A method for pre-matching a car lamp cover and a shell by welding

Abstract

The application discloses a kind of automobile headlamp cover and shell welding pre-matching method, comprising the following steps: pre-matching mechanism extends to between cover and shell;Multiple displacement sensors detect each corresponding position of cover bottom, obtain the current posture of cover;Multiple laser displacement sensors detect the corresponding position of shell, obtain the current posture of shell;Displacement sensor and laser displacement sensor are same in number, one-to-one correspondence, obtain the deviation of each direction;When mold clamping heating welding, the pressure sensor below lower die clamp monitors the pressure condition when pressing, compares actual value and preset value, carries out corresponding servo feeding work according to corresponding comparison value, completes welding;Clamp composite structure supports 6 degrees of freedom adjustment, cover and shell are automatically adjusted pre-matching, and multiple degrees of freedom adjustment, clamp pressure and penetration detection, servo feeding are fused, and welding precision is improved.

Description

Technical Field

[0001] This invention belongs to the field of automotive lamp welding technology, specifically relating to a pre-matching method for welding automotive lamp covers and housings. Background Technology

[0002] Currently, adhesive application-compacting and welding technologies are the most commonly used solutions in automotive lighting manufacturing. Adhesive application-compacting is mainly applicable to headlights. Other lighting fixtures are mainly produced using welding processes, including laser welding, hot plate welding, vibration friction welding, and ultrasonic welding. Adhesive application-compacting and welding fixtures generally consist of upper and lower fixtures. The upper fixture is typically used to hold and fix the lamp cover, while the lower fixture is used to position the lamp housing. The adhesive application-compacting fixture applies adhesive to a designated area of ​​the lower housing before pressing the cover together with the housing. Depending on the welding method, the welding fixture uses upper and lower mold closing actions to press the lamp cover and housing together before or after heat fusion.

[0003] Currently, with existing technology, the upper and lower molds of a fixture are typically connected by four guide shafts (also called optical shafts) or guide rails. Depending on the equipment, the upper or lower mold moves along the guides until mold closing is complete. In this design, there is no direct dimensional correlation between the positioning of the upper mold and the lower mold for the face mask. Direct dimensional correlation here refers to calibrating the deviation between the shell and the face mask using the same spatial coordinate system. This problem leads to a relative deviation between the upper and lower molds, resulting in a relative dimensional deviation after the face mask and shell are molded (the mating surfaces cannot be perfectly aligned and pressed together). This, in turn, leads to a low yield rate, material waste, and increased manufacturing costs.

[0004] The raw materials (face mask and shell) are injection molded and produced in batches according to the production plan. There may be significant differences in size and deformation between different batches of injection molded face masks and shells. This difference will further aggravate the relative dimensional deviation of the face mask and shell after mold assembly, resulting in a low yield rate of finished products, material waste, and increased manufacturing costs.

[0005] Due to the aforementioned injection molding issues, during the fixture positioning design process, to ensure that the parts can be smoothly loaded into the fixture, the fixture is generally designed according to the maximum material principle or avoids the skin (to prevent scratches). However, the existence of actual part deviations leads to gaps between the fixture and the part in general positioning situations. These gaps result in poor positioning and exacerbate post-manufacturing deviations.

[0006] Under current technological conditions, pressing is generally carried out pneumatically or electrically, with the pressing time and force adjusted based on experience. Due to the reliance on manual, experience-based adjustments, improper adjustments under the current technology system may cause problems such as part cracking (excessive pressing force), cracking of the mating surface (insufficient melt depth or insufficient holding time), and burns on the surface (improper control of heat fusion time). Summary of the Invention

