A center of gravity measuring method and device for large-size tooling

Abstract

The application discloses a center of gravity measuring method and device for large-size tooling, and belongs to the technical field of aircraft part machining, and comprises the following steps: S1, rotary connecting frames are respectively arranged at two ends of the tooling to be measured, a measuring disc is eccentrically arranged on the rotary connecting frame, and the measuring disc is arranged in a sliding groove of a supporting frame, so that the measuring disc can drive the tooling to be measured to freely swing in the sliding groove around the axis of the rotary connecting frame; S2, in a first connecting position, the tooling to be measured is released, a first space vertical line passing through the center of the measuring disc is obtained; S3, the measuring disc is adjusted to a second connecting position, the tooling to be measured is released, and a second space vertical line passing through the center of the measuring disc is obtained; and S4, the intersection of the two vertical lines is determined, and the center of gravity of the tooling to be measured is determined. The device adopts the above method, has simple structure, is convenient to operate, can effectively avoid the interference of environmental factors on the measuring result, and is not limited by the size of the tooling.

Description

Technical Field

[0001] This invention relates to the field of aircraft parts processing technology, and in particular to a method and apparatus for measuring the center of gravity of large-size tooling. Background Technology

[0002] When manufacturing large composite parts, such as wing panels, advanced fiber placement equipment is typically preferred to achieve high-quality prepreg placement. During this process, large-sized tooling needs to be connected to the fiber placement equipment port using devices such as rotary connecting frames and transition plates. After connection, the tooling can move back and forth and rotate on the fiber placement machine to cooperate with the fiber placement head to complete various operations.

[0003] However, large-sized tooling, due to its significant mass, possesses substantial inertia and rotational moment of inertia. This poses safety and stability risks when the tooling moves and rotates on the machine tool. To effectively address this issue, accurately measuring the center of gravity of large-sized tooling is crucial. Only by ensuring that the tooling's center of gravity aligns with the yarn placement rotation center, maintaining the balance of the placement system, can a good placement effect be achieved while simultaneously guaranteeing the safety of the production process.

[0004] Currently, conventional methods for measuring the center of gravity of large-sized tooling fall into two categories. First, software calculations can be used. While theoretical values ​​can be derived from digital models, there is often a discrepancy between the actual center of gravity and the theoretical value. Therefore, the theoretical center of gravity calculated by software can only serve as a reference and cannot accurately reflect the actual position of the tooling's center of gravity. Second, precision instruments such as full-station scanners and multi-sensor fusion systems can be used for measurement. However, for large-sized tooling, these measuring tools may not be able to achieve complete coverage. Furthermore, these measurement methods are greatly affected by environmental factors such as temperature and vibration, easily introducing systematic errors. In addition, using these precision instruments also suffers from drawbacks such as high cost and poor real-time performance, hindering their widespread application in actual production. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for measuring the center of gravity of large-size tooling, so as to solve the technical problems of large error and high cost in the existing methods for measuring the center of gravity of large-size tooling.

[0006] To achieve this objective, the present invention adopts the following technical solution: On one hand, the present invention provides a method for measuring the center of gravity of large-size tooling, the method comprising: S1. Install rotary connecting frames at both ends of the fixture to be tested. Eccentrically assemble a measuring disk on the rotary connecting frame and place the measuring disk in the slide groove of the support frame, so that the measuring disk can drive the fixture to be tested to swing freely around the axis of the rotary connecting frame in the slide groove; wherein, the connection position between the measuring disk and the rotary connecting frame is adjustable to change the orientation of the center of the measuring disk relative to the axis of the rotary connecting frame; S2. In the first connection position, release the tooling to be tested, so that the tooling to be tested can swing freely under the action of gravity and reach a stable equilibrium state. At this time, obtain the first spatial vertical line passing through the center of the measuring disk. S3. Adjust the connection position between the measuring disk and the rotary connecting frame to the second connection position, release the tooling to be tested, and let the tooling to be tested swing freely under the action of gravity and reach a stable equilibrium state, and obtain the second spatial vertical line passing through the center of the measuring disk. S4. Determine the intersection point of the first spatial perpendicular line and the second spatial perpendicular line. The intersection point is the location of the center of gravity of the tooling to be tested.

