Differential gear assembly welding production line and process

Abstract

The application discloses a differential gear assembling and welding production line and process, cooling and heating are respectively carried out on the gear shaft and the gear, the gear is expanded by heat, the gear shaft is contracted by cold, then the two are pressed and assembled, the heating temperature and time are optimized according to the pressing pressure during heating and pressing, in addition, the product is clamped and fed to the welding position by clamping and feeding devices to be welded by a welding robot, during the welding process, the clamping and feeding devices rotate the product to form a circle welding, and the welding position is adjusted up and down to perform a second circle welding, the firmness of the connection is improved, in addition, the clamping and feeding devices realize high precision adjustment, compared with only relying on the welding robot to adjust the height and the laser direction, the efficiency is higher, the error is less likely to occur, and the precision is guaranteed, in addition, two sets of clamping and feeding devices are arranged, the products are alternately clamped and fed, when one set of welding is completed and is discharged, the welding robot welds the products on the other set, the welding robot is avoided from being in a waiting state during the discharging, feeding and transferring processes, and the welding efficiency is further improved.

Description

Technical Field

[0001] This invention relates to differential welding lines and processes, and more particularly to differential gear assembly and welding production lines and processes. Background Technology

[0002] The main function of the differential gear is to automatically adjust the speed of the left and right wheels when the vehicle is turning or driving on uneven roads to adapt to different driving needs, and it plays a vital role in the driving of the vehicle.

[0003] Patent application number 2018102956427 discloses a welding process for a differential assembly, including the following steps: (1) preparing a differential housing and differential gear that can be matched with each other, (2) laser cleaning, (3) press fitting, (4) wire filling and laser spot welding, (5) ring welding, (6) cleaning the weld seam, (7) ultrasonic flaw detection, and (8) gear grinding.

[0004] The aforementioned patent employs a welding method of wire filling and laser spot welding. This welding method involves melting the welding wire with the high temperature of a laser for spot welding, followed by ring welding. Factors such as the wire filling speed and the need for ring welding after spot welding affect the welding accuracy and efficiency, resulting in both welding accuracy and efficiency failing to reach the ideal state. Summary of the Invention

[0005] To address the shortcomings of existing technologies that use a combination of laser spot welding and ring welding, which result in low welding precision and low welding efficiency, this invention provides a differential gear assembly and welding production line and process.

[0006] The technical solution adopted by this invention to solve the above-mentioned technical problems is: a differential gear assembly and welding production line, comprising:

[0007] A ring-cooled conveyor mechanism is used to convey gear shafts and control their temperature.

[0008] The heating mechanism is used to heat the gear to be welded, causing the gear to expand thermally.

[0009] A press-fitting mechanism, used to press gears onto gear shafts;

[0010] The pre-welding runout detection mechanism is set up side by side with the heating mechanism and the pressing mechanism and is located on one side of the ring cooling conveyor mechanism. It is used to detect the concentricity after pressing.

[0011] A welding feeding mechanism is located at the tail side of the pre-welding runout detection mechanism and is used to transport the product after the pre-welding runout detection.

[0012] The FNK welding mechanism, located at the tail end of the welding feeding mechanism, is used to weld the gears and gear shafts conveyed by the welding feeding mechanism.

[0013] The assembly line is located on the other side of the ring cooling conveyor and its head extends to the FNK welding mechanism.

[0014] An ultrasonic flaw detection mechanism is installed at the end of the assembly line and is used to perform ultrasonic flaw detection on the welded products.

[0015] A post-weld runout detection mechanism is set at the end of the assembly line and is used to detect the concentricity after welding.

[0016] Multiple robotic arms are configured to respectively transport gear shafts from the cooling conveyor mechanism to the pressing mechanism, transport gears to the heating mechanism and then to the pressing mechanism after heating, transfer pressed products to the pre-welding runout detection mechanism for inspection, transfer products after pre-welding runout detection to the welding feeding mechanism, transfer welded products to the assembly line, transfer products on the assembly line to the ultrasonic flaw detection mechanism, transfer products after ultrasonic flaw detection to the post-welding runout detection mechanism, and unload products from the post-welding runout detection mechanism.

[0017] Preferably, the FNK welding mechanism includes a laser welding robot and a clamping and feeding device, wherein there are two parallel sets of clamping and feeding devices, and the laser welding robot is positioned between the two sets of clamping and feeding devices.

[0018] Preferably, the clamping and feeding device includes:

[0019] Translation mechanism, which moves in the horizontal direction;

[0020] The bottom turntable rotates on a translation mechanism, which is equipped with a first drive mechanism to drive its rotation.

[0021] The rotating assembly, which is fixed to the bottom turntable by a column, includes a cylindrical upper cylinder and a cylindrical lower cylinder, and a connecting structure connecting the upper cylinder and the lower cylinder. The upper cylinder and the lower cylinder are arranged opposite each other and the diameter of their inner holes is the same. A gap is provided between the bottom wall of the upper cylinder and the top wall of the lower cylinder. The gap has two high points and two low points of the same height. The gap gradually spirals upward from the low point to the high point and is sinusoidal in shape after unfolding.

