Screw running-in device, running-in method and control method

Abstract

The present invention relates to a screw running-in device, a running-in method and a control method, comprising a grinding platform, a front mounting seat, a middle mounting seat and a rear mounting seat fixedly arranged on the grinding platform, a pushing electric cylinder fixedly installed between the rear mounting seat and the middle mounting seat, and the telescopic end of the pushing electric cylinder is fixedly connected to the connecting portion; a driving portion is provided on the front mounting seat, and a running-in fixture is provided at the driving end of the driving portion; an extension cylinder is fixedly provided on the front mounting seat, and the center lines of the telescopic end of the pushing electric cylinder, the screw, the running-in fixture and the extension cylinder are located on the same horizontal line; when running-in, the pushing electric cylinder pushes the screw into the extension cylinder while the driving portion drives the running-in fixture to run-in the screw; the running-in working mode is modified to avoid the screw being subjected to longitudinal pressure during the running-in process, resulting in damage to the running-in accuracy, and at the same time, the method of running-in by pushing the screw can ensure the concentricity between the screw and the running-in fixture during the running-in process, thereby improving the running-in accuracy of the screw.

Description

Technical Field

[0001] The present application relates to the technical field of screw running-in, and in particular to a screw running-in device, a running-in method and a control method. Background Art

[0002] Domestic box-type missile launchers often utilize locking mechanisms to secure the missile. Currently, the most common locking mechanism utilizes a screw-driven slider that moves left and right, driving the up and down movement of a latch. This type of structure involves multiple moving parts, making it difficult to ensure component consistency due to machining errors. This often results in problems such as jamming and stiff rotation. A common practice is to perform multiple run-in cycles after assembly and adjustment.

[0003] At present, during the running-in process, the running-in nut is driven by a motor to move on the lead screw to achieve the running-in of the lead screw. Although this method can achieve the running-in of the lead screw, during the running-in process, since the motor needs to drive the running-in fixture to move on the lead screw to achieve the running-in, the lead screw will be subjected to the downward pressure of the running-in fixture during the running-in process, resulting in increased longitudinal pressure. The lead screw is more laborious during the running-in process, resulting in the problem of low accuracy of the run-in lead screw. At the same time, since the motor drives the fixture to move on the lead screw for running-in, it cannot guarantee that the concentricity is maintained consistently during the running-in process, resulting in a lower yield rate of the lead screw after running-in. At the same time, during the running-in process, the running-in data cannot be used to determine whether the lead screw meets the standards after running-in. Independent manual inspection and judgment are required, which increases the cost of the running-in process. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the main purpose of the present invention is to provide a screw running-in device, a running-in method and a control method that can improve the running-in accuracy and change the running-in method.

[0005] To achieve the above-mentioned object, the present invention adopts the following technical solution: a screw running-in device, comprising a grinding platform, a front mounting seat, a middle mounting seat, and a rear mounting seat fixedly mounted on the grinding platform; a pushing electric cylinder is fixedly mounted between the rear mounting seat and the middle mounting seat; the telescopic end of the pushing electric cylinder passes through the middle mounting seat and is fixedly connected to a connecting portion provided between the front mounting seat and the middle mounting seat; a driving portion is fixedly mounted on the front mounting seat, and a running-in jig is provided at the driving end of the driving portion;

[0006] An extension tube is fixedly provided at the end of the front mounting seat away from the middle mounting seat, and the end of the extension tube passes through the front mounting seat and faces the connecting portion;

[0007] One end of the screw rod to be run-in is fixedly connected to the connecting portion, and the other end passes through the running-in jig and extends into the extension tube and is in non-destructive sliding contact with the inner wall of the extension tube; and the center lines of the telescopic end of the pushing electric cylinder, the screw rod, the running-in jig and the extension tube are located on the same horizontal line;

[0008] During the running-in process, the pushing electric cylinder pushes the lead screw into the extension tube, while the driving unit drives the running-in fixture to run-in the lead screw.

[0009] Preferably, the running-in jig includes a first retaining ring fixedly connected to the driving end of the driving part, a second retaining ring connected to the first retaining ring, an inner connecting ring fixedly installed inside the first retaining ring, a snap is provided on the axial surface of the first retaining ring, a seat that cooperates with the snap is provided on the axial surface of the second retaining ring, a copper sleeve is provided inside the second retaining ring, and also includes a running-in nut for running-in the screw rod, after the first retaining ring and the second retaining ring are fixedly connected by the snap and the seat, the copper sleeve and the inner connecting ring complete the fixing and limiting of the running-in nut; wherein the inner connecting ring is provided with a plurality of limiting holes, and the second retaining ring is provided with a limiting pin that cooperates with the limiting holes.

[0010] Preferably, the front mounting seat and the middle mounting seat are fixedly connected by two positioning shafts, a connecting plate is provided between the front mounting seat and the middle mounting seat, the two positioning shafts pass through the two ends of the connecting plate and are slidingly connected to the connecting plate, the telescopic end of the pushing electric cylinder is fixedly connected to the connecting plate, and the connecting part is fixedly connected to the connecting plate.

