Method for improving dynamic balance mass of differential shell of passenger car

Abstract

The invention discloses a method for improving the dynamic balance quality of a differential shell of a passenger car. The method comprises the steps of 1, problem analysis and current situation evaluation; 2, carrying out structure optimization design; step 3, process subsidy adjustment; step 4, optimizing a production process; step 5, quality detection and feedback; step 6, mass production popularization and continuous improvement; according to the invention, the balance material is added on the flange surface, the balance material is subjected to addition and subtraction adjustment to balance the influence of gram weight, and the adverse influence caused by the fact that the diameter of the flange surface is large, the feeding distance is long and a solidification bottleneck is easily formed due to the deep groove is weakened, so that the gradient of the solidification sequence is established, the feeding channel is optimized, and the risk of shrinkage porosity is reduced; by adjusting the size and position of the process subsidy and increasing the reference point, the dynamic balance reference is controlled by the blank surface, the shrinkage porosity is ensured to meet the standard, the tolerance of dynamic balance after machining is met, and the method has the advantages that the wall thickness transition is reasonable, and castings can be solidified according to the sequence.

Description

Technical Field

[0001] The invention relates to the technical field of differential housings, and in particular to a method for improving the dynamic balance quality of a differential housing of a passenger car. Background Art

[0002] The differential case, which is usually connected to the drive shaft, is the outer shell of the differential and houses all moving parts, such as planetary gears, axle gears, etc. Its main functions include protecting the internal parts of the differential and preventing external impurities from entering the differential and causing damage to parts; maintaining ventilation to help dissipate heat inside the differential and keep its operating temperature within the normal range; and keeping the drive axis between the differential and the rear axle drive wheels unchanged to ensure smooth power transmission.

[0003] The existing differential housing has the following defects: First, there is a groove between the central column and the flange surface, which is easy to cause a bottleneck in the shrinkage channel; at the same time, there are pin holes in the parts, and the asymmetric processing affects the dynamic balance; second, although the increase in the diameter of the flange surface may help to improve the connection strength and stability, it also brings about the problem of increasing the distance of the shrinkage channel; the area far away from the riser is difficult to be effectively compensated, and shrinkage is very likely to occur, which not only reduces the mechanical properties of the parts, but also may cause serious consequences such as cracks and fractures; therefore, this design limits the selection and optimization space of the production process to a certain extent; third, the differential housing has the problem of uneven height and thickness distribution in structure; in particular, the middle part is relatively weak, and the position of the riser is often unable to directly compensate the central column below effectively; at the same time, since the riser cannot be directly placed in this area for shrinkage compensation, additional process subsidies are required to ensure that the shrinkage problem is controlled; however, this approach not only increases production costs and complexity, but may also cause problems with the consistency of machining reference positioning, thereby affecting the processing accuracy and assembly quality of parts. Summary of the invention

[0004] The object of the present invention is to provide a method for improving the dynamic balance quality of a differential housing of a passenger car, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a method for improving the dynamic balance quality of a differential housing of a passenger car, comprising step one, problem analysis and status evaluation; step two, structural optimization design; step three, process subsidy adjustment; step four, production process optimization; step five, quality inspection and feedback; step six, mass production promotion and continuous improvement;

[0006] In the above step 1, the design data of the differential housing is collected to evaluate the dynamic balancing quality, scrap rate and production efficiency of the existing products;

[0007] In the above step 2, the differential structure is optimized and designed;

[0008] In the above step 3, the size and position of the process subsidy are adjusted according to the mold flow simulation results, and reference points are added;

[0009] In the above step 4, the production process is optimized according to the optimized structural design;

[0010] In the above step 5, dynamic balancing test is performed on the trial-produced products to ensure that they meet the design requirements;

[0011] In the above step six, mass production is carried out according to the new process, and various indicators in the production process are continuously tracked.

[0012] As a further technical solution of the present invention, in step one, the design drawings, production process flow and quality inspection reports of existing passenger car differential housings are collected, the dynamic balancing quality, scrap rate and production efficiency of existing products are evaluated, and key factors affecting dynamic balancing are identified.

[0013] As a further technical solution of the present invention, in step one, the main objectives of improving the dynamic balancing quality of the differential housing are determined, including shortening the process development cycle, reducing production costs, reducing shrinkage risks, and improving product qualification rate.