[0022] The lifting column includes a lifting column and a splined shaft located at the bottom of the lifting column. The lifting column extends from the inner hole of the lower cylinder into the inner hole of the upper cylinder, and the side wall of the lifting column is provided with a cylindrical rod that extends into the gap between the upper cylinder and the lower cylinder and matches the width of the gap.

[0023] The second drive mechanism includes a gear ring rotatably mounted on the translation mechanism and a second drive motor that drives the gear ring to rotate. The gear ring has internal teeth and external teeth, and the spline shaft of the lifting column is slidably inserted into the inside of the gear ring and meshes with the internal teeth.

[0024] The pneumatic clamping plate is vertically slidably mounted on the upper cylinder, and its clamping and releasing are controlled by a pneumatic controller.

[0025] Preferably, the connection structure includes an upper connecting ring disposed on the top side of the upper cylinder, a lower connecting ring disposed on the bottom side of the lower cylinder, and a plurality of connecting bolts disposed between the upper connecting ring and the lower connecting ring to connect the two.

[0026] Preferably, the clamping and feeding device also includes:

[0027] The first limiting post group includes two first limiting posts disposed between the upper connecting ring and the lower connecting ring and located on both sides of the lowest point of the gap for clamping the cylindrical rod for limiting the position. The outer one is fixedly connected to the upper connecting ring and the lower connecting ring, and the inner one is an electrically telescopic structure.

[0028] The second limiting post assembly includes two second limiting posts located between the upper connecting ring and the lower connecting ring and on both sides of the highest point of the gap, used to clamp the cylindrical rod for limiting. The outer one is fixedly connected to the upper connecting ring and the lower connecting ring, and the inner one is an electric telescopic structure. The electric telescopic structure includes a motor push rod and a limiting rod. The limiting rod is located at the output end of the electric push rod, and the electric push rod drives the limiting rod to extend and retract.

[0029] Two laser sensors are installed and located on opposite sides of the electric telescopic structure. When the cylindrical rod moves to the lowest or highest point and passes through the irradiation range of the laser sensor, the laser sensor detects a decrease in distance and sends a signal to the control unit of the electric telescopic structure to control the electric telescopic structure to extend and limit the cylindrical rod, so as to prevent the lifting column from rotating during the welding process and causing vertical movement of the lifting column, which would lead to the welding position shift.

[0030] There are two pressure sensors, one located on the side wall at the lowest point and the other at the highest point, used to detect the pressure value of the cylindrical rod. They are connected to the pneumatic control system. When the pressure sensor is within the threshold range, it feeds the signal back to the pneumatic controller to control the pneumatic clamping plate to clamp.

[0031] Preferably, the first drive mechanism is a self-locking first drive motor, which is connected to the bottom turntable. The first drive motor is equipped with an angle sensor for controlling its rotation angle. Specifically, the motor shaft of the first drive motor and the bottom turntable are both connected through a translation mechanism and a set of transmission gears.

[0032] Preferably, the translation mechanism includes a machine base and a translation trolley mounted on the machine base. The bottom turntable is mounted on the translation trolley. The machine base is equipped with three sets of position sensors. The three sets of position sensors are used to detect the loading position, welding position and unloading position respectively, and feed the position information back to the translation trolley to control the translation trolley to stop at three different positions for loading, welding and unloading.

[0033] Preferably, the translation trolley and the machine platform are equipped with mutually cooperating sliders and slide rails. The bottom of the translation trolley is equipped with a traveling gear driven by a drive device. The machine cabinet is equipped with a rack that meshes with the traveling gear. The drive device drives the gear to travel along the rack and has a self-locking function.

[0034] The differential gear assembly and welding production process, which uses the aforementioned differential gear assembly and welding production line, includes the following steps:

[0035] S1, Gear shaft conveying, the gear shaft is conveyed through the ring cooling conveyor line;

[0036] S2, Gear heating: The gear is fed onto the heating mechanism and heated to cause it to expand;

[0037] S3, Press fitting: Load the gear shaft onto the press fitting mechanism, and load the heated gear from step S2 onto the gear shaft. Then start the press fitting mechanism to press the gear onto the side wall of the gear shaft.

[0038] S4, Pre-welding runout detection: The press-fitted product is fed to the pre-welding runout detection mechanism for pre-welding runout detection;

[0039] S5, Welding: After inspection in step S4, the product is moved to the FNK welding mechanism via the welding feeding mechanism for welding the top and bottom of the gear's inner hole. During welding, the product, after pre-welding inspection, is first moved to the pneumatic chuck for clamping. After clamping, it is moved to the welding station via the translation mechanism. The laser welding robot is then activated and aligned with the welding position. Simultaneously, the bottom turntable is driven to rotate at a constant speed for one revolution via the first drive mechanism to weld one side of the gear. After welding on this side is completed, the laser welding robot is turned off. The lifting column is then driven to rotate via the second drive mechanism, causing the cylindrical rod on the side wall of the second lifting column to move from the low point of the gap to the high point or from... The gap high point is moved to the low point, and the height of the product is adjusted before and after the movement. After the adjustment, the laser welding robot is turned on again and aligned with the welding position for welding. At the same time, the bottom turntable is driven to rotate at a constant speed for one revolution through the first drive mechanism to weld the other side of the gear. After the welding of this side is completed, the laser welding robot is turned off and the welded product is unloaded. In this step, the welding feeding mechanism feeds the material through two clamping feeding devices. While the product on one clamping feeding device is being unloaded after welding, the laser welding robot welds the product on the other clamping feeding device, and the welding is carried out alternately.