[0007] Preferably, the measuring disk has multiple connecting holes along its circumference. By selecting different connecting holes on the measuring disk to connect with the rotary connecting frame, the orientation of the center of the measuring disk relative to the axis of the rotary connecting frame can be changed.

[0008] Preferably, adjusting the connection position of the measuring disk and the tooling to be tested to the second connection position includes: disassembling the measuring disk from the first connection position, rotating it by a preset angle around the center of the measuring disk, and then reassembling it to the rotary connecting frame to form the second connection position.

[0009] Preferably, the preset angle corresponds to the angle corresponding to the counterclockwise rotation of the two connecting holes on the measuring disk.

[0010] Preferably, in step S2, at the first connection position, a laser tracker is used to measure and record the vertical line passing through the center of the measuring disk in a stable equilibrium state to obtain the first spatial perpendicular line; in step S3, at the second connection position, the laser tracker is used to measure and record the vertical line passing through the center of the measuring disk in a stable equilibrium state to obtain the second spatial perpendicular line.

[0011] Preferably, S3 further includes: adjusting the connection position between the measuring disk and the rotary connecting frame to the third connection position, releasing the test fixture, allowing the test fixture to swing freely under gravity and reach a stable equilibrium state, obtaining a third spatial perpendicular line passing through the center of the measuring disk, and verifying whether the third spatial perpendicular line passes through the intersection point of the first spatial perpendicular line and the second spatial perpendicular line.

[0012] Preferably, the method further includes S5: calculating the eccentricity between the center of gravity of the tooling to be tested and the axis of the rotary connecting frame based on the position of the intersection point.

[0013] Preferably, the slide is an arc-shaped groove formed on the top of the support frame, and limit members are provided at both ends of the slide.

[0014] Preferably, the diameter of the measuring disc is larger than the diameter of the assembly disc of the rotary connecting frame.

[0015] On the other hand, the present invention also provides a center of gravity measuring device for large-size tooling, which is applied to the above-described method. Specifically, the device includes: A support frame, wherein a sliding groove is provided on the support frame; Two rotary connecting frames are respectively fixedly installed at both ends of the fixture to be tested; Two measuring discs are respectively eccentrically mounted on the rotary connecting frame at both ends of the fixture to be tested. The connection position between the measuring disc and the rotary connecting frame is adjustable to change the orientation of the center of the disc relative to the axis of the rotary connecting frame. The measuring disc is mounted in the slide groove and can roll freely in the slide groove so that the fixture to be tested can swing freely around the axis of the rotary connecting frame. The measuring unit is used to acquire at least two spatial perpendicular lines passing through the center of the measuring disk at different connection positions when the tooling under test is in a stable equilibrium state.