[0011] Preferably, a center rod is fixedly connected to the connecting part, and a screw rod is sleeved on the center rod. A slider is fixedly connected to the end of the center rod away from the connecting part. The slider is fixedly connected to the end of the center rod by a screw, and the slider is slidably connected to the inside of the extension tube, and the step protrusion provided on the end of the slider is inserted into the center hole of the screw rod.

[0012] Preferably, the connecting portion includes a connecting piece connected to the screw rod and a locking piece fixedly connected to the connecting plate, and the connecting piece is fixedly connected to the connecting plate via the locking piece.

[0013] Preferably, the grinding platform is also provided with a front protective cover buckled outside the front mounting seat and a rear protective cover buckled outside the rear mounting seat; the grinding platform is also provided with parallel slide rails, a middle protective cover buckled outside the middle mounting seat, and the two sides of the middle protective cover are respectively slidably connected to the slide rails.

[0014] Preferably, the grinding platform is provided with a process mandrel for correcting the concentricity of the pushing electric cylinder, the running-in fixture and the extension cylinder, and the radius of the process mandrel is the same as the radius of the screw rod.

[0015] A screw rod running-in method uses a screw rod running-in device to run-in a screw rod to be run-in, comprising:

[0016] Step 1: Put the process mandrel on the center rod, and then fix the connector to one end of the center rod;

[0017] Step 2: Pass the process mandrel through the running-in fixture and fix the slider to the other end of the center rod to complete the limit fixation of the process mandrel;

[0018] Step 3: The connecting piece at one end of the process mandrel with the position limit completed is fixed to the connecting plate by a locking piece, and the slider is inserted into the extension tube;

[0019] Step 4: Adjust the concentricity of the push cylinder, process mandrel, running-in fixture, and extension cylinder. When the center lines of the push cylinder, process mandrel, running-in fixture, and extension cylinder are on the same straight line, the concentricity adjustment is completed.

[0020] Step 5: Remove the process mandrel from the screw running-in device, fix the screw to be run-in at the position of the original process mandrel, and start the electric cylinder and the drive unit to run-in the screw to be run-in.

[0021] Furthermore, in order to achieve automated control and utilize the running-in parameters of the screw during the running-in process to judge the quality of the screw after running-in, a control method for a screw running-in device includes:

[0022] Start the screw running-in device and enter the product information of the screw to be run-in;

[0023] Enter the initial running-in parameter values ​​and the number of running-in times for pre-running-in;

[0024] Obtaining operating data of the screw running-in device during the pre-running-in process, the operating data including current value, voltage value, tension value, pressure value, vibration value, single reciprocating time and movement speed;

[0025] Preprocessing the operating data during the pre-running-in process, and performing discrete distribution analysis on the preprocessed operating data, and using the current value, voltage value, and vibration value obtained after the discrete distribution analysis as the running-in parameters of the screw running-in device;

[0026] The obtained running-in parameters are input into the running-in device, and the running-in parameters are used to run-in the screw to be run-in, and the operating data during the running-in is obtained. The signal-to-noise ratio of the current-force ratio in the operating data is used to determine whether the running-in device has an abnormality. If there is an abnormality, the running-in device is repaired; if there is no problem, the running-in device is continued to be used to run-in the screw;

[0027] The operating data after the screw rod is run-in is used to perform multi-parameter fusion, and the multi-parameter fusion results are used to determine whether the run-in screw rod is qualified.

[0028] The multi-parameter fusion method includes:

[0029] Using each running-in parameter obtained at each moment during the running-in process to calculate information entropy, using the information entropy obtained for each running-in parameter to perform weight distribution, and obtaining the weight of each running-in parameter;

[0030] Use the weight of each running-in parameter to weight its corresponding running-in parameter and parameter mean;

[0031] The weighted running-in parameters are used to form a covariance matrix, and the Mahalanobis distance is obtained based on the running-in parameters and parameter means in the covariance matrix;

[0032] The obtained Mahalanobis distance is used to determine whether there is any abnormality in the running-in screw.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] 1. The running-in jig is placed at one end of the running-in platform. During the running-in process, the electric cylinder is pushed to move the lead screw. During the movement, the running-in work of the lead screw is completed by the running-in jig. The working mode is modified, and the mobile running-in jig is changed to a fixed running-in jig. This avoids the lead screw being subjected to longitudinal pressure during the running-in process, which may cause the running-in accuracy to be damaged. At the same time, the running-in method of pushing the lead screw can ensure the concentricity between the lead screw and the running-in jig during the running-in process, thereby improving the running-in accuracy of the lead screw.