[0040] S6, Post-weld runout detection: The welded product is moved to the assembly line and transported to the ultrasonic testing unit for ultrasonic testing to detect the welding quality.

[0041] S7, Post-weld runout detection: The product after ultrasonic flaw detection is moved to the post-weld runout detection mechanism for post-weld runout detection.

[0042] Preferably, the following method is used for control during the welding process: In the initial stage, the cylindrical rod is at the low point of the gap and is limited by the first limiting column group. When the second drive mechanism drives the lifting column to rotate, the retractable first and second limiting columns retract. The lifting column rises under the action of the cylindrical rod. When the cylindrical rod reaches the opposite side of one of the second limiting columns, the laser sensor detects the passage of the cylindrical rod through distance detection and controls the second limiting column to extend through the controller. When the cylindrical rod reaches the high point of the gap, the second limiting column group clamps and fixes the cylindrical rod. At the same time, when the pressure sensor detects that the pressure reaches the preset threshold, the second drive mechanism is controlled to stop.

[0043] In the heating and pressing steps, pressure sensors and temperature control devices are respectively installed in the pressing mechanism and the heating mechanism. The pressure required for pressing detected by the pressure sensors is fed back to the temperature control device to adjust the heating temperature and heating time of the gear by the heating mechanism. The adjustment algorithm is as follows:

[0044] 1. Let the target pressing pressure be P. t ;

[0045] 2. Actual press-fit pressure P a It can be detected by a pressure sensor;

[0046] 3. The pressure deviation is defined as follows:

[0047] e(t) = P t -P a

[0048] 4. Heating adjustments are as follows:

[0049]

[0050] Where K p K is the proportionality coefficient. i K is the integral coefficient; d For differential coefficients, K t This is a heating time adjustment factor;

[0051] 5. The time compensation amount is as follows:

[0052]

[0053] Where K t Is with K p The relevant heating time adjustment factor is used to balance the relationship between temperature and time;

[0054] 6. Total heating time A = T S +Δt, where T S This is the time since the last heating.

[0055] Compared with the prior art, the advantages of this invention are as follows: This application separately cools and heats the gear shaft and the gear, causing the gear to expand thermally and the gear shaft to contract coldly, and then presses them together. During heating and pressing, the heating temperature and time are optimized according to the pressing pressure. In addition, the product is gripped and fed to the welding position by a gripping and feeding device to cooperate with the welding robot for welding. During the welding process, the gripping and feeding device rotates the product to form a ring weld and adjusts the welding position by raising and lowering to perform a second ring weld, which improves the strength of the connection. In addition, the gripping and feeding device achieves precise height adjustment. Compared with relying solely on the welding robot to adjust the height and laser direction, it is more efficient, less prone to errors, and ensures accuracy. Furthermore, this application sets up two sets of gripping and feeding devices to alternately grip and feed the product. When one set is finished welding and unloading, the welding robot welds the product on the other set, avoiding the welding robot being in a waiting state during unloading, loading, and transferring, further improving the welding efficiency. Attached Figure Description

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the invention. Furthermore, unless specifically indicated, the drawings are only schematic representations of the composition or structure of the described objects and may contain exaggerated depictions, and the drawings are not necessarily drawn to scale.

[0057] Figure 1 This is a perspective view of the present application;

[0058] Figure 2 This is a perspective view of the present application (excluding the welding area);

[0059] Figure 3 A perspective view of the clamping and feeding device;

[0060] Figure 4 Exploded view of the translational and gripping parts of the clamping and feeding device (electric push rod);

[0061] Figure 5 A perspective view of the translating and gripping parts of the clamping and feeding device;

[0062] Figure 6 A perspective view of the translating and gripping parts of the clamping and feeding device;

[0063] Figure 7 Exploded view of the translational and gripping parts of the clamping and feeding device (pneumatic gripper);

[0064] In the diagram: 01, robotic arm; 02, welding feeding mechanism; 10, ring cooling conveyor mechanism; 20, heating mechanism; 30, pressing mechanism; 40, pre-welding runout detection mechanism; 50, FNK welding mechanism; 5002, welding robot; 500; 501, gripping and feeding device; 5011, machine base; 5012, slide rail; 5013, slider; 5014, translation trolley; 5015, rack; 5016, drive device; 5017, traveling gear; 5018, bottom turntable; 50181, 50191, transmission gear; 50182, column; 5019, first drive mechanism; 5020, the... 5021, Second limit post group; 5022, Pneumatic chuck; 50221, Slide table; 5023, Lifting column; 50231, Cylindrical rod; 50232, Splined shaft; 5024, Rotating assembly; 50241, Lower cylinder; 50242, Upper cylinder; 502421, Slide groove; 50243, Clearance; 50244, Lower connecting ring; 50245, Upper connecting ring; 50246, Connecting bolt; 5025, Second drive mechanism; 50251, Second drive motor; 60, Unloading device; 70, Continuous conveyor line; 80, Ultrasonic flaw detection mechanism; 90, Post-weld runout detection mechanism. Detailed Implementation

[0065] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of the invention.

