Relying on the hydrauli★‍c power device, the h'↑≈ydraulic crushing hammer plays th ↕' e role of impact, hammering and gr←βavel. Due to a series of adv‌¥"antages of wide application range and h£★←igh work efficiency, the hydraulic cr Ωushing hammer is widely used in mi€ ≤ning, metallurgy, trans∞✔÷ portation, railway, tunne∏★l and other industries.


In the use of hydrau∑₹lic crushing hammer,✘★Ω due to the influence of e§¶>nvironment, operation, component∏¥♠s and other factors, there will ≤α×♥be faults such as poor impact continuσ§λity, drop of impact force, insuff÷®icient impact frequency, abnorm÷φφ¶al oil pipe vibration and oil l₹•δeakage of hydraulic crushing haσΩ∏mmer. These faults will affect th↑‍★≈e performance and efficien₽™cy of hydraulic crushing hammer and incε"rease the potential safety hazar↕"÷ds of crushing operation. This papeδ≤r shares several cases of hydraulic≠§ breaking hammer failure.


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1. The drill rod breaks in₽☆€ a short period of time



Inspection and analys♠₩Ωis:


When prying, the drill rod iσ±>s subjected to the action of F, ® and a huge moment (M bending) is genera★≈✔₹ted at point a. Point B o€π→∏f the drill rod is under tension and♥‍÷  point a is under pressure.™¶₩∏ Under the action of strong external foβ↕★₩rce F, the drill rod ₹×€αproduces some micro crack sour÷♥σces at point B and continues to ∏ →expand under the action of stresφ¶∏s. When the bearing force ex 'σ×ceeds the tensile strength©↔∏ limit of the material, the drill rod β↔ ₹will be completely broken insε>tantly.


According to the section of ≈∞the drill rod, it is clearly seen th£¶•at the starting point of fracture isπ↕®™ point B, there are obvious  ★ metal tensile cracks aroun βd it, the grains at the metal end∑₽ > face are uniform and fine, and≥↕₽ there are no small slag‍↓♥ inclusion and hidden ≈㶙crack defects. The g"<♥roove in point a are™₹®a is a typical reflection of materi✔♠λ♣al compression damage.


Conclusion: the broken£​ hammer is used to pry and bend, result☆ε ←ing in the fracture of t₽σ≈∑he drill rod.



2. Abnormal wear of tool rod (and bu¥ shing) in a short timπ₽$e

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Inspection and analysis: when the β∞hydraulic crushing hammer works, the₹≤♣φ friction between the drill rod and th←±e bushing will produce a lot δαof heat. Heat can cause premature we ♣ar of drill rods and bushi±'ngs and damage to component™→s. Therefore, grease ₽∏ shall be added for 2 hour &¥≠s to form an oil film to prevent★≤ dry friction and prolong ≥σ​±the service life of the drill ro↑₩d and its bushing.


Conclusion: the wear surface of the™ε€ drill rod shown in the fig€δ‌ure is lack of or no lubricating•  grease, resulting in ser↕×↔ious burns on the contact surfa₩→©€ce.



3. The stop pin of the •÷‌εdrill rod is broken for÷¶™ a short time


Inspection and analy ♣sis: according to the dβγrill rod and the broken dri♥☆☆ll rod stop pin, the upper part of tσ®₹♥he contact between t≤•≤he drill rod and the s♦φtop pin is abnormally worn, but the δ™₩÷lower part is almost not wor€β n. The red contact area in ←≠←the figure is worn far beyond the low≥÷er part, and the drill rod is damage£© d and the retaining p≈♠βπin is broken at the same time, which ✔★shows that the last hit object iΩ≥÷₩n the crushing work does not₩™∏ stop in time after the fragment>∑↑✘ation, and the drill rod strikes th>÷¥e retaining pin of the drill rod ‌↔♠↑many times.


Conclusion: there are more illegal air•≤↕ games.



4. The crushing hammer stops strikβ"ing


Inspection and analysis: dis♣♣→×assemble the hammer body and check the £©★reversing valve. It isφ×‌  found that the sliding valve plug is π×easy to get stuck. After the valve ≠δ₩™core of the directionaφ←l valve was removed, it≠↑∏₹ was found that there were many sΩβtrain marks on the valve body≤♦, resulting in the clampi↕ ∞ng of the directional valve du≠​ring operation, the normal direc&≠ tion could not be reversπ​ed, and the crushing hammer stγ₽ opped working.


