In the forum, a lot of friends to see how to test the car, we all know that in fact, in fact, most of the test car should be idle, the idle speed small accelerator test can reflect the performance of the various aspects of the excavator. The idle speed of the small excavation is generally controlled in 900 turns, and the control is about 1000 turns, but the specific operation and process are still more critical.
1, after the excavator starts to idle a few minutes: after starting the engine, the engine oil pump needs to circulate for a period of time, to achieve the required pressure value to provide reliable lubrication to the engine, strictly prohibit the throttle. Especially in winter, the oil viscosity is high and the damage to the engine is large.
2. Idle time should not be too long: too long time will lead to poor engine lubrication carbon deposition, turbocharged bearing damage. It is generally not more than 15 minutes.
The test process is divided into five parts
1. Idling combination (* * - engine hydraulic)
1. Mini-excavation idle bulldozer: Put the throttle to the lowest, idle bulldozer, while the small throttle to watch the table and exhaust.
For a small excavation with a weight of less than 10 tons. If the small shovel idling up the roof easily and the engine turning at 100-200 is normal, the performance is basically good.
Conversely, if the equipment is easily choked out, or the engine is transferred outside the 200 turn, the engine is shaking badly, indicating that the force is not very large, and the pressure of the engine and the large pump does not match.
2, idling big arm car: put the excavator's arms and arms to the lowest level, turn the bucket out, and use the horse's head to touch the ground. The horse's head is at the top of the car. See if you can put it up. (Note: Xiao Song, Komatsu 56, Kubota series is not supported by the car's own design).
The same push to push the earth, as a big dig without shovel, can cooperate with this action, the force of the arm of the big arm is very large, the car at the same time watch the engine number table, the idle speed is usually 1000 turn, hold the car in 100-200. If the idle speed can not be supported, the engine turns more than the range is large or suffocated, indicating that the engine power of the excavator is not matched with the large pump pressure, and there is serious wear. The performance can be judged accordingly.
3.. Idle speed limit action: hold up to the highest and the lowest. Hold the car once with the big throttle. While holding the car, observe the engine turn and engine exhaust color.
Small and small throttle with the use of small dig: idle speed standard 900 turn, turn 100-200 in normal, the maximum throttle does not exceed 300. Big dig: idle 1000 turn, turn in 100-200 normal. (200 turn less: any engine with good performance will turn 200 times within a high speed overflow).
Sum up:
It mainly determines whether the power of the engine matches the pressure of the hydraulic pump and whether the oil circuit is smooth.
The three actions need to be interspersed with each other to operate, all of which refer to the number of revolutions, hold back the car. In the actual operation of the excavator, these data and conditions can not reach the standard, the equipment will turn, even be suffocated when the equipment is hard to dig, and it is commonly known as suffocating, if the performance is not good, it can not be qualified for the long term. Yes. This is the most important performance parameter of the excavator.
Two, the wear gap of each part
1. The clearance between working devices is worn to lift the excavated arm to the horizontal position and rotate around. The main points of observation are three positions:
(1) the gap between the Mara head and the brachial arm;
(2) the gap between the small arm and the large arm;
(3) the gap between the big arm and the main frame.
Among them, these two spaces are normal if they are not very large. Because we know that the normal excavator work, iron and iron friction must wear, mainly to see the gap between the main arm and main frame. If the gap is very large, the wear condition of the car will be serious and the maintenance is bad. Or with a broken hammer can also have a great impact.
2. Cylinder clearance wear: big and small arms put flat bucket gently roof, look at the arm, two arms, bucket several cylinder socket clearance. The smaller the gap is, the lighter the wear is and the better the lubrication is. The larger the gap is, the more serious the wear is, the worse lubrication is.
Both the size arm and the oil cylinder are the most important work devices. Through the combination of several actions, we can analyze the maintenance and maintenance status of the excavator and the specific work strength.
Three. Test turn clearance and rotary speed reduction (waist part X).