[0066] Example 1

[0067] Differential gear assembly and welding production line, such as Figure 1-7 As shown, it includes:

[0068] The ring-cooled conveyor mechanism 10 is used to convey the gear shaft and control its temperature. Specifically, it surrounds the conveyor line and sets up an air-cooling device around the conveyor line to cool the gear shaft and cause it to shrink.

[0069] Heating mechanism 20 is used to heat the gear to be welded, causing the gear to expand thermally. Specifically, it includes an annular placement step, on which the gear is fitted. A heating tube or a liftable heating coil is installed inside the placement step. The gear is surrounded by the step and then energized to heat the gear.

[0070] The pressing mechanism 30 is used to press the gear onto the gear shaft. Specifically, it has a pressing table with a positioning groove for inserting and positioning the gear shaft and a liftable annular pressing table. When the gear is moved to the top of the gear shaft by the robot arm 01, the annular pressing table lowers by a preset height to press the gear onto the gear shaft.

[0071] The pre-welding runout detection mechanism 40 is arranged side by side with the heating mechanism 20 and the pressing mechanism 30 and is located on one side of the ring cooling conveyor mechanism 10. It is used to detect the concentricity after pressing. Specifically, it can be detected by existing dynamic detection instruments, runout checkers and coaxiality measuring instruments.

[0072] Welding feeding mechanism 02 is located at the tail side of pre-welding runout detection mechanism 40 and is used to transport the product after pre-welding runout detection.

[0073] FNK welding mechanism 50, which is located at the tail end of welding feeding mechanism 02, is used to weld the gear and gear shaft conveyed by welding feeding mechanism 02. This welding mechanism is a laser welding mechanism.

[0074] The assembly line 70 is located on the other side of the ring cooling conveyor mechanism 10 and its head extends to the FNK welding mechanism 50. Specifically, it uses a belt conveyor for conveying.

[0075] An ultrasonic flaw detection mechanism 80 is located at the end of the assembly line 70 and is used to perform ultrasonic flaw detection on the welded products.

[0076] The post-weld runout detection mechanism 90 is set at the end of the assembly line 70 and is used to detect the concentricity after welding. Specifically, it can be detected by existing gear runout detectors, runout checkers and coaxiality measuring instruments.

[0077] The robotic arm 01, which has multiple units, is used to respectively send the gear shaft on the cooling conveyor 10 to the pressing mechanism 30, send the gear to the heating mechanism 20 and send it to the pressing mechanism 30 after heating, transfer the pressed product to the pre-welding runout detection mechanism 40 for inspection, transfer the product after pre-welding runout detection to the welding feeding mechanism 02, transfer the welded product to the assembly line 70, transfer the product on the assembly line 70 to the ultrasonic flaw detection mechanism 80, transfer the product after ultrasonic flaw detection to the post-welding runout detection mechanism 90, and unload the product at the post-welding runout detection mechanism 90.

[0078] Preferably, the FNK welding mechanism 50 includes a laser welding robot 5002 and a clamping and feeding device 501, wherein the clamping and feeding device 501 is provided in two parallel sets, and the laser welding robot 5002 is arranged between the two sets of clamping and feeding devices 501.

[0079] Preferably, the clamping and feeding device 501 includes:

[0080] Translation mechanism, which moves in the horizontal direction;

[0081] The bottom turntable 5018 is rotated on a translation mechanism, and the translation mechanism is provided with a first drive mechanism 5019 to drive its rotation.

[0082] The rotating component 5024 is fixed to the bottom turntable 5018 by the column 50182. It includes a cylindrical upper cylinder 50242 and a cylindrical lower cylinder 50241, and a connecting structure connecting the upper cylinder 50242 and the lower cylinder 50241. The upper cylinder 50242 and the lower cylinder 50241 are arranged opposite each other and have the same inner hole diameter. A gap 50243 is provided between the bottom wall of the upper cylinder 50242 and the top wall of the lower cylinder 50241. The gap 50243 has two high points and two low points of the same height. The gap gradually spirals upward from the low point to the high point and is sinusoidal after unfolding. Two cylindrical rods 50231 can be provided. One rod moves between the two limiting column groups, and the other rod is on the opposite side and has no limiting structure. Providing two rods can increase the stability of the support.

[0083] The lifting column 5023 includes a lifting column and a splined shaft 50232 located at the bottom of the lifting column. The lifting column extends from the inner hole of the lower cylinder 50241 into the inner hole of the upper cylinder 50242, and the side wall of the lifting column is provided with a cylindrical rod 50231 that extends into the gap 50243 between the upper cylinder 50242 and the lower cylinder 50241 and matches the width of the gap 50243.

[0084] The second drive mechanism 5025 includes a gear ring rotatably mounted on the translation mechanism and a second drive motor 50251 that drives the gear ring to rotate. The gear ring has internal teeth and external teeth. The spline shaft 50232 of the lifting column 5023 is slidably inserted into the inside of the gear ring and meshes with the internal teeth.