[0016] The beneficial effects of this invention are: The proposed method for measuring the center of gravity of large-sized tooling involves first installing rotary connecting frames at both ends of the tooling under test, and then eccentrically mounting a measuring disk on the rotary connecting frames. The measuring disk is then placed within a groove in a support frame, creating a swinging system with the axis of the rotary connecting frames as its rotation center and the measuring disk as its supporting foundation. Since the connection position between the measuring disk and the rotary connecting frames is adjustable, the orientation of the measuring disk's center relative to the axis of the rotary connecting frames can be changed, providing the necessary degrees of freedom for subsequent measurements under different suspension postures. Next, the tooling under test is released from its first connection position, allowing it to swing freely under gravity until it reaches a stable equilibrium state. Based on the principle of a simple pendulum, when the system reaches static equilibrium, the center of gravity of the tooling under test must lie within a vertical plane passing through the axis of the rotary connecting frames. At this point, because the measuring disc and the rotary connecting frame are eccentrically connected, and the center of the measuring disc has a definite geometric relationship with the axis of the rotary connecting frame, the first spatial perpendicular line passing through the center of the measuring disc actually represents the vertical line passing through the axis of the rotary connecting frame in the equilibrium state, i.e., a spatial straight line where the center of gravity is located. Subsequently, by adjusting the connection position between the measuring disc and the rotary connecting frame to the second connection position, the orientation of the center of the measuring disc relative to the axis of the rotary connecting frame is changed, thereby changing the suspension posture of the fixture under test relative to the support point. After releasing the fixture under test again, allowing it to swing freely and reach stable equilibrium, similarly, the second spatial perpendicular line passing through the center of the measuring disc at this time is another vertical line passing through the axis of the rotary connecting frame in the new equilibrium state, i.e., another spatial straight line where the center of gravity is located. Finally, the intersection point of the first and second spatial perpendicular lines is determined. Since the center of gravity of the fixture under test is a uniquely determined point in space, and both the first and second spatial perpendicular lines are vertical lines passing through the center of gravity, the intersection of the first and second spatial perpendicular lines in space is the actual position of the center of gravity of the fixture under test. In summary, this method, by constructing an adjustable eccentric swing system, utilizes the physical principle that the center of gravity of the fixture under test, when freely suspended under gravity, must lie on the vertical line of the suspension point. The spatial position of the center of gravity can be determined simply through two balance measurements at different attitudes. This method avoids the deviation between the physical object and the model caused by relying on software theoretical calculations, and also eliminates the need for precision optical or sensor measurement systems susceptible to environmental factors. Its measurement process is entirely based on mechanical structure and gravity, is simple to operate, has good environmental adaptability, and can effectively cover the measurement needs of large-sized fixtures, thus achieving accurate measurement of the center of gravity of large-sized fixtures at a relatively low cost. Attached Figure Description

[0017] Figure 1 This is a flowchart of a method for measuring the center of gravity of large-size tooling provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the center of gravity measuring device for large-size tooling provided in an embodiment of the present invention; Figure 3 This is an exploded structural diagram of the center of gravity measuring device for large-size tooling provided in an embodiment of the present invention; Figure 4 This is a side view of the center of gravity measuring device for large-size tooling provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the support frame provided in an embodiment of the present invention.

[0018] In the picture: 1. Fixture to be tested; 2. Rotary connecting frame; 3. Measuring plate; 31. Connecting hole; 4. Support frame; 41. Slide groove; 5. Laser tracker. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. 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.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] like Figures 1 to 5As shown, this embodiment of the invention provides a method for measuring the center of gravity of large-size tooling. This embodiment can be applied to scenarios where the center of gravity position of various large composite molding toolings is calibrated.

[0024] In this context, the tooling to be tested 1 refers to a molding die or assembly fixture used to support or position large composite material parts. As an example, the tooling to be tested 1 can specifically be a molding die used to form aircraft wing panels, which typically has a shape profile matching the wing's curvature and is relatively large, with a length exceeding ten meters. As another example, the tooling to be tested 1 can also be a laying mold used for fuselage skin installation, its structure generally being cylindrical or semi-cylindrical, also characterized by large size and weight. Furthermore, the tooling to be tested 1 can also be an assembly fixture used for components such as the aircraft's vertical tail or horizontal tail.

[0025] It should be noted that the fixture 1 to be tested described in this embodiment is not limited to the specific forms listed above. Any large-sized fixture that needs to be connected to a rotary device during wire laying, tape laying, or assembly operations, and has a large moment of inertia due to its large size and weight, can be measured using the center of gravity measurement method provided in this embodiment of the invention. The specific structural form, material, or function of the fixture 1 to be tested will not affect the determination of its center of gravity position by this method, as long as the fixture can be equipped with rotary connecting frames 2 at both ends and can swing freely.