1. Test the upper and lower clearance of the market: lifting the bulldozer shovel and placing the excavator at the horizontal position. Lift the arm and magnify the arm. To increase the frequency and speed, let the two parts of the excavator to slosh, and people squatting in the middle of the large plate to observe the gap between the upper and lower plates: the excessive clearance indicates that the wear of the car is relatively serious, and the most obvious digging machine for a long time hit the broken hammer is caused by the pressure transmission of the large pump and the violent shaking of the upper and lower pumps. The gap between the upper and lower plates is too large. Serious conditions will affect the normal work of the excavator and therefore need to be repaired. (example: for example, for some municipal greening projects, land leveling requirements are very high. When working, the drastic shaking of the whole dish will cause the cab to shake, and the driver will operate the pilot handle in the cab with slight shaking. It is difficult to find a balance. It is recommended that dial bearing be used for measuring or measuring dial bearings.
2, test the left and right clearance of the market: idle speed, gently point the rotation, if the excavator turns immediately, it proves that the clearance is very small. On the other hand, there will be a few seconds of retardation after the point, which indicates that the gear wear is serious, the deceleration gear can not be stuck between the gear and the gear is not bitten by the gap, and the big arm of the excavator can be lifted, the two arm vertical ground, and the gap is gently retreated.
3, test whether the rotary brake is over range: idle speed, maximum throttle minimum throttle test. It stops suddenly during the rotation of the left and right, and sees whether the rotation of the excavator can stop, and usually has a certain brake protection when the rotation stops, and there is a small amount of buffer. But if the deceleration distance is too large to control, it will affect the work. （举例：在挖机从事装车或者甩土方的情况下过大的减速超程会把物料甩在规定范围之外。 Increase the driver's difficulty in the operation of the excavator.
4. Three action combinations to listen to motor and deceleration whether there is abnormal sound: do the above action but also listen to motor and rotary deceleration whether there is abnormal sound, there is a lag.
Summary:
Rotary speed reducer and back loading motor are very important as the waist part of the excavator, and the cost of maintenance is very high. The performance tests of the above four movements are reflected in the testing process, for example, the measurement of the upper and lower gaps in the large plate will be measured with a dial meter to zero zero millimeters.
Four. Chassis parts testing (lower leg part four wheel area)
1, the speed of idle walking is strong: idle move the left side of the walking control handle, do not see whether the original place can spin. On the other hand, test the right. This action can not only test whether the walking motor is strong, but also test whether the engine and the walking motor are power matching. If the position is stationary or suppressed, the power does not match, or the motor has problems.
2, whether or not to walk: the digging machine is placed horizontally, and the walking rod is pushed to see whether it is straight. If you just walk, the deviation indicates that the wear degree of the two sides of the motor is different, or the flow of the pump valve to the two motors is uneven. It is a serious case that needs maintenance.
3, walking fast and slow gear: commonly known as tortoise rabbit files, during the process of holding down switches to debug. For example, under special conditions, the excavator needs fast gear to walk. Lack of speed and speed will affect the speed and efficiency of work.
4, chassis vulnerable parts check: finish the above three movements, use the big arm and the shovel to support the car, watch chain plate, chain rib, chain bone (chain), support wheel, drag wheel, drive gear and other chassis parts wear and tear. Close the key door, maintain the state of the vehicle, and check whether the pressure of several cylinders is released.
Five, the degree of movement matching: (brain part - main control valve)
Commonly known as dry work moves, we can show various combinations of movements to our customers.
1, you can demonstrate a set of car movements (digging bucket, big arm, rotary combination to see whether the work is fluent).
2, go along the line to do action (walking mode to do basic movements to see if the card is serious).
3. Top car rotating big plate (slewing combination size arm).
Through this series of action combinations, we can determine whether the car's action is matched and whether the main valve is stuck. At the same time, the sensitivity of each action can be measured in side. The power of the engine, the flow of the hydraulic pump, the walking motor, the deceleration, the deceleration of the rotary motor can all be coherent, and the performance of the excavator is judged comprehensively.