[0085] The pneumatic chuck 5022 is vertically slidably mounted on the upper cylinder 50242. Specifically, the inner wall of the upper cylinder 50242 has several vertically extending grooves, and the side wall of the pneumatic chuck 5022 has several sliding tables 50221 that extend into the grooves and slide vertically along the grooves. The clamping and releasing are controlled by a pneumatic controller. In this design, the rotation of the rotating component 5024 changes the circumferential welding position, while the rotation of the lifting column 5023 causes the cylindrical rod 50231 to move within the gap 50243, thereby adjusting the height and changing the welding height. This allows for welding on both sides of the gear, improving the stability of the connection. The lifting adjustment, combined with the laser welding robot 5002, reduces the adjustment actions of the welding robot 5002, distributing the welding position adjustment actions between the two systems, which is beneficial for improving welding efficiency and welding accuracy.

[0086] Preferably, the connection structure includes an upper connecting ring 50245 disposed on the top side of the upper cylinder 50242, a lower connecting ring 50244 disposed on the bottom side of the lower cylinder 50241, and a plurality of connecting bolts 50246 disposed between the upper connecting ring 50245 and the lower connecting ring 50244 to connect the two. The two connecting rings in this design are used for the installation and fixing of the two cylinders and for installing other components, such as the limiting post assembly described below.

[0087] Preferably, the clamping and feeding device 501 further includes:

[0088] The first limiting post group 5020 includes two first limiting posts disposed between the upper connecting ring 50245 and the lower connecting ring 50244 and located on both sides of the lowest point of the gap 50243 for clamping the cylindrical rod 50231 for limiting. The outer one is fixedly connected to the upper connecting ring 50245 and the lower connecting ring 50244, and the inner one is an electrically telescopic structure.

[0089] The second limiting post group 5021 includes two second limiting posts disposed between the upper connecting ring 50245 and the lower connecting ring 50244 and located on both sides of the highest point of the gap 50243 for clamping the cylindrical rod 50231 for limiting. The outer one is fixedly connected to the upper connecting ring 50245 and the lower connecting ring 50244, and the inner one is an electrically telescopic structure.

[0090] Two laser sensors are provided and located on opposite sides of the electric telescopic structure. When the cylindrical rod 50231 moves to the lowest or highest point and passes through the irradiation range of the laser sensor, the laser sensor detects a decrease in distance and sends a feedback signal to the control unit of the electric telescopic structure to control the electric telescopic structure to extend and limit the cylindrical rod 50231. This prevents the lifting column 5023 from rotating during the welding process, which would cause the lifting column 5023 to move vertically and cause the welding position to shift. The electric telescopic structure includes a motor push rod 500 and a limiting rod. The limiting rod is located at the output end of the electric push rod 500, and the electric push rod 500 drives the limiting rod to extend and retract.

[0091] Two pressure sensors, one at the lowest point and the other at the highest point of the sidewall, are used to detect the pressure value of the cylindrical rod 50231. These sensors are connected to the pneumatic control system. When the pressure sensor readings are within a threshold range, they feed the signal back to the pneumatic controller to control the pneumatic clamping plate 5022 to clamp the rod. The two limit post groups provided in this solution are used to limit the cylindrical rod 50231 at two extreme positions, preventing it from wobbling during welding and causing changes in product height. This helps ensure the accuracy of the welding position and improves welding quality. Additionally, the two pressure sensors provide pressure feedback to control the clamping and releasing of the pneumatic grippers.

[0092] Preferably, the first drive mechanism 5019 is a self-locking first drive motor, which is connected to the bottom turntable 5018. The first drive motor is equipped with an angle sensor for controlling its rotation angle. Specifically, the motor shaft of the first drive motor and the bottom turntable both pass through the translation mechanism and are connected by a set of transmission gears 50181 and 50191. The first drive mechanism 5019 drives the bottom turntable 5018 to rotate one revolution each time welding is performed, thereby welding the product one revolution.

[0093] Preferably, the translation mechanism includes a machine base 5011 and a translation trolley 5014 mounted on the machine base 5011. A bottom turntable 5018 is mounted on the translation trolley 5014. The machine base 5011 is equipped with three sets of position sensors, which are used to detect the loading position, welding position, and unloading position, respectively, and feed the position information back to the translation trolley 5014 to control the translation trolley 5014 to stop at three different positions for loading, welding, and unloading. In this solution, three different positions are set for loading, welding, and unloading, and positioning is achieved through position sensors.

[0094] Preferably, the translation trolley 5014 and the machine base 5011 are equipped with mutually cooperating sliders 5013 and slide rails 5012. The bottom of the translation trolley 5014 is equipped with a traveling gear 5017 driven by a drive device 5016. The machine base is equipped with a rack 5015 that meshes with the traveling gear 5017. The drive device 5016 drives the gear to move along the rack 5015 and has a self-locking function. In this solution, the traveling trolley and the machine base 5011 are slidably engaged by the slide rail 5012 and slider 5013. In addition, the traveling gear 5017 is set on the traveling trolley and the rack 5015 is set on the machine base 5011 so that the traveling gear 5017 moves along the rack 5015. After moving to the corresponding position, the drive device 5016 self-locks, and the traveling gear 5017 is locked on the rack 5015 to ensure that the traveling trolley is in that position for loading, welding or unloading.