[0007] This invention provides a pre-matching method for welding automotive headlight covers and housings to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a pre-matching method for welding automotive headlight covers and housings, the method comprising the following steps: S1: Manually install the mask under the upper mold fixture; S2: Manually install the housing onto the upper part of the lower mold fixture; S3: Activate the lateral telescopic mechanism, which drives the pre-matching mechanism on it to extend between the mask and the shell; S4: The longitudinal telescopic mechanism in the middle of the pre-matching mechanism drives multiple upward displacement sensors to move upward to a set height. The multiple displacement sensors detect the corresponding positions at the bottom of the mask to obtain the current posture of the mask. The lower mold pushing mechanism drives the lower mold fixture to move upward, and at the same time, the shell moves upward to a set height position. Multiple laser displacement sensors below the pre-matching mechanism detect the corresponding positions of the shell to obtain the current posture of the shell. S5: The number of displacement sensors and laser displacement sensors are the same, and their positions correspond one-to-one, so that the deviation values ​​in each degree of freedom direction can be obtained. S6: When the current part can be pressed and matched, the lateral telescopic mechanism drives the pre-matching mechanism on it to retract and reset, and the lower mold pushing mechanism pushes the lower mold fixture into place; when the current part cannot be pressed and matched, the posture of the shell is adjusted by the lower mold adjustment mechanism connected to the lower mold fixture, and the posture of the mask is adjusted by the upper mold adjustment mechanism connected to the upper mold fixture, until the current part can be pressed and matched, and the lower mold pushing mechanism pushes the lower mold fixture into place; S7: During mold closing heating and welding, the pressure sensor under the lower mold fixture monitors the pressure during pressing, compares the actual value with the preset value, and performs corresponding servo feed based on the comparison value; the displacement detection mechanism detects the displacement of the lower mold fixture, and stops feeding when the displacement reaches the maximum preset value; S8: After hot melting, apply pressure to the parts to stabilize the welding results until the weld surface solidifies; S9: Then the servo feeds in reverse, the upper and lower mold fixtures are reset, and the welding is completed.

[0009] Preferably, the upper mold adjustment mechanism is a three-point adjustment mechanism, which realizes the two-degree-of-freedom posture adjustment of the mask through the lifting and lowering of three contact points with the upper mold fixture.

[0010] Preferably, the lower mold adjustment mechanism is a three-degree-of-freedom adjustment platform.

[0011] Preferably, the displacement detection mechanism uses multiple equal-height columns in conjunction with a fixture displacement sensor mounted on the lower mold fixture to perform displacement detection. The number of equal-height columns and fixture displacement sensors are the same and they correspond one-to-one.

[0012] Preferably, the pre-matching mechanism includes two separable upper and lower parts. The upper part is fixedly connected to multiple displacement sensors, and the lower part is fixedly connected to multiple laser displacement sensors. The upper and lower parts are guided and positioned by four sets of guiding and positioning mechanisms, each including a linear bearing and a positioning shaft respectively disposed on the upper and lower parts.

[0013] Preferably, the lateral telescopic mechanism realizes the lateral telescopic movement of the pre-matching mechanism through a drive screw and a guide rail. The pre-matching mechanism is mounted on the guide rail, and the lead screw of the drive screw is connected to the lead screw nut on the pre-matching mechanism.

[0014] Preferably, the adjustment of the distance between the upper and lower die clamps of the lower die pushing mechanism adopts a five-degree-of-freedom iterative algorithm. Based on the value given by the technical requirements and the performance parameters of the welding equipment, the difference between the distance between the upper and lower die clamps and the penetration depth is solved, and the compensation value is calculated. The lower die pushing mechanism then performs the compensation.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The innovative addition of a three-point adjustment device for the upper clamp, a three-degree-of-freedom adjustment device for the lower clamp, a clamp pressure and melt depth detection device, a lower mold pushing mechanism, and a pre-matching mechanism enables the clamp composite structure to support 6 degrees of freedom adjustment, thereby improving the clamp's adaptability. 2. The innovative addition of a 5-DOF adjustment control system and a pressure melting depth monitoring system, through the data obtained by the pre-matching mechanism (the deviation between the actual value and the theory), and the algorithm processing, provides the adjustment amount of a three-point adjustment device for the upper clamp and a three-DOF adjustment device for the lower clamp, so as to achieve automatic pre-matching of the mask and the shell.