[0014] As a further technical solution of the present invention, in the step 2, the mold flow simulation software is used to perform castability analysis on the differential housing to simulate the flow and solidification process of the molten metal. According to the principle of uniform wall thickness design, the wall thickness of the differential housing is adjusted to ensure that the molten metal can solidify in sequence and reduce the occurrence of shrinkage and shrinkage cavities.

[0015] As a further technical solution of the present invention, in the step 2, in order to solve the problem that the diameter of the flange surface is large and there is a groove between the center column and the flange surface, material is added on both sides of the flange surface to weaken the adverse effects caused by the long shrinkage feeding distance due to the large diameter of the flange surface and the solidification bottleneck easily formed due to the deep groove, thereby establishing a gradient of the solidification sequence, optimizing the shrinkage feeding channel, and reducing the risk of shrinkage. The influence of the dynamic balance weight is adjusted according to the addition and subtraction of the material added here.

[0016] As a further technical solution of the present invention, in the step three, the position and size of the process subsidy to be added are determined based on the mold flow simulation results. Through experiments and simulations, the size and position of the process subsidy are continuously optimized to ensure that both the shrinkage requirements can be met and the dynamic balance weight can be effectively controlled.

[0017] As a further technical solution of the present invention, in step three, reference points are added to the optimized structure to ensure that the dynamic balancing reference is controlled by the blank surface, so that the dynamic balancing reference is controlled by the blank surface, which ensures that the shrinkage meets the standard and the tolerance of the dynamic balance after machining.

[0018] As a further technical solution of the present invention, in the step four, a new production process flow is formulated according to the optimized structural design, including casting, machining and testing links, and the production operators are trained in the new process to ensure that they can master the new process and operating specifications, and small-batch trial production is carried out to verify the stability and feasibility of the new process.

[0019] As a further technical solution of the present invention, in step five, dynamic balancing test is performed on the trial-produced products to ensure that they meet the design requirements. Non-destructive testing methods are used to detect whether the products have shrinkage and shrinkage defects. Statistical analysis is performed on the test data to promptly discover and solve existing problems and further optimize the process.

[0020] As a further technical solution of the present invention, in step six, after confirming that the new process is stable and feasible, preparations for mass production are carried out, including equipment debugging and raw material procurement, mass production is carried out according to the new process, and various indicators in the production process are continuously tracked. According to the feedback and data in the mass production process, the production process and structural design are continuously optimized to improve product quality and production efficiency.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adds balancing material on the flange surface and adjusts the balancing material to achieve the effect of balancing gram weight, thereby weakening the adverse effects caused by the large diameter of the flange surface, the long shrinkage feeding distance and the easy formation of a solidification bottleneck due to the deep groove, thereby establishing a gradient of the solidification sequence, optimizing the shrinkage feeding channel, reducing the risk of shrinkage, adjusting the size and position of the process subsidy, and adding reference points, so that the dynamic balancing reference is controlled by the blank surface, which not only ensures that the shrinkage meets the standard and meets the tolerance of the dynamic balance after machining, but also has the advantages of reasonable wall thickness transition, which is conducive to the sequential solidification of the casting, thereby improving the castability of the casting, and after the product design is optimized, the requirements for the process and machining process are reduced and the strict requirements for dynamic balance are met, which is conducive to the mass production of castings, and the optimization of the process reduces the increase in product weight, improves the product qualification rate and reduces quality redundancy, thereby saving production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a flow chart of the method of the present invention;

[0023] Figure 2 This is a comparison diagram of the feeding channel before and after the improvement of the present invention;

[0024] Figure 3This is a comparison diagram of the heat section before and after the improvement of the present invention;

[0025] Figure 4 This is a comparison chart of shrinkage cavity results before and after improvement of the present invention. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Please refer to the attached Figure 1 -Attached Figure 4 The present invention provides an embodiment: a method for improving the dynamic balance quality of a differential housing of a passenger car, comprising step one, problem analysis and status evaluation; step two, structural optimization design; step three, process subsidy adjustment; step four, production process optimization; step five, quality inspection and feedback; step six, mass production promotion and continuous improvement;

[0028] In the above step 1, the design drawings, production process flow and quality inspection reports of the existing passenger car differential housing are collected, the dynamic balancing quality, scrap rate and production efficiency of the existing products are evaluated, the key factors affecting the dynamic balancing are identified, and the main goals of improving the dynamic balancing quality of the differential housing are determined, including shortening the process development cycle, reducing production costs, reducing shrinkage risks and improving product qualification rate;

