In view of the fact that there are few pictures of the 6×6 drive of the new wheeled chariot family and the 8× 8 drive model named VN 1 infantry chariot, the author makes a simple analysis of the new 8× 8 drive wheeled chariot in China based on the public information and basic knowledge of vehicle engineering.
Contour design
Judging from the shape of VNl wheeled infantry fighting vehicle, its overall design style is basically the same as the newly developed 8〤8 wheeled fighting vehicle in the west: the power cabin and cockpit are juxtaposed in the front of the car body, the combat cabin is in the middle, and the passenger cabin is in the back of the car body. From the layout point of view, the car abandons the traditional design with the cockpit in front and the engine in the middle, and adopts a forward power design that can make full use of the head space of the car body, while ensuring that the side-by-side cockpit has a good forward perspective. The cockpit of the car adopts two seats in series, with the driver's seat in front and the conductor's seat behind. It should be noted that the layout of ground weapons with two seats in series in the cockpit has always been regarded as an oriental design, but it is actually a fallacy. Western wheeled armored transport vehicles adopt this layout everywhere, including Bison 8×8 armored transport vehicle produced by Canadian General Motors Defence Company (authorized by Piranha II of Swiss Movage Company) and 8×8 AMV wheeled infantry fighting vehicle developed by Patria Vehicle Company of Finland, a new European country. However, in view of the fact that most wheeled vehicles in the west are used to using double turrets, these vehicles move the captain's seat from the cockpit to the turret, resulting in a single cockpit design. With a single cockpit, the spacious space behind the driver can only be idle. Even the compact and highly utilized American "Strick" car family can only install engine air intake filters and turbo charging equipment in this space.
As far as the overall layout of vehicles is concerned, VNl wheeled infantry fighting vehicles conform to the current development trend of international ground weapons. From the vehicle appearance, VN 1 wheeled infantry fighting vehicle adopts box-type loading body. The front end of the car body is wedge-shaped, and the front lower armor plate inclines to the inside of the front wheel. The front upper floor inclines inward and upward, and is connected with the roof, which extends horizontally to the rear of the car. The two sides of the car body are vertical and straight, the upper part of the side line of the car body and the lower part of the wheel bin opening line are slightly inclined inward, and the rear part of the car body is almost vertical and straight, with a sloping lower hatch. From the information disclosed in various aspects at present, not all models of VNl sedan family adopt inclined tailgate, except infantry fighting vehicles, other models with the same chassis still adopt traditional single right tailgate. These subtle changes show that the designers of China's ground weapons have accepted the western concept, that is, to open the tailgate under the gangway board to shorten the time for infantry to enter and leave the passenger compartment. The external lines of the car body are closer to the square and soft of the western wheeled vehicles, which changes the rigid style of the traditional wheeled armored vehicles in China, and is beneficial to the integration of the internal space of the vehicle and the laying of additional armor outside the vehicle. The front breakwater of VNl wheeled infantry fighting vehicle is usually folded upwards and closed at the front end of the vehicle body. There is a large rectangular power cabin roof on the right rear of the front upper armor of the car body, and its rear edge is connected with the front edge of the rectangular radiator on the right side of the upper part of the car body. That is to say, as long as the bolts on this armor plate are opened and the radiator is hoisted to the upper right, the power system and transmission system can be hoisted as a whole, and the whole process may take less than a quarter of an hour in the hands of skilled maintenance personnel.
Discussion on equipment system and manufacturing
From the display of vehicle equipment, there is a small turret in the center of the top of VNl car body, and its appearance is basically the same as the new 30mm turret previously used to modify 86 tracked infantry fighting vehicles and 92 wheeled infantry fighting vehicles. It is not difficult to imagine that it should be one of the standard turrets for ground weapons in China in the future. However, it is worth noting that the design of the side of the car body has changed a lot compared with the traditional ground weapons in China: both sides of the VNl car body are relatively flat and smooth, the engine exhaust muffler and car air conditioner are embedded in the middle and rear part of the right side of the car body, and there are grille guards outside. There are two circular shooting holes in the left rear of the car body, and the same shooting hole appears in the upper part of the tailgate. Compared with the same type of old ground weapons in China, the number of shooting holes in the passenger compartment of this vehicle is very small, and even the shooting holes are simply cancelled on other models with the same chassis, which is also in line with the mainstream trend of the development of infantry fighting vehicles at present. There are propeller water propellers with protective covers on both sides of the rear of the car body, which shows that the design of ground weapons in China still takes the southern water network operation and sea crossing landing operation as important parameters.