[0035] 2. The present invention uses a process mandrel for calibration before running-in, which ensures the concentricity between the screw and the running-in jig during the running-in process, avoiding the need to adjust the concentricity during the running-in process, which reduces the running-in efficiency;

[0036] 3. During the running-in process, the parameters of the running-in process are used to judge the quality of the screw after running-in, which reduces the running-in cost of the entire running-in. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 1 is a schematic structural diagram of a screw rod running-in device according to an embodiment of the present invention;

[0038] Figure 2 This is a structural schematic diagram of a screw running-in device according to another embodiment of the present invention;

[0039] Figure 3 Schematic diagram of the connection structure of the running-in fixture in an embodiment of the present invention;

[0040] Figure 4 Schematic diagram of the top view of the screw running-in device in an embodiment of the present invention;

[0041] Figure 5 This is an overall axial view of the screw running-in device in an embodiment of the present invention;

[0042] Figure 6 Schematic diagram of the cross-sectional structure of a running-in jig according to an embodiment of the present invention;

[0043] Figure 7 Schematic diagram of the cross-sectional structure of the connecting portion in an embodiment of the present invention;

[0044] Figure 8 Flowchart of the control method in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0046] like Figure 1 and Figure 2 As shown, this embodiment provides a screw grinding device, including a grinding platform 1, a front mounting seat 2, a middle mounting seat 3 and a rear mounting seat 4 fixedly arranged on the grinding platform 1, as shown in FIG. Figure 1 As shown, the front mounting seat 2, the middle mounting seat 3 and the rear mounting seat 4 in this embodiment are fixedly installed on the grinding platform 1 from right to left in sequence. Specifically, a plurality of mounting holes are evenly arranged on the grinding platform 1. During installation, the front mounting seat 2, the middle mounting seat 3 and the rear mounting seat 4 are fixed in the corresponding mounting holes according to the required size, and the fixed installation is completed by screws. At the same time, after the installation is completed, the centers of the front mounting seat 2, the middle mounting seat 3 and the rear mounting seat 4 remain on the same horizontal line.

[0047] A pushing electric cylinder 9 is fixedly installed between the rear mounting seat 4 and the middle mounting seat 3. Specifically, the cylinder base of the pushing electric cylinder 9 is fixedly installed on the rear mounting seat 4 by bolts, and the cylinder body at the front end of the pushing electric cylinder 9 is fixedly connected to the middle mounting seat 3, and it is ensured that the telescopic end of the pushing electric cylinder 9 can pass through the middle mounting seat 3 to extend to the end of the front mounting seat 2; and it is fixedly installed at the connecting part between the middle mounting seat 3 and the front mounting seat 2.

[0048] In one embodiment, Figure 4The mounting seat 3 and the front mounting seat 2 are fixedly connected by two positioning shafts 10. The surface of the positioning shaft 10 is smoothed to reduce friction. A connecting plate 15 is connected to the two positioning shafts 10. Specifically, two through holes are provided on the left and right sides (or front and back sides) of the connecting plate 15 to penetrate the connecting plate 15. Two copper sleeves made of brass are embedded in the through holes. The positioning shaft 10 passes through the copper sleeves and the connecting plate 15 is slidably connected to the positioning shaft 10 to ensure that the connecting plate 15 can move on the positioning shaft 10; at the same time, the telescopic end of the pushing electric cylinder 9 is fixedly connected to the connecting plate 15, which can ensure that the pushing electric cylinder 9 can drive the connecting plate 15 to move left and right (that is, the connecting plate 15 reciprocates between the front mounting seat 2 and the rear mounting seat 4). The connecting part 8 is fixedly mounted on the connecting plate 15, specifically, it is fixedly mounted in the middle part of the connecting plate 15 to ensure that the connecting plate 15 drives the connecting part 8 to move during the movement.

[0049] A connecting plate 15 is provided between the front mounting seat 2 and the middle mounting seat 3 , and the two positioning shafts 10 pass through both ends of the connecting plate 15 and are slidably connected to the connecting plate 15 . The telescopic end of the pushing electric cylinder 9 passes through the connecting plate 15 and is fixedly connected to the connecting part 8 .

[0050] An extension tube 12 is fixedly provided at the end of the front mounting seat 2 away from the middle mounting seat 3, and the end of the extension tube 12 passes through the front mounting seat 2 and faces the connecting portion 8; specifically, a through hole is opened in the front mounting seat 2, and the end of the extension tube 12 is inserted into the through hole to complete the installation of the extension tube 12, ensuring that the run-in screw rod will enter the extension tube 12 during operation.

[0051] A running-in jig 6 is provided on the front mounting seat 2. The running-in jig 6 is mainly used to run in the screw rod 13 to be run in. Specifically, the running-in jig 6 is installed near the end of the middle mounting seat 3, and the screw rod 13 can enter the extension cylinder 12 through the running-in jig 6. At the same time, a drive 5 is provided on the front mounting seat 2. The drive part 5 is used to drive the running-in jig 6 to run in the screw rod 13 to be run in.

