Pneumatic impact reamer and reaming construction process

Abstract

The invention discloses a pneumatic impact reamer and a reaming construction process. The pneumatic impact reamer comprises an upper joint, an upper end cover, a central spindle, an outer cylinder, apunch hammer and a drill. The upper joint belongs to a switching buckle type upper joint. The upper joint is connected with the central spindle. The upper end cover is in threaded connection with thecentral spindle and the outer cylinder. A supporting sleeve and a bushing are sleeved with the outer cylinder in sequence. The punch hammer is sleeved with the bushing, the outer cylinder and a spacersleeve. The drill is fixedly mounted in the outer cylinder through a spline sleeve. A centralizing joint is arranged at the end, far away from the upper joint, of the drill. The centralizing joint isprovided with a plurality of air guide holes and liquid guide holes. According to the pneumatic impact reamer and the reaming construction process provided by the invention, compared with a bundled impact reamer, the pneumatic impact reamer is simpler in structure, free of welded components, integrally more resistant to impact and more reliable in operation; the pneumatic impact reamer is much larger than the bundled impact reamer through the effective impacting mass of the punch hammer, can reach higher impacting energy and has much higher rock breaking efficiency.

Description

technical field [0001] The invention relates to the technical field of hole reamers, in particular to a pneumatic impact reamer and a hole reaming construction process. Background technique [0002] In the process of horizontal directional crossing pipe laying construction, the reamer is used for reaming construction after the pilot hole construction is completed. Existing reamers used in rock formations include: bundled impact reamers, roller reamers, and hob reamers. There are certain defects in using these reamers for horizontal directional crossing pipelaying construction. [0003] (1) The bundled impact reamer uses several conventional down-the-hole hammers and drill bits to bind on the mandrel to realize the function of large-diameter hole reaming. It has the following disadvantages: 1). The binding structure is complicated and the reliability is low; 2. ). The drill bit inevitably produces eccentric wear. Because of the existence of these defects, the bundled impact...

AI Technical Summary

Problems solved by technology

[0003] (1) The bundled impact reamer uses several conventional down-the-hole hammers and drill bits to bind on the mandrel to realize the function of large-diameter hole reaming. It has the following disadvantages: 1). The binding structure is complicated and the reliability is low; 2. ). The drill bit inevitably produces eccentric wear

Because of these defects, the bundled impact reamer has not been widely used in the market

[0004] (2) Existing cone reamers, hob reamers, etc. have low drilling efficiency in hard rock reaming drilling, and a large amount of high-ratio mud is used, resulting in high construction costs

[0005] (3) The existing reaming construction technology adopts mud chip removal. In order to effectively discharge the cuttings in the drill hole, a large amount of high-ratio mud must be used, which will increase the cost of mud use

Moreover, even with a high-ratio mud, there are still large particles of cuttings remaining in the hole, which requires secondary crushing of the drill bit, which affects the drilling efficiency of the hole reaming

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