Main reason: after observing the resi≈∏£©dual hydraulic oil inside the crushing £≠≈hammer, it is found that the quality o✘↓‍f the hydraulic oil is poor. ±✔♦∑Check the hydraulic oil flowing out of®∞★ the excavator pipeline > Ω‍for the same problem. In addi↑>≥tion, the inspection f↑™ound that the oil filter of the α‌Ω★crushing hammer pipeline rarely &"replaced the filter element, and the ex ‌cavator did not replace the hydraulic o÷σil regularly according δ$ ↑to the specified requirements, r≤& ♣esulting in the deterioration o ✔f the hydraulic oil, which directly afλσ↕♦fected the directional valve of < ✔the crushing hammer.


Conclusion: the direction↓<al valve is jammed.


Other reasons why the crus✘£€δhing hammer stops str✘₩∏♦iking:


Improper bushing replacement.©¥£' After replacing the bus™•™hing, the crushing hammer>ε stops working. It does not strik±£ ★e when pressed down, and ¥≈there is striking action after β§slightly lifting. After replacing th<≈♦e bushing, the piston position isΩ☆ higher, resulting in that some smλ₩•all directional valve control oil ci®>α‌rcuits in the cylinder body have been c♣ losed at the starting position, the ÷ directional valve stops working, aε✘≤≈nd the crushing hammer sto®δ‌ps working. (replace the orσλβiginal or regular bushing)


Rear cover oil inlet. (upper©×∏ cylinder) the crushing ham÷₽¶mer gradually becomes weak durinλβφg the striking process, and f©'♠↕inally stops striking. MeΩ ↑£asure the nitrogen pressure. The p↔•₹ressure is too high. Aft£↓§er release, it can s÷ trike, and soon stop strikin¥↔g. After measurement, the pressure bec<÷omes higher. After disassembly, it waββε©s found that the upper  ♣ cylinder was filled®γ♥​ with hydraulic oil, and the£•$ piston could not be compressed b←γ •ackward, resulting in the failu€€re of the crushing hammer.÷γ (replace seal assembly)

The accumulator components in the£ " line fall into the line. During the i ×₹€nspection, it is found that₽≈♥ the deformed parts in the direct∏​ional valve are stuck in the direct>φional valve.


In addition to the a✔→bove reasons, the valve plate of ↓♦≥the excavator is stuck, or the O♦™®₹-ring on the valve plate comes out of¶¥☆π the groove, which alsoσ¥↔♥ causes the crushing hammer not to st↔∞₽rike.



5. Weak impact of crushin✔♠g hammer


Inspection and analysis: the crushi↕£φπng hammer is weak, and the hose≥• ₩ shakes violently on α★¶φsite. The accumulator pre‍&ssure of the crushing hammer is≤Ω"≥ detected. It is found that t©≈☆™he accumulator has no press ×¥ure and a little hydraulic oil seeps ou£™t. It is judged that the accumulator'←∏β has been damaged. Remove the ac•→cumulator cover, take out the broken ε​leather wrist, clean and dry the accum♥γ<≤ulator shell and install a new leα≠ather wrist.


Conclusion: the skin wrist of t↔βhe accumulator is broken.



6. Oil leakage at piston


Oil leakage I


Inspection and analysis: during the usε©×​e of the crushing hammer, a lΩε★✘arge amount of hydra→ €←ulic oil leaks from the low φer cylinder block and is turb♥∏↔&id. It is judged that the seal₹α$'ing component has been damag≠π₩βed. During disassembly in↔✘spection, it was found ±®♣♠that a large amount of gre®'ase and hydraulic oil mixture w₩"as mixed between the i∏÷‍✘nner bushing and the piston∏♥, and a large amount of dirtδ≤ ↓ was also contaminated on the piston he¶∏ad (see the above figure).


Conclusion: improper gr∑>ease filling will damage the se​∏ al assembly and cause oil leak≈±↕age at the piston.


Correct filling method♠λ≠♥: when filling grease, pα •lace the crushing hammer vertically ×®≥★and press the drill rod with the cru♥β<shing hammer, that is, fill ​™→€when the drill rod is close  €to the piston and fill it appropriat≤§©₹ely. There can be wet☆↔Ω grease at the drill rod.


