

[0015] S1, tighten the four cross-shaped reference bolts;

[0016] S2, calculate the center coordinates of the auxiliary tooling;

[0017] S3, calculate the extension distance and offset angle between the tightening mechanism and the bolt to be tightened based on the center coordinate position of the auxiliary tooling;

[0018] S4, based on the distance and offset distance between the tightening mechanism and the bolt to be tightened, the lead screw and offset cylinder adjust the extension distance and offset angle of the tightening mechanism.

[0019] Furthermore, after the auxiliary tooling is fixed on the workpiece, the starting device causes the tightening mechanism to reach the preset reference bolt. One of the tightening mechanisms points to the center of the bolt, and the telescopic arm is manually adjusted to align it with the center of the bolt. Then, the telescopic arm and the offset cylinder are manually adjusted to align the other tightening mechanism with the center of the bolt.

[0020] Further, step S2 specifically involves: establishing a rectangular coordinate system with the center of the workpiece as the origin (X0, Y0), with the center of the first reference bolt in step S1 on the X-axis, setting the center coordinates of the auxiliary tooling as (X1, Y1), and the coordinates of the second reference bolt as (X2, Y2).

[0021] Let L1 be the distance between the center of the auxiliary fixture and the first reference bolt, L2 be the distance between the center of the auxiliary fixture and the end of the telescopic arm after the tightening mechanism is aligned with the second reference bolt, L0 be the distance between the center of the workpiece and the center of the bolt, and L3 be the vertical offset distance of the tightening mechanism relative to the X-axis when aligned with the second reference bolt. Then the center coordinates of the auxiliary fixture are:

[0022] X1=L1*cos[arctan{L3 / (L1+L2)}]-L0;

[0023] Y1=L1*sin[arctan{L3 / (L1+L2)}].

[0024] Further, step S3 specifically involves: using the preset center coordinates of the bolt to be tightened and the center coordinates of the auxiliary fixture, the extension distance between the center of the bolt to be tightened and the center of the auxiliary fixture, as well as the offset angle of the center of the bolt to be tightened relative to the center of the auxiliary fixture, can be calculated.

[0025] Further, step S4 specifically involves: based on the distance between the center of the bolt to be tightened and the center of the auxiliary tooling, the lead screw drives the telescopic arm to extend or shorten to compensate for the telescopic distance; based on the offset distance of the center of the bolt to be tightened relative to the center of the auxiliary tooling, the offset cylinder drives the tightening mechanism to move to compensate for the offset angle.

[0026] The beneficial effect of the above-mentioned calculation method for an automatic bolt tightening system is that if the center of the auxiliary tooling does not coincide with the center of the workpiece, the actual position of the auxiliary tooling can be calculated by recording the moving distance of the manually adjusted lead screw and offset cylinder. During the automatic bolt tightening process, the position of the tightening mechanism can be adjusted by the lead screw and offset cylinder to compensate for the extension distance and offset angle. No extra time is needed to calibrate and adjust the accuracy, which greatly improves work efficiency. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0028] Figure 1 This is a front view of an automatic bolt tightening system according to an embodiment of the present invention;

[0029] Figure 2 for Figure 1 The diagram shown is a schematic of an automatic bolt tightening system;

[0030] Figure 3 A schematic diagram of the auxiliary tooling center point calculation method for an automatic bolt tightening system provided in one embodiment of the present invention;

[0031] Figure 4A schematic diagram of the calculation of the bolt to be tightened provided in an embodiment of the present invention for a calculation method of an automatic bolt tightening system;

[0032] Figure label:

[0033] 10-Auxiliary tooling, 11-Mounting bracket, 111-Reference arm, 112-Quick change arm, 12-Rotating support arm, 121-Lead screw, 122-Telescopic arm, 123-Offset cylinder, 13-Servo motor;

[0034] 20-Tightening mechanism, 21-Tightening shaft, 22-Lifting cylinder. Detailed Implementation

[0035] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0036] Please see Figures 1 to 2 The present invention provides an automatic bolt tightening system, including an auxiliary fixture 10 and a tightening mechanism 20. The auxiliary fixture 10 is fixed on the workpiece, and the tightening mechanism 20 rotates around the workpiece to tighten the bolts in sequence.

[0037] Specifically, such as Figure 1 and Figure 2 As shown, the auxiliary fixture 10 includes a mounting bracket 11, a rotating arm 12, and a servo motor 13. The mounting bracket 11 is detachably connected to the workpiece. The rotating arm 12 is rotatably mounted on the mounting bracket 11, and both ends are equipped with tightening mechanisms 20. The servo motor 13 is mounted on the mounting bracket 11 and can drive the rotating arm 12 to rotate on the mounting bracket 11. In this embodiment, the mounting bracket 11 is a triangular mounting bracket 11 with three reference arms 111 evenly spaced around the circumference. The outer ends of the reference arms 111 are bolted to quick-change arms 112, which are bolted to the workpiece. The triangular mounting bracket 11 provides good stability when connected to the workpiece, and by changing the quick-change arms 112, it can be used for workpieces of different diameters, making it widely applicable and easy and quick to install, thus improving work efficiency.