[0016] 3. It integrates multi-degree-of-freedom adjustment, fixture pressure and penetration depth detection, and servo feed to improve the crimping accuracy of the welding process. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system flow of the present invention; Figure 2 This is a schematic diagram of the five-degree-of-freedom iterative algorithm of the present invention; Figure 3 This is a schematic diagram of the pressure penetration monitoring, iterative algorithm, and lower die fixture feed linkage of the present invention; Figure 4 This is a schematic diagram of the clamp operation of the present invention; Figure 5 This is a three-dimensional structural diagram of an embodiment of the present invention. Figure 1 ; Figure 6 This is a three-dimensional structural diagram of an embodiment of the present invention. Figure 2 .

[0018] In the diagram: 1. Mask; 2. Upper mold fixture; 3. Housing; 4. Lower mold fixture; 5. Lateral telescopic mechanism; 6. Pre-matching mechanism; 7. Longitudinal telescopic mechanism; 8. Displacement sensor; 9. Laser displacement sensor; 10. Lower mold adjustment mechanism; 11. Upper mold adjustment mechanism; 12. Height column; 13. Fixture displacement sensor; 14. Linear bearing; 15. Positioning shaft; 16. Drive screw; 17. Guide rail. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1-6 This invention provides a pre-matching method for welding automotive headlight covers and housings, the method comprising the following steps: S1: Manually install the mask 1 under the upper mold fixture 2; S2: Manually install the housing 3 onto the upper part of the lower mold fixture 4; S3: Activate the lateral telescopic mechanism 5. The lateral telescopic mechanism 5 drives the pre-matching mechanism 6 on it to extend between the mask 1 and the shell 3. S4: The longitudinal telescopic mechanism 7 in the middle of the pre-matching mechanism 6 drives multiple upward displacement sensors 8 to move upward to a set height. The multiple displacement sensors 8 detect the corresponding positions at the bottom of the mask 1 to obtain the current posture of the mask 1. The lower mold pushing mechanism below drives the lower mold clamp 4 to move upward. At the same time, the shell 3 moves upward to a set height position. The multiple laser displacement sensors 9 below the pre-matching mechanism 6 detect the corresponding positions of the shell 3 to obtain the current posture of the shell 3. S5: The number of displacement sensors 8 and laser displacement sensors 9 are the same, and their positions correspond one-to-one. The deviation values ​​in each degree of freedom direction are obtained. The measured values ​​u1-un of the upper mold mask and d1-dn of the lower mold shell are known. The theoretical center line of the mold mating surface (hereinafter referred to as the mold mating center line) and the spatial curve function f are known. The functions of the upper mold mating center line f(u) and the lower mold mating center line f(d) are also known. The spatial deviation Δf between f(u) and f(d) is calculated. It is assumed that Y, a, b, and c are not adjusted, and X is the variable. Solve the following: If a solution exists, write the solution ΔX to the register; if no solution exists, substitute the approaching value of X into the solution to find the new deviation ΔfX; solve with Y as a variable; if a solution exists, write the solution ΔY to the register; solve with c as a variable; if a solution exists, write the solution ΔC to the register; after writing ΔX, ΔY, and ΔC to the register, substitute them into the function f(d) for composition; execute the three-point adjustment algorithm, the algorithm solves a and b, if a solution exists, write the solutions LA-a, LB-b, and LC-c to the register; if no solution exists, warn the user that the current part cannot be matched, and substitute them into the function f(u) for composition. S6: When the current part can be pressed and matched, the lateral telescopic mechanism 5 drives the pre-matching mechanism 6 on it to retract and reset, and the lower mold pushing mechanism pushes the lower mold fixture 4 into place; when the current part cannot be pressed and matched, the posture of the housing 3 is adjusted by the lower mold adjustment mechanism 10 connected to the lower mold fixture 4, and the posture of the mask 1 is adjusted by the upper mold adjustment mechanism 11 connected to the upper mold fixture 2, until the current part can be pressed and matched, the lower mold pushing mechanism pushes the lower mold fixture 4 into place, and after the solution is available in S5, the upper mold adjustment mechanism 11 adjusts the mask 1 into place, and the lower mold adjustment mechanism 10 adjusts the housing 3 into place; S7: During mold closing heating and welding, the pressure sensor under the lower mold fixture 4 monitors the pressure during pressing, compares the actual value with the preset value, and performs corresponding servo feed based on the comparison value; the displacement detection mechanism detects the displacement of the lower mold, and stops feeding when the displacement reaches the maximum preset value; S8: After hot melting, apply pressure to the parts to stabilize the welding results until the weld surface solidifies; S9: Then the servo feeds in reverse, the upper and lower mold fixtures are reset, and the welding is completed.

