What are the emergency maintenance methods for construction machinery on site?

In the operation of construction machinery, the on-site environment is often not good. For instance, during engineering construction, as the construction is mostly carried out in relatively remote areas, coupled with tight construction funds and a wide variety and diverse models of mechanical equipment, once the mechanical equipment is damaged, it often affects the use of the machinery and the construction period due to the lack of individual components. In motor vehicle maintenance, when a vehicle suddenly breaks down while in operation and standard parts cannot be purchased for the time being. Therefore, we should be able to flexibly handle some seemingly difficult problems in the use and maintenance of construction machinery. This often leads to twice the result with half the effort. For example, we can use some easily available daily necessities as emergency substitutes, which can achieve relatively good results.

Here, this article introduces several simple and feasible emergency repair methods.

I. Reasons for the malfunction of components and how to solve them on site

1. Installation errors of components: For instance, in some construction machinery, the support rings in the hydraulic cylinder seals (mainly made of PTFE material) have poor elasticity. Therefore, before installation, they should be soaked in 100 ° C oil for 10 to 20 minutes to soften them, and then installed when they have greater elasticity.

2. Issues in the operation of components: There are many problems caused by this aspect, especially during the operation of engineering vehicles when new drivers are not familiar with the performance of the machines. For instance, the splines on the half shaft of an engineering vehicle often wore out. Later, it was found that the driver had kept the differential lock in place, which increased the load on the transmission part during use and caused severe wear. Therefore, the operation needs to be improved.

3. Faults in related parts cause damage to components. For instance, two walking hydraulic motors on an excavator broke down simultaneously. After inspection, it was found that the oil seal on the multi-way rotary joint was damaged and blocked the circuit. Therefore, this problem must be solved in time; otherwise, the hydraulic motors will be damaged again in the future.

4. Quality issues of parts: For instance, there was a excavator whose hydraulic motor, hydraulic pump and reducer bearings were all damaged. Even after replacing the original factory bearings, they still broke down. Eventually, the problem was solved by installing imported bearings. Similarly, the oil seal of this excavator's boom cylinder often broke down in summer. Later, it was found that the clearance between the original factory piston and the cylinder barrel was too large. After the piston was reprocessed on site, the oil seal has never broken again.

Ii. Several Emergency Repair Techniques

1. Skillfully use a wrench to tighten bolts

Sometimes, due to the lack of suitable wrenches, it is difficult to disassemble and assemble parts, especially for some bolts of imported construction machinery. When disassembling and assembling, the domestic wrenches used are either large or small. In addition, sometimes problems may occur during disassembly and assembly due to incomplete wrenches carried randomly. At this point, the following methods can solve the urgent problem (mainly for box wrenches, open-end wrenches (fixed wrenches), and Allen wrenches. Try to use adjustable wrenches and pipe wrenches as little as possible, otherwise the components are prone to damage). If the box wrench or open-end wrench used is larger than the bolt head (or nut) to be tightened, and the Allen wrench is smaller than the bolt head to be tightened, You can place some copper sheets, iron wires or screwdrivers inside or outside the wrench (for box wrenches and open-end wrenches), and then gradually increase the force to disassemble and assemble. When the open-end wrench is smaller than the bolt head (or nut) and the Allen wrench is larger than the bolt head, a file can be used respectively to file the opening of the open-end wrench larger and the hexagonal dimensions of the Allen wrench smaller. In most cases, emergency disassembly and assembly work can be solved through the above treatment, and the modified wrench can be reserved for future use.

2. Skillfully disassemble the bearing housing ring

The connecting rod bearings of the W4-60 excavator air pump (SKI-82 type) are often prone to damage. After damage, the outer ring of the bearing is still embedded in the connecting rod hole and is difficult to remove. Due to the hardness of the outer ring, it is easy to slip when sawing with a hacksaw, and hard hammening is also likely to damage the connecting rod. At this point, the connecting rod can be clamped onto the bench vise. Use the socket of a heavy-duty socket wrench. On one side, use a socket slightly smaller than the outer ring of the bearing to hold against the outer ring of the bearing, and on the other side, use a socket slightly larger than the size of the connecting rod bearing hole to hold against the side of the connecting rod hole. Then gradually increase the force to clamp the bench vise. In this way, the outer ring of the bearing will be slowly pressed out. If there is a gas cutting tool, the outer ring of the bearing can be directly cut by gas cutting.

3. Skillfully remove the tires

When disassembling the tires of large wheel loaders and bulldozers, it is rather difficult to separate the tires from the rims. Due to long-term use without disassembly, the rims may rust, causing the tires and rims to stick tightly together. The disassembly method of releasing air and walking back and forth to crush is not very effective. However, the following method can achieve better results: That is, after removing the lock ring (some imported construction machinery, such as the WD140 bulldozer, has an outer ring on the tire), add water between the tire and the rim to facilitate lubrication. Use two bulldozer blades to press the two sides of the tire respectively, and place an iron rod of appropriate length across the rim in the middle. Then, thread a steel wire rope and lift it with a crane or loader, etc. In this way, the tire and the rim can be easily separated.

