A novel gear repair device and method based on high-energy beam

Abstract

The present invention belongs to the field of gear laser repair, and provides a novel gear repair device and method based on high-energy beams. The device includes a high-energy beam generator, a working head, a base, a powder feeder, an indexing mechanism, and a three-axis moving mechanism; a three-axis moving mechanism is arranged on the base, the three-axis moving mechanism is connected to the working head, the output ends of the high-energy beam generator and the powder feeder are integrated on the working head, the working head faces the gear to be repaired, and the position of the working head is adjusted by the three-axis moving mechanism so that the output ends of the high-energy beam generator and the powder feeder face the area to be repaired of the gear to be repaired; the laser high-energy beam repair technology of the present invention has a high bonding strength between the cladding layer and the matrix, increasing the wear resistance of the gear tooth surface; while restoring the geometric dimensions of the workpiece during gear repair, synchronous surface strengthening can be achieved, improving the comprehensive service performance and service life of the gear; the heat-affected zone and thermal deformation of the repaired part are small, and the metal properties of the workpiece matrix are not changed.

Description

Technical Field

[0001] The present invention belongs to the field of gear laser repair, and particularly relates to a novel gear repair device and method based on high-energy beam. Background Art

[0002] Under extreme working conditions of high speed, impact and heavy load, if the number of teeth and module of a gear are large, the tooth surface will be damaged to varying degrees such as pitting and wear after long-term operation, thus affecting the transmission efficiency. In this case, it is obviously uneconomical to scrap and replace the new gear.

[0003] Traditional repair processes mainly include traditional electro-brush plating, spraying, surfacing, etc. The electro-brush plating equipment is simple and the operation is flexible, but the repair efficiency is low and it is only suitable for the repair of local damage with small area and small thickness, and the repair layer and the substrate are mechanically combined and are easy to peel off during service. Although the spraying has high efficiency, the repair layer and the substrate are still mechanically combined, and the repair layer is a multi-layer porous non-uniform structure. Obviously, these two repair processes cannot be applied to extreme working conditions of high speed, impact and heavy load. Although traditional surfacing can obtain a repair layer with metallurgical bonding, due to high heat input, there are also problems such as large welding deformation, large heat affected zone and high dilution rate, and it is not suitable for the repair of precision parts.

[0004] The present invention has its unique advantages in the rapid and precise repair of gear tooth surfaces by using laser high-energy beam cladding repair technology. The high-energy beam cladding remanufacturing technology is a new material forming technology that uses a laser high-energy density beam as a heat source and combines the digital discrete deposition concept for material additive repair and manufacturing. The high-energy beam additive remanufacturing technology has a series of advantages such as small heat affected zone, high precision, and being not limited by the part structure and material, and is particularly suitable for the rapid manufacturing and repair of metal parts with high strength, high hardness, high corrosion resistance and complex structure serving under extreme working conditions. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a novel gear repair device and method based on high-energy beam to solve the problems in the prior art. The technical solution adopted by the present invention is as follows:

[0006] A novel gear repair device based on high-energy beam, comprising a high-energy beam generator, a working head, a base, a powder feeder, an indexing mechanism and a three-axis moving mechanism;

[0007] The three-axis moving mechanism is arranged on the base, the three-axis moving mechanism is connected to the working head, the output ends of the high-energy beam generator and the powder feeder are integrated on the working head, the working head faces the gear to be repaired, and the position of the working head is adjusted by the three-axis moving mechanism so that the output ends of the high-energy beam generator and the powder feeder face the area to be repaired of the gear to be repaired;

[0008] The gear to be repaired is installed on the indexing mechanism, the indexing mechanism is arranged on the base, and the indexing mechanism is used to drive the gear to be repaired to rotate, and the rotation angle each time is the pitch angle of the gear to be repaired.

[0009] Further, the three-axis moving mechanism includes a pillar, a lifting block, a transverse moving block, front and rear guide rails, a lifting guide rail and a transverse moving guide rail;

[0010] The bottom of the pillar is connected to the base through the front and rear guide rails; the side of the pillar is connected to the lifting block through the lifting guide rail; the lifting block is connected to the transverse moving block through the transverse moving guide rail; the working head is fixedly connected to the transverse moving block.

[0011] Further, the indexing mechanism includes a motor, a main shaft, a box body, a driven rod and a cam;

[0012] The motor is installed on the box body, the output end of the motor is fixedly connected to the cam, the cam is located inside the box body, and the bottom of the driven rod is arranged within the rotation range of the cam; the main shaft is rotatably connected to the box body, and the bottoms of the main shaft and the driven rod are both located inside the box body; the top of the main shaft passes through the box body and is connected to the gear to be repaired;

[0013] The cam is used to push the driven rod to rotate around the main shaft, so that the main shaft drives the gear to be repaired to rotate by an angle of its pitch angle.

[0014] Further, the indexing mechanism further includes a reset assembly, a driven sleeve, an elastic ejector rod, a pawl and a driven wheel;

[0015] The driven rod is connected to the box body through the reset assembly for resetting when the driven rod does not contact the cam; the side of the driven rod is fixedly connected to the outer side of the driven sleeve through a connecting rod;

[0016] The driven sleeve is sleeved on the main shaft, the driven sleeve is rotatably connected to the box body, the inner side of the driven sleeve is rotatably connected to one end of the pawl, the other end of the pawl is clamped in the tooth groove of the driven wheel, the driven wheel is sleeved on the main shaft, the elastic ejector rod is installed on the side wall of the driven sleeve, and the end of the elastic ejector rod abuts against the outside of the pawl.