"The engine of the new armored vehicle (6×6 drive) adopts an intercooled supercharged V-type water-cooled diesel engine with a power of 300 kW, which has the characteristics of small volume, light weight, low noise, high power and low fuel consumption". According to the author's understanding of the internal combustion engine industry, domestic enterprises that can produce high-speed on-board diesel engines above 300 kW are Weichai Power, Heavy Duty Truck Jidong, Heavy Duty Truck Hangfa, Dongfeng Cummins, Chongqing Cummins, Xi 'an Ankang Cummins, Shaanxi Weiyang, FAW Dachai, FAW Xichai, Yuchai Group, Shangchai Co., Ltd. and Hebei Huachai, among which the diesel engines produced by enterprises are mostly in-line cylinders, and only those produced by Hebei Huachai. It can be seen from its official website that among the three series of products such as BFM413BFM513 ~ DBFML015, the first two are air-cooled engines, and the latter belongs to water-cooled engines. Coincidentally, according to the data published by the company, the rated "vehicle power" of BF6M 10 1 5C/MV diesel engine is completely consistent with the publicly reported data. Considering that Hebei Huachai is a subsidiary of China Ordnance Industry Corporation-Tuangong Company, it is normal for VNl wheeled infantry fighting vehicles to adopt BF6M 10 15C/MV diesel engines as standard configuration. However, the VN 1 wheeled infantry fighting vehicle driven by 8〤8 requires high power, so it is not excluded to use the engine of VN10/5 series eight-cylinder BF8M 10 15 diesel engine.
Then, what is the technical level of BF6M 10 15 diesel engine? According to the information from official website, BF6M 10 1 5 diesel engine was produced by the Military Industry Group and Hebei Huachai with the technology of Deutz10/5 diesel engine imported from Germany according to the license. The latter is a new generation diesel engine developed by Deutz AG in 1990s, including American Caterpillar C series (in which C9 is equipped with a variety of new wheeled vehicles), Detroit DDC60 series, German Benz OM500/900 series (equivalent to MTU880), MAN D2800 series, Swedish Volvo D 12D series (equipped with French VBCI infantry fighting vehicles). At present, Deutz 10 15 series diesel engines have been selected as standard configuration by the military off, but compared with the above mainstream diesel engines, BF6m10/0/5 diesel engines still have some defects such as insufficient unit power. Even the latest model of BF6M 10 15 diesel engine-BF10/5cp/mv, is only at the international level in the mid-1990s, and its maximum power and displacement of 330 kW is the same as that of Scania DI/kloc-0 with 12 liter. Based on the MTU⑧90 series high-density power diesel engines used in "Boxer" wheeled armored transport vehicle jointly developed by Germany and Holland, the future development direction of on-board diesel engines is listed. Needless to say, VNl wheeled infantry fighting vehicle adopts BF6M 10 15C/MV diesel engine, which is at the second-rate level among international ground weapon engines.
Although it has been 30 years since the reform and opening up, there are still serious problems in the field of machinery industry, such as the compartmentalization of military industry and local government, the lack of national and national overall planning strategy, breaking down barriers and establishing independent intellectual property alliances. In foreign cooperation, we still rely on imported technology to maintain the advanced nature of our products, and the technology we introduce is often eliminated or ready to be eliminated by others. In fact, even if the imported products are produced by others, the technology is often deliberately short of weight by foreign countries, not to mention the difference between military and civilian diesel engines abroad. Take Huachai BF6M 10 15 as an example. According to its technical level, it is a leader among domestic diesel engines, and the gap is not too big compared with the current international civil vehicle engines. However, some data show that the maximum power of BF6M 10 15 produced in Germany has reached more than N400 kW, which is more than 30% higher than that of domestic models. This gap is precisely foreign internal combustion engines. We should see that at present, while the international internal combustion engine industry is "combining military and civilian" and "combining military and civilian", the trend of "supporting the army with the people and feeding the people with the army" is becoming more and more obvious. More importantly, the industrial alliance between foreign diesel engine manufacturers and power enterprises is getting closer and closer, including technical cooperation between Renault-Volvo, Man-Benz and MTU. DDC, especially the alliance of the latter, promoted the birth of high-power diesel engines and monopolized most technical patents of the next generation diesel engines. On the other hand, in China's diesel engine industry, not only the methods and technical standards of the military industry and local governments are different, but also local diesel engine enterprises are caught in pure vicious competition, and cooperation between them is out of the question. In this sense, China's on-board diesel engine industry is too big but not strong to support the future development of China's wheeled vehicles. It's time for us to feel the pain and calm down and think about it. Only from the strategic height of national and domestic security and the joint efforts of the whole internal combustion engine industry can the military and civil diesel engines on board go hand in hand.