[0026] S1. Install rotary connecting frames 2 at both ends of the fixture 1 to be tested. Eccentrically assemble measuring disk 3 on the rotary connecting frame 2 and place the measuring disk 3 in the slide groove 41 of the support frame 4, so that the measuring disk 3 can drive the fixture 1 to be tested to swing freely around the axis of the rotary connecting frame 2 in the slide groove 41. The connection position between the measuring disk 3 and the rotary connecting frame 2 is adjustable to change the orientation of the center of the measuring disk 3 relative to the axis of the rotary connecting frame 2.

[0027] The rotary connecting frame 2 includes a mounting flange for fixed connection to the end of the fixture 1 under test and an assembly plate for assembling the measuring disc 3. The mounting flange has multiple bolt holes, and high-strength bolts are used to detachably connect it to the flange at the end of the fixture 1 under test, ensuring that the two form a rigid whole without relative displacement during measurement. The assembly plate is located on the side of the rotary connecting frame 2 opposite to the fixture 1 under test, and its axis coincides with the rotation axis of the rotary connecting frame 2, for mounting the measuring disc 3.

[0028] To achieve the eccentric assembly and adjustable connection position of the measuring disc 3 on the rotary connecting frame 2, as a specific implementation, the assembly disc of the rotary connecting frame 2 has multiple sets of threaded holes radially formed. The measuring disc 3 is coaxially connected to the assembly disc through its central mounting hole, and the measuring disc 3 has multiple circumferentially distributed connecting holes 31 corresponding to the multiple sets of threaded holes on the assembly disc. By selecting different threaded holes and connecting holes 31 for bolt tightening, the radial eccentricity of the center of the measuring disc 3 relative to the axis of the rotary connecting frame 2, as well as the change of the eccentricity angle, can be achieved.

[0029] The support frame 4 has a groove 41 for supporting the measuring disk 3. To facilitate the smooth rolling or sliding of the measuring disk 3 on the support frame 4, in one specific embodiment, the groove 41 is an arc-shaped groove on the top of the support frame 4, with limiting components at both ends. The arc-shaped groove is designed to fit the outer circumference of the measuring disk 3. When the measuring disk 3 is placed in the arc-shaped groove, the two form an arc-shaped contact, which can provide stable support for the measuring disk 3 and allow the measuring disk 3 to swing smoothly back and forth in the groove. At the same time, the limiting components, such as limiting blocks or limiting screws, at both ends of the groove 41 can block the measuring disk 3 when the swing amplitude is too large, preventing the measuring disk 3 from falling out of the groove 41, thereby ensuring the safety and reliability of the measurement process.

[0030] Understandably, two support frames 4 are provided, and each support frame 4 corresponds to and cooperates with the measuring discs 3 at both ends of the fixture 1 to be tested. Specifically, after the measuring discs 3 are installed at both ends of the fixture 1 to be tested via the rotary connecting frame 2, the two measuring discs 3 are respectively placed in the slide grooves 41 of the two support frames 4. The two support frames 4 are independently set on the foundation or platform, and their positions are arranged according to the span of the fixture 1 to be tested, to ensure that the two measuring discs 3 can accurately fall into their respective slide grooves 41. During the measurement process, the two support frames 4 jointly bear the entire weight of the fixture 1 to be tested, and allow the measuring discs 3 at both ends to swing freely and synchronously within their respective slide grooves 41.

[0031] Considering the size differences of various test fixtures 1 and the different measurement height requirements of operators, the height of the support frame 4 is adjustable as a preferred embodiment. Specifically, the support frame 4 can adopt a split structure, including a base and a lifting column. The relative position of the base and the lifting column can be adjusted and locked through threaded pairs, guide sleeves and guide columns with pin holes, or hydraulic telescopic mechanisms. By adjusting the height of the support frame 4, on the one hand, different sized test fixtures 1 can maintain a suitable ground clearance after installation, avoiding interference between the bottom of the test fixture 1 and the ground; on the other hand, the test fixture 1 can be adjusted to a suitable height for operators to observe and mark, improving the convenience and adaptability of the measurement operation.