[0029] In the above step 2, mold flow simulation software is used to perform castability analysis on the differential housing, simulate the flow and solidification process of molten metal, and adjust the wall thickness of the differential housing according to the principle of uniform wall thickness design to ensure that the molten metal can solidify in sequence and reduce the generation of shrinkage and shrinkage holes. In view of the problem that the flange surface has a large diameter and there is a groove between the central cylinder and the flange surface, by adding material on both sides of the flange surface, the adverse effects caused by the large diameter of the flange surface, the long shrinkage feeding distance and the easy formation of a solidification bottleneck due to the deep groove are weakened, thereby establishing a gradient of the solidification sequence, optimizing the shrinkage feeding channel, and reducing the risk of shrinkage. The influence of the dynamic balance weight is adjusted according to the addition and subtraction of the material added here;

[0030] In the above step 3, according to the mold flow simulation results, the position and size of the process subsidy to be added are determined. Through experiments and simulations, the size and position of the process subsidy are continuously optimized to ensure that both the shrinkage requirements can be met and the dynamic balance weight can be effectively controlled. Reference points are added to the optimized structure to ensure that the dynamic balance reference is controlled by the blank surface, so that the dynamic balance reference is controlled by the blank surface, which ensures that the shrinkage meets the standard and the tolerance of the dynamic balance after machining is met;

[0031] In the above step 4, according to the optimized structural design, a new production process is formulated, including casting, machining and testing, and new process training is conducted for production operators to ensure that they can master the new process and operating specifications, and small-batch trial production is carried out to verify the stability and feasibility of the new process;

[0032] In the above step 5, dynamic balancing test is performed on the trial-produced products to ensure that they meet the design requirements. Non-destructive testing methods are used to detect whether the products have shrinkage and shrinkage defects. Statistical analysis is performed on the test data to promptly discover and solve existing problems and further optimize the process.

[0033] In step six above, after confirming that the new process is stable and feasible, preparations for mass production are carried out, including equipment debugging and raw material procurement. Mass production is carried out according to the new process, and various indicators in the production process are continuously tracked. Based on the feedback and data in the mass production process, the production process and structural design are continuously optimized to improve product quality and production efficiency.

[0034] Based on the above, the advantages of the present invention are: the present invention realizes precise control of the balancing weight by adding balancing materials to the flange surface and accurately adding and subtracting these materials, effectively weakening the adverse effects of the long shrinkage compensation distance caused by the large diameter of the flange surface and the easy formation of a solidification bottleneck due to the deep groove. Through this method, a gradient of the solidification sequence is established, and the shrinkage compensation channel is optimized, thereby greatly reducing the risk of shrinkage. Secondly, the present invention has made detailed adjustments to the size and position of the process subsidy, and added reference points to ensure that the dynamic balancing reference can be accurately controlled by the blank surface, which not only meets the requirements of the shrinkage standard, but also ensures that the tolerance of the dynamic balance after machining is within an acceptable range. At the same time, through a reasonable wall thickness transition design, it is beneficial to the sequential solidification of the casting, further improving the castability of the casting. In addition, after the product design is optimized, the requirements for the process and machining process are The weight of the product is reduced significantly, and simpler and more efficient processes and machining methods can be used in the production process, thereby reducing production costs. At the same time, the optimized product design can still strictly meet the requirements for dynamic balancing, providing a strong guarantee for the mass production of castings. By accurately adjusting the balancing materials and process subsidies, the weight of the product is successfully reduced while ensuring product quality. This further improves the product qualification rate and reduces quality redundancy, which not only helps to improve the market competitiveness of the product, but also saves production costs for the enterprise and maximizes economic benefits. In summary, the implementation of the present invention brings many beneficial effects, including optimizing the shrinkage compensation channel, reducing the risk of shrinkage, improving dynamic balancing accuracy, reducing process and machining requirements, reducing product weight and saving production costs. These improvements not only improve the quality and reliability of the product, but also bring significant economic benefits and market competitiveness to the enterprise. Figure 2 Comparing the feeding channels before and after the improvement, a bottleneck appeared at the front edge of the riser neck before the improvement, resulting in the formation of an isolated liquid phase area on the casting, that is, shrinkage. After the improvement, the feeding channel is better, the riser can effectively feed the casting, making the riser the last to solidify, so the risk of shrinkage on the casting is greatly reduced. Figure 3 The heat node here can be compared before and after the improvement. Before the improvement, the heat node is larger, that is, it tends to form an isolated liquid phase area, which is difficult to be compensated for shrinkage; after the improvement, the heat node is eliminated, which is conducive to the formation of sequential solidification of the casting. Figure 4 The shrinkage results before and after the improvement can be compared. Before the improvement, the riser could not effectively compensate for the shrinkage of the casting, and the last solidified area of ​​the casting produced shrinkage. After the improvement, the riser became the last solidified area, and the casting was effectively compensated for shrinkage, that is, no shrinkage occurred.