[0038] Specifically, the tightening mechanism 20 includes a tightening shaft 21 and a lifting cylinder 22. The lifting cylinder 22 is mounted on the rotating support arm 12 and connected to the tightening shaft 21. The end of the tightening shaft 21 is provided with a rotatably connected tightening sleeve. When the tightening mechanism 20 is aligned with the bolt, the lifting cylinder 22 drives the tightening shaft 21 to move and tightens the bolt through the tightening sleeve.

[0039] Specifically, the rotating arm has a lead screw 121, a telescopic arm 122, and an offset cylinder 123. Both ends of the rotating arm 12 are rotatably connected to the lead screw 121, and the telescopic arm 122 is also mounted on the rotating arm 12. The lead screw 121 can drive the telescopic arm 122 to move axially along the rotating arm 12. The offset cylinder 123 is mounted on the telescopic arm 122, and the tightening mechanism 20 is connected to the telescopic arm 122 via the offset cylinder 123. After the auxiliary fixture 10 is installed, its center may have a slight deviation from the center of the workpiece. The system can calculate and control the lead screw 121 to extend or shorten the telescopic arm 122, and the offset cylinder 123 to move the tightening mechanism 20 to compensate for the extension / retraction distance and offset angle, thus eliminating the need for extensive fixture calibration.

[0040] The specific calculation method includes the following steps:

[0041] S1, tighten the four cross-shaped reference bolts;

[0042] S2, calculate the center coordinates of the auxiliary tooling;

[0043] S3, calculate the extension distance and offset angle between the tightening mechanism and the bolt to be tightened based on the center coordinate position of the auxiliary tooling;

[0044] S4, based on the distance and offset distance between the tightening mechanism and the bolt to be tightened, the lead screw and offset cylinder adjust the extension distance and offset angle of the tightening mechanism.

[0045] Specifically, step S1 involves tightening the four reference bolts in two stages, with two bolts tightened each time. After fixing the auxiliary fixture onto the workpiece, the device is activated to bring the tightening mechanism to the preset position of the reference bolt. If the center of the auxiliary fixture deviates from the center of the workpiece, both tightening mechanisms will be offset from the corresponding reference bolt. The servo motor is manually adjusted so that one tightening mechanism points to the center of the corresponding reference bolt. The telescopic arm is then adjusted to align this tightening mechanism with the bolt center. Finally, the telescopic arm and offset cylinder on the other side are manually adjusted to align the other tightening mechanism with the bolt center.

[0046] Specifically, step S2 involves establishing a rectangular coordinate system with the center of the workpiece as the origin (X0, Y0). The reference bolt aligned with the first tightening mechanism in step S1 is used as the reference. The Y value of the reference bolt is set to 0, meaning the center of the circle is on the X-axis. Thus, a rectangular coordinate system is established, and it can be determined that the center of the other reference bolt is also on the X-axis.

[0047] Let the center coordinates of the auxiliary tooling be (X1, Y1), and the coordinates of the second reference bolt be (X2, Y2). Let the distances between the center of the auxiliary tooling and the ends of the two telescopic arms after manual adjustment be L1 and L2, respectively. That is, the distance between the center of the auxiliary tooling and the center of the first reference bolt is L1, and the distance between the center of the auxiliary tooling and the end of the telescopic arm near the second reference bolt is L2. L1 and L2 are data recorded by the system after manually adjusting the telescopic arms. The distance between the center of the workpiece and the center of the bolt is L0, which can be obtained based on the preset bolt position on the workpiece. After the tightening mechanism is aligned with the second reference bolt, the vertical offset distance relative to the X-axis is L3, which is data recorded by the system after manually adjusting the offset cylinder. Thus, the center coordinates of the auxiliary tooling can be obtained.

[0048] X1=L1*cos[arctan{L3 / (L1+L2)}]-L0;

[0049] Y1=L1*sin[arctan{L3 / (L1+L2)}];

[0050] by Figure 3 For example, L1 = 151, L2 = 148.99, L0 = 150.

[0051] but:

[0052] X1=151*cos{arctan{1.99 / (151+148.99)}}-150=0.996677;

[0053] Y1=151*sin{arctan{1.99 / (151+148.99)}}=1.001644;

[0054] The center coordinates of the auxiliary tooling are (0.996677, 1.001644).

[0055] Specifically, step S3 involves calculating the extension distance between the center of the bolt to be tightened and the center of the auxiliary tooling, as well as the offset angle of the center of the bolt to be tightened relative to the center of the auxiliary tooling, using the preset center coordinates of the bolt to be tightened and the center coordinates of the auxiliary tooling.

