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CN-122007831-A - Diesel engine part gram hole machining process

CN122007831ACN 122007831 ACN122007831 ACN 122007831ACN-122007831-A

Abstract

A process for machining the gram hole of diesel engine includes such steps as machining the external holes at two ends of gram hole, replacing the oil holes whose axial line is inclined to that of gram hole, installing the boring tool on mainshaft, orienting the tool nose to the inclined angle of oil hole, radial reverse bias, feeding it to the internal cavity of gram hole, and radial forward bias reset. According to the invention, burrs can be synchronously removed by drilling the oil holes and boring the oil holes, and a single cutter can finish full-process machining without a flat rotating disc, so that the problem of cutter interference is solved, the machining precision is high, the working procedure is simple, and the cost is greatly reduced and the efficiency is improved.

Inventors

  • CHEN QIHANG
  • ZHANG XUZHONG

Assignees

  • 南京林业大学

Dates

Publication Date
20260512
Application Date
20260409

Claims (10)

  1. 1. The utility model provides a diesel engine part gram hole processing technology, gram hole is the step hole that sets up in diesel engine cylinder block bottom, and the aperture of both ends outer hole is less than the aperture of middle hole, and the hole is connected with the oilhole, its characterized in that, the processing technology in gram hole includes following steps: s1, processing outer holes, namely sequentially processing gram Kong Jizhun holes preset in a cylinder block, and processing the aperture size of gram Kong Waikong for a reference hole; S2, oil hole machining, namely replacing an angle milling head, and drilling an oil hole, wherein the axis of the oil hole and the axis of the gram hole form an inclined angle; S3, assembling a cutter, namely assembling a forming boring cutter on a main shaft of a numerical control machine tool, wherein the forming angle of a cutting edge of the forming boring cutter is matched with the inner and outer chamfers to be processed of the gram hole, and the processing outer diameter is matched with the aperture size of the inner hole of the gram hole; s4, feeding and positioning, namely orienting the cutter point of the forming boring cutter to an inclined angle consistent with the axis of the oil hole, controlling the cutter point to deviate along the radial reverse direction, and feeding the forming boring cutter into the inner cavity of the gram hole along the axial direction of the gram hole so that the cutter point is coaxial with the axis of the oil hole; s5, inner hole machining, namely controlling the cutter point of the forming boring cutter to deviate along the positive direction along the radial direction, and carrying out reciprocating feed cutting along the axial direction of the gram hole, so as to machine the inner hole of the gram hole; s6, internal chamfering, namely orienting the cutter point of the forming boring cutter to be parallel to the central axis of the gram hole, controlling the cutter point to deviate in the radial reverse direction, feeding the forming boring cutter into the gram hole to the internal chamfering depth, controlling the cutter point to deviate in the radial positive direction, and finishing chamfering in the gram hole; And S7, performing outer chamfering, namely orienting the cutter point of the forming boring cutter to be parallel to the central axis of the gram hole, controlling the cutter point to deviate in the radial reverse direction, respectively moving the forming boring cutter to the reference positions of the outer end surfaces of the two sides of the gram hole in the axial direction, and controlling the cutter point to deviate in the radial positive direction to finish the outer chamfering of the gram hole.
  2. 2. The diesel engine part gram hole processing technology according to claim 1, wherein an oil inlet hole for conveying lubricating oil is formed in the bottom of the diesel engine cylinder block, and the oil inlet hole is communicated with the oil hole.
  3. 3. The process of claim 2, wherein the forming boring tool enters the aglycone hole from the bottom of the cylinder block, an inner chamfer of the aglycone hole near the bottom of the cylinder block is a proximal inner chamfer, a single-side hole wall of the oil hole is positioned in the proximal inner chamfer, extends from the aglycone hole to the oil inlet hole and is orthogonal to the oil inlet hole.
  4. 4. The diesel engine part gram hole processing technology according to claim 1, wherein the outer hole diameter is 280 mm-284 mm, the hole diameter of the oil hole is 15 mm-17 mm, and the inner hole diameter is 284 mm-295 mm.
  5. 5. The process for machining a gram hole of a diesel engine part according to claim 4, wherein an inclination angle between the axis of the oil hole and the central axis of the gram hole is 15 ° to 20 °.
  6. 6. The diesel part gram hole machining process according to claim 5, wherein the chamfer angle in the gram hole is 20 ° to 25 °.
  7. 7. The diesel engine part gram hole processing technology according to claim 6, wherein the deviation of the tip of the forming boring cutter in the radial direction is 5 mm-8 mm.
  8. 8. The diesel part gram hole machining process according to claim 7, wherein the inner hole diameter is 283mm, the oil hole diameter is 16mm, the outer hole diameter is 289mm, the inclination angle is 17 °, the chamfer angle is 20 °, the main deflection angle of the forming boring cutter is 20 °, and the deflection amount of the tip of the forming boring cutter in the radial direction is 5mm.
  9. 9. The diesel engine part gram hole processing technology according to claim 1, wherein the same forming boring cutter is adopted in S3-S7, and no cutter changing operation is adopted in the processing process.
  10. 10. The diesel engine part gram hole processing technology according to claim 1 or 9, wherein the forming boring cutter is a single-edge boring cutter, the cutting angle of the cutter tip of the forming boring cutter is matched with the angle of a chamfer to be processed, and the boring cutting and the chamfer forming processing are completed synchronously.

