1. Impact of crushing

　　When the reaming bit works at the bottom of the well, the impact and crushing action of the gear teeth on the rock caused by the longitudinal vibration of the drill bit is the main method of the reaming bit to break the rock. When the drill bit is rotated, the teeth are pressed into the rock at a speed impact. This crushing method is similar to the characteristics of the static press crushing test. The teeth press for the rock and require sufficient specific pressure and contact time. Therefore, the axial load acting on the rock by the teeth of the rearing bit includes static pressure and impact load. The bit pressure applied to the drill bit is the static pressure part; the impact load is caused by the longitudinal vibration of the drill bit rotating at the bottom of the well, causing the bit-drill string system to continuously compress and stretch, and the lower drill string transmits this periodic elastic deformation energy to It is caused by the cone, which is the source of the impact pressure of the teeth when the drill bit breaks the rock. Increasing the impact pressure of the bit teeth on the formation can improve the efficiency of rock fragmentation.

　　2, sliding shear action

　　In the rock with high plasticity, in addition to the impact crushing effect of the teeth on the bottom of the well, the sliding action of the teeth on the stratum is also required, so that the teeth can shear the rock to expand the crushing effect of the rock. It is very important when drilling in soft formations. The measures to cause the cone to slip when rolling at the bottom of the well include overtop, compound taper, and shift axis.

　　(1) Super top. Overtop means that the cone top of the cone exceeds the centerline of the drill bit. The distance between the top of the cone and the centerline is called the super-top distance. The larger the overtop distance, the greater the amount of sliding. The overtop has slipped in the tangential direction, cutting off the rock between the teeth on each ring gear of the cone.

　　(2) Compound cone. The compound cone causes the cone to slide in the tangential direction, and the rock between the teeth on each ring gear of the cone is also cut off like the super crown.

　　(3) Shift axis. Axis shift refers to the translation of the axis of the cone relative to the axis of the bit. This distance is called the wheelbase. If the axle shift is larger, the sliding amount of the cone is greater, and the shearing effect is greater. The axle shift causes the teeth to produce axial sliding, which cuts off the rocks between the ring gears on the cone.

　　3. The shearing effect of the tooth itself

　　When the tooth eats into the rock under the action of axial pressure (weight on bit), the wedge-shaped surface of the tooth generates a horizontal shear force on the rock in contact with it, and the rock is sheared and broken along the shear surface. Moving and picking out the broken rock is the shearing effect of the tooth itself on the rock.

　　As we all know, the reaming bit is a tool for drilling and exploration in the petroleum industry. If we want to maximize the service life of the tool, we need to do a good job in the maintenance and protection of this tool, so what are the specific implementation matters? What?

　　The reaming bit is required to reinforce the workpiece when drilling thin plates. When it is drilling large workpieces, ensure the stability of the workpiece. When the tool is drilling steel parts, please ensure sufficient cooling and use metal cutting fluid. At the beginning and end of each drilling, its feed rate should be reduced by one third. The tool's good drill pipe rigidity and guideway clearance can improve the accuracy of drilling and the life of the rearing bit. Please ensure that the product magnetic base and the workpiece are level and clean. For materials with a large amount of fine powder during drilling, such as cast iron, cast copper, etc., you can use compressed air to help chip removal without using coolant. Please promptly wrap the iron filings on the drill body to ensure smooth chip removal.