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Driving safer with automatic brake gap adjustment arm explained
● What is an automatic brake adjuster arm? The automatic brake adjuster arm, or 'auto adjuster arm' for short, as the name suggests, is a device that can adjust the brake clearance in real time automatically, ensuring the brake clearance stays at a proper value, making the brakes timely and reliable, which is very beneficial for driving safety. It's worth noting that the use of the auto adjuster arm is limited to drum brake systems. Also, vehicles equipped with ABS cannot guarantee optimal performance without an auto adjuster arm, because manually adjusting can lead to variations in the lever arm and braking force of individual brake calipers.
2014年汉诺威车展上隆中控股展出的自动调整臂产品
Currently, the manually adjusted brake clearance arm, which is widely used in the domestic market, has certain drawbacks. First, manual adjustment has a certain cycle. Towards the end of this cycle, before the next brake clearance adjustment, the brake clearance has already reached a relatively large value, which may result in longer braking travel, insufficient braking response, and in severe cases, weakened braking force, posing safety risks. Second, manual adjustment makes it difficult to ensure high consistency of clearance among all wheels, which may lead to wheel misalignment and vehicle fishtailing. In Europe and America, heavy trucks, buses, and trailer manufacturers have made automatic brake clearance adjustment arms a standard part for drum brakes. In China, they are commonly used on buses, but the matching rate on trucks is very low, less than ten percent. Overseas brands are mainly Hande, taking up most of the overseas market, while in the domestic market, there are many brands; the one with a larger market share is Longzhong, and other brands we know of include Hengxin, Shenyu, Anjie, and Tiege Men.
We also conducted a phone interview with Yang Liying, General Manager of the Sales Centre at Longzhong Holdings Group, about the issue of automatic brake adjustment arms. According to Yang, by the end of last year, Longzhong Holdings' automatic adjustment arms had a 55% share in the domestic bus market and 42% in the truck market; this year, the production of Longzhong automatic adjustment arms reached 580,000 units, and it is expected that by the end of this year, the market share in trucks will exceed 50%.
According to an industry insider, most customers for automatic adjustment arms currently come from bus manufacturers, with truck users being a minority, and some coming from a small number of logistics fleets.
● Why hasn’t the automatic adjustment arm become widespread in China?
First, manual adjustment arms are cheaper. Switching to automatic adjustment arms increases the cost per drum brake axle by 200-300 yuan.
装有自动调整臂的五十铃
Currently, the price of manual adjustment arms on the market is around 50 yuan, while domestic automatic adjustment arms are about 150 yuan, with the more expensive ones possibly reaching 200 yuan. Imported Hande automatic adjustment arms are around 260 yuan. It can be seen that there is a significant price difference between automatic and manual adjustment arms, and since a vehicle uses multiple adjustment arms, the price gap is multiplied, making it understandable that users may find it hard to accept. Second, national policy does not require trucks to be mandatorily fitted with automatic adjustment arms. In the current national standards, only drum brakes on passenger vehicles are required to have automatic adjustment arms, and there are no mandatory measures for trucks yet. Third, people's awareness of safety is not deep enough; driving safety is the greatest benefit, and the losses caused by accidents cannot be measured against the cost increase brought by automatic adjustment arms.
装于457车桥上的自动调整臂
Fourth, users lack proper understanding of the automatic adjustment arm. Some users experience poor compatibility after using it, and coupled with the high cost, it’s easy for them to return to choosing manual adjustment arms. I also learned from forums that some maintenance workers are not familiar with automatic adjustment arms and have damaged them, which has led to many maintenance workers being hesitant to handle them, seriously hindering the promotion of automatic adjustment arms. The new national standard means automatic adjustment arms will become standard. The national standard GB 12676-2014, released on October 10 this year, clearly requires that road transport vehicles with a vehicle-equipped weight over 3.5 tonnes must be equipped with automatic brake clearance adjustment arms. This standard will be implemented from 1 July 2015, and by then automatic adjustment arms will be standard equipment on road freight vehicles over 3.5 tonnes. This national standard will greatly promote the popularisation and development of automatic adjustment arms in China, contributing significantly to the improvement of the safety of our road transport. Note from the editor: The mandatory implementation of the national standard is just a strong push; what matters more is improving people's awareness of safety, so that automatic adjustment arms can be more widely known and accepted. With the release of the national mandatory standard, automatic adjustment arms are expected to see a surge in the Chinese truck sector, with a very broad market outlook. For more information on automatic adjustment arms, please follow Truck Home’s follow-up articles.
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