[0056] Step S4 is as follows: Based on the distance between the center of the bolt to be tightened and the center of the auxiliary tooling, the lead screw drives the telescopic arm to extend or shorten to compensate for the telescopic distance; based on the offset distance of the center of the bolt to be tightened relative to the center of the auxiliary tooling, the offset cylinder drives the tightening mechanism to move to compensate for the offset angle.

[0057] by Figure 4 For example, let the coordinates of the center of the bolt to be tightened be (X... P Y P The distance between the center of the auxiliary tooling and the center of the bolt to be tightened is L.p Through L p Construct a right triangle with the hypotenuse as the base, then L p 2 =(X P -X1) 2 +(Y P -Y1) 2 The angle between the bolt to be tightened and the center of the auxiliary tooling is φ, which can be obtained by using trigonometric functions.

[0058] When the servo motor drives the rotating arm to rotate according to the preset bolt position, and moves the tightening mechanism to the bolt to be tightened, the lead screw and offset cylinder can make corresponding compensation according to the center coordinates of the auxiliary tooling, so that the tightening mechanism is aligned with the bolt to be tightened.

[0059] Using the aforementioned automatic bolt tightening system and calculation method, the device can be quickly and accurately positioned between the tightening mechanism and the bolt by fixing the auxiliary fixture to the workpiece. If there is an error between the device and the workpiece, the actual center coordinates of the auxiliary fixture can be calculated using the tightening reference bolt, and the error can be compensated by the lead screw and offset cylinder. This eliminates the need for extensive device calibration, thus significantly improving work efficiency.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A calculation method for an automatic bolt tightening system, characterized in that, Includes auxiliary tooling and tightening mechanisms; The auxiliary tooling includes a mounting bracket, a rotating arm, and a servo motor. The mounting bracket is detachably connected to the workpiece, and the servo motor is mounted on the mounting bracket and can drive the rotating arm to rotate on the mounting bracket. Both ends of the rotating arm are provided with tightening mechanisms. The tightening mechanism includes a tightening shaft and a lifting cylinder. The lifting cylinder is located at the end of the rotating arm and is connected to the tightening shaft. The end of the tightening shaft is provided with a tightening sleeve. The rotating support arm is equipped with a lead screw, a telescopic arm, and an offset cylinder. Both ends of the rotating support arm are rotatably connected to lead screws, which can drive the telescopic arm to move axially. The offset cylinder is mounted on the telescopic arm and connected to the tightening mechanism. It also includes the following calculation steps: S1, tighten the four cross-shaped reference bolts; S2, calculate the center coordinates of the auxiliary tooling; S3, calculate the extension distance and offset angle between the tightening mechanism and the bolt to be tightened based on the center coordinate position of the auxiliary tooling; S4, based on the distance and offset distance between the tightening mechanism and the bolt to be tightened, the lead screw and offset cylinder adjust the extension distance and offset angle of the tightening mechanism; Step S1 is as follows: After the auxiliary tooling is fixed on the workpiece, the device is started so that the tightening mechanism reaches the preset reference bolt. One of the tightening mechanisms points to the center of the bolt, and the telescopic arm is manually adjusted to align with the center of the bolt. Then, the telescopic arm and the offset cylinder are manually adjusted to align the other tightening mechanism with the center of the bolt. Step S2 is as follows: Establish a rectangular coordinate system with the center of the workpiece as the origin (X0, Y0), with the center of the first reference bolt in step S1 on the X-axis, and set the center coordinates of the auxiliary tooling as (X1, Y1) and the coordinates of the second reference bolt as (X2, Y2). Let L1 be the distance between the center of the auxiliary fixture and the first reference bolt, L2 be the distance between the center of the auxiliary fixture and the end of the telescopic arm after the tightening mechanism is aligned with the second reference bolt, L0 be the distance between the center of the workpiece and the center of the bolt, and L3 be the vertical offset distance of the tightening mechanism relative to the X-axis when aligned with the second reference bolt. Then the center coordinates of the auxiliary fixture are: X1=L1*cos[arctan{L3 / (L1+L2)}]-L0; Y1=L1*sin[arctan{L3 / (L1+L2)}].

2. The calculation method for an automatic bolt tightening system according to claim 1, characterized in that, Step S3 specifically involves calculating the extension distance between the center of the bolt to be tightened and the center of the auxiliary fixture, as well as the offset angle of the center of the bolt to be tightened relative to the center of the auxiliary fixture, using the preset center coordinates of the bolt to be tightened and the center coordinates of the auxiliary fixture.

3. The calculation method for an automatic bolt tightening system according to claim 2, characterized in that, Step S4 is as follows: Based on the distance between the center of the bolt to be tightened and the center of the auxiliary tooling, the lead screw drives the telescopic arm to extend or shorten to compensate for the telescopic distance; based on the offset distance of the center of the bolt to be tightened relative to the center of the auxiliary tooling, the offset cylinder drives the tightening mechanism to move to compensate for the offset angle.

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