[0017] Further, the elastic ejector rod includes a connecting bolt, a connecting head, an elastic sleeve and a bendable elastic member;

[0018] The connecting bolt is threadedly connected to the side wall of the driven sleeve, the end of the connecting bolt is detachably connected to the connecting head, the end of the connecting head is connected to the elastic sleeve, the bendable elastic member is arranged inside the elastic sleeve, and the end of the elastic sleeve abuts against the outside of the pawl.

[0019] Further, the reset component includes an arc-shaped rod, an arc-shaped opening, an arc-shaped inner hole, and an elastic member;

[0020] The arc-shaped inner hole is provided at the top of the box body, the arc-shaped opening is provided at one end of the arc-shaped inner hole, and the arc-shaped rod, the arc-shaped inner hole, the driven sleeve, and the main shaft are coaxially arranged;

[0021] One end of the arc-shaped rod is arranged in the arc-shaped inner hole, the elastic member is arranged in the arc-shaped inner hole, the elastic member abuts against the arc-shaped rod, and the other end of the arc-shaped rod is fixedly connected to the driven rod, and the driven rod is located in the arc-shaped opening.

[0022] Further, the top opening of the box body is detachably connected to a double-layer cover plate, the double-layer cover plate includes two plate bodies, and arc-shaped grooves are provided on the opposite surfaces of the two plate bodies, and the two arc-shaped grooves are arranged opposite to each other to jointly form the arc-shaped inner hole.

[0023] A gear repair method based on a high-energy beam, the method comprising:

[0024] Step 1, installing a detection and recognition module on the working head;

[0025] Step 2, the indexing mechanism drives the gear to be repaired to rotate, and the detection and recognition module identifies the area to be repaired of the gear to be repaired;

[0026] Step 3, adjusting the position of the working head through a three-axis moving mechanism so that the output ends of the high-energy beam generator and the powder feeder face the area to be repaired of the gear to be repaired;

[0027] Step 4, the high-energy beam generator and the powder feeder work simultaneously to generate a high-energy beam and powder onto the area to be repaired, thereby forming a cladding layer to repair the gear.

[0028] Further, the detection and recognition module includes a multi-spectral industrial camera array and a laser displacement sensor;

[0029] In the step 2, when identifying the area to be repaired of the gear to be repaired through the detection and recognition module, the following steps are included:

[0030] Step 2.1, establishing a geometric projection model of the multi-camera array:

[0031] Let the transformation matrix from the k th camera coordinate system to the world coordinate system be , where is the rotation matrix, and is the translation vector;

[0032] The imaging formula is:

[0033] ,

[0034] where is the camera intrinsic matrix, and are pixel coordinates, X w ，Y w ，Z w are world coordinates;

[0035] Step 2.2, multispectral fusion: Weighted fusion is performed on the spectral intensities of each pixel point in N bands:

[0036] ,

[0037] The weight is optimally allocated according to the defect-sensitive bands;

[0038] Step 2.3, laser three-dimensional topography measurement: The laser line of the laser displacement sensor is projected onto the surface of the gear to be repaired (2), and the relationship between the reflected light spot at the imaging position of the sensor and the height is:

[0039] ,

[0040] where is the baseline distance, is the laser emission angle, is the lens focal length;

[0041] Combined with the gear rotation angle , the two-dimensional laser profile is converted into a three-dimensional point cloud:

[0042] ,

[0043] where is the radial distance;

[0044] Step 2.4, The raw data collected by the multispectral industrial camera array and the laser displacement sensor are preprocessed in real time through the edge computing node;

[0045] Step 2.5, Feature extraction is performed through the defect recognition model of the deep convolutional neural network based on the ResNet-50 architecture. For this defect recognition model, a loss function is set, and this loss function is obtained by combining the FocalLoss loss function and the DiceLoss loss function to get a total loss function;

[0046] Step 2.6: Synchronize the data of the multispectral industrial camera array and the laser displacement sensor in time and register them in space. Through calibration, unify the data of each sensor under the same coordinate, and then use the Kalman filter formula to obtain more accurate coordinates, so as to realize the positioning of the coordinates of the area to be repaired on the gear (2) to be repaired.

[0047] Further, in Step 2.5, the FocalLoss loss function is expressed by the following formula:

[0048] ,

[0049] where, is the modulation factor, used to adjust the ratio between the losses of positive and negative samples, is an adjustable focusing parameter;

[0050] The DiceLoss function is expressed by the following formula:

[0051] ,

[0052] is the value of the i-th pixel predicted by the model, is the value of the i-th pixel of the true label, is the smoothing coefficient;

[0053] The total loss function is expressed by the following formula:

[0054] ,

[0055] where, ; is the scale factor.