[0021] Please see Figure 5-6 The upper mold adjustment mechanism 11 is a three-point adjustment mechanism. The three-point adjustment mechanism realizes the two-degree-of-freedom attitude adjustment of the mask 1 by raising and lowering the three contact points with the upper mold clamp 2. In this embodiment, the attitude adjustment around the X-axis and around the Y-axis can be realized by raising and lowering the three contact points with the upper mold clamp 2.

[0022] Please see Figure 5-6The lower mold adjustment mechanism 10 is a three-degree-of-freedom adjustment platform. In this embodiment, a conventional three-degree-of-freedom adjustment platform can be used to adjust the lower mold fixture in three degrees of freedom: X-axis, Y-axis and rotation around Z-axis.

[0023] Please see Figure 5-6 The displacement detection mechanism uses multiple equal-height columns 12 in conjunction with a fixture displacement sensor 13 mounted on the lower mold fixture 4 to perform displacement detection. The number of equal-height columns 12 and fixture displacement sensors 13 are the same and they correspond one-to-one. In this embodiment, the melt depth is detected by the fixture displacement sensor 13 and the corresponding equal-height column 12.

[0024] Please see Figure 5-6 The pre-matching mechanism 6 includes two separable upper and lower parts. The upper part is fixedly connected to multiple displacement sensors 8, and the lower part is fixedly connected to multiple laser displacement sensors 9. The upper and lower parts are guided and positioned by four sets of guiding and positioning mechanisms. The guiding and positioning mechanisms include linear bearings 14 and positioning shafts 15 respectively disposed on the upper and lower parts. In this embodiment, the guiding cooperation between the linear bearings 14 and the positioning shafts 15 can ensure the motion accuracy when the upper and lower parts of the pre-matching mechanism 6 are separated.

[0025] Please see Figure 5-6 The lateral telescopic mechanism realizes the lateral telescopic movement of the pre-matching mechanism 6 through the drive screw 16 and the guide rail 17. The pre-matching mechanism 6 is mounted on the guide rail 17, and the lead screw of the drive screw 16 is connected to the lead screw nut on the pre-matching mechanism 6. In this embodiment, by driving the lead screw 16 to rotate the lead screw and cooperating with the lead screw nut, the pre-matching mechanism 6 can be accurately driven to telescopically move on the guide rail 17.

