CN2106158U - Limiter for electric hoist - Google Patents

Abstract

Disclosed is a limiter for an electric hoist. The utility model is composed of by a rising cam assembly and a descending cam assembly which are connected by a gear speed reducer. Each cam assembly is composed of third cams with mutually different angles, and the two cam assemblies are both fixedly connected with the same driven shaft. Every cam is provided with a corresponding limit switch. The utility model has the advantages of simple structure, safe and convenient operation, high reliability, low cost, long service life, and all-wave phase-faulty protection.

Description

Limiter for electric hoist

The utility model relates to a kind of application of power-controlled cucurbit limit switch, belong to elevator, bont field.

Limiting device is the requisite a kind of safety guard of electric block; the electric block limiting device of domestic production at present all is rod-pulling types; it is that the reel limit is provided with isometric pull bar; the two ends of pull bar are provided with positive stop (adjustable); a limit switch and end of limit pull rod is ined succession; when on the reel along with rising or decline and the rope guide of sway when running into positive stop; just touch limit switch; reach spacing purpose, the limiting device of this structure is because pull bar and cable drum are isometric, and the cucurbit lifting altitude is high more; pull bar is long more; pull bar is easily hit curved, and unstability causes limiting device malfunctioning.Cucurbit brake slide amount is proportional to lifting velocity in addition, when cucurbit descends fast with big speed, though rope guide has hit the block on the pull bar, the limit switch action, but because the brake slide amount exists, rope guide will move forward, makes limit switch be subjected to big inertia impact, damages limit switch.Recently, China has introduced the DH electric block that several German DEMAG companies make, the DGS limiting device that it adopts then adopts from the cable drum main shaft and is connected with coupler, give wide, narrow two cam set that are connected on the driven shaft by reduction gear apparatus from two slower different rotating speeds of driven shaft output speed, the limit that is parallel to two cam set is provided with depression bar, the two ends of depression bar can be subjected to the extruding of width two cams, make connecting in the middle of the depression bar promote limit switch with the contacted plunger of limit switch, reach spacing purpose.But there is following several defective in the limiting device of said structure: (1) complex structure, parts are many, the cost height.Reduction gear apparatus transmission complexity has the doubly-linked gear of five kinds of different numbers of teeth, the individual gears of two kinds of different gears, and totally seven kinds of gear parts, casing, pedestal Plastic Parts die cavity are quite complicated, the die cost height, the finished product rate is low.(2) two axles wide, narrow cam are bearing on casing, the pedestal, and axle support bit length is the hanging beam structure less than cam department of assembly bit length, and insufficient rigidity is being adjusted, locking, and cam set is easily rocked during cam action, influences setting up accuracy.(3) this limiting device requires the rotating speed difference to turn to consistent wide, narrow parallel promotion depression bar of two cams while to move, and limit switch could move.It is big that cam is adjusted difficulty, simultaneously, adjusts the back and come locking cam by a M4 screw, the normal M4 of discovery screw head is all twisted and is stuck with paste in actual the use, but cam locking is fully not yet skidded when causing cam work, can not play spacing real effect, functional reliability reduces greatly.(4) limit switch dysplasia, the limit switch movable contact spring is a rigid body, movable contact spring slowly moves with pull bar, plunger, and dynamic and static contact contact stress slowly reduces, and contact resistance slowly increases, until disjunction, as seen breaking speed is slower, will cause contactless switch shake, arcing, and cucurbit becomes the crawl mode of operation, influence contactless switch, the service life of cucurbit.This limit switch has only the normally closed contact impermanence to open the contact in addition, when the cucurbit different operating is required, and mode change difficulty.(5) spike of cam is wide in a narrow margin has only 1.5mm, and limit switch can be because of the existence of cucurbit downslide amount, make in a narrow margin that cam inertia rotates, and departs from control position, and the limit switch that has moved is resetted again, causes misoperation.(6) contact of limit switch, fixture wire are exposed at the case outside, directly link to each other with main circuit contact device control desk from limit switch contact fixture wire, and control desk and limiting device have relative motion, so fixture wire easily pulls.(7) this limiting device can only have the fast rise fault-phase protection, maybe can only establish station heavy duty spacing (mean soon at a slow speed and automatically switch, be as follows) and does not have the misphase protection.

The purpose of this utility model is in order to overcome the deficiency of above-mentioned existence, and provides a kind of relatively simple for structure, and cost is lower, and is easy to make, good reliability, the electric block limiting device of long service life.

The purpose of this utility model is finished by following technical solution; promptly be provided with rising, decline two cam set; every group of cam composition that cam is settled by three mutual different angles (adjustable); and every group of cam all is provided with fast accordingly, at a slow speed, three limit switch devices of fault-phase protection; promptly be mounted with six limit switches respectively and form the limit switch group corresponding to six cams, above-mentioned six cams all are connected on the same driven shaft.

The purpose of this utility model also can come to finish jointly by following technical solution, and two cam set of the present utility model are connected on the driven shaft by the jam nut at two ends.The utility model selects for use micro-switch as limit switch.