[0032] S2. In the first connection position, release the fixture 1 to be tested, so that the fixture 1 to be tested can swing freely under the action of gravity and reach a stable equilibrium state. At this time, obtain the first spatial vertical line passing through the center of the measuring disk 3.

[0033] It should be noted that the first connection position refers to a specific connection state between the measuring disk 3 and the rotary connecting frame 2. As mentioned earlier, since the connection position between the measuring disk 3 and the rotary connecting frame 2 is adjustable, the center of the measuring disk 3 can have different eccentricities relative to the axis of the rotary connecting frame 2 in different radial directions. When the two are in the first connection position, a specific eccentric direction and eccentric distance of the center of the measuring disk 3 relative to the axis of the rotary connecting frame 2 are determined.

[0034] In step S2, the assembled fixture 1 is first lifted using a crane and a lifting device, and slowly moved to the two pre-placed support frames 4, so that the measuring discs 3 at both ends are aligned and fall into the grooves 41 of the support frames 4. After the measuring discs 3 are securely placed in the grooves 41, the crane is operated to gradually release the lifting device, so that the entire weight of the fixture 1 is borne by the two support frames 4. Since the center of gravity of the fixture 1 is usually not exactly located at the midpoint of the line connecting the axes of the two rotating connecting frames 2 in the horizontal direction, at the moment of release, the fixture will naturally roll in a certain direction along the grooves 41 under the action of gravity until it reaches a stable equilibrium state. As an example, the rolling distance of the fixture 1 is usually about 200 mm, and the specific distance depends on the degree of offset of the center of gravity of the fixture 1.

[0035] Once the rolling motion of the fixture 1 under test has completely stopped and the system is in a stable equilibrium state, the lifting device connected to it can be removed to ensure that the constraint force of the lifting device will not interfere with the free swinging state of the fixture 1 under test. At this time, according to the principle of statics, in a free suspension system where only gravity acts, the center of gravity of the fixture 1 under test must lie in the vertical plane passing through the axis of the rotary connecting frame 2. Since the measuring disk 3 and the rotary connecting frame 2 are rigidly connected and have a definite geometric relationship, the vertical line passing through the center of the measuring disk 3 is the same as the vertical line passing through the axis of the rotary connecting frame 2, which is a straight line in space where the center of gravity of the fixture 1 under test lies.

[0036] To accurately record the position of this spatial line, as a specific implementation method, a laser tracker 5 and other measuring equipment are used for data acquisition. The operator sets up the laser tracker 5 in a suitable position, and by measuring multiple points on the outer circumference of the measuring disk 3, fits the coordinates of the center of the measuring disk 3. Combined with a high-precision level or gravity direction reference, the vertical line passing through the center of the disk in a stable equilibrium state can be determined, and this vertical line is recorded as the first spatial perpendicular line. This first spatial perpendicular line is the spatial line through which the center of gravity of the fixture 1 under test passes.

[0037] S3. Adjust the connection position between the measuring disk 3 and the rotary connecting frame 2 to the second connection position, release the fixture 1 to be measured, so that the fixture 1 to be measured can swing freely under the action of gravity and reach a stable equilibrium state, and obtain the second spatial vertical line passing through the center of the measuring disk 3.

[0038] In step S3, the connection position between the measuring disk 3 and the rotary connecting frame 2 needs to be adjusted from the first connection position to the second connection position. The second connection position is a different specific connection state from the first connection position, that is, changing the eccentric orientation of the center of the measuring disk 3 relative to the axis of the rotary connecting frame 2.

[0039] As a specific implementation method, the adjustment process of the measuring disk 3 includes: removing the measuring disk 3 from the rotary connecting frame 2 at the first connection position, rotating the measuring disk 3 by a preset angle with the center of the measuring disk 3 as the center, and then reassembling it onto the rotary connecting frame 2 to form the second connection position.