[0052] Specifically, during the running-in, one end of the screw rod 13 to be run-in is fixedly connected to the connecting part 8, and the other end of the screw rod 13 passes through the running-in jig 6 and enters the extension tube 12. At this time, it is necessary to ensure that the center lines of the telescopic end of the pushing electric cylinder 9, the screw rod 13, the running-in jig 6 and the extension tube 12 are located on the same horizontal line, and the concentricity of the screw rod 13, the running-in jig 6 and the extension tube 12 is improved; that is, to ensure that the pushing electric cylinder 9 pushes the screw rod 13 and the screw rod 13 is running-in through the running-in jig 6, to ensure that the screw rod 13 can achieve complete linear motion, thereby improving the accuracy of the screw rod 13 during running-in.

[0053] In one embodiment, Figure 3 and Figure 6 The running-in jig 6 includes a first snap ring 601 fixedly connected to the driving end of the driving part 5. The first snap ring 601 is fixedly connected to the driving end of the driving part 5, and can ensure that the driving part 5 drives the first snap ring 601 to rotate. Specifically, the driving part 5 includes at least one driving motor, and a driving gear is fixedly provided on the driving shaft of the driving motor. A driven gear meshing with the driving gear is provided on the outer sleeve of the first snap ring 601, and then the first snap ring 601 can be driven to rotate by the driving motor, that is, the first snap ring 601 can be driven to rotate around the center line. A second snap ring 7 is also fixedly connected to the first snap ring 601. The center of the second snap ring 7 is concentric with the center of the first snap ring 601. The second snap ring 7 can be driven to rotate during the rotation of the first snap ring 601 (that is, the second snap ring 7 can rotate around the center line); an inner connecting ring 602 is embedded and fixed in the first snap ring 601, and a running-in nut 603 for running-in the screw rod 13 is embedded in the inner connecting ring 602. During the running-in , the running-in nut 603 can drive the first clamping ring 601 and the inner connecting ring 602 to rotate by the driving motor to achieve the purpose of running-in the screw rod 13 to be run-in; at the same time, in order to ensure that the running-in nut 603 does not rotate when running in the screw rod 13, a clamping seat 701 is provided on the axial surface of the second clamping ring 7, and a copper sleeve 702 is provided at the center of the second clamping ring 7. When running in, the copper sleeve 702 is sleeved on the outside of the screw rod 13, and when the clamping seat 701 and the axial surface of the first clamping ring 601 are fixed with a buckle 605 When fixedly connected, the copper sleeve 702 is sleeved on the screw nut 603 to limit the screw nut 603, thereby preventing the screw nut 603 from slipping during the running-in process. The screw nut 603 completes the fixing and limiting functions through the copper sleeve 702 and the inner connecting ring 602; in one embodiment, a through hole is provided on the holder 701, and the holder 701 is inserted into the buckle 605, and then the holder 701 and the buckle 605 are fixedly connected by a pin, thereby realizing the fixed connection between the first snap ring 601 and the second snap ring 7. In another embodiment, in order to facilitate alignment, a circle of limiting holes 604 are evenly distributed on the inner connecting ring 602, and a limiting pin is provided on the end face of the second retaining ring 7 facing the first retaining ring 601. During the connection process, the limiting pin can be directly inserted into the limiting hole 604 for limiting. During the limiting process, the limiting pin can be inserted into any of the limiting holes 604 to achieve the purpose of limiting, avoiding the need to rotate the second retaining ring 7 to achieve fixed limiting.

[0054] In another embodiment, to ensure that the screw rod 13 can perform absolute linear motion during the running-in process, and the force it receives when pushing the electric cylinder 9 is reduced as much as possible, a center rod 19 is fixedly connected to the connecting portion 8, and the screw rod 13 is sleeved on the center rod 19. The end of the center rod 19 away from the connecting portion 8 is fixedly connected to a slider 20, and the slider 20 is fixedly connected to the end of the center rod 19 by a screw 21, and the slider 20 is slidably connected to the inside of the extension tube 12, and the step protrusion provided on the end of the slider 20 is inserted into the center hole of the screw rod 13. The slider 20 is made of brass and can slide in the extension tube 12 with less friction. At the same time, the existence of the slider 20 can effectively limit the path of the screw rod 13 during the running-in process, providing a conditional path for achieving linear motion. When the slider 20 is installed, it is fixed to the end of the center rod 19 by screws. The diameter of the slider 20 is larger than the diameter of the screw rod 13, and the screw rod 13 is sleeved on the center rod 19. Therefore, the connection between the screw rod and the center rod 19 is completed by the limitation of the slider 20. Furthermore, a stepped cone surface is provided at the end of the slider 20, which can be inserted into the through hole of the screw rod 13. The screw rod 13 is fixed by the extrusion installation of the slider and the connecting part to reduce damage to the screw rod 13.

[0055] In one embodiment, Figure 7 The connecting portion 8 shown includes a connecting piece 801 connected to the screw rod 13 and a locking piece 802 fixedly connected to the connecting plate 15. The connecting piece 801 is fixedly connected to the connecting plate 15 via the locking piece 802. The connecting piece 801 in this example is made of yellow-green copper. Specifically, when connecting, the end of the center rod 19 with the screw rod 13 is inserted into the connecting piece for fixed connection. At the same time, the end of the connecting piece is inserted into the through hole of the screw rod 13. The screw rod 13 is squeezed and fixed to the center rod 19 through the connecting piece 801 and the slider 20. After the screw rod 13 is fixed, the connecting piece 801 is fixedly connected to the locking piece 802 to complete the connection between the connecting plate 15 and the screw rod 13.