4. Skillfully change the pin sleeve

The pin sleeves at each pin shaft of the W4-60C excavator have been damaged due to long-term use and lack of lubrication. If the replacement method is not paid attention to, the pin sleeves are often not installed properly, resulting in damage to the ends. For this, the pin sleeve can be placed on the corresponding pin shaft, then the pin shaft can be inserted into the pin sleeve seat hole for centering and positioning. After that, the end of the pin shaft can be hammered with a hand hammer to make the head of the pin shaft press the pin sleeve into the pin sleeve seat hole. This method does not damage the pin sleeve, does not cause skewing, and is simple and reliable.

Iii. Use daily necessities for emergency substitution

Using daily necessities as emergency substitutes is an unavoidable emergency measure and must be based on reality: First, it should be simple and easy to implement, with a short production time; Second, it is necessary to ensure driving safety. Third, it is necessary not to damage the original device and not cause damage to other parts. Fourth, after an emergency, regular spare parts should be replaced in a timely manner.

1. Use bicycle parts for emergencies

1.1 If the small steel ball in the inner hole of the diesel engine fuel injector ejector rod is lost, it can be replaced by the ball bearing of a bicycle flywheel or the small steel ball in a scrapped grease injector.

When the return spring of the clutch release bearing of a farm vehicle breaks, the tension spring under the bicycle seat can be used as a substitute.

If the pins that fix the steering forks and steering arms on the Dongfeng-12 type walk-behind tractor are worn out, they can be replaced with bicycle crank pins.

When inflating or deflating a tire, it is often necessary to unscrew the valve core. Sometimes, due to improper force application or after long-term use, the lower part of the valve core's thread breaks inside the valve stem, and the broken part is rather difficult to remove. At this point, you can take a bicycle spoke, forcibly screw the threaded end into the valve stem with a broken core, allowing the spoke thread to penetrate into the broken core. Then, forcefully pull the spoke out, and the broken core remaining in the valve stem can be removed. This method is simple and easy to implement, and it has always worked.

2. Use daily necessities for emergencies

When cleaning the engine oil pan or the inner surface of the engine body, if there are too many iron filings and impurities that are difficult to clean thoroughly, you can use an appropriate amount of dough to stick and absorb.

2.2 When the float of the carburetor of a gasoline engine is damaged, the cork of a thermos can be modified to replace it.

2.3 If the brake fluid of a motor vehicle leaks or is lost, it can be replaced with white spirit or soapy water of a certain concentration.

2.4 Toothpaste contains abrasive materials. It can be used to grind micro-scratches on valves and valve seats, three precision pairs of diesel engines, and the glass of motor vehicle headlamps

2.5 Household detergent and the like can be used to clean mechanical parts, especially rubber parts, without swelling or deformation after washing.

2.6 Clean the parts contaminated with lubricating oil with laundry detergent and sawdust.

2.7 If the electrolyte level of the battery is found to be too low, to prevent sulfation of the plates, pure water or space water from the market can be purchased and poured into the battery.

2.8 By cutting open the shell of an aluminum can, it is very convenient to make aluminum gaskets for motor vehicles or funnels for refueling and adding water.

2.9 When it is found that multiple tube (core) components such as water tanks, oil coolers and hydraulic oil radiators are damaged, causing oil leakage, water leakage and air leakage, to quickly determine the damaged area, the cigarette blowing method can be used to locate the leakage point. Light a cigarette, take a few deep breaths, hold the cigarette in your mouth, block one end of the suspected faulty tube (core), and blow smoke towards the other end. The area where smoke is coming out of the tube (core) is the faulty part, and then look for the next part. This method is simple, easy to implement, effective and reliable, but safety should be noted.

3. Use electrical appliances in emergencies

3.1 If there is oil leakage at the shoulder of the high-pressure oil pipe joint of the diesel engine, cut a section of No. 16 electrical fuse and wind it under the fastening nut.

3.2 If the high-voltage contact carbon rod is accidentally lost during the disassembly of the magneto, resulting in the magneto being unable to generate high-voltage electricity, a section of the carbon core from a dry battery can be ground short and used as a substitute. If the carbon rod at the center electrode of the car distributor cover is damaged or lost, it can be slightly ground with the carbon rod from a No. 5 dry battery for future use.

4. Other emergency measures

4.1 If there is oil leakage at the nipple of the high-pressure oil pipe, a small ring can be cut from a plastic sheet or a soft metal sheet and placed in the cavity of the joint.

4.2 When the carbon brushes of the generator are excessively worn or the spring force is insufficient, affecting power generation, small pieces of the same length and width as the carbon brushes can be cut from wooden blocks or tree bark and placed between the spring and the carbon brushes to increase the contact pressure between the carbon brushes and the commutator.

4.3 Washed loofah can be used to replace the wire filter element of the air filter.

4.4 If the self-tightening spring of the rubber oil seal is too loose, it can be compensated by adding rubber bands.

4.5 The mating surfaces of the parts are usually sealed with gaskets, and a layer of oil-resistant sealant is applied on the gasket to enhance the sealing effect. However, if sealant is not available for the time being, paint can also be used as a substitute. The paint has a high viscosity and hardens after drying, which makes the seal reliable and the effect better. For instance, a Nissan WD140-4 bulldozer's air pump malfunctioned. After repair and installation, a layer of paint was applied to the sealing gasket of the pump cover due to the lack of sealant. It has been proven through use that the effect is very good.