[0056] The present invention has the following beneficial effects: The cladding layer of the laser high-energy beam repair technology of the present invention has a high bonding strength with the substrate, increasing the wear resistance of the gear tooth surface; while restoring the geometric dimensions of the workpiece during gear repair, synchronous surface strengthening can be achieved, improving the comprehensive performance and service life of the gear; the heat-affected zone and thermal deformation of the repaired part are small, without changing the metal properties of the workpiece substrate; the cladding layer can realize customization of the surface properties of the workpiece, such as corrosion resistance, wear resistance, high temperature resistance, etc.; the heat-affected zone and thermal deformation of the repaired part are small, without changing the metal properties of the workpiece substrate; the cladding layer can realize customization of the surface properties of the workpiece, such as corrosion resistance, wear resistance, high temperature resistance, etc. The repair process is automatically controlled by the machine, which can greatly improve the repair efficiency while ensuring the quality of the workpiece, and the construction period can be greatly shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0058] Figure 2 It is a structural schematic diagram of a indexing mechanism;

[0059] Figure 3 It is a schematic diagram of the connection relationship of the ratchet pawl

[0060] Figure 4 is Figure 3 The enlarged schematic diagram at position A in

[0061] Figure 5 It is a schematic diagram of an arc-shaped opening;

[0062] Figure 6 It is a schematic diagram of the connection relationship of the arc-shaped rod;

[0063] In the figure: control system 1, gear to be repaired 2, high-energy beam generator 3, detection and identification module 4, working head 5, support column 6, base 7, powder feeder 8, lifting block 9, transverse movement block 10, bracket 11, indexing mechanism 12, motor 121, main shaft 122, elastic component 123, double-layer cover plate 124, box body 125, connecting rod 126, driven rod 127, cam 128, arc-shaped inner hole 129, driven sleeve 130, elastic ejector rod 131, ratchet pawl 132, driven wheel 133, damping seat 134, arc-shaped rod 135, arc-shaped opening 136, slider 137, connecting bolt 1310, connecting head 1311, elastic sleeve 1312, bendable elastic part 1313. Specific embodiments

[0064] Next, in combination with the Figures 1-6 in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. If not specifically specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. It should be noted that in the present invention, unless otherwise specified, "detachable connection" can be achieved by means such as bolts and buckles.

[0065] Such as Figure 1 、 One A new type of gear repair device based on high-energy beam, including a high-energy beam generator 3, a working head 5, a base 7, a powder feeder 8, an indexing mechanism 12 and a three-axis moving mechanism;

[0066] The three-axis moving mechanism is arranged on the base 7, the three-axis moving mechanism is connected to the working head 5, the output ends of the high-energy beam generator 3 and the powder feeder 8 are integrated on the working head 5, the working head 5 faces the gear 2 to be repaired, and the position of the working head 5 is adjusted by the three-axis moving mechanism so that the output ends of the high-energy beam generator 3 and the powder feeder 8 face the area to be repaired of the gear 2 to be repaired;

[0067] The gear 2 to be repaired is installed on the indexing mechanism 12, and the indexing mechanism 12 is arranged on the base 7. The indexing mechanism 12 is used to drive the gear 2 to be repaired to rotate, and the rotation angle each time is the pitch angle of the gear 2 to be repaired.

[0068] The base 7 is the basic mounting seat of the present invention. The high-energy beam generator 3 and the powder feeder 8 are both prior arts. The high-energy beam generator 3 is a laser, and the high-energy beam is a laser beam. The energy and focusing degree of the laser beam are adjusted through the control system 1 to meet the requirements of different materials and damage characteristics. The powder feeder 8 is a prior art. The powder feeder 8 usually includes components such as a powder storage tank and a powder delivery pipe, and is responsible for uniformly and continuously delivering metal powder to the working head 5. The output end of the high-energy beam generator 3 is a laser head, and the output end of the powder feeder 8 is a nozzle. Both the nozzle and the laser head are fixed on the working head 5. The working head 5 can be structures such as a frame, a plate, or a block, and the nozzle and the laser head are fixed by means of buckles, pipe clamps, etc. to achieve the spatio-temporal synchronization of the powder flow and the energy beam.

[0069] In one implementation manner of the present invention, through the control of the control system 1, the three-axis moving mechanism makes the working head 5 accurately irradiate the damaged part of the gear according to a preset path. The high-energy beam and the powder material interact with each other, and the damaged layer is removed by means of melting, evaporation, or chemical reaction, etc., while promoting the formation of new tissues or the deposition of filling materials. The high-energy beam melts the powder and the base material at the same time to form a clad layer. The clad layer and the matrix of the area to be repaired are metallurgically bonded, dense and with high bonding strength. After repairing one tooth surface, the indexing mechanism 12 drives the gear 2 to be repaired to rotate, so that the next tooth surface of the gear 2 to be repaired faces the working head 5. The function of the indexing mechanism 12 is to make the repaired gear 2 rotate by the angle of its pitch angle each time, so that each tooth surface of the repaired gear 2 alternately passes through the working head 5. In the present invention, the pitch angle is the angle between two adjacent teeth of the repaired gear 2.

[0070] The clad layer of the high-energy beam repair technology of the present invention has a high bonding strength with the matrix, increasing the wear resistance of the gear tooth surface; while restoring the geometric dimensions of the workpiece during gear repair, synchronous surface strengthening can be achieved, improving the comprehensive service performance and service life of the gear; the heat affected zone and thermal deformation of the repaired part are small, without changing the metal properties of the workpiece matrix; the clad layer can realize the customization of the surface properties of the workpiece, such as corrosion resistance, wear resistance, high temperature resistance, etc.; the heat affected zone and thermal deformation of the repaired part are small, without changing the metal properties of the workpiece matrix; the clad layer can realize the customization of the surface properties of the workpiece, such as corrosion resistance, wear resistance, high temperature resistance, etc. The repair process is automatically controlled by the machine, which greatly improves the repair efficiency while ensuring the quality of the workpiece, and the construction period can be greatly shortened.