Description

Diesel engine part gram hole machining process Technical Field The invention belongs to the field of diesel engine manufacturing, and particularly relates to a diesel engine part gram hole processing technology. Background The flange hole is a key precise hole system which is arranged at the bottom of a diesel engine cylinder body and is used for installing a piston rod stuffing box and providing reciprocating motion guide for the piston rod, is a typical special-shaped step hole in structure and has a special form of small pore diameter at two ends and large pore diameter in the middle, and meanwhile, an inclined lubricating oil hole is designed on the side wall of the middle hole section, the axis of the oil hole forms a preset inclined angle with the vertical central axis of the flange hole, and the oil hole is in an orthogonal through state with an oil delivery threaded hole at the bottom surface of the cylinder body and is used for constructing a forced lubricating channel of a piston rod and stuffing box friction pair. The method is limited by the compound constraint of the step structure and the space oblique oil hole, the gram hole cannot be directly machined by adopting a conventional through hole boring process, and the problems of cutter interference, hole wall scratch, oil hole position deviation, insufficient chamfer forming precision and the like are very easy to occur in the machining process, so that the method belongs to one of the key working procedures with the highest difficulty and the most strict precision control in the cylinder body machining. At present, two types of process routes are mainly adopted for processing the gram holes in the industry: And a flat rotating disc is adopted on the numerical control boring machine to be matched with a turning tool for processing, and the control system drives the flat rotating disc to drive the tool to execute a complex radial feeding track so as to realize the forming processing of the stepped hole and the positive and negative chamfer angles. The scheme relies on high-cost accessories such as a flat rotating disc, equipment investment is large, programming and debugging are complex, requirements on skills of operators are high, and in the processing process, a cutter is hung and stretched, rigidity is poor, vibration and cutter yielding are easy to generate, so that hole wall roughness and form and position tolerance are difficult to guarantee stably. The method comprises the steps of adopting multi-cutter sequencing processing on a numerical control machine tool, firstly carrying out rough boring processing on an integral hole site, then replacing a forming disc milling cutter on a main shaft, completing rough processing according to a middle large hole track through two-shaft linkage, and finally adopting a fine boring cutter and a chamfering cutter to respectively finish two end reference holes and inner and outer chamfers in sequence. The scheme has the advantages of complex working procedures, multiple times of tool changing, accumulated positioning errors caused by multiple times of clamping and tool changing, poor consistency of key precision such as coaxiality, chamfer angle and the like, low processing efficiency and high production cost. The two traditional processes adopt a process of firstly processing a middle big hole and then drilling a slant lubrication oil hole, burrs and flanges generated by drilling the oil hole are positioned on the surface of a finished hole wall, are difficult to remove, scratch a piston rod in the running process of a diesel engine, damage a sealing ring, even cause oil way blockage, and influence the lubrication and sealing reliability. Meanwhile, the inherent defects of repeated tool changing, complex path control and post oil hole machining make the machining precision, production efficiency and product consistency of the gram holes difficult to meet the large-scale manufacturing requirements of high quality, high efficiency and low cost of the modern large-scale low-speed diesel engine, and restrict the further improvement of the manufacturing level of key parts of the marine diesel engine. Disclosure of Invention The invention aims to provide a gram hole processing technology of a diesel engine part, which aims to solve the technical problems that the conventional boring method cannot be adapted, a cutter is easy to interfere and scratch, burrs of an oil hole are difficult to remove, the working procedure is complicated, and the forming precision is difficult to guarantee stably in the existing gram hole processing technology. In order to achieve the above purpose, the specific technical scheme of the diesel engine part gram hole processing technology is as follows: The utility model provides a diesel engine part gram hole processing technology, gram hole is the step hole that sets up in diesel engine cylinder block bottom, and the aperture of both ends outer hole is less than the aperture of mid