[0040] The preset angle here can be set according to the distribution pattern of the connecting holes 31 on the rotary connecting frame 2 and the measuring disk 3. For example, when the assembly disk of the rotary connecting frame 2 has multiple threaded holes evenly opened along the circumference, and the measuring disk 3 has multiple corresponding connecting holes 31, the measuring disk 3 can be rotated counterclockwise by the angle corresponding to two connecting holes 31. That is, if the included angle between adjacent connecting holes 31 is α, then the rotation angle is 2α, thereby changing the eccentric orientation. In this way, the direction of the center of the measuring disk 3 relative to the axis of the rotary connecting frame 2 changes, while the eccentricity itself can remain unchanged. Of course, the eccentricity can also be changed simultaneously according to actual needs.

[0041] After the measuring disc 3 is reassembled to the second connection position, the fixture 1 to be tested is lifted again using a crane and a lifting device, so that the measuring discs 3 at both ends are placed in the slide grooves 41 of the support frame 4. Then, the lifting device is slowly released. Similar to step S2, the fixture 1 to be tested will swing freely along the slide grooves 41 under the action of gravity, and eventually reach a new stable equilibrium state. Since the connection position between the measuring disc 3 and the rotary connecting frame 2 has changed, that is, the orientation of the center of the measuring disc 3 relative to the center of gravity of the fixture 1 to be tested has changed, the overall posture of the fixture 1 to be tested relative to the vertical line when the system reaches equilibrium will be different from the posture in the first connection position. After the swing of the fixture 1 to be tested has completely stopped and the system is in a stationary state, the lifting device is removed.

[0042] At this point, according to the same physical principle, in this equilibrium state, the center of gravity of the fixture 1 under test must be located in the vertical plane passing through the axis of the rotary connecting frame 2. That is, the vertical line passing through the center of the measuring disk 3 is another spatial straight line where the center of gravity is located. To accurately record the position of this spatial straight line, a laser tracker 5 is also used for measurement to obtain the vertical line passing through the center of the measuring disk 3 when in a stable equilibrium state at the second connection position, which is recorded as the second spatial vertical line.

[0043] To further verify the accuracy of the intersection point determined by the first and second spatial perpendicular lines, as a preferred embodiment of this invention, a verification measurement can also be performed after step S3. Specifically, the connection position between the measuring disk 3 and the rotary connecting frame 2 is readjusted to a third connection position, which is different from both the first and second connection positions. For example, the measuring disk 3 is rotated another preset angle. The release and measurement process is then repeated, allowing the fixture 1 to swing freely in the third connection position until it reaches a stable equilibrium state, thus obtaining the third spatial perpendicular line passing through the center of the measuring disk 3. If the first two measurements are accurate, the third spatial perpendicular line should also pass through the intersection point of the first and second spatial perpendicular lines. In actual operation, the measurement error can be evaluated by measuring the spatial distance between the third spatial perpendicular line and the intersection point. If the distance is within the allowable range, it indicates that the results of the first two measurements are reliable, and the intersection point is the accurate center of gravity position of the fixture 1. By increasing the number of measurements and verifications under different postures, random errors can be effectively eliminated, further improving the accuracy of the center of gravity positioning.

[0044] S4. Determine the intersection of the first spatial perpendicular line and the second spatial perpendicular line. The intersection point is the location of the center of gravity of the fixture 1 to be measured.

[0045] After obtaining the first spatial perpendicular line at the first connection position and the second spatial perpendicular line at the second connection position, it is necessary to determine the intersection point of these two spatial lines in space. Since both the first and second spatial perpendicular lines are vertical lines passing through the center of gravity of the fixture 1 to be measured, and the center of gravity is a uniquely determined point in space, these two lines must intersect at one point, which is the actual position of the center of gravity of the fixture 1 to be measured.

[0046] In one specific implementation, the measurement data of the first and second spatial perpendicular lines are imported into the computer-aided design model. The laser tracker 5 and other measuring devices have already recorded the precise position and direction vector of each spatial perpendicular line in the global coordinate system during data acquisition. In the model environment, by constructing two spatial straight lines and calculating their intersection coordinates, the precise spatial position of the center of gravity of the fixture 1 under test can be obtained. These intersection coordinates can be positional data relative to the fixture's own coordinate system or relative to the axis of the rotary connecting frame 2.

