when the front bumper is removed, we can see a piece of black foam. The main function of this foam is to reduce the damage of collision to pedestrians. Take this foam away and you can see the anti-collision steel beam.
whether it is a front anti-collision steel beam or a rear anti-collision steel beam, their most important function is to deal with low-speed collisions. In other words, the role of this steel beam is to "sacrifice" itself to protect the more expensive parts in the engine compartment or the body frame that is not easy to replace, thus reducing the maintenance cost. Therefore, the anti-collision steel beam itself has little to do with the safety of a car in high-speed collision.
The front anti-collision steel beam of Tiguan L is made of steel, and the middle part is spot welded with double-layer stamped steel plates, with a thickness of 3.5mm, and the edge is single-layer steel plates with a thickness of 2.4mm.. The reason why the double-layer welding process is adopted is to optimize the cross-section design of the front anti-collision beam and improve the strength under the premise of reasonable cost control. The technology of rear anti-collision steel beam is relatively simple, with a single-layer stamping structure and a thickness of 1.6 mm.
in terms of coverage, the coverage of the front anti-collision steel beam of Tiguan L is 63.8%, which is relatively average. Compared with the overseas version of Tiguan's BIW, the domestic Tiguan L obviously has a lower coverage rate, which is considered as a reduced distribution part.
Compared with the front anti-collision steel beam, the coverage rate of the rear anti-collision steel beam is higher, reaching 67%. However, due to its thickness of 1.6 mm, it may be difficult to ensure that the body frame is not damaged in a relatively fast rear-end collision.
while observing the rear anti-collision steel beam, we also found a detail. When the energy-absorbing box of Tiguan L rear anti-collision steel beam was installed on the frame, one bolt was missing, four on the right side and only three on the left side. As for the reason, it should not be that the domestic version of Jane saves costs, because the purchase price of this bolt is really not much money, and through consulting the information, we found that the overseas version of Tiguan does not.
after on-site analysis and communication with experts, we guess that this bolt may not be installed because of the process. If the external exhaust is installed before the rear anti-collision steel beam is installed, the bolt will interfere with it during installation, and forced installation will waste time and affect the efficiency of the whole assembly line. Therefore, in the end, we think that the original intention of the missing bolt is not because of the reduction.
after removing the rear bumper, we found a small device, a one-way ventilation grille. The scientific name of this device is the exhaust ventilation device in the passenger area. Its main function is to exhaust the relatively high-pressure air in the car at the moment when the door is closed, so as to avoid the discomfort of the passenger's eardrum caused by the rapid change of the air pressure in the car.
The front and rear taillights of Volkswagen Tiguan L are all from Shanghai otaru, and this brand may not know too many friends. Xiao Ben is a Japanese brand, whose main business is to produce all kinds of car lamps.
compared with Haila, which is familiar to everyone, the products of Xiaocan are relatively low-end, but the quality is still good. In the global automotive lighting suppliers, it is also the top three level. As for Shanghai Bun, it is the abbreviation of Bun's joint venture company in China. Although the lamps are made in China, the quality should be no problem. Therefore, in terms of headlights, Tiguan L is still kind.
The protection of the chassis is also a concern of many consumers. After we raise Tiguan L, we can see that the chassis of Tiguan L is basically covered with resin fender. At the bottom of the three-way catalyst with relatively high working temperature, there is also a metal guard to assist heat dissipation. In addition, local PVC spraying is also done in the first half of the chassis as a double protection. Therefore, in terms of chassis anti-corrosion and chassis flatness, Tiguan L is not a big problem.
After the Tiguan L is lifted, the chassis structure of this car may be clearly seen. Several important components of the suspension, such as the lower swing arm, the upper and lower support arms, the half shaft and so on, are all made of steel, and only the steering knuckle of the front wheel and the bearing seat of the rear wheel are made of aluminum alloy.
why should we care about the material of suspension components? First of all, the first reason is that chassis components need strong anti-corrosion performance. In this respect, aluminum alloy is much better than steel. Although steel can solve the problem of corrosion to a certain extent by painting, these components of the chassis are very vulnerable to stone impact in daily driving, and once the paint surface of steel is damaged, it is easy to rust. The second reason is that many components of the chassis belong to the statistical category of unsprung weight. Under the same conditions, the smaller the unsprung weight, the better the performance of a car in terms of fuel consumption, power and handling. Aluminum alloy material can be made lighter on the premise of ensuring strength, and the better the optimization of unsprung weight. But unfortunately, the cost of aluminum alloy parts is slightly higher, and Tiguan L, which strictly controls the cost, does not use too many aluminum alloy parts on the chassis.