[0071] After the repair is completed, necessary post-treatment is carried out on the gear surface, such as polishing, cleaning, or heat treatment, to restore its original performance. The detection equipment is used again to evaluate the repaired area to ensure that the repair quality meets the standards.

[0072] In addition, the present invention can also be provided with some auxiliary facilities, which are not shown in the figure. A protective gas supply system (to prevent oxidation), such as argon, nitrogen, etc., a dust removal and exhaust system (to keep the working environment clean), a safety shield (to protect the operator from radiation damage), etc. are arranged around the main working area. Since the high-energy beam irradiation will cause the temperature of the gear surface to rise, a cooling system needs to be set up to cool the gear to ensure the repair effect and equipment safety. The cooling system can adopt methods such as water cooling and air cooling.

[0073] Furthermore, the three-axis moving mechanism includes a pillar 6, a lifting block 9, a transverse moving block 10, front and rear guide rails, a lifting guide rail and a transverse moving guide rail;

[0074] The bottom of the pillar 6 is connected to the base 7 through the front and rear guide rails; the side of the pillar 6 is connected to the lifting block 9 through the lifting guide rail; the lifting block 9 is connected to the transverse moving block 10 through the transverse moving guide rail; the working head 5 is fixedly connected to the transverse moving block 10.

[0075] The front and rear guide rails, the lifting guide rail and the transverse moving guide rail are all prior arts, such as electric guide rails. The working directions of the three are in the space XYZ directions. Specifically, the front and rear guide rails drive the pillar 6 to move back and forth, the lifting guide rail drives the lifting block 9 to move up and down, and the transverse moving guide rail drives the transverse moving block 10 and the working head 5 to move left and right, so that the three degrees of freedom of movement of the working head 5 in space can be realized.

[0076] Such as Figures 2-6 , the indexing mechanism 12 includes a motor 121, a main shaft 122, a box body 125, a driven rod 127 and a cam 128;

[0077] The motor 121 is installed on the box body 125, the output end of the motor 121 is fixedly connected to the cam 128, the cam 128 is located inside the box body 125, and the bottom of the driven rod 127 is arranged in the rotation range of the cam 128; the main shaft 122 is rotatably connected to the box body 125, and the bottoms of the main shaft 122 and the driven rod 127 are both located inside the box body 125; the top of the main shaft 122 passes through the box body 125 and is connected to the gear 2 to be repaired.

[0078] The cam 128 is used to push the driven rod 127 to rotate around the main shaft 122, so that the main shaft 122 drives the gear 2 to be repaired to rotate by the angle of its pitch angle.

[0079] Specifically, the rotation axis of the cam 128 is horizontally arranged, while the follower rod 127 is vertically arranged. The follower rod 127 has no freedom in the vertical direction and cannot move up and down. However, in the circumferential direction of the main shaft 122, the follower rod 127 can move around the main shaft 122. When the cam 128 rotates, the protruding part of the cam 128 periodically contacts the follower rod 127, and only when the protruding part contacts the follower rod 127, the follower rod 127 moves. Therefore, during the rotation of the cam 128, the follower rod 127 moves periodically, and the rotation range of the main shaft 122 driven by the follower rod 127 exactly makes the repair gear 2 rotate by the angle of its pitch angle. Those skilled in the art can obtain this matching relationship through calculation, debugging and other methods.

[0080] The bottom of the box body 125 can be fixed on the base 7 through the bracket 11.

[0081] Furthermore, the indexing mechanism 12 further includes a reset assembly, a driven sleeve 130, an elastic ejector rod 131, a pawl 132 and a driven wheel 133;

[0082] The follower rod 127 is connected to the box body 125 through the reset assembly and is used to reset when the follower rod 127 does not contact the cam 128; the outer side of the follower rod 127 is fixedly connected to the outer side of the driven sleeve 130 through a connecting rod 126;

[0083] The driven sleeve 130 is sleeved on the main shaft 122. The driven sleeve 130 is rotatably connected to the box body 125. The inner side of the driven sleeve 130 is rotatably connected to one end of the pawl 132. The other end of the pawl 132 is clamped in the tooth groove of the driven wheel 133. The driven wheel 133 is sleeved on the main shaft 122. The elastic ejector rod 131 is installed on the side wall of the driven sleeve 130, and the end of the elastic ejector rod 131 abuts against the outside of the pawl 132.

[0084] An annular chamber is separated between the driven sleeve 130 and the driven wheel 133, and this chamber is used to arrange the pawl 132. The main function of the reset assembly is to reset the follower rod 127. After the follower rod 127 is driven by the cam 128 to move, the reset assembly makes the follower rod 127 return to the initial position. The function of the elastic ejector rod 131 is to apply an elastic force to the pawl 132 to enable the pawl 132 to reset.

[0085] Furthermore, a plurality of the pawl 132 and the elastic ejector rod 131 are correspondingly arranged.