[0026] Please see Figure 3 The adjustment of the distance between the upper and lower die clamps of the lower die propulsion mechanism adopts a five-degree-of-freedom iterative algorithm. Based on the value given by the technical requirements and the performance parameters of the welding equipment, the difference between the distance between the upper and lower die clamps and the penetration depth is solved, and the compensation value is calculated. The lower die propulsion mechanism performs the compensation. In this embodiment, a five-degree-of-freedom iterative algorithm is adopted. Given the composite function f(d), the composite function f(u), Lr is the value given by the technical requirements, Lq is the performance parameter of the welding equipment, the penetration depth requirement Lr is known, the difference between the distance |du| between the upper and lower die clamps and the penetration depth ΔL is solved, and the pneumatic feed Lq is known, the servo compensation value Lz = ΔL - Lq is solved, and Lz is output to the lower die propulsion mechanism for compensation.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for pre-matching welding of an automotive headlight cover and its housing, characterized in that, The method includes the following steps: S1: Manually install the mask under the upper mold fixture; S2: Manually install the housing onto the upper part of the lower mold fixture; S3: Activate the lateral telescopic mechanism, which drives the pre-matching mechanism on it to extend between the mask and the shell; S4: The longitudinal telescopic mechanism in the middle of the pre-matching mechanism drives multiple upward displacement sensors to move upward to a set height. The multiple displacement sensors detect the corresponding positions at the bottom of the mask to obtain the current posture of the mask. The lower mold pushing mechanism drives the lower mold fixture to move upward, while the housing moves upward to a set height position. Multiple laser displacement sensors below the pre-matching mechanism detect the corresponding position of the housing to obtain the current posture of the housing. S5: The number of displacement sensors and laser displacement sensors are the same, and their positions correspond one-to-one, so that the deviation values ​​in each degree of freedom direction can be obtained. S6: When the current part can be pressed and matched, the lateral telescopic mechanism drives the pre-matching mechanism on it to retract and reset, and the lower mold pushing mechanism pushes the lower mold fixture into place; when the current part cannot be pressed and matched, the posture of the shell is adjusted by the lower mold adjustment mechanism connected to the lower mold fixture, and the posture of the mask is adjusted by the upper mold adjustment mechanism connected to the upper mold fixture, until the current part can be pressed and matched, and the lower mold pushing mechanism pushes the lower mold fixture into place; S7: During the mold closing heating process, the pressure sensor under the lower mold fixture monitors the pressure during pressing, compares the actual value with the preset value, and performs corresponding servo feed based on the comparison value; the displacement detection mechanism detects the displacement of the lower mold fixture, and stops feeding when the displacement reaches the maximum preset value; S8: Then, apply pressure to the parts to stabilize the welding results until the weld surface is solidified; S9: Then the servo feeds in reverse, the upper and lower mold fixtures are reset, and the welding is completed.

2. The pre-matching method for welding automotive lamp covers and housings according to claim 1, characterized in that, The upper mold adjustment mechanism is a three-point adjustment mechanism, which realizes the two-degree-of-freedom posture adjustment of the mask through the lifting and lowering of three contact points with the upper mold fixture.

3. The pre-matching method for welding automotive lamp covers and housings according to claim 1, characterized in that, The lower mold adjustment mechanism is a three-degree-of-freedom adjustment platform.

4. The pre-matching method for welding automotive lamp covers and housings according to claim 1, characterized in that, The displacement detection mechanism uses multiple equal-height columns in conjunction with a fixture displacement sensor mounted on the lower mold fixture to detect displacement. The number of equal-height columns and fixture displacement sensors are the same and they correspond one-to-one.

5. The pre-matching method for welding automotive lamp covers and housings according to claim 1, characterized in that, The pre-matching mechanism includes two separable upper and lower parts. The upper part is fixedly connected to multiple displacement sensors, and the lower part is fixedly connected to multiple laser displacement sensors. The upper and lower parts are guided and positioned by four sets of guiding and positioning mechanisms, which include linear bearings and positioning shafts respectively disposed on the upper and lower parts.

6. The pre-matching method for welding automotive lamp covers and housings according to claim 1, characterized in that, The lateral telescopic mechanism realizes the lateral telescopic movement of the pre-matching mechanism through the drive screw and guide rail. The pre-matching mechanism is mounted on the guide rail, and the lead screw of the drive screw is connected to the lead screw nut on the pre-matching mechanism.

7. The pre-matching method for welding automotive lamp covers and housings according to claim 1, characterized in that, The adjustment of the distance between the upper and lower die clamps of the lower die propulsion mechanism adopts a five-degree-of-freedom iterative algorithm. Based on the value given by the technical requirements and the performance parameters of the welding equipment, the difference between the distance between the upper and lower die clamps and the penetration depth is solved, and the compensation value is calculated. The lower die propulsion mechanism then performs the compensation.

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