[0035] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for improving the dynamic balance quality of a differential housing of a passenger car, comprising step 1, problem analysis and status evaluation; step 2, structural optimization design; step 3, process subsidy adjustment; step 4, production process optimization; step 5, quality inspection and feedback; step 6, mass production promotion and continuous improvement; characterized in that: In the above step 1, the design data of the differential housing is collected to evaluate the dynamic balancing quality, scrap rate and production efficiency of the existing products; In the above step 2, the differential structure is optimized and designed; In the above step 3, the size and position of the process subsidy are adjusted according to the mold flow simulation results, and reference points are added; In the above step 4, the production process is optimized according to the optimized structural design; In the above step 5, dynamic balancing test is performed on the trial-produced products to ensure that they meet the design requirements; In the above step six, mass production is carried out according to the new process, and various indicators in the production process are continuously tracked.

2. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 1, characterized in that: In the step 1, design drawings, production process flow and quality inspection reports of existing passenger car differential housings are collected, the dynamic balancing quality, scrap rate and production efficiency of existing products are evaluated, and key factors affecting dynamic balancing are identified.

3. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 2, characterized in that: In the step 1, the main objectives of improving the dynamic balancing quality of the differential housing are determined, including shortening the process development cycle, reducing production costs, reducing shrinkage risks, and improving product qualification rate.

4. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 1, characterized in that: In the step 2, mold flow simulation software is used to perform castability analysis on the differential housing to simulate the flow and solidification process of the molten metal. The wall thickness of the differential housing is adjusted according to the principle of uniform wall thickness design to ensure that the molten metal can solidify in sequence and reduce the generation of shrinkage and shrinkage cavities.

5. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 4, characterized in that: In the step 2, in order to solve the problem that the flange surface has a large diameter and there is a groove between the central column and the flange surface, material is added on both sides of the flange surface to weaken the adverse effects caused by the long shrinkage feeding distance due to the large diameter of the flange surface and the solidification bottleneck easily formed due to the deep groove, thereby establishing a gradient of the solidification sequence, optimizing the shrinkage feeding channel, and reducing the risk of shrinkage. The influence of the dynamic balance weight is adjusted according to the addition and subtraction of the material added here.

6. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 1, characterized in that: In the step three, the position and size of the process allowance to be added are determined based on the mold flow simulation results. Through experiments and simulations, the size and position of the process allowance are continuously optimized to ensure that both the shrinkage requirements can be met and the dynamic balance weight can be effectively controlled.

7. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 6, characterized in that: In the step three, reference points are added to the optimized structure to ensure that the dynamic balancing reference is controlled by the blank surface, so that the dynamic balancing reference is controlled by the blank surface, which ensures that the shrinkage meets the standard and meets the tolerance of the dynamic balance after machining.

8. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 1, characterized in that: In step 4, a new production process flow is formulated according to the optimized structural design, including casting, machining and testing links, and new process training is conducted for production operators to ensure that they can master the new process and operating specifications, and small-batch trial production is carried out to verify the stability and feasibility of the new process.

9. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 1, characterized in that: In step five, dynamic balancing tests are performed on trial-produced products to ensure that they meet design requirements. Nondestructive testing methods are used to detect whether the products have shrinkage and shrinkage defects. Statistical analysis is performed on the test data to promptly discover and resolve existing problems and further optimize the process.

10. The method for improving the dynamic balance quality of a differential case of a passenger car according to claim 1, characterized in that: In step six, after confirming that the new process is stable and feasible, preparations for mass production are carried out, including equipment debugging and raw material procurement. Mass production is carried out according to the new process, and various indicators in the production process are continuously tracked. Based on the feedback and data in the mass production process, the production process and structural design are continuously optimized to improve product quality and production efficiency.

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