[0086] The working principle of the indexing mechanism 12 is as follows: The motor 121 drives the cam 128 to rotate. The protruding part of the cam 128 pushes the follower rod 127 to move around the main shaft 122. The follower rod 127 drives the driven sleeve 130 to rotate through the connecting rod 126. The rotation of the driven sleeve 130 drives the pawl 132 to rotate. The end of the pawl 132 abuts against the driven wheel 133, so that the driven wheel 133 and the main shaft 122 rotate, and then the gear 2 to be repaired rotates by an angle of one pitch angle. When the protruding part of the cam 128 disengages from the follower rod 127 during rotation, the follower rod 127 is reset by the reset assembly and waits for the next contact of the cam 128. When the follower rod 127 is reset, it rotates back and drives the driven sleeve 130 to rotate back. While the driven sleeve 130 rotates back, the pawl 132 rotates in the reverse direction and contacts the driven wheel 133 to generate vibration. The elastic ejector rod 131 abuts against the pawl 132 to keep the pawl 132 in contact with the driven wheel 133. During the reverse rotation of the pawl 132, it cannot drive the driven wheel 133 to rotate. In addition, in order to eliminate the friction influence between the pawl 132 and the driven wheel 133 during the rotation of the driven sleeve 130, a damping seat 134 can be arranged at the bottom of the main shaft 122. The damping seat 134 is rotatably connected to the bottom of the main shaft 122 and realizes rotational damping through components such as rubber rings, which can prevent the main shaft 122 from rotating under a small torque.

[0087] Further, the elastic ejector rod 131 includes a connecting bolt 1310, a connecting head 1311, an elastic sleeve 1312 and a bendable elastic member 1313;

[0088] The connecting bolt 1310 is threadedly connected to the side wall of the driven sleeve 130. The end of the connecting bolt 1310 is detachably connected to the connecting head 1311. The end of the connecting head 1311 is connected to the elastic sleeve 1312. The bendable elastic member 1313 is arranged inside the elastic sleeve 1312. The end of the elastic sleeve 1312 abuts against the outside of the pawl 132.

[0089] A blind hole can be arranged at the end of the connecting bolt 1310. One end of the connecting head 1311 is inserted into the blind hole. A convex part can be arranged at the other end of the connecting head 1311. One end of the elastic sleeve 1312 is open and the other end is closed. Its open end is sleeved on the convex part and can be connected by threads. The elastic sleeve 1312 can be made of rubber. The bendable elastic member 1313 can be components such as a spring and rubber. During the reverse rotation of the pawl 132, the vibration offset generated by the pawl 132 causes the elastic sleeve 1312 to generate a bending deformation.

[0090] Further, the reset assembly includes an arc rod 135, an arc opening 136, an arc inner hole 129 and an elastic member 123;

[0091] The top of the box body 125 is provided with the arc-shaped inner hole 129. One end of the arc-shaped inner hole 129 is provided with the arc-shaped opening 136. The arc-shaped rod 135, the arc-shaped inner hole 129, the driven sleeve 130 and the main shaft 122 are coaxially arranged;

[0092] One end of the arc-shaped rod 135 is arranged in the arc-shaped inner hole 129. The elastic component 123 is arranged in the arc-shaped inner hole 129. The elastic component 123 abuts against the arc-shaped rod 135. The other end of the arc-shaped rod 135 is fixedly connected to the driven rod 127. The driven rod 127 is located in the arc-shaped opening 136.

[0093] The arc-shaped opening 136 is an arc-shaped long strip through hole structure. The elastic component 123 can be an arc-shaped spring. The elastic component 123 applies an extrusion force to the arc-shaped rod 135, so that the driven rod 127 abuts against one end of the arc-shaped opening 136. In this state, it is the initial state position of the driven rod 127, such as Figure 5 the state in. When the driven rod 127 is driven by the cam 128 to move, the arc-shaped rod 135 moves in the arc-shaped inner hole 129 and squeezes the elastic component 123. When the bottom of the driven rod 127 disengages from the protruding part of the cam 128, the elastic component 123 restores its deformation and drives the driven rod 127 to reset at the same time.

[0094] In addition, the end of the arc-shaped rod 135 can be fixedly connected to the slider 137. The slider 137 is adapted to the arc-shaped inner hole 129. The slider 137 abuts against the elastic component 123.

[0095] Furthermore, the top opening of the box body 125 is detachably connected to the double-layer cover plate 124. The double-layer cover plate 124 includes two plate bodies. Arc-shaped grooves are arranged on the opposite surfaces of the two plate bodies. The two arc-shaped grooves are arranged oppositely to jointly form the arc-shaped inner hole 129. The significance of setting the double-layer cover plate 124 is to facilitate the machining of the arc-shaped inner hole 129 and also facilitate the assembly of the driven rod 127 and the arc-shaped rod 135.

[0096] The area to be repaired of the gear 2 to be repaired in the present invention can be manually identified by oneself. After observing the area to be repaired manually, through the combined action of the indexing mechanism 12 and the three-axis moving mechanism, the working head 5 repairs the area to be repaired. The following method can also be adopted:

[0097] A gear repair method based on high-energy beam. A detection and recognition module 4 is arranged on the working head 5. The tooth surface of the gear 2 to be repaired is detected by the detection and recognition module 4 to identify the positions of wear, cracks or other defects. A multi-spectral industrial camera array is used to scan each tooth surface of the gear 2 to be repaired driven by the indexing mechanism 12 to collect image data. And the three-dimensional topography data is synchronously obtained in combination with a laser displacement sensor. After the collected original data is preprocessed in real time by the edge computing node, feature extraction is performed through a defect recognition model of a deep convolutional neural network based on the ResNet-50 architecture, and micro-cracks as small as 0.02 mm, tooth profile deviations of 0.1 mm, and abnormal hardness regions caused by uneven quenching can be accurately identified.