[0056] In another embodiment, the grinding platform 1 is further provided with a front protective cover 16 buckled outside the front mounting seat 2 and a rear protective cover 18 buckled outside the rear mounting seat 3; heat dissipation holes are provided in the front protective cover 16 and the rear protective cover 18 corresponding to the driving part and the pushing electric cylinder, which are used to dissipate heat from the driving motor and the pushing electric cylinder in the driving part. The front protective cover 16 and the protective cover 18 are fixedly connected to the grinding platform 1 to achieve protection for the entire grinding platform;

[0057] At the same time Figure 5The grinding platform 1 is also provided with mutually parallel slide rails 14, which are buckled onto the outside of the middle mounting seat 3. The two sides of the middle protective cover 17 are slidably connected to the slide rails 14. The middle protective cover 17 mainly protects the operating section of the screw during the running-in process. When operation is required, the middle protective cover 17 is pushed away from the operating section to perform the operation. When the operation is completed and the running-in is required, the middle protective cover is pulled back to the operating section to prevent accidents during the running-in process that may harm the operator's personal safety.

[0058] In one embodiment, in order to improve concentricity and enable verification before grinding, thereby avoiding concentricity adjustment during the running-in process, a process mandrel 11 is provided on the grinding platform 1 for calibrating the concentricity of the push cylinder 9, the running-in jig 6, and the extension cylinder 12. The radius of the process mandrel 11 is the same as the radius of the screw 13. Using the process mandrel 11 to verify concentricity before running-in improves the running-in efficiency.

[0059] Example 2

[0060] A screw rod running-in method, using the screw rod running-in device provided in Example 1 to run-in a screw rod 13 to be run-in, comprises:

[0061] Step 1: Pass the process mandrel 11 through the center rod 19, and then fix the connecting piece 801 to one end of the center rod 19; the process mandrel 11 in this embodiment has the same size and model as the screw rod 13 to be run-in. The process mandrel 11 is used to check the concentricity in the running-in device before running-in, and the running-in of the screw rod is carried out after the check is completed; when the process mandrel 11 is connected to the connecting piece 801, the connection method of the screw rod and the connecting piece 801 is the same, that is, the end of the connecting piece 801 is inserted into the through hole of the process mandrel 11;

[0062] Step 2: Pass the process mandrel 11 through the running-in jig 6 and fix the slider 20 to the other end of the center rod 19 to complete the limited fixation of the process mandrel 11. At this time, the process mandrel 11 is squeezed and installed on the center rod 19 by the joint action of the slider 20 and the connecting piece 801.

[0063] Step 3: After the limited installation is completed, the connecting piece 801 at one end of the process mandrel 11 is fixedly connected to the connecting plate 15 through the locking piece 802, and the slider 20 is inserted into the extension tube 12; the installation of the process mandrel 11 is completed;

[0064] Step 4: After completing the installation of the process mandrel 11, the operator adjusts the concentricity of the pushing electric cylinder 9, the process mandrel 11, the running-in jig 6, and the extension cylinder 12. When the center lines of the pushing electric cylinder 9, the process mandrel 11, the running-in jig 6, and the extension cylinder 12 are on the same straight line, the concentricity adjustment is completed;

[0065] Step 5, remove the process core shaft 11 from the screw running-in device. During disassembly, remove the slider 20 from the center rod 19, then withdraw the process core shaft 11 from the center rod 19, and then pass the screw rod 13 to be run-in on the center rod 19, and finally fix the slider 20 to the center rod 19 to complete the extrusion and fixed installation of the screw rod 13. Finally, start the pushing electric cylinder 9 and the driving part 5 to run-in the screw rod 13 to be run-in. The pushing electric cylinder 9 and the driving motor in the driving part 5 in this embodiment are controlled by the background software, and the power supply can be municipal electricity.

[0066] Example 3

[0067] like Figure 8 The embodiment shown provides a control method for a screw running-in device, comprising:

[0068] S1. Start the screw running-in device and enter the product information of the screw to be run-in; the information of the screw to be run-in includes the product model of the screw 13, which is used to match the product. When the ground detection software has product information of the screw that needs to be run-in, there is no need to enter it, just select it directly. When there is no product information in the software, enter the product model of the screw 13;

[0069] After completing the entry of the product model, the corresponding running-in initial parameter values ​​are selected according to the product model, and the screw rod 13 is pre-runned using the initial parameters. The number of pre-running in this embodiment is not less than 30 times; the initial parameters in this embodiment are current value, voltage value and vibration value, etc.;

[0070] S2 obtains the operating data of the screw running-in device during the pre-running process, which includes the current value, voltage value, tension value, pressure value, vibration value, single reciprocating time and movement speed;

[0071] The operating data during the pre-running-in process is preprocessed. The preprocessing in this embodiment includes first de-noising the collected data. This de-noising method is to process the vibration signal and the current signal using the Nyquist sampling theorem. For example, if the frequency range of the vibration signal is 0-500Hz, then the sampling frequency is greater than 1kHz during sampling. According to this scheme, the collected data is de-noised (i.e., filtered).

