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本科毕业设计(论文)
外文翻译
译文题目: 使用智能液压缸增加起重机的稳定性 学 院: 机电学院 专 业: 机械设计制造及其自动化 学生姓名: XXX 学 号: 1234567890 指导教师: XXX 完成时间: 2017年3月12日
From:Hitchcox, Alan. Smart cylinders stabilize cranes[J]. Hydraulics & Pneumatics; Cleveland (Sep 12, 2013): n/a.
Smart cylinders stabilize cranes
Hitchcox, Alan.
ASM International, Penton Media, OTP Industrial Solutions
(formerly Ohio Transmission & Pump Co)
Abstract:It's not unusual for cranes to reach 100 ft or more into the air at major construction sites. Traditionally, cranes are transported to a work area and assembled on-site. More recently, as truck-mounted cranes become bigger and more powerful, they have found favor because they are quicker to set up than traditional cranes. Truck-mounted cranes have a telescoping hydraulic boom mounted on commercial truck chassis. Their portability and lower setup costs have led to their widespread use at construction and utility sites around the world. But as loads get heavier and lifting distances become higher, designers of truck-mounted cranes must provide the stability to ensure that safety remains the top priority.
Truck-mounted cranes use outrigger systems to ensure stable operation. The outriggers extend from the main body of the truck and contact the ground several feet away from the truck. This distributes the crane's load over a much larger area, thereby increasing stability. Manitowoc Company Inc., Manitowoc, Wis., takes this a step further by using smart cylinders in the A-frame outrigger systems of its National Crane line of truck-mounted cranes. The crane's hydraulic system is driven from a power takeoff on the truck's transmission. The crane operator then runs all crane functions through a series of lever-operated valves at a control station.
The ELA is an externally mounted LDT that uses Hall-effect technology to sense the location of a magnet embedded in the cylinder's piston through the cylinder's carbon steel barrel. A microprocessor then assigns an analog voltage to the magnet's corresponding absolute position. For example, when the cylinder is fully retracted; the voltage may be 0.55 V. As the cylinder extends, the voltage gradually increases until 4.5 V is reached at full extension.
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Accuracy of the transducer is typically +-0.5 mm (0.02 in.) - more than adequate for most mobile equipment. That position is then sent to the ECM and compared to the known maximum horizontal extension. After this, an indication is given to the operator about the outrigger state. The position update happens within milliseconds.
Full Text
It's not unusual for cranes to reach 100 ft or more into the air at major construction sites. Traditionally, cranes are transported to a work area and assembled on-site. More recently, as truck-mounted cranes become bigger and more powerful, they have found favor because they are quicker to set up than traditional cranes. Truck-mounted cranes have a telescoping hydraulic boom mounted on commercial truck chassis. Their portability and lower setup costs have led to their widespread use at construction and utility sites around the world. But as loads get heavier and lifting distances become higher, designers of truck-mounted cranes must provide the stability to ensure that safety remains the top priority.
Truck-mounted cranes use outrigger systems to ensure stable operation. The outriggers extend from the main body of the truck and contact the ground several feet away from the truck. This distributes the crane's load over a much larger area, thereby increasing stability. Manitowoc Company Inc., Manitowoc, Wis., takes this a step further by using smart cylinders in the A-frame outrigger systems of its National Crane line of truck-mounted cranes. The crane's hydraulic system is driven from a power takeoff on the truck's transmission. The crane operator then runs all crane functions through a series of lever-operated valves at a control station.
An important function for lifting, moving, and lowering heavy loads is to ensure that outrigger beams are properly positioned. The outriggers are attached to the truck frame and are extended downward by hydraulic cylinders at an angle to create an A-frame structure that is wider at its base than at the top. This provides a stable framework to level and support the loaded and extended crane.
Adding smarts to outriggers
For the past several years, National Crane has added outrigger-monitoring systems (OMSs) to its cranes. With the OMS, operators monitor the horizontal extension of the crane's outriggers at a control station. The OMS used with A-frame model cranes includes an ELA
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