The sub-frames of p>MQB platform are all non-full-frame sub-frames, which are also commonly known as ingot beams. Compared with the full-frame subframe, the ingot beam is lighter and cheaper, but compared with the full-frame subframe, the energy absorption effect is not good enough in case of collision.
The penetration rate of laser welding on the body of Tiguan L is still quite high. In addition to the well-known roof, the door frame is also laser welded.
A careful friend should see several spot welding marks on the door frame. There is no need to think too much about this, just to press and position the two parts for laser welding.
In addition, the anti-rust technology of wax injection into the cavity has not fallen, and the overflowing wax can be seen everywhere around the chassis longitudinal beam, so the anti-rust treatment of the longitudinal beam has not shrunk significantly.
You can see this whole piece of "black heart" soundproof cotton when you lift the carpet. Judging from the impression of this cotton, it is really not very good. After careful observation, it can be seen that this should be what everyone calls recycled cotton. However, we also looked at the sound insulation cotton in other parts of the car body, all of which are white.
Does recycled cotton have more pollutants than white soundproof cotton? This is difficult for us to judge, so after sampling, we hand it over to an authoritative testing agency for testing. As of press time, the report on pollutant detection has not yet come out, so we will talk about it in the third issue, and please continue to pay attention.
when disassembling the interior, we found the package of the large line in Tiguan L's car very interesting. The wiring harness at the right front door is still tightly wrapped, but the wiring harness at the back door and the left front door is very sparse, and the protection of the wiring harness is not in place.
After disassembling the door of Tiguan L, we can see that the door of Tiguan L is formed by integral stamping, which can be praised, but the vibration stop plate of the door panel contains a certain amount of asphalt, which is not very environmentally friendly.
In the evaluation, Tiguan L performed well in the noise test. But unexpectedly, after dismantling, we found that there was no soundproof cotton in the door of this car, which still surprised us a little. It can also be seen from this detail that the NVH performance of a car may not necessarily be directly proportional to the amount of sound insulation cotton, and many optimizations for NVH are targeted. For example, when we remove the rear bumper, we can see that a circle of sound-proof cotton is attached to the rear wheel arch. For a brand with extremely strict cost control such as Volkswagen, sound insulation cotton is used in that seemingly unimportant part. Obviously, the vibration or noise generated in this part has a great influence on the NVH of the whole vehicle.
So, friends who plan to buy a car, if you are particularly concerned about the NVH performance of a car, you must choose a car that is quiet when you choose a car. It is not particularly safe to expect to install sound insulation cotton later.
it's not hard to find that the tiguan l car, at first glance, is excellent in all aspects. The workmanship is neat and the seams are even, but it is really not forbidden to dismantle. A car of about 2, yuan, basically all the details of materials and design all point to cost saving. At present, it can be praised that most of the interior decorative panels are made of sound insulation cotton and cavity wax injection laser welding. There are several aspects that can be spit out. For example, the coverage of the front anti-collision steel beam is lower than that of the overseas version, and the pedestrian protection measures are not as comprehensive as those of the imported version. All components of chassis suspension are basically made of steel, which is not excellent in corrosion protection and weight reduction. In detail, the wrapping of wire harness, the lack of sound insulation cotton for doors and the less environmentally friendly vibration-proof sound insulation materials are all places that need to be optimized and improved in the future. In short, with reference to the pricing of Tiguan L, many of the problems mentioned above can be done better in themselves, but they are limited by strict cost control and have not reached the extreme. Then, we will further break up Tiguan L, take a look at the white body of Tiguan L, and analyze why Tiguan L "overturned" in the 25% offset collision. In addition, Volkswagen, which everyone is very concerned about, still burns engine oil. The problem that DSG is unreliable today will be analyzed in the next issue, so please look forward to the next issue of "Knowing the Big Bang".