Introduction to the production and application of domestic air impact molding line
in December 1997, jyb124 air impact compaction molding was installed and put into production in the second foundry company of Dongfeng Industrial Company. The automatic line is designed by Luoyang fourth Design Institute of the Ministry of machinery and manufactured by Suzhou foundry machinery factory. We can find that there are different structural casting automatic lines in the pressure testing machine. After more than four years of production and operation, it has high reliability and low failure rate. It is produced in two shifts a day. At present, the daily output has exceeded 800 boxes
main parameters of molding line
inner cavity size of sand box 1050 × seven hundred × 300/300mm
Design beat 120 boxes/hour
number of circulating sand boxes/trolleys 136 pairs/145 knots
total power of the whole line 362.95kw
annual output and actual shift output statistics (2002 is the planned output) are shown in the following table: annual output level trend chart
annual actual maximum daily output level trend chart
in 1998, as the automatic line was just completed and put into operation, there were not enough products for its production, and the supporting facilities of the automatic line were only to open up the process joints, It is not prepared according to the capacity of the automatic line. For example, molten iron is only produced in a 5T electric arc furnace, sand treatment and other facilities are not prepared in place, and the production process is basically intermittent
since 1999 and 2000, through continuous development of new products, and the launch of Dongfeng heavy vehicle market in 2001, the casting output of the new double rear axle balanced suspension system we developed and matched has continued to rise. We have strengthened the construction of the supporting facilities of the automatic line and taken a series of management measures to give full play to the asset advantages of the automatic line and improve the operation efficiency and starting rate of the automatic line. For example, a forklift is used to transport the molten iron of the 3T frequency furnace in the old base to the line, and a 3T electric arc furnace is added in the second half of the year, so that the shift production of the automatic line can reach 3000 boxes. In March 2002, we added a 3T electric arc furnace according to the relevant data, and the shift production is expected to reach 450 boxes, At the same time, the shutdown risk of the automatic line should be prevented, the reserve of spare parts and the allocation of personnel should be increased, and the shutdown failure of the automatic line should be minimized. The annual output of castings is expected to exceed 12000t. Basically achieve the expected capacity of the design
the castings produced by this production line are mainly chassis blanks supporting automobiles. There are nearly 100 kinds of castings, such as flywheel of Cummins engine, flywheel housing, balance shaft support and balance bearing hub of double rear axle heavy-duty vehicles. The weight ranges from 1kg to 60kg. More than 90% are ductile iron castings, with grades of qt/, QT, QT, and a small number of gray iron castings, with grades of HT200, TH250, etc. Its products are mainly produced by Dongfeng Automobile Co., Ltd. and it has also produced eight kinds of nodular cast iron parts such as heavy-duty vehicle brakes for the auto parts group of Asia Investment Corporation. Its products are exported to the United States
features of the automatic line equipment
utilization in concrete 1. Jyb124 air impact molding line adopts double host molding, and the air impact pressure is controlled at 0 60MPa, the mold plate adopts a duplex rotary machine, which is convenient and fast to switch. The sand mold produced has a smooth appearance and uniform hardness, forming a rough surface and stable size of the casting. Weight deviation and casting defects are at a good level
2. Some key components used in the automatic line should be compared with the characteristics of the sample as far as possible and through the superposition of curves. Imported components with high reliability or components produced by domestic imported technology should be selected, such as oil cylinders and proportional valves used in hydraulic systems
3. The whole line is controlled by computer, which can set machine parameters and process parameters, monitor the operation of the whole line, and have the functions of fault analysis, display, statistics, printing, etc
in the past four years, the automatic line has generally operated well, but there are also many problems such as small failures, which are mainly reflected in the following aspects:
1. The unreasonable design of the box hook of the sand box causes the box hook to fall off frequently, resulting in equipment downtime in the production process, sand box fire escape, pouring and lifting, large amount of repeated maintenance and other problems, and the damage rate of the box hook and sand box pin is high. Recently, we have further improved the sand box and box hook to alleviate this prominent contradiction
2. the failure rate of the machine and sub box is also high. In the original design, the gear shaft is easy to bend when driven by impact, resulting in more equipment shutdown failures. We have improved it by adding two gears to avoid direct impact, and the failure rate is greatly reduced
3. The main reason for the high failure rate of the double box turnover machine is that the shaft is easy to fall out of the bearing cover due to the influence of axial force during the driving process of the driving axle of the box turnover machine, causing bending or fracture at the journal, etc. through further improvement of the shaft, the failure rate here is greatly reduced
4. there is a dead angle in the rotation of the main machine plate transposition rotating mechanism, which cannot be overcome in design. In addition, when the spindle sleeve of the rotating mechanism is damaged and worn and needs to be replaced, it is difficult to disassemble and assemble. (end)
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