How to check the crane hook

Crane hook assembly as shown in drawings, the main by a pulley, pulley shaft 2, anti-decoupling device 3, leptospirosis 4, beams 5, bearing 6, the combination of bolts 7, round nut 8, 9 and plywood guidewire block 10 and other components. To ensure the normal use of the  bridge crane  hook, crane operators, maintenance personnel, as appropriate, to carry out security checks on these parts, check the contents include three: First, check the technical documents, two is to check the appearance and surface cracks, three is a measure of the amount of wear, opening degree, reversing the deformation and so on.

1 matching technical documents

Put into use before the new crane, the operator should check the hook assembly relevant technical documentation. Signs which hook assembly of the standard load rating should be consistent with the actual lifting loads, the related technical documentation and factory certification should be complete.
2. Visual inspection

The operator has the appearance of each hook assembly should be checked, each component requires the following: 1 pulley shaft 2 to rotate the pulley should be flexible, no looseness; pulley rim 1 should be no breakage or crack, or should be replaced ; Anti-decoupling device 3 should open and close freely, the spring should be intact, in order to prevent the rope from slipping off the hook body 4; leptospirosis four bearings in the beam 5 6 should be flexible rotation; round nut 7 and 8 can not be combined with loose bolts .

3. Check the hook surface cracks

First with kerosene Leptospira 4, and then 20 times magnifying glass to check whether there are cracks leptospirosis, coloring method used when necessary testing. For large-tonnage  hoist crane  hook, but also using non-destructive testing method (magnetic testing, ultrasonic testing) check hook inside and outside the presence of cracks. Such as leptospirosis four surface and internal cracks should be replaced immediately.

4. Measurement geometry leptospirosis

(1) Wear

Conducting periodic inspection crane should be used when measuring calipers caliper or wear surface leptospirosis 4 the amount of wear. If a larger cross-section wear its force reached 10% of the original size should be replaced. Crane overhaul, respond hook assembly for dismantling and measure pulley shaft 2, beams 5, 6 and plywood 10 shaft bearing bore wear. When the wear reaches 5% of the original size, it should be replaced.

(2) the degree of opening

Leptospira four openings measuring method is as follows: According to the hook on the label of the rated load for load test, the load incrementally and gradually increase to 1.25 times the rated load, lifting time of less than 10min. Measured with a caliper after unloading hook opening degree, the value is compared with the original opening size, the opening degree of the increase should not exceed 0.25%.

When the opening of the new hook, the hook body 4 can punch on each side of the opening punch a mark, the measured distance between the marks 2 and the opening size of the original recording.hoist gantry crane If the degree of deformation of leptospirosis four openings than the original 15% increase in the degree of opening, should be replaced.

(3) torsional deformation

Inspection Leptospira four torsional deformation measurement methods are as follows: the side with a ruler positioned against the side of the shank 4, view check ruler with leptospirosis four sides of the gap. If leptospirosis four different sides of the gap, indicating leptospirosis four torsion deformation. For accurate measurement of the torsional deformation of leptospirosis 4, it can be disassembled with crossed feet on the platform testing. Leptospira four torsion over10 ° should be replaced.