[0072] The filtered operating data is processed by a noise filtering method. The noise filtering method in this embodiment is a Kalman filter, which can eliminate high-frequency noise. Since the Kalman filter method is a conventional denoising method in the art, the detailed process will not be described in detail in this embodiment.

[0073] S3. A discrete distribution analysis is performed on the preprocessed operating data. The discrete analysis method used in this embodiment uses kernel density estimation (KDE) instead of the traditional histogram method to improve the flexibility of interval division and information retention. The kernel density estimation method in this embodiment is as follows:

[0074]

[0075] Among them, K is the Gaussian kernel function, , h is the bandwidth, calculated according to the Silverman criterion:

[0076]

[0077] Distribution feature extraction:

[0078] Calculate skewness and kurtosis to identify the data distribution type:

[0079]

[0080] Measures the symmetry of the distribution (positive skewness indicates a long right tail, negative skewness indicates a long left tail);

[0081]

[0082] A measure of the thickness of the distribution's tails (relative to a normal distribution);

[0083] 3 indicates a normal distribution, >3 indicates a peaked and thick-tailed distribution, and <3 indicates a flat peaked and thin-tailed distribution;

[0084] in:

[0085] : estimated probability density function value;

[0086] n: number of samples (the amount of data after preprocessing. For example, if discrete distribution analysis is performed on the preprocessed current value, the amount of data is the number of all current values ​​after preprocessing);

[0087] g: normalization constant (usually 1);

[0088] X i : the i-th sample point (the i-th data after preprocessing);

[0089] h: bandwidth (controls the degree of smoothing);

[0090] : Kernel function (here is Gaussian kernel: );

[0091] : expected value;

[0092] X: random variable;

[0093] : Mean (mean of preprocessed data, such as the mean of current values);

[0094] : Standard deviation (such as the standard deviation of current values).

[0095] S4. The current value, voltage value and vibration value obtained after discrete distribution analysis are used as the running-in parameters of the screw running-in device; the data collected after pre-running are processed as new running-in parameters to improve the authenticity of the running-in;

[0096] S5. The obtained running-in parameters are input into the running-in device, and the running-in screw to be run-in is run-in using the running-in parameters. Operational data during the running-in is obtained, and the signal-to-noise ratio of the current-to-force ratio in the operation data is used. The signal-to-noise ratio of the current-to-force ratio in this embodiment is determined using the signal-to-noise ratio (SNR) concept in the Taguchi method, and the specific method is as follows:

[0097]

[0098] Coefficient of variation threshold setting:

[0099] Based on the central limit theorem, the sample mean distribution approaches normality, and a two-sided confidence interval is set:

[0100]

[0101] SNR : signal-to-noise ratio (a larger value indicates better ratio stability);

[0102] n: number of samples; (the number of current values ​​or force values ​​collected in the running data during the running-in process; the number of current values ​​and force values ​​corresponds one to one);

[0103] I i : the i-th current value;

[0104] F i : the i-th force value;

[0105] : Maximum allowable coefficient of variation;

[0106] : Two-sided quantile of the standard normal distribution (such as = 0.05 corresponds to (Z = 1.96);

[0107] : population standard deviation;

[0108] : overall mean;

[0109] The obtained signal-to-noise ratio is used to determine whether there is any abnormality in the running-in device. If there is any abnormality, the running-in device is repaired; if there is no problem, the running-in of the screw rod is continued using the running-in device. When making the judgment, this embodiment uses the obtained signal-to-noise ratio of the current-force ratio to compare with the set threshold value of the signal-to-noise ratio of the current-force ratio. When the obtained signal-to-noise ratio of the current-force ratio is greater than or equal to the threshold value, it indicates that the equipment is running smoothly and the running-in work can continue using the device. When the obtained signal-to-noise ratio of the current-force ratio is less than the threshold value, it indicates that the equipment operation stability is relatively poor and the running-in device has an abnormality, and it is necessary to stop the machine and repair the running-in device.

[0110] S6. Perform multi-parameter fusion using the operating data after the screw rod is run-in, and use the multi-parameter fusion result to determine whether the run-in screw rod is qualified.