According to public reports, VNl wheeled infantry fighting vehicle adopts mechanical transmission with synchronizer shift and H-type transmission system. So, what kind of transmission system is this? At present, the transmissions used in international wheeled ground weapons can be roughly divided into three categories: manual transmission, automatic transmission and mechanical automatic transmission.
Manual mechanical transmission (MT), also known as manual transmission, mainly realizes the meshing of different gears through the driver's manual control system, so as to achieve the purpose of speed change and torque change. Because the number of teeth in each gear set is fixed, the speed ratio of each gear is also fixed. The rotational speeds of the input shaft and the output shaft of the transmission are not naturally matched, and there is a problem that the rotational speeds of the input shaft and the output shaft are not synchronized when shifting gears. Two gears with different rotational speeds are forced to mesh, which will inevitably lead to impact and damage to the gears. Therefore, the shift of the old transmission should adopt the way of "two-foot clutch", the upshift should stop in neutral position for one minute, and the downshift should be in neutral position to reduce the speed difference of the gear. However, this operation is complicated and difficult to master accurately, so the designer created a "synchronizer", through which the gears to be engaged can reach a consistent speed and mesh smoothly. Based on the above principles, we can judge that the transmission used by VNl infantry fighting vehicles should be of this type. Vehicles using this kind of transmission device often require higher driver's control technology, but it is still adopted by large wheeled ground weapons in many developing countries because of its low cost, simple structure, durability and strong maintainability.
Automatic transmission (AT), also known as automatic transmission. It is beneficial to use the speed and load (the stroke of the accelerator pedal) to carry out two-parameter numerical control, and the gear automatically rises and falls according to the above two parameters to realize the purpose of changing speed and torque. When land-wheeled weapons are developed in countries and regions lacking in on-board technology, even if high-performance engines and automatic transmissions are used, there are always various technical obstacles that are difficult to eliminate, which will reduce the reliability of vehicles because of the insufficient integration ability of on-board data bus (CAN) circuits for on-board sensor control and control signals. In terms of technical development, European and American ground weapons suppliers have mastered the core intellectual property rights of electronic control and control technology of power transmission system, and with their rich experience in vehicle manufacturing, they often adopt automatic transmission as the standard configuration. For example, AMV in Finland, VBCI in France, GTKf in Germany and Piranha IV in Switzerland all adopt ECOMAT series automatic transmission of ZF company in Germany.
Automatic mechanical transmission (AMT), also known as electronically controlled mechanical transmission, is a modification based on the original mechanical transmission, mainly changing the manual shift control part, that is, adding an automatic control system controlled by a microcomputer under the condition that the overall structure of the transmission remains unchanged, so as to realize shift automation. So AMT is actually a robot system to complete the clutch operation and gear selection. Its core technology is microcomputer control, and electronic technology and quality will directly determine the performance and operation quality of AMT. Compared with automatic transmission, the initial mechanical automatic transmission has less technical difficulty in overall design and manufacturing process. At present, China has made some progress in the research and development of heavy-duty mechanical automatic transmission, and it is believed that in the near future, China's new combat vehicles will also realize automatic operation.
According to public reports, VNl wheeled infantry fighting vehicle adopts H-type transmission system. Compared with the I-type transmission, the H-type transmission reduces the space occupied in the vertical direction, thus reducing the overall height of the vehicle and increasing the available space in the middle and rear parts of the vehicle. Power is transmitted from the gearbox to the mechanical transfer case through the first transmission shaft, and then to the secondary differential in the second axle through the central differential in the transfer case. The secondary differential divides the power into two paths, one path is forward, the other differential in the second bridge transmits the power to the reducers of the second and first bridges, and the other path is backward, and then it is transmitted to the reducers of the third and fourth bridges through the differential in the third bridge. Each bridge slows down and then passes through the half shaft. H-type transmission structure has been used in the "Centauri" series wheeled armored vehicles produced by Italian Iveco Fiat Company and Otto Melella Company, and the technology is mature. However, this kind of transmission device has higher requirements on the manufacturing process of vehicle transmission parts and more procurement costs. More importantly, if any axle of the vehicle adopts this transmission mode is damaged, it will lead to the loss of vehicle maneuverability, so it is not the mainstream design of large wheeled ground weapons at present.