Description of drawings is as follows:

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is the plan structure scheme drawing of Fig. 1.

Below will the utility model is further introduced by accompanying drawing: rotatablely moving of cable drum be passed to by imput shaft 2 by coupler 1 during the cucurbit lifting, tween drive shaft 3 and a miniature gears 4 that is fixed on the imput shaft 2, three empty cover dual gears 5, the reduction gear apparatus that the big gear wheel 7 that is fixed on the driven shaft 6 is formed, and by driven shaft 6 pass motion to rising, two cam set descend.Each cam set settles the cam of (adjustable) to form by three mutual different angles; the equal correspondence of cam in every group is provided with fast; at a slow speed; three limit switches of fault-phase protection; promptly corresponding to six cams respectively correspondence be mounted with fast rise IS; 3S rises at a slow speed; rising fault-phase protection 5S; quick decline 2S; 4S descends at a slow speed; six limit switches of decline fault-phase protection 6S are also formed the limit switch group; six cams all are inserted on same driven shaft 6, and its two ends are connected on the driven shaft 6 two groups of cams with jam nut 18, and limit switch all adopts micro-switch; its position is that spacing sleeve 9 is fixing by two cover string pin bolts 8.Said apparatus all is placed on the frame, frame is by base plate 10, middle connecting plate 11, top board 12, four double end external threaded 13, four double end negative thread screw rods 14, organism glass totally enclosed frame 15 compositions such as grade, on the top board 12 of limiting device mechanical type unidirectional counter 16 is housed, this counting machine 16 links to each other with driven shaft 6, is used to write down the accumulation period of service of cucurbit; Limit switch fixture wire socket 17 also is housed on the top board 12 of limiting device in addition.Six cams forming rising, two cam set that descend have three kinds of specifications.And corresponding six micro-switchs are a kind of specification, promptly select 83 serial micro-switchs for use, and the contact shifting time is less than 20ms, and electric life is 1,000,000 times, and be 10,000,000 mechanical life, but upper and lower two groups of direction of action.Among the figure, micro-switch 1S, 2S are respectively upper and lower station heavy duty limit switch, and corresponding two cams are the wide cut cam; 3S, 4S are respectively upper and lower limit limit switch, and corresponding two cams are middle width of cloth cam; 5S, 6S is respectively corresponding two cams of upper and lower misphase limit switch and is cam in a narrow margin, according to cucurbit real work needs, can adjust the angle between upper and lower two groups of cams, to adapt to the upper and lower real work height of cucurbit, in addition, adjust angle between cam on the same group, to change the cushion stroke of (fast, slow, misphase) between three kinds of functions, and all engrave 0 °～360 ° angle grooves with middle connecting plate 11 inboards at the top board 12 of cam set both sides, with the convenient yardstick of adjusting, the limiting device of above-mentioned composition is installed in the control box casing.

The course of action of this limiting device is: when the electric block fast rise, at first the fast rise cam brushes up against station heavy duty limit switch 1S, fast rise is cut off, but because of 1S normal open switch closure has automatically been connected rising at a slow speed, then electric block will rise at a slow speed, brush up against limit switch 3S up to the cam that rises at a slow speed, rise at a slow speed and just be cut off, realized that last station is fast, automatically switch at a slow speed, in like manner, when electric block descends fast, the cam that descends at first fast brushes up against down station heavy duty limit switch 2S, descending fast to being cut off and having connected automatically at a slow speed descends, and brushes up against limit switch 4S up to the cam that descends at a slow speed, and descending at a slow speed just is cut off.When electric block power phase mistake; fast and at a slow speed cam though rise or in the decline cam set has brushed up against limit switch separately; promptly normal spacing out of control up and down; still can not cut off corresponding motion; at this moment have only when the fault-phase protection cam brushes up against fault-phase protection switch 5S or 6S and could cut off contactless switch; realize the fast fault-phase protection of four kinds of working conditions up and down at a slow speed, at this moment as long as recover normal power phase, cucurbit gets final product normal operation.For the ease of electrically operated, the utility model adopts widely used at present double-deck control button both at home and abroad, and promptly each button has two strokes; First stroke (up stroke) is at a slow speed, and second stroke (down stroke) is quick.

The utility model compared with prior art, have simple in structure, safety easy to use, good reliability can comprehensive fault-phase protection, cost is low, the characteristics such as long service life.

Claims (4)

1, a kind of by coupler, reduction gear apparatus, frame, cam set, the electric block limiting device that limit switch group etc. are formed, it is characterized in that described cam set is divided into rising and descending two organizes, and the cam that every group of cam formed by three mutual different angles is formed, and two groups of cams all are connected on the same driven shaft 6, all be mounted with a limit switch corresponding to every cam, to form the limit switch group.

2, electric block limiting device as claimed in claim 1 is characterized in that described cam set is connected on the driven shaft 6 by the jam nut 18 at two ends.

3, electric block limiting device as claimed in claim 1 or 2 is characterized in that described limit switch is 83 serial micro-switchs.

4, electric block limiting device as claimed in claim 3 is characterized in that being equiped with on the described frame limit switch fixture wire socket 17.

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