Intrinsic Cause of Impact Weakness of Breaking Hammer - Piston Pulling

2022-11-02

　　HammerThere are many factors for impact fatigue, such as insufficient nitrogen pressure, insufficient pressure of the accumulator, insufficient oil pressure, but the main cause of internal leakage is the roughening of the piston or cylinder.

The main causes of piston pulling are described below.

As the key spare part of the breaker, the piston has extraordinary functions. However, there are many objections caused by the longitudinal damage of the imported piston. Therefore, the editor sorted out some work experience and explained the main reasons for the roughening of the piston, hoping to give some advice to customers. some reminders.

(1) The hydraulic oil is not cleaned

If residues are infiltrated into the oil, such residues can cause damage as soon as they are wedged into the gap between the piston and the cylinder. This type of damage has the following characteristics: generally there are grooves with a depth of more than 0.1mm, the number is small, and the length Equivalent to the stroke of the piston.

(2) The gap between the piston and the cylinder is too small

This kind of thing often occurs when the piston is replaced. If the gap is too small, the hydraulic breaker is working. In view of the increase in oil temperature, the gap will change. At this time, the piston and the cylinder are easy to cause damage. The characteristics are: pull marks The depth is shallow, the range is large, and its length is equivalent to the stroke of the piston.

(3) The hardness value of the piston and cylinder is low

The piston is affected by external force during the movement. In view of the low hardness of the surface of the piston and the cylinder, it is prone to damage. Its characteristics are: shallow depth and large range.

(4) The drill rod guide sleeve fails

The guide sleeve is poorly lubricated or the wear resistance of the guide sleeve is poor, which accelerates the wear of the guide sleeve. Sometimes the gap between the drill rod and the guide sleeve reaches more than 10mm. At this time, the center line of the drill rod is very easy to deflect. When the rod is at the tail end, the recoil force received by the piston is an eccentric force, and a component of this force produces a radial force acting on the piston. The piston is deflected to one side under the action of the radial force, so that the original gap disappears and the oil film is affected. Damage, dry friction, quickly damage the surface of the piston and cylinder. Its characteristic is that the damage area is relatively large, about 1\/3 of the cylinder area, and the damage trace is slightly shorter, which is equivalent to the displacement of the drill rod.