[0095] Additionally, it should be noted that this embodiment is equipped with a welding chamber and a material unloading device 60. The clamping and feeding device 501 and the material unloading device 60 extend from outside the welding chamber to inside the welding chamber. The welding chamber achieves closed welding to prevent personnel from entering and causing danger. The material unloading device 60 includes a material unloading conveyor and a material transfer robot. The material transfer robot clamps the product on the clamping and feeding device 501 and places it on the material unloading conveyor to transport it outside the welding chamber.

[0096] Example 2

[0097] The differential gear assembly and welding production process, which adopts the differential gear assembly and welding production line described in Example 1, includes the following steps:

[0098] S1, Gear shaft conveying: The gear shaft is conveyed through a cooling conveyor line. During the conveying process, the gear shaft is cooled and shrinks.

[0099] S2, Gear heating: The gear is fed onto the heating mechanism 20 and heated to make it expand;

[0100] S3, Press fitting: The gear shaft is loaded onto the press fitting mechanism 30, and the heated gear in step S2 is loaded onto the gear shaft. Then the press fitting mechanism 30 is started to press down to press the gear onto the side wall of the gear shaft.

[0101] S4, Pre-welding runout detection: The press-fitted product is fed to the pre-welding runout detection mechanism at point 40 for pre-welding runout detection;

[0102] S5, Welding: The product inspected in step S4 is moved to the FNK welding mechanism 50 via the welding feeding mechanism 02 to weld the top and bottom of the gear's inner hole. During welding, the product, after pre-welding inspection, is first moved to the pneumatic chuck 5022 for clamping. After clamping, it is moved to the welding station via the translation mechanism. The laser welding robot 5002 is activated and aligned with the welding position for welding. Simultaneously, the first drive mechanism 5019 drives the bottom turntable 5018 to rotate at a constant speed for one revolution to weld one side of the gear. After welding on this side is completed, the laser welding robot 5002 is turned off. The second drive mechanism 5025 drives the lifting column 5023 to rotate, causing the cylindrical rod 50231 on the side wall of the second lifting column 5023 to move from the lowest point of the gap 50243. The product height is adjusted once before and after the movement, either from the highest point or from the highest point of gap 50243 to the lowest point. After adjustment, the laser welding robot 5002 is turned on again and aligned with the welding position for welding. At the same time, the bottom turntable 5018 is driven to rotate at a constant speed for one revolution through the first drive mechanism 5019 to weld the other side of the gear. After the welding on this side is completed, the laser welding robot 5002 is turned off and the welded product is unloaded. In this step, the welding feeding mechanism 02 feeds the product through two gripping feeding devices 501. While the product on one gripping feeding device 501 is being unloaded after welding, the laser welding robot 5002 welds the product on the other gripping feeding device 501 and performs welding alternately.

[0103] S6, Post-weld runout detection: The welded product is moved to the conveyor line 70 and transported to the ultrasonic flaw detection mechanism 80 for ultrasonic flaw detection to detect the welding quality.

[0104] S7, Post-weld runout detection: The product after ultrasonic flaw detection is moved to the post-weld runout detection mechanism at position 90 for post-weld runout detection.

[0105] Preferably, the following method is used to control the welding process: In the initial stage, the cylindrical rod 50231 is at the low point of the gap 50243 and is limited by the first limiting post group 5020. When the second drive mechanism 5025 drives the lifting column 5023 to rotate, the retractable first and second limiting posts retract, and the lifting column 5023 rises under the action of the cylindrical rod 50231. When the cylindrical rod 50231 reaches the opposite side of one of the second limiting posts, the laser sensor detects the passage of the cylindrical rod 50231 through distance detection and controls the second limiting post to extend through the controller. When the cylindrical rod 50231 reaches the high point of the gap 50243, the second limiting post group 5021 clamps and fixes the cylindrical rod 50231. At the same time, when the pressure sensor detects that the pressure reaches the preset threshold, the second drive mechanism 5025 is controlled to stop.

[0106] During the heating and pressing process, a pressure detection sensor and a temperature control device are respectively installed in the pressing mechanism 30 and the heating mechanism 20. The pressure required for pressing detected by the pressure detection sensor is fed back to the temperature control device to adjust the heating temperature and heating time of the gear by the heating mechanism 20. The adjustment algorithm is as follows:

[0107] 1. Let the target pressing pressure be P. t ;

[0108] 2. Actual press-fit pressure P a It can be detected by a pressure sensor;

[0109] 3. The pressure deviation is defined as follows:

[0110] e(t) = P t -P a

[0111] 4. Heating adjustments are as follows:

[0112]

[0113] Where K p This is a proportionality coefficient, and its value range is gradually adjusted according to the system response, but the initial value is 1.0;

[0114] K i The integral coefficient, according to the Ziegler-Nichols method, can be set to...