[0098] This method specifically includes:

[0099] Step 1, install the detection and recognition module 4 on the working head 5;

[0100] Step 2, the indexing mechanism 12 drives the gear 2 to be repaired to rotate, and the area to be repaired of the gear 2 to be repaired is identified through the detection and recognition module 4;

[0101] Step 3, adjust the position of the working head 5 through the three-axis moving mechanism so that the output ends of the high-energy beam generator 3 and the powder feeder 8 face the area to be repaired of the gear 2 to be repaired;

[0102] Step 4, the high-energy beam generator 3 and the powder feeder 8 work simultaneously to generate a high-energy beam and powder onto the area to be repaired, thereby forming a cladding layer to repair the gear.

[0103] Further, the detection and recognition module 4 includes a multi-spectral industrial camera array and a laser displacement sensor;

[0104] In the said Step 2, when identifying the area to be repaired of the gear 2 to be repaired through the detection and recognition module 4, it includes the following steps:

[0105] Step 2.1, establish a geometric projection model of the multi-camera array:

[0106] Let the transformation matrix from the k th camera coordinate system to the world coordinate system be , where is the rotation matrix, is the translation vector;

[0107] The imaging formula is:

[0108] ,

[0109] where is the camera internal parameter matrix, and are pixel coordinates, Xw ，Y w ，Z w are the world coordinates; from the camera coordinate system to the image coordinate system, it belongs to the perspective projection relationship, converting from 3D to 2D. At this time, the unit of the projection point p is still mm, not pixel, and it needs to be further converted to the pixel coordinate system. The pixel coordinate system and the image coordinate system are both on the imaging plane, but their respective origins and measurement units are different. The origin of the image coordinate system is usually the midpoint of the imaging plane, and the unit is mm, which belongs to the physical unit. While the unit of the pixel coordinate system is pixel, and we usually describe a pixel point in terms of rows and columns.

[0110] Step 2.2, multispectral fusion: For each pixel point perform weighted fusion on the spectral intensities in N bands:

[0111] ,

[0112] weights are optimized and allocated according to the defect-sensitive bands. For example, near-infrared is sensitive to cracks;

[0113] Step 2.3, laser three-dimensional topography measurement: The laser line of the laser displacement sensor is projected onto the surface of the gear 2 to be repaired, and the reflected light spot is at the imaging position of the sensor and the height relationship:

[0114] ,

[0115] wherein, is the baseline distance, is the laser emission angle, is the lens focal length;

[0116] Combined with the gear rotation angle , convert the two-dimensional laser profile into a three-dimensional point cloud:

[0117] ,

[0118] wherein, is the radial distance, which is obtained in real-time synchronization through the encoder;

[0119] Step 2.4, the original data collected by the multispectral industrial camera array and the laser displacement sensor are preprocessed in real-time through the edge computing node, such as noise reduction, enhancement, segmentation, etc.;

[0120] Step 2.5, feature extraction is performed through a defect recognition model of a deep convolutional neural network based on the ResNet-50 architecture. The deep convolutional neural network of the ResNet-50 architecture is characterized by using a residual network structure, which has 50 layers in depth, can effectively alleviate the degradation problem, achieve a deeper network structure design, and improve the training accuracy of the network. The composition of this model is as follows:

[0121] (1) Residual module: It includes 3 convolutional layers (1×1 dimensionality reduction, 3×3 feature extraction, 1×1 dimensionality increase), and realizes feature reuse through skip connections, solves the problem of gradient disappearance, and enhances the sensitivity to tiny defects.

[0122] (2) Feature pyramid structure: It includes a 50-layer deep network (34 residual blocks + 16 transition layers), and realizes multi-scale feature extraction from local texture to global morphology through gradually expanding convolutional kernels (7×7 → 3×3).

[0123] (3) Transfer learning mechanism: Usually, it is fine-tuned based on pre-training on ImageNet. By replacing the final fully connected layer (such as changing it to a Softmax classification layer), the model is made to adapt to the defect classification requirements of specific industrial scenarios.

[0124] (4) Feature fusion module: Some improved versions will combine an attention mechanism (such as the SE module) or cascade with the UNET structure to enhance the feature weights of the defect area while retaining the spatial localization ability.

[0125] The loss function is a key regulator of the model performance. Its role is to optimize the model performance, enhance the distinguishability of defect features, and improve the accuracy. It directly affects the sensitivity and classification performance of the model to defect features. Therefore, for this defect recognition model, a specific loss function is set. This specific loss function is obtained by combining the FocalLoss loss function and the DiceLoss loss function to get a total loss function;

[0126] In addition, the deep convolutional neural network of the ResNet-50 architecture usually accepts an input of 224×224 RGB images, but gear defects involve images with higher resolutions, such as 512×512 grayscale images. Therefore, the input layer needs to be modified, changing the number of channels from 3 to 1, and adjusting the parameters of the subsequent convolutional layers to adapt to the new size.

[0127] Step 2.6, synchronize the data of the multi-spectral industrial camera array and the laser displacement sensor in time and register them in space. Through calibration, unify the data of each sensor under the same coordinate, and then use the Kalman filter formula to obtain more accurate coordinates, so as to achieve sub-pixel level positioning (positioning accuracy reaches 0.01mm) of the coordinates of the area to be repaired on the gear 2 to be repaired.