[0047] After determining the center of gravity position in step S4, in another embodiment, step S5 can also be performed, namely, calculating the eccentricity between the center of gravity of the fixture 1 to be tested and the axis of the rotary connecting frame 2 based on the position of the intersection point. Specifically, since the axis of the rotary connecting frame 2 is a known geometric element during the measurement process, the spatial position of the axis can be determined by measuring feature points on the rotary connecting frame 2 or fitting its cylindrical surface. The vertical distance from the center of gravity to the axis is calculated in the digital model, thus obtaining the required eccentricity. This eccentricity data has important engineering application value. For example, when installing the fixture 1 to be tested onto the yarn laying equipment, a special transition plate can be designed and manufactured based on this eccentricity. One side of the transition plate is connected to the rotation center of the yarn laying equipment, and the other side is connected to the rotary connecting frame 2 at the end of the fixture, and the transition plate is equipped with a corresponding eccentricity compensation structure. Through the transition plate, the actual center of gravity of the fixture can be kept consistent with the rotation center of the equipment during rotation, thereby effectively eliminating the additional inertial torque caused by the center of gravity offset, ensuring the dynamic balance of the laying system during rotation, and improving the safety of equipment operation and yarn laying quality.

[0048] Furthermore, embodiments of the present invention also provide a center of gravity measuring device for large-size tooling, which is applied to the above-described center of gravity measuring method for large-size tooling.

[0049] Specifically, the device includes a support frame 4, a rotary connecting frame 2, a measuring disk 3, and a measuring unit. The support frame 4 is provided with a sliding groove 41; two rotary connecting frames 2 are fixedly mounted at both ends of the fixture 1 to be tested; two measuring disks 3 are eccentrically mounted on the rotary connecting frames 2 at both ends of the fixture 1, and the connection position between the measuring disks 3 and the rotary connecting frames 2 is adjustable to change the orientation of the center relative to the axis of the rotary connecting frame 2; the measuring disks 3 are mounted within the sliding groove 41 and can roll freely within the sliding groove 41, allowing the fixture 1 to swing freely around the axis of the rotary connecting frame 2; the measuring unit is used to acquire at least two spatial vertical lines passing through the center of the measuring disk 3 at different connection positions when the fixture 1 is in a stable equilibrium state. As a specific implementation, the measuring unit can use a laser tracker 5 to fit the coordinates of the center by measuring the outer circumference of the measuring disk 3, and determine the vertical line passing through the center by combining the gravity direction reference.

[0050] Through the cooperation of the above components, the device can realize the free swing of the fixture 1 under different eccentric postures, and accurately record the spatial vertical line passing through the center of the measuring disk 3 in each equilibrium state. Then, the center of gravity of the fixture 1 under test is determined by finding the intersection of the two spatial vertical lines. The device has a simple structure, is easy to operate, can effectively avoid the interference of environmental factors on the measurement results, and is not limited by the size of the fixture.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for measuring the center of gravity of large-size tooling, characterized in that, include: S1. Install rotary connecting frames (2) at both ends of the fixture (1) to be tested. Eccentrically assemble measuring disk (3) on the rotary connecting frame (2) and place the measuring disk (3) in the slide groove (41) of the support frame (4) so ​​that the measuring disk (3) can drive the fixture (1) to be tested to swing freely in the slide groove (41) around the axis of the rotary connecting frame (2). The connection position between the measuring disk (3) and the rotary connecting frame (2) is adjustable to change the orientation of the center of the measuring disk (3) relative to the axis of the rotary connecting frame (2). S2. In the first connection position, release the tool to be tested (1) so that the tool to be tested (1) swings freely under the action of gravity and reaches a stable equilibrium state. At this time, obtain the first spatial vertical line passing through the center of the measuring disk (3). S3. Adjust the connection position between the measuring disk (3) and the rotary connecting frame (2) to the second connection position, release the tool to be tested (1), so that the tool to be tested (1) swings freely under the action of gravity and reaches a stable equilibrium state, and obtain the second spatial vertical line passing through the center of the measuring disk (3); S4. Determine the intersection point of the first spatial perpendicular line and the second spatial perpendicular line. The intersection point is the location of the center of gravity of the tooling to be tested (1).