[0115]

[0116] T U The oscillation period;

[0117] K d For the differential coefficients, according to the Ziegler-Nichols method, their values ​​can be set as follows:

[0118]

[0119] T U The oscillation period is K; t This is the heating time adjustment factor, with a value ranging from 1 to 1.3;

[0120] 5. The time compensation amount is as follows:

[0121]

[0122] Where K t Is with K p The relevant heating time adjustment factor is used to balance the relationship between temperature and time;

[0123] 6. Total heating time A = T S +Δt, where T S This is the time since the last heating.

[0124] The differential gear assembly and welding production line and process provided by this invention have been described above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand this invention and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A differential gear assembly and welding production line, characterized in that, include: A ring-cooled conveyor mechanism is used to convey gear shafts and control their temperature. The heating mechanism is used to heat the gear to be welded, causing the gear to expand thermally. A press-fitting mechanism, used to press gears onto gear shafts; The pre-welding runout detection mechanism is set up side by side with the heating mechanism and the pressing mechanism and is located on one side of the ring cooling conveyor mechanism. It is used to detect the concentricity after pressing. A welding feeding mechanism is located at the tail side of the pre-welding runout detection mechanism and is used to transport the product after the pre-welding runout detection. The FNK welding mechanism, located at the tail end of the welding feeding mechanism, is used to weld the gears and gear shafts conveyed by the welding feeding mechanism. The assembly line is located on the other side of the ring cooling conveyor and its head extends to the FNK welding mechanism. An ultrasonic flaw detection mechanism is installed at the end of the assembly line and is used to perform ultrasonic flaw detection on the welded products. A post-weld runout detection mechanism is set at the end of the assembly line and is used to detect the concentricity after welding. Multiple robotic arms are configured to respectively transport gear shafts from the cooling conveyor mechanism to the pressing mechanism, transport gears to the heating mechanism and then to the pressing mechanism after heating, transfer pressed products to the pre-welding runout detection mechanism for inspection, transfer products after pre-welding runout detection to the welding feeding mechanism, transfer welded products to the assembly line, transfer products on the assembly line to the ultrasonic flaw detection mechanism, transfer products after ultrasonic flaw detection to the post-welding runout detection mechanism, and unload products from the post-welding runout detection mechanism.

2. The differential gear assembly and welding production line according to claim 1, characterized in that, The FNK welding mechanism includes an automatic laser welding machine and a clamping and feeding device, wherein there are two parallel sets of clamping and feeding devices, and the automatic laser welding machine is located between the two sets of clamping and feeding devices.

3. The differential gear assembly and welding production line according to claim 2, characterized in that, Clamping and feeding devices include: Translation mechanism, which moves in the horizontal direction; The bottom turntable rotates on a translation mechanism, which is equipped with a first drive mechanism to drive its rotation. The rotating assembly, which is fixed to the bottom turntable by a column, includes a cylindrical upper cylinder and a cylindrical lower cylinder, and a connecting structure connecting the upper cylinder and the lower cylinder. The upper cylinder and the lower cylinder are arranged opposite each other and the diameter of their inner holes is the same. A gap is provided between the bottom wall of the upper cylinder and the top wall of the lower cylinder. The gap has two high points and two low points of the same height. The gap gradually spirals upward from the low point to the high point and is sinusoidal in shape after unfolding. The lifting column includes a lifting column and a splined shaft located at the bottom of the lifting column. The lifting column extends from the inner hole of the lower cylinder into the inner hole of the upper cylinder, and the side wall of the lifting column is provided with a cylindrical rod that extends into the gap between the upper cylinder and the lower cylinder and matches the width of the gap. The second drive mechanism includes a gear ring rotatably mounted on the translation mechanism and a second drive motor that drives the gear ring to rotate. The gear ring has internal teeth and external teeth. The spline shaft of the lifting column is slidably inserted into the gear ring and meshes with the internal teeth. The pneumatic chuck is vertically slidably mounted on the upper cylinder and is controlled to clamp and release by a pneumatic controller.

4. The differential gear assembly and welding production line according to claim 3, characterized in that, The connection structure includes an upper connecting ring disposed on the top side of the upper cylinder, a lower connecting ring disposed on the bottom side of the lower cylinder, and a number of connecting bolts disposed between the upper connecting ring and the lower connecting ring to connect the two.

5. The differential gear assembly and welding production line according to claim 4, characterized in that, The clamping and feeding device also includes: The first limiting post group includes two first limiting posts disposed between the upper connecting ring and the lower connecting ring and located on both sides of the lowest point of the gap for clamping the cylindrical rod for limiting the position. The outer one is fixedly connected to the upper connecting ring and the lower connecting ring, and the inner one is an electrically telescopic structure. The second limiting post assembly includes two second limiting posts located between the upper connecting ring and the lower connecting ring and on both sides of the highest point of the gap, used to clamp the cylindrical rod for limiting the position. The outer one is fixedly connected to the upper connecting ring and the lower connecting ring, and the inner one is an electrically telescopic structure. Two laser sensors are installed and located on opposite sides of the electric telescopic structure. When the cylindrical rod moves to the lowest or highest point and passes through the irradiation range of the laser sensor, the laser sensor detects a decrease in distance and sends a signal to the control unit of the electric telescopic structure to control the electric telescopic structure to extend and limit the cylindrical rod, so as to prevent the lifting column from rotating during the welding process and causing vertical movement of the lifting column, which would lead to the welding position shift. There are two pressure sensors, one located on the side wall at the lowest point and the other at the highest point, used to detect the pressure value of the cylindrical rod. They are connected to the pneumatic control system. When the pressure sensor is within the threshold range, it feeds the signal back to the pneumatic controller to control the pneumatic clamping plate to clamp.