[0128] And the digital twin technology is adopted to align the detected coordinates with the virtual model. Considering the coordinate system transformation, the rigid body transformation and the registration algorithm ICP (Iterative Closest Point) are used. In this way, the detection results are mapped to the virtual gear model in real time (error ±0.03mm). These data are input into the control system 1 to provide accurate target coordinates for subsequent high-energy beam repair and compare the repaired results with the gear model data, and timely adjust the repair strategy to ensure the accuracy of the repaired gear.

[0129] Among them, the rigid body registration adopts the ICP algorithm, which includes the following steps:

[0130] Minimize the actual point cloud and the model point cloud distance:

[0131] ,

[0132] Solve for the optimal rotation and translation .

[0133] Dynamic error compensation: Introduce a feedback control term to correct the mapping error:

[0134] ,

[0135] Among them, , is the proportionality coefficient, which is adjusted by the PID controller.

[0136] The detection and recognition module 4 of the present invention may further include sensors such as temperature and gas, which are used to monitor parameters such as temperature, molten pool morphology, and gas composition during the repair process in real time, as well as the dimensional accuracy and surface quality after repair. This information is fed back to the control system for real-time adjustment of the repair strategy.

[0137] Furthermore, in step 2.5, the FocalLoss loss function is expressed by the following formula:

[0138] ,

[0139] Among them, is the modulation factor, which is used to adjust the ratio between the positive and negative sample losses, , is an adjustable focusing parameter, which can adjust the degree of reduction of the weights of easy-to-classify samples, the larger, the greater the degree of weight reduction. By adjusting the weight coefficients of easy and difficult samples, the model is prevented from biasing towards the majority class;

[0140] The DiceLoss function is expressed by the following formula:

[0141] ,

[0142] is the value of the i-th pixel predicted by the model, is the value of the i-th pixel of the true label, is the smoothing coefficient;

[0143] The total loss function is expressed by the following formula:

[0144] ,

[0145] where, is the scaling factor. In industrial inspection, high precision and robustness are required. Usually, the adaptability design of the loss function needs to be carried out according to scenario characteristics such as defect morphology (point-like, linear defects), data volume (small sample / large data), etc., so as to optimize the model performance. By proportion adjustment, a specific loss function suitable for gear surface defects is found.

[0146] After repeated verification, when , the adaptability of the total loss function is the highest. The values of the above three parameters are obtained through repeated model training to obtain a loss function matching the defect recognition task.

[0147] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, those of ordinary skill in the art

[0148] make various deformations, variations, modifications, and substitutions to the technical solutions of the present invention, and all should fall within the protection scope determined by the claims of the present invention.

Claims

1. A new gear repair device based on high energy beam, characterized in that: It comprises a high energy beam generator (3), a working head (5), a base (7), a powder feeder (8), a dividing mechanism (12) and a three-axis moving mechanism; The three-axis moving mechanism is arranged on the base (7), the three-axis moving mechanism is connected to the working head (5), the output ends of the high-energy beam generator (3) and the powder feeder (8) are integrated on the working head (5), the working head (5) faces the gear to be repaired (2), and the working head (5) adjusts its position through the three-axis moving mechanism so that the output ends of the high-energy beam generator (3) and the powder feeder (8) face the area to be repaired of the gear to be repaired (2); The gear to be repaired (2) is mounted on the indexing mechanism (12), the indexing mechanism (12) is arranged on the base (7), the indexing mechanism (12) is used to drive the gear to be repaired (2) to rotate, and each rotation angle is the pitch angle of the gear to be repaired (2); The indexing mechanism (12) comprises a motor (121), a main shaft (122), a housing (125), a driven rod (127) and a cam (128); The motor (121) is mounted on the housing (125); the output end of the motor (121) is fixedly connected to the cam (128); the cam (128) is located in the housing (125); the bottom of the driven rod (127) is arranged within the rotation range of the cam (128); the main shaft (122) is rotatably connected to the housing (125); the bottom of the main shaft (122) and the bottom of the driven rod (127) are both located in the housing (125); the top of the main shaft (122) passes through the housing (125) and is connected to the gear (2) to be repaired; The cam (128) is used to push the driven rod (127) to rotate around the main shaft (122), so that the main shaft (122) drives the gear (2) to be repaired to rotate at the angle of its tooth pitch angle; The indexing mechanism (12) further comprises a reset assembly, a driven sleeve (130), an elastic push rod (131), a ratchet pawl (132) and a driven wheel (133); The driven rod (127) is connected to the box body (125) via the reset assembly, so as to reset the driven rod (127) when it is not in contact with the cam (128); the side surface of the driven rod (127) is fixedly connected to the outer side surface of the driven sleeve (130) via a connecting rod (126); The driven sleeve (130) is sleeved on the main shaft (122), the driven sleeve (130) is rotatably connected to the box body (125), the inner side surface of the driven sleeve (130) is rotatably connected to one end of the pawl (132), the other end of the pawl (132) is clamped in the tooth groove of the driven wheel (133), the driven wheel (133) is sleeved on the main shaft (122), the elastic push rod (131) is installed on the side wall of the driven sleeve (130), and the end of the elastic push rod (131) abuts against the outer side of the pawl (132).