2. The method for measuring the center of gravity of large-size tooling according to claim 1, characterized in that, The measuring disk (3) has multiple connecting holes (31) along its circumference. By selecting different connecting holes (31) on the measuring disk (3) to connect with the rotary connecting frame (2), the orientation of the center of the measuring disk (3) relative to the axis of the rotary connecting frame (2) can be changed.

3. The method for measuring the center of gravity of large-size tooling according to claim 2, characterized in that, The adjustment of the connection position between the measuring plate (3) and the fixture (1) to the second connection position includes: The measuring disc (3) is disassembled from the first connection position, rotated by a preset angle around the center of the measuring disc (3), and then reassembled onto the rotary connecting frame (2) to form the second connection position.

4. The method for measuring the center of gravity of large-size tooling according to claim 3, characterized in that, The preset angle corresponds to the angle corresponding to the counterclockwise rotation of the two connecting holes (31) on the measuring disk (3).

5. The method for measuring the center of gravity of large-size tooling according to claim 1, characterized in that, In S2, at the first connection position, a laser tracker (5) is used to measure and record the vertical line passing through the center of the measuring disk (3) in a stable equilibrium state to obtain the first spatial vertical line; In S3, at the second connection position, the laser tracker (5) is used to measure and record the vertical line passing through the center of the measuring disk (3) in a stable equilibrium state to obtain the second spatial vertical line.

6. The method for measuring the center of gravity of large-size tooling according to claim 1, characterized in that, S3 further includes: adjusting the connection position between the measuring disk (3) and the rotary connecting frame (2) to the third connection position, releasing the test fixture (1), allowing the test fixture (1) to swing freely under gravity and reach a stable equilibrium state, obtaining the third spatial vertical line passing through the center of the measuring disk (3), and verifying whether the third spatial vertical line passes through the intersection of the first spatial vertical line and the second spatial vertical line.

7. The method for measuring the center of gravity of large-size tooling according to claim 1, characterized in that, It also includes S5: Calculate the eccentricity between the center of gravity of the tooling to be tested (1) and the axis of the rotary connecting frame (2) based on the position of the intersection point.

8. The method for measuring the center of gravity of large-size tooling according to claim 1, characterized in that, The slide (41) is an arc-shaped groove opened on the top of the support frame (4), and the two ends of the slide (41) are provided with limiting members.

9. The method for measuring the center of gravity of large-size tooling according to claim 1, characterized in that, The diameter of the measuring disc (3) is larger than the diameter of the assembly disc of the rotary connecting frame (2).

10. A center of gravity measuring device for large-size tooling, characterized in that, The method for measuring the center of gravity of a large-size tooling as described in any one of claims 1-9 includes: Support frame (4), on which a sliding groove (41) is provided; Two rotary connecting frames (2) are fixedly installed at both ends of the fixture (1) to be tested; Two measuring discs (3) are respectively eccentrically mounted on the rotary connecting frame (2) at both ends of the fixture (1) to be tested. The connection position between the measuring disc (3) and the rotary connecting frame (2) is adjustable to change the orientation of the center of the disc relative to the axis of the rotary connecting frame (2). The measuring disc (3) is mounted in the slide groove (41) and can roll freely in the slide groove (41) so that the fixture (1) to be tested can swing freely around the axis of the rotary connecting frame (2). The measuring unit is used to acquire at least two spatial vertical lines passing through the center of the measuring disk (3) at different connection positions when the tooling to be measured (1) is in a stable equilibrium state.

Images