6. The differential gear assembly and welding production line according to claim 5, characterized in that, The first drive mechanism is a self-locking drive motor, which is connected to the bottom turntable via transmission. The drive motor is equipped with an angle sensor for controlling its rotation angle.

7. The differential gear assembly and welding production line according to claim 5, characterized in that, The translation mechanism includes a machine base and a translation trolley mounted on the machine base. The bottom turntable is mounted on the translation trolley. The machine base is equipped with three sets of position sensors, which are used to detect the loading position, welding position and unloading position respectively, and feed the position information back to the translation trolley to control the translation trolley to stop at three different positions for loading, welding and unloading.

8. The differential gear assembly and welding production line according to claim 7, characterized in that, The translation trolley and the machine are equipped with sliding blocks and slide rails that cooperate with each other. The bottom of the translation trolley is equipped with a traveling gear driven by a drive device. The cabinet is equipped with a rack that meshes with the traveling gear. The drive device drives the gear to move along the rack and has a self-locking function.

9. A differential gear assembly and welding production process, characterized in that, This process is carried out using the differential gear assembly and welding production line described in any one of claims 5-8, and includes the following steps: S1, Gear shaft conveying, the gear shaft is conveyed through the ring cooling conveyor line; S2, Gear heating: The gear is fed onto the heating mechanism and heated to cause it to expand; S3, Press fitting: Load the gear shaft onto the press fitting mechanism, and load the heated gear from step S2 onto the gear shaft. Then start the press fitting mechanism to press the gear onto the side wall of the gear shaft. S4, Pre-welding runout detection: The press-fitted product is fed to the pre-welding runout detection mechanism for pre-welding runout detection; S5, Welding: After inspection in step S4, the product is moved to the FNK welding mechanism via the welding feeding mechanism for welding the top and bottom of the gear's inner hole. During welding, the product, after pre-welding inspection, is first moved to the pneumatic chuck for clamping. After clamping, it is moved to the welding station via the translation mechanism. The automatic laser welding machine is turned on and aligned with the welding position for welding. Simultaneously, the bottom turntable is driven to rotate at a uniform speed for one revolution via the first drive mechanism to weld one side of the gear. After welding on this side is completed, the automatic laser welding machine is turned off. The lifting column is driven to rotate via the second drive mechanism, causing the cylindrical rod on the side wall of the second lifting column to move from the low point of the gap to the high point or from... The gap high point is moved to the low point, and the height of the product is adjusted before and after the movement. After adjustment, the automatic laser welding machine is turned on again and aligned with the welding position for welding. At the same time, the bottom turntable is driven to rotate at a constant speed for one revolution through the first drive mechanism to weld the other side of the gear. After the welding of this side is completed, the automatic laser welding machine is turned off and the welded product is unloaded. In this step, the welding feeding mechanism feeds the material through two clamping feeding devices. While the product on one clamping feeding device is unloaded after welding, the automatic laser welding machine welds the product on the other clamping feeding device, and the welding is carried out alternately. S6, Post-weld runout detection: The welded product is moved to the assembly line and transported to the ultrasonic testing unit for ultrasonic testing to detect the welding quality. S7, Post-weld runout detection: The product after ultrasonic flaw detection is moved to the post-weld runout detection mechanism for post-weld runout detection.

10. The differential gear assembly and welding production process according to claim 9, characterized in that, During the welding process, the following control method is adopted: In the initial stage, the cylindrical rod is at the low point of the gap and is limited by the first limit column group. When the second drive mechanism drives the lifting column to rotate, the retractable first limit column and second limit column retract. The lifting column rises under the action of the cylindrical rod. When the cylindrical rod reaches the opposite side of one of the second limit columns, the laser sensor detects the passage of the cylindrical rod through distance detection and controls the second limit column to extend through the controller. When the cylindrical rod reaches the high point of the gap, the second limit column group clamps and fixes the cylindrical rod. At the same time, when the pressure sensor detects that the pressure reaches the preset threshold, the second drive mechanism is controlled to stop. During the heating and pressing process, a pressure sensor and a temperature control device are respectively installed in the pressing mechanism and the heating mechanism. The pressure sensor detects the required pressing pressure and feeds it back to the temperature control device to adjust the heating temperature and heating time of the gear by the heating mechanism. The adjustment algorithm is as follows:

1. Let the target pressing pressure be P. t ; 2. Actual press-fit pressure P a It can be detected by a pressure sensor; 3. The pressure deviation is defined as follows: e(t)=P t -P a 4. Heating adjustments are as follows: Where K p K is the proportionality coefficient. i K is the integral coefficient; d For differential coefficients, K t This is a heating time adjustment factor; 5. The time compensation amount is as follows: Where K t Is with K p The relevant heating time adjustment factor is used to balance the relationship between temperature and time; 6. Total heating time A = T S +Δt, where T S This is the time since the last heating.

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