Oil leakage phenomenon II


Inspection and analysis: the hydraul§™♦ic oil leaks from the lower ★ασ®cylinder block when the cru≤£shing hammer is stored for <↑<Ωa period of time. After inspection, it ☆♣is found that there is hydraβ♥>ulic oil leakage and←​ the crushing hammer shell i≠ ×↑s seriously rusted (upper left ™Ω₽figure). It may be caused by not do✔β•<ing a good job in moisture protecε∑tion during storage.


After disassembly and ¶∞inspection, it was found that there wa♠↓ε♠s a section of water rust on the pi"←✘↕ston head (upper right figure),÷±σ£ which directly caused the ten←↓sile damage and failure of the piston s&₹☆σeal assembly, resulting in the le↑​>akage of hydraulic oil.


Conclusion: improper storage will ≠÷'cause piston corrosion, damagφπ™‌e sealing components and c $ause oil leakage.


Correct storage: for↕♣♣​ long-term storage, the gas in the nitr↓₩ogen chamber must be‌÷♥→ discharged to make the piston r‍✔♠eturn to the cylinder body."  Refer to the instruction manual.


Oil leakage phenomenon III


Inspection and analysis: a large amou↔‍αnt of hydraulic oil leaks from∑✔∑ the lower cylinder b×↓¥σlock of the crushing hammer durin&≥€g use. Through observaα±♣±tion, it is found that t÷↑γ•here is a lot of digging dur↓♥ing the use of the cru±δshing hammer. After disassembling the >∑crushing hammer, it is found that  ∏≤←there are a large number of smal ≤l gravel chips inside the shell. A♣Ωδ©fter pulling out the pisto₩♠¥δn, it was found that↕Ω∏ the piston and cylindε±>er block had a large area of tenα™sile damage, resulting i§✔<n the tensile failure of the s★¥φ<ealing assembly and the l¥₽<eakage of hydraulic oil.


Main reason: illegal d♣λigging operation brings a large ↔<÷↓number of small gravel chips ↕ into the hammer body. Part of the gr→✔avel is attached to the front end ≥★φσof the piston and brouΩσght into the cylinder bloc £₩k with the reciprocating m★δ¥ovement of the piston. On the o÷Ω∞Ωne hand, it rubs between the ↓↑ ©piston and the cylinder block, pulling↕‌¶ the piston and the cyl§↑₩inder block, on the ↕★₽®other hand, it directly damages t↕☆₩he sealing components, re&​sulting in hydraulic oil leakage.♥¥€


Conclusion: improper operation ↑ and use will cause piston strain↔©•$, damage sealing components anα¶↔d cause oil leakage.



7. The front end of the×£™ piston is damaged


Inspection and analysis: metal fragmenα↓ts fall from the lower >≠φ₩cylinder during the use of the crusσσhing hammer. After disas‍↑±sembly and inspection of the cr₹₩ushing hammer, it was found that th§¥↑e striking surface at the fron≥♥ ​t end of the piston was d≥♥→amaged (see the figure above), and the α÷drill rod used was not₽€φ₽ damaged.


Main reason: the hardness o♠≥¶∞f the drill rod is higher than that o'&¥₽f the piston rod, which directly damage✔σs the piston. The dri≥Ω♠ll rod itself is a lossy p×≥art, and its service life is‍♥¶π lower than that of the pistoσ€n, so the hardness is strictly con↕©trolled and mastered.


Too soft, too short service l✘→↑ife and too hard damage to the pi€ ♦$ston, so it is strictly prohibited ∑εto use non pure drill≈&β↑ rods for the crushing hammer. ★ Ω•The piston head is cor•λ₽÷rected and leveled by a grinder and €₽₩can be used at a certain limit size.α∏>♥ If it stops working after repair, p ↓lease replace the pi✘≥ston.


Conclusion: the hardness of✘↓ the drill rod does not match that of tλ÷∏he piston.



Correct operation is ★$conducive to efficient crushi×↓ng. In case of improper oper™&"∞ation, the striking force cannot be bro•↓ught into full play, but will ≥‍reverberate to the crushe©β÷↔r body, guard plate and the &₩®"operating arm of the excavator body, re♠β↕÷sulting in damage to the parts o≠Ω≥f the crushing hammer. Corr¥↕ectly operate and maintain the hydraul™♠ic breaking hammer to avoid sλ♣• ome faults and get twice the resultε ±↔ with half the effort!