Safety device for lifting platform
时间：2018-05-08 16:24:22 点击：次
In order to ensure the safety factor of the lifting platform, safety device for lifting platform a lot. Today we are going to talk about anti falling safetydevice and safety switch:
1, the anti falling safety device
Anti falling safetydevice is a lifting platform is an important component, to rely on it to eliminate the cage fall accidents occurred, to ensure the life safety of the passengers. So anti falling safetydevice factory test was very strict, before leaving the factory by the statutory inspection unit of torque measurement, critical speed measurement, measurement of the amount of compression spring, each is accompanied by testing report, assembled to lift were rated load drop test, and site of the lifting platform must every three months to a drop test. The factory lifting platform for two years of anti falling safetydevice (anti falling safetydevice of ex factory date), must also be sent to the statutory inspection unit testing, after testing once a year. So far there are few inspection, some sites even every three months a drop test and don't do, that their anti falling safetydevice no problem, but once out of the accident to regret it. Why not according to the system of periodic test and inspection? The use of units of the blind, even if good. Actually anti falling safetydevice of good or bad is only through the test and inspection to determine whether good or bad, daily operation is unable to determine whether it is good or bad, to those extended service of anti falling safetydevice, recommendations or earlier inspection and periodic tests only accomplish know fairly well to malignant accident nip in the bud. (anti falling safetydevice detection, can send: Changsha National Construction Machinery Quality Inspection Center, Shanghai Research Institute of building science, Shanghai Jiao Tong University)
2, safety switch
Safety switch for elevator is according to the need for the design of the security, threshold of the fence, cage threshold, forehead limit, the limit switch, upper and lower limit switches, for weight control rope breaking protection switch etc.. Some site in order to save some limit switch position artificially cancelled and the short connecting or damaged is not timely repair, is equal to the cancelled the security line of defence, hidden dangers of accidents. Cases: cage to load from east to west, in the suspension coop not need to extend out of the hanging cage, and man-made cancel threshold or forehead limit, in case the safety facilities imperfect or incomplete, still carrying people and objects, the exercise of violate the rules and regulations is to take life joking, in order to avoid the hidden dangers of accidents occurred, hope using the unit leadership to strengthen management, strict requirements lifting platform maintenance and operation of the safety and reliability of the staff to periodically check the various kinds of safety devices, to prevent accidents from happening.
In order to ensure the safety of the lifting platform, the safety device is equipped with many, today we will talk about gear, rack and pinion wear replacement, temporary load and buffer:
3, gear, rack and wear replacement
Site construction, operation conditions are harsh, cement, mortar, dust impossible to eliminate clean, mutual grinding of gear and rack, tooth wear tip up, still in use, should pay attention to. It is well known that the tooth shape is like a cantilever beam, when the wear to a certain size, it is necessary to replace the gear (or rack). Wear to what extent to stop using the replacement of the new it? 25-50mm law line micrometer can be used to measure, when the gear base tangent length by 37.1mm wear to less than the size of the 35.1mm (2 teeth) must to replace the new gear. When the wear of the rack, by the measurement of tooth thickness calipers, chord height of 8mm tooth thickness from 12.56mm wear to less than 10.6mm rack must change. However, on the site of a lot of old-fashioned gear rack lifting platform still in extended service, for the sake of safety must be replaced with new parts.
4, temporary load rate
Lift on the site of frequent operation, high utilization rate, but had to consider the motor continuous duty is often said that the temporary load rate of problem (sometimes called load sustained rate of) its definition is FC= working period of time / time x 100% load, the cycle time for load time and downtime. Some sites on the lifting platform is leased to the company, the total want to make full use of, and the temporary load rate (FC=40% or 25%) is completely ignored, motor how not fever? Some even run out of focus, which is not normal operation. If the elevator drive system lubrication or running resistance is too large, overload use, or make frequent start, it is a small horse drawn carts. So every driver on the construction site must understand the concept of temporary load, according to scientific laws, such as the motor itself is designed according to the discontinuous operation.
Elevator buffer of the lifting platform safety of the last line of defense. First, it must be set up. Second, it must have a certain strength, bear the brunt of lift rated load and play a buffer role. And now many of the site, although some has set, but not enough to play a role in the buffer, the site has no buffer, this is extremely wrong, hope to use the unit for inspection, do not despise this last line of defense.