2. A novel gear repair device based on high energy beam according to claim 1, characterized in that: The three-axis moving mechanism comprises a support (6), a lifting block (9), a transverse moving block (10), front and rear guide rails, a lifting guide rail and a transverse moving guide rail; The bottom of the support (6) is connected to the base (7) via front and rear guide rails; the side of the support (6) is connected to the lifting block (9) via lifting guide rails; the lifting block (9) is connected to the lateral movement block (10) via lateral movement guide rails; and the lateral movement block (10) is fixedly connected to the working head (5).

3. The novel gear repair device based on high energy beam according to claim 1 is characterized in that: The elastic push rod (131) comprises a connecting bolt (1310), a connecting head (1311), an elastic sleeve (1312) and a bendable elastic member (1313); The connecting bolt (1310) is threadedly connected to the side wall of the driven sleeve (130); the end of the connecting bolt (1310) is detachably connected to the connecting head (1311); the end of the connecting head (1311) is connected to the elastic sleeve (1312); the bendable elastic member (1313) is arranged inside the elastic sleeve (1312); and the end of the elastic sleeve (1312) abuts against the outer side of the ratchet (132).

4. The novel gear repair device based on high energy beam according to claim 1 is characterized in that: The resetting assembly comprises an arc-shaped rod (135), an arc-shaped opening (136), an arc-shaped inner hole (129), and an elastic component (123); The top of the box body (125) is provided with the arc-shaped inner hole (129), one end of the arc-shaped inner hole (129) is provided with the arc-shaped opening (136), and the arc-shaped rod (135), the arc-shaped inner hole (129), the driven sleeve (130) and the main shaft (122) are coaxially arranged; One end of the arc-shaped rod (135) is arranged in the arc-shaped inner hole (129), the elastic component (123) is arranged in the arc-shaped inner hole (129), the elastic component (123) abuts against the arc-shaped rod (135), and the other end of the arc-shaped rod (135) is fixedly connected to the driven rod (127), and the driven rod (127) is located in the arc-shaped opening (136).

5. A novel gear repair device based on high energy beam according to claim 4, characterized in that: The top opening of the box body (125) is detachably connected to the double-layer cover plate (124), and the double-layer cover plate (124) comprises two plate bodies, and arc-shaped grooves are arranged on opposite sides of the two plate bodies, and the two arc-shaped grooves are arranged opposite to each other to form the arc-shaped inner hole (129).

6. A gear repair method based on high energy beam, characterized in that: A novel gear repair device based on high energy beam as described in any one of claims 1 to 5, the method comprising: Step 1, installing a detection and identification module (4) on a working head (5); Step 2, the indexing mechanism (12) drives the gear to be repaired (2) to rotate, and identifies the area to be repaired of the gear to be repaired (2) through the detection and identification module (4); Step 3, adjusting the position of the working head (5) by means of a three-axis moving mechanism so that the output ends of the high-energy beam generator (3) and the powder feeder (8) face the area to be repaired of the gear (2) to be repaired; In step 4, the high energy beam generator (3) and the powder feeder (8) work simultaneously to generate a high energy beam and powder onto the area to be repaired, thereby forming a cladding layer to repair the gear.

7. The gear repair method based on high energy beam according to claim 6, characterized in that: The detection and identification module (4) includes a multi-spectral industrial camera array and a laser displacement sensor; In the step 2, when the area to be repaired of the gear (2) to be repaired is identified by the detection and identification module (4), the following steps are included: Step 2.1, establish a multi-camera array geometric projection model: Set up k The transformation matrix from the camera coordinate system to the world coordinate system is ,in is the rotation matrix, is the translation vector; The imaging formula is: ， in is the camera intrinsic parameter matrix, and is the pixel coordinate, X w ，Y w ，Z w is the world coordinate; Step 2.2, multispectral fusion: for each pixel Weighted fusion of spectral intensities in N bands: ， Weight Optimize allocation according to defect-sensitive bands; Step 2.3, laser 3D profile measurement: The laser line of the laser displacement sensor is projected onto the surface of the gear to be repaired (2), and the reflected light spot is at the sensor imaging position. With height Relationship: ， in, is the baseline distance, is the laser emission angle, is the focal length of the lens; Combined gear rotation angle , convert the 2D laser profile into a 3D point cloud: ， in, is the radial distance; Step 2.4, the raw data collected by the multispectral industrial camera array and the laser displacement sensor are preprocessed in real time through the edge computing node; Step 2.5, feature extraction is performed through a defect recognition model based on a deep convolutional neural network of the ResNet-50 architecture. For the defect recognition model, a loss function is set. The loss function is combined with the FocalLoss loss function and the DiceLoss loss function to obtain a total loss function. Step 2.6, synchronize the data of the multi-spectral industrial camera array and the laser displacement sensor in time and align them in space. Through calibration, unify the data of each sensor to the same coordinate, and then use the Kalman filter formula to obtain more accurate coordinates, so as to realize the positioning of the coordinates of the repair area of ​​the gear to be repaired (2).

8. The gear repair method based on high energy beam according to claim 7, characterized in that: In step 2.5, the FocalLoss loss function is expressed by the following formula: ， in, is the modulation factor, Used to adjust the ratio between positive and negative sample losses. is an adjustable focus parameter; The DiceLoss function is expressed by the following formula: ， The model predicts The value of pixels, is the true label The value of pixels, is the smoothing coefficient; The total loss function is expressed by the following formula: ， in, ; is the scale factor.

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