[0111] The multi-parameter fusion method in this embodiment includes:

[0112] S601. Calculate the information entropy of each running-in parameter at each moment during the running-in process, and use the information entropy obtained from each running-in parameter to perform weight distribution to obtain the weight of each running-in parameter;

[0113] Specifically, during the running-in process, the operating data of each minute is obtained, and the corresponding running-in parameters are extracted from the operating data to obtain a data set of each running-in parameter of each screw during the running-in process. The information entropy is calculated using each running-in parameter data set. The calculation method is as follows:

[0114] First, each parameter data in the running-in parameter set is normalized to obtain a normalized value;

[0115] The information entropy is calculated as follows:

[0116]

[0117] Where: : the information entropy of the j-th running-in parameter;

[0118] : The normalized value of the i-th sample in the j-th running-in parameter set;

[0119] : natural logarithm; n is the number of parameters in the running-in parameter set;

[0120] The information entropy of each parameter is used to calculate the weight, and the calculation method is as follows:

[0121]

[0122] Use this method to calculate the weight of each parameter;

[0123] S602. Using the weight of each running-in parameter, weight the corresponding running-in parameter and parameter mean. In this embodiment, each running-in parameter in the corresponding running-in parameter set is weighted using the weight of each parameter to obtain a weighted running-in parameter data set. Simultaneously, the mean of the running-in parameter data set before weighting is weighted to obtain a weighted parameter mean. This completes the weighting of the running-in parameter data set and the weighting of the parameter mean.

[0124] S603 and use the weighted running-in parameters to form a covariance matrix, and obtain the Mahalanobis distance based on the running-in parameters and parameter mean in the covariance matrix;

[0125] In this embodiment, when constructing the covariance matrix, the running-in parameter data set after each parameter is weighted is used for construction, and then the Mahalanobis distance is calculated using the constructed covariance matrix and the weighted parameter mean. The formula of the Mahalanobis distance used in this embodiment is as follows:

[0126]

[0127] Where: D represents the Mahalanobis distance; X is the sample vector in the covariance matrix; u represents the mean vector in the covariance matrix; represents the covariance matrix; T represents the transpose.

[0128] S604. Use the obtained Mahalanobis distance to determine whether there is any abnormality in the running-in screw. Specifically, the obtained Mahalanobis distance is compared with a set threshold. When the Mahalanobis distance is greater than the set threshold, it indicates that there is a problem with the parameters during the running-in process. This indicates that there is a problem with the running-in screw, and the screw is determined to not meet the quality requirements. When the calculated Mahalanobis distance is less than or equal to the set threshold, it is determined that the parameters remain stable during the running-in process. Under these stable parameters, the running-in screw quality meets the requirements.

[0129] This embodiment utilizes real-time collection of parameter changes (parameters in operating data) during the running-in process, and uses the changes in parameters to measure the running-in quality of the screw rod, avoiding the need for manual inspection of the screw rod after the running-in is completed, and reducing the running-in cost of the screw rod.

[0130] The above embodiments are merely examples of the present invention and do not limit the scope of protection of the present invention. Any designs that are identical or similar to the present invention fall within the scope of protection of the present invention.

Claims

1. A screw running-in device, comprising a grinding platform (1), a front mounting seat (2), a middle mounting seat (3) and a rear mounting seat (4) fixedly arranged on the grinding platform (1), characterized in that: A driving electric cylinder (9) is fixedly mounted between the rear mounting seat (4) and the middle mounting seat (3), and the telescopic end of the driving electric cylinder (9) passes through the middle mounting seat (3) and is fixedly connected to a connecting portion (8) provided between the front mounting seat (2) and the middle mounting seat (3); a driving portion (5) is fixedly mounted on the front mounting seat (2), and a running-in jig (6) is provided at the driving end of the driving portion (5); An extension tube (12) is fixedly provided on the end of the front mounting seat (2) away from the middle mounting seat (3), and the end of the extension tube (12) passes through the front mounting seat (2) and faces the connecting portion (8); One end of the screw rod (13) to be ground-in is fixedly connected to the connecting portion (8), and the other end passes through the running-in jig (6) and extends into the extension tube (12) and is in non-destructive sliding contact with the inner wall of the extension tube (12); and the center lines of the telescopic end of the pushing electric cylinder (9), the screw rod (13), the running-in jig (6) and the extension tube (12) are located on the same horizontal line; During the running-in process, the driving electric cylinder (9) pushes the screw rod (13) into the extension tube (12), while the driving unit (5) drives the running-in fixture (6) to run-in the screw rod (13); The running-in jig (6) comprises a first retaining ring (601) fixedly connected to the driving end of the driving portion (5), a second retaining ring (7) connected to the first retaining ring (601), an inner connecting ring (602) fixedly installed in the first retaining ring (601), a buckle (605) provided on the axial surface of the first retaining ring (601), a seat (701) matched with the buckle (605) provided on the axial surface of the second retaining ring (7), and a copper sleeve (702) provided in the second retaining ring (7). ), further comprising a running-in nut (603) for running-in the screw rod (13), wherein after the first retaining ring (601) and the second retaining ring (7) are fixedly connected via a buckle (605) and a clamping seat (701), the copper sleeve (702) and the inner connecting ring (602) complete the fixing and limiting of the running-in nut (603); wherein the inner connecting ring (602) is provided with a plurality of limiting holes (604), and the second retaining ring (7) is provided with a limiting pin that cooperates with the limiting hole (604); The front mounting seat (2) and the middle mounting seat (3) are fixedly connected via two positioning shafts (10); a connecting plate (15) is provided between the front mounting seat (2) and the middle mounting seat (3); the two positioning shafts (10) pass through both ends of the connecting plate (15) and are slidably connected to the connecting plate (15); the telescopic end of the pushing electric cylinder (9) is fixedly connected to the connecting plate (15); and the connecting portion (8) is fixedly connected to the connecting plate (15); The connecting portion (8) is fixedly connected to a center rod (19), and the screw rod (13) is sleeved on the center rod (19). The end of the center rod (19) away from the connecting portion (8) is fixedly connected to a slider (20). The slider (20) is fixedly connected to the end of the center rod (19) by a screw (21), and the slider (20) is slidably connected to the inside of the extension tube (12). The step protrusion provided on the end of the slider (20) is inserted into the center hole of the screw rod (13).

