[Introduction: Recently, Tesla issued a recall for its best-selling SUV Model Y. Although the cause of this recall is the so-called "broken axis" problem that can most arouse the nerves of the Chinese people, its impact is not large. However, unlike other OEMs with the same type of recall, this time the related parts company Tuopu was pushed to the forefront, which also made Tesla once again become the focus of media discussion. 】
Written| by Zhang Dachuan and editor | Hezi
On December 3, the State Administration for Market Regulation announced that Tesla will recall some domestically produced Model Y electric vehicles from February 4, 2021 to October 30, 2021, totaling about 21,599 units. Some vehicles within the scope of this recall, the strength of the front and rear steering knuckles may not meet the design requirements, the knuckles may be deformed or broken during the use of the vehicle, and the suspension linkage may be detached from the knuckle under extreme stress conditions, affecting the driving control of the vehicle, increasing the risk of collision accidents, and there are safety hazards.
Recall cause analysis
In addition to the relevant information released by the State Administration of Market Regulation, Tesla also supplemented the reasons for the recall, that is, its steering knuckle supplier Ningbo Tuopu did not use enough quenching fluid to fully quench the parts in the process of producing the knuckles, resulting in the strength of the relevant parts not reaching the predetermined design strength. This is also believed to be the root cause of Tesla's multiple suspension failures.
In this regard, Tuopu Group, another protagonist of this recall, also issued an official announcement immediately after the relevant recall report. It first limited the relevant scope to a Model Y model, and explained that the reason for the relevant defects was that the quenching tank water level was insufficient in a heat treatment production line, so that individual products were not completely immersed in the quenching fluid, resulting in the strength of the steering knuckle may not meet the design requirements. Most critically, Tuopu Group emphasized that the probability of defects in the batch of suspicious products was estimated to be about 0.2%-1.0%. In other words, although the number of recalls is quite large, there are not many models that actually need to be replaced for the steering knuckle. To this end, Tuopu has sent relevant testing equipment to Tesla's stores to identify which steering knuckles need to be replaced and which do not. This also ensures that the relevant operating indicators of Tuopu Group will not be affected.
Why are the steering knuckles the hardest hit area?
The problem of broken shafts, in fact, many OEMs have encountered. At present, car lightweight is a trend, and the weight reduction of the whole vehicle is often calculated in grams. Chassis components, especially steering knuckles, as a large contributor to weight, are naturally one of the main targets for weight reduction. At present, the main calculation basis for weight reduction must be simulation calculation and durability test under various working conditions of the vehicle, which is more important for the accumulation of experience of the main engine plant. Once the definition of the relevant indicators is too loose, although the weight reduction goal can be completed, it is difficult to guarantee whether the customer will break the shaft during the driving process in the later stage. The pursuit of extreme design parameters, leaving a small deviation for manufacturing redundancy. Therefore, the lack of water level in the quenching tank in the manufacturing process will directly lead to the lack of strength of Tesla's steering knuckle.
Therefore, for the main engine factory, the future will inevitably need to take a conservative route in the design of the steering knuckle. Every driver has their own driving habits, and different areas have different road conditions. If the design pursues the ultimate lightweight, then the design redundancy in the face of various working conditions is very worrying. In the event of a disconnected shaft, the negative impact is far greater than the increase in range or fuel economy that is actually of relatively limited significance.
The main engine factory is the first responsible person for the relevant recall accident
In fact, according to the statements of all parties, before this recall, there was no particularly vicious consequence, or simply from the perspective of the number of cases involved, the absolute number is not large, and there will be no obvious impact on the operating performance of Tesla and Tuopu. After all, after the establishment of the active recall system in China, almost all brands have not been spared, and there will be more or less related cases. However, unlike most OEMs who choose to act in a low-key manner, this time Tesla took the initiative to push the steering knuckle supplier to the front desk and put all the responsibility on this manufacturer, which is very different from the practices of other OEMs.
The car is a whole composed of tens of thousands of parts, and any problem with any one part may lead to problems in the performance of the whole vehicle. Therefore, an important task of the main engine factory is to control the quality of each sub-part. So Tesla is the first responsible person for the customer's vehicle. Even if the parts supplier has such and such problems, Tesla must also shoulder the relevant responsibilities. As for Tesla's claim against Tuopu, it can be based on the agreement signed by the two parties before, whether it is from the actual costs incurred in this recall or from the damage to Tesla's reputation.
Comments
Taking a step back ten thousand steps, even if there is a problem with the supplier's own quality management, is the main engine factory not responsible? The answer is no. For Tesla's customers, they buy cars with Tesla logos on them, not Tuopu cars. Tesla put Tuopu on the front line, hoping to ease public doubts about it, which is understandable. However, tesla in the launch of Tuopu at the same time, but also need to deeply review themselves, whether it needs to strengthen the quality control of suppliers. Even from the design point of view, if you improve design redundancy to avoid defects in the production process may lead to the relevant parameters can not meet the design indicators. This is what Tesla, as a responsible OEMs, really needs to think about.
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