CN87210349U - Over-load limiter for lifting machine - Google Patents

Abstract

The utility model discloses an integrated over-load limiter for lifting machine comprising a hanging shelf (1), a weighting sensor (2), an electric controller (3) and a pipe joint (4), which is suitable for electric hoisters, a single-beam lifting and part of lifting apparatus of bridge-type. The sensor and the electric controller are formed into an integration, which can be directly hanged on the fixed end of a steel wire. The utility model has the advantages of convenient installation and high reliability. Besides, the integrated over-load limiter for lifting machine need not change the original apparatus or the original design. The weighting sensor is in the ring form of double orifice plates. The measuring circuit adopts a ratio circuit. The control element adopts a bidirectional thyristor. The circuit is simple. Electric parts all adopt polyurethanes to cast and seal, which has good moisture-proof.

Description

Over-load limiter for lifting machine

The elevator machinery load limiter is applicable to electric block, and single-beam hangs and part bridge-type class weight-lifting equipment.It is a kind of safety guard that prevents that elevator machinery from moving under the overload situation.

The overload crane killer of producing both at home and abroad all is that LOAD CELLS and electric controller are two parts at present, be installed in two places respectively, and volume is bigger.The De Mage company (DEMAG) of West Germany and the Ke Ni company (KoNE) of Finland.Domestic 702 what developed also is the load limiter of this form.The load limiter of this form is not easy to install, and especially hangs etc. in the weight-lifting equipment of compact conformation at electric block, single-beam, need carry out bigger change to existing equipment or original design and could use.Thereby make the widespread use of killer have certain difficulty.

The utility model has solved the problem of above existence, and LOAD CELLS and electric controller design is as a whole, has reduced volume, and is only more bigger than the sensor bulk of existing killer, but saved the bigger electric controller of original killer volume.Simple in structure, mounting means is reasonable, and is convenient, need not to change original equipment or original design, easy to utilize.

The structure of monolithic devices load limiter (seeing Fig. 1 front view and Fig. 2 lateral plan) by: pylon (1), LOAD CELLS (2), electric controller (3), cover of wedge parts such as (4) are formed.It is characterized in that: sensor and electric controller are made an integral body, directly hang fixed end at steel rope.Application easy for installation and direct need not to change original equipment or original design.The body of pylon (1) and weight-lifting equipment links, the upper end of sensor (2) with adopted the variation of oscillating bearing connecting of pylon (1) with the adjusting strained condition.In the both sides of sensor (2) two rectangular boxes being housed is electric controller (3), is placed with electrical measurement circuit and control circuit respectively.The electrical measurement circuit has adopted ratio type circuit form, and control circuit has adopted the triac solid-state relay.Electric controller (3) is a quad with exterior electric the connection, and two cores are AC power cord, but other two cores are the contactless for hoisting of control output line direct control hoisting crane, and warning indicator lamp and buzzer phone are equipped with in the electric controller surface.The lower end of sensor (2) connects cover of wedge (4) and is connected with steel rope.All with polyurethane casting sealing, its moisture resistance is good for the electric part of load limiter.

Fig. 3,4 is the electric controller schematic circuit diagram, LOAD CELLS is output as the voltage small-signal with the variation of weight through resistance-strain electric bridge R when the elevator machinery hoisting heavy, deliver to the input end of amplifier F, amplifier F amplifies 200 times of voltage signals that are output as 0～4V with the small-signal of 0～20mV, amplifier F and benchmark D setting voltage value are delivered to two voltage comparator A, B, four input ends, voltage comparator compares two incoming signals.Sound and light alarm is sent in then voltage comparator A action immediately when overload crane 〉=20%, and the silicon control solid-state relay disconnects crane hoisting contactless switch Z simultaneously, makes hoisting crane can not continue lifting.When overload crane 〉=10% and＜20% the time, the voltage comparator B action promotes single stabilization delay circuit C, disconnects crane hoisting contactless switch Z through 0.3～0.8 second time-delay rear drive silicon control solid-state relay, the restriction hoisting crane continues lifting.The effect of single stabilization delay circuit C is to avoid owing to the crane loading momentary overload that additional moment caused of moment by 0.3～0.8 second time-delay, guarantees that hoisting crane can normally promote when the lifting rated load.Sensor resistance strain bridge R, amplifier F, voltage comparator AB, reference voltage D all use the power supply of one group ± 6V constant voltage power suspply in the electric controller circuit, and characteristics are to have constituted ratio type circuit form.The sort circuit form be sensor resistance strain bridge R and reference voltage circuit D shared-the 6V power supply, thereby overcome effectively since for bridge voltage fluctuation or reference voltage fluctuation to the error of measuring and control accuracy causes.To cause the variation of sensor output for the variation of bridge voltage, but owing to adopt same power supply with reference voltage circuit, reference voltage is also followed by the certain ratio respective change simultaneously, thereby offset the influence that change of voltage caused, guaranteed the observing and controlling precision, and power circuit is simplified, and has saved high-precision bridge and the reference voltage source of supplying, and has reduced cost.Control circuit has adopted the triac of 1A1000V to replace electromagnetic relay commonly used as solid-state relay, has improved service life, has reduced cost, has dwindled volume.

The overall structure form of load limiter is compared with similar technology with the design of electric controller, and its advantage shows: 1. the monolithic devices structural volume is little, is convenient to install.2. the mounting means of this killer can be used for current weight-lifting equipment, also can satisfy the requirement of new range weight-lifting equipment.3. circuit adopts ratio type structure, has saved high-precision bridge power supply and reference voltage source, simplifies circuit and has reduced cost.Observing and controlling precision and reliability have been improved.4. adopt the triac solid-state relay to replace general purpose power electro-magnetic relay, reduced volume has improved the power consumption that has reduced power supply service life.5. all adopt the moistureproof anti-shake performance of polyurethane casting sealing technology good to electric part.

Claims (3)

1, a kind of elevator machinery monolithic devices load limiter, form by pylon (1), LOAD CELLS (2), electric controller (3) and cover of wedge (3) and cover of wedge (4), it is characterized in that: this killer is made an integral body with LOAD CELLS and electric controller, directly hang fixed end at steel rope, pylon (1) links with the body of weight-lifting equipment, the upper end of sensor (2) and pylon (1) adopt oscillating bearing to connect, and the sound and light alarm element is equipped with on the load limiter surface.

2, load limiter according to claim 1, it is characterized in that: it is electric controller (3) that two rectangular boxes are housed in the both sides of sensor (2), be placed with electrical measurement circuit and control circuit respectively, the electrical measurement circuit has adopted ratio type circuit form, control circuit has adopted the triac solid-state relay, and electric controller (3) is a quad with exterior electric the connection, and two cores are source of AC, other two cores are the control output line, but the contactless for hoisting of direct control hoisting crane.

3, load limiter according to claim 1 is characterized in that: electrical appliance part seals with the polyurethane casting.

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