2. A screw running-in device according to claim 1, characterized in that: The connecting portion (8) comprises a connecting piece (801) connected to the screw rod (13) and a locking piece (802) fixedly connected to the connecting plate (15). The connecting piece (801) is fixedly connected to the connecting plate (15) via the locking piece (802).

3. The screw running-in device according to claim 1, characterized in that: The grinding platform (1) is further provided with a front protective cover (16) buckled on the outside of the front mounting seat (2) and a rear protective cover (18) buckled on the outside of the rear mounting seat (4); the grinding platform (1) is further provided with mutually parallel slide rails (14), a middle protective cover (17) buckled on the outside of the middle mounting seat (3), and both sides of the middle protective cover (17) are respectively slidably connected to the slide rails (14).

4. The screw running-in device according to claim 1, characterized in that: The grinding platform (1) is provided with a process core shaft (11) for correcting the concentricity of the push electric cylinder (9), the running-in fixture (6) and the extension cylinder (12), and the radius of the process core shaft (11) is the same as the radius of the screw rod (13).

5. A screw running-in method using the device according to any one of claims 1 to 4, characterized in that: A screw (13) to be ground-in is run-in using any one of the screw running-in devices according to claims 1-4, comprising: Step 1, threading the process mandrel (11) onto the center rod (19), and then fixing the connector (801) to one end of the center rod (19); Step 2: Pass the process mandrel (11) through the running-in fixture (6), and fix the slider (20) to the other end of the center rod (19) to complete the position fixing of the process mandrel (11); Step 3, the connecting piece (801) at one end of the process mandrel (11) that has completed the limiting is fixedly connected to the connecting plate (15) through the locking piece (802), and the slider (20) is inserted into the extension tube (12); Step 4, adjusting the concentricity of the push cylinder (9), the process mandrel (11), the running-in jig (6) and the extension tube (12), and completing the concentricity adjustment when the center lines of the push cylinder (9), the process mandrel (11), the running-in jig (6) and the extension tube (12) are located on the same straight line; Step 5, remove the process mandrel (11) from the screw running-in device, fix the screw (13) to be run-in at the position of the original process mandrel (11), and start the electric cylinder (9) and the drive unit (5) to run-in the screw (13) to be run-in.

6. A method for controlling screw running-in using the device according to any one of claims 1 to 4, characterized in that: include: Start the screw running-in device and enter the product information of the screw to be run-in; Enter the initial running-in parameter values ​​and the number of running-in times for pre-running-in; Obtain the operating data of the screw running-in device during the pre-running-in process, including current value, voltage value, tension value, pressure value, vibration value, single reciprocating time and movement speed; Preprocessing the operating data during the pre-running-in process, and performing discrete distribution analysis on the preprocessed operating data, and using the current value, voltage value, and vibration value obtained after the discrete distribution analysis as the running-in parameters of the screw running-in device; The obtained running-in parameters are input into the running-in device, and the running-in screw to be run-in is performed using the running-in parameters. The operating data during the running-in is obtained, and the signal-to-noise ratio is obtained using the current-to-force ratio in the operating data. The obtained signal-to-noise ratio is used to determine whether the running-in device has an abnormality. If an abnormality is found, the running-in device is repaired. If there is no problem, continue to use the running-in device to run-in the screw; The operating data after the screw rod is run-in is used to perform multi-parameter fusion, and the multi-parameter fusion results are used to determine whether the run-in screw rod is qualified.

7. The control method of a screw running-in device according to claim 6, characterized in that: The multi-parameter fusion method includes: Using each running-in parameter obtained at each moment during the running-in process to calculate information entropy, using the information entropy obtained for each running-in parameter to perform weight distribution, and obtaining the weight of each running-in parameter; Use the weight of each running-in parameter to weight its corresponding running-in parameter and parameter mean; The weighted running-in parameters are used to form a covariance matrix, and the Mahalanobis distance is obtained based on the running-in parameters and parameter means in the covariance matrix; The obtained Mahalanobis distance is used to determine whether there is any abnormality in the running-in screw.

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