The diagnosis of diesel engine connecting rod mechanism sound

2021 - diesel engine connecting rod mechanism of sound diagnosis 02 - 26 Ren Qiwu wang qiang ( Unit 65066 corps of teaching and research section jinzhou district of dalian city, liaoning province) 1. Knocked cylinder piston cylinder sound parts generally occur in the upper body, similar with a small hammer percussion produced during the cement floor of rhythmic 'clicking' sound. Idle, voice clear and clear; The voice temperature increase, decrease and even disappear; When the throttle sound more quickly and ring. The cause of type cylinder basically has the following kinds: piston and cylinder improper assembly or as a result of wear fit clearance is too large; The poor lubrication piston and cylinder wall straight contact touch; Deformation caused by the piston connecting rod eccentric wear make clearance. Diagnostic methods for each cylinder oil cut-off method. If you give a cylinder oil cut-off, sound significantly reduced or disappeared, and can hear clear recovery oil 'clicking sound, shows that the cylinder piston type cylinder. 2. Piston pin sound piston pin sounded on the body parts, like two steel ball and the 'tete' voice. Idle or is lower than the medium speed, sound general clear; After the temperature rise, noise generally not too big change, sometimes more clearly, this is with the piston type cylinder sound one major difference. Piston pin sound reason mainly has: caused by poor lubrication of piston pin and connecting rod bushing wear ranks, fit clearance is too large; Card ring on the piston pin loosening, move to free piston pin up; Connecting rod bushing location dimension in the process of repair master, bushings and connecting rod with bad; Not according to standard requirement in the repair will pressure into the connecting rod little head bushing. If the diesel engine at low temperature can hear the sound of continuous when idle speed, speed up to medium speed after noise disappear, and give a cylinder oil cut-off noise also disappear, but noise resumed after recovery oil, can be concluded that the cylinder piston pin and the clearance between the connecting rod bushing hole is too big. If the diesel engine noise at a certain speed, adopt cylinder oil cut-off method to a cylinder oil cut-off, weakened noise and clutter; Recovery oil supply, sound recovery. At this point can be concluded that the cylinder piston pin and piston pin hole to the large clearance b etween coordination. Unclear if there is a continuous noise, often is the piston pin and piston pin hole, the piston pin into the connecting rod bushing hole clearance is too large and at the same time. If the tapping sound, can be concluded that for the piston pin card or packing ring is broken. 3. Connecting rod shaft sound the sound parts occurred in the middle of the body, the noise characteristics for 'dangdang' and 'lattice stare blankly. When the diesel engine acceleration, have distinct 'dangdang' tapping, continuous sound is ringing, short, solid, and increases with the diesel engine speed, load increases; When diesel engine temperature, noise changed little; When idle speed and medium speed operation, can hear the sound of the 'lattice stare blankly; Break oil experiment, less noise. Main causes of the connecting rod shaft sound: fitting clearance of connecting rod journal and the connecting rod do not conform to the standard, oil brand wrong or oil pipeline leak and cause poor lubrication, quicken the wear and tear of connecting rod, so that the tile burning; The quality of the connecting rod or there is something wrong with the installation, make connecting rod deformation, lead to fall off the alloy and the tile burning; Lost big end bore wear and bearing shell cylindrical circular, and blockage of the oil hole and shaft neck oval, connecting rod, and shaft neck poor contact will lead to sound connecting rod shaft. Satisfy the following conditions, can determine the connecting rod shaft sound: gradually step on the gas, from the idle speed to medium speed diesel engine running, the noise increases with the rotation speed of diesel engine; Slowly, step on the gas, can hear the sound of 'lattice stare blankly, and noise at the instant of the gas is more obvious; Noise is reduced, when a cylinder oil cut-off recovery oil instantaneous sound recovery; Remove the oil filler cap, can hear the tapping of a strong 'dangdang; Diesel engine oil pressure drop. 4. Spindle tile louder sound parts occur in the lower part of the body, the noise can be characterized as' empty, empty, empty blunt the tapping of a dumb. Performance of diesel engine acceleration, have obvious heavy noise in a row, the body produces fluttering; The noise increases with the diesel engine speed, load, but has nothing to do with the temperature change of diesel engine; Single cylinder oil cut-off when no change, two adjacent cylinder oil cut-off at the same time, less noise, oil pressure significantly decreased at the same time. Of the main causes of main shaft tile sound has the following kinds: fitting clearance of the spindle and the spindle neck for bearing wear loose kuang; Crank shaft axial clearance is big, the crankshaft deformation; Choose oil brand not in conformity with the requirements of the, or ruptured oil filter makes huge loss of engine oil, cause poor lubrication; Engine long-term overloaded, ultra high temperature work led super oil viscosity reducing and tile burning. When high speed diesel engines, sound obvious, the body has great vibration, and a significant reduction in the oil pressure, signifying a pine kuang or alloy spindle tile fall off; Noise, medium-speed diesel engine at idle speed or below, high-speed voice become cluttered, may be the crankshaft bending; Diesel engine at low and medium speed operation, when accelerating noise, can determine the main shaft tile kuang. Source: 'engineering machinery and maintenance'