Method for machining high-position-precision deep hole in connection rod of diesel engine

Abstract

The invention provides a method for machining a high-position-precision deep hole in a connection rod of a diesel engine. Bolt holes are firstly machined by adopting a gun drill so that position precision between the holes is guaranteed; and the bolt holes are machined to technically required sizes by utilizing a reamer and the surface roughness of the holes is guaranteed, so that the quality and machining efficiency of products are guaranteed. With the adoption of the method provided by the invention, manual polishing does not need to be carried out again, so that procedures and labor cost are saved and the working efficiency is extremely improved; and the method has a very high practical value.

Description

technical field [0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a method for processing deep holes with high position precision on connecting rods of diesel engines. Background technique [0002] There are 4 bolt holes on the connecting rod of a certain type of diesel engine. The hole diameter is φ20.6mm and the hole depth is 192mm. The outlets are all within ±0.05mm. The existing processing method is: the equipment uses a horizontal machining center, the machining center has an internal cooling function, and the pressure must reach 40Kg, install a fixture on the workbench of the horizontal machining center, and install the connecting rod. To the fixture, after the positioning is accurate, clamp it. Before processing with a gun drill, first use a center drill to process four center holes on the connecting rod, then use a φ20mm drill to process four shallow holes with a depth of 25mm, and then use a boring tool to bo...

AI Technical Summary

Problems solved by technology

Although this method can ensure the position accuracy of the hole, because the material selected for the connecting rod has good toughness, the iron filings generated by the gun drill are relatively long, which is easy to strain the processed bolt hole and cannot reach the surface roughness of Ra3.2. It is required that the bolt holes can only be polished by hand after the gun drilling process. The specific method is: hold a round rod with a hand electric drill, slot the head of the round rod, wrap the emery cloth in the groove, and put the round rod into the bolt hole, grind the bolt hole with a hand-held electric drill

Considering the surface quality of the bolt holes is guaranteed by the current technology, the feed rate of the tool is very low, only 0.02mm / r, and the processing efficiency is low; if the iron filings seriously damage the bolt holes, the manual grinding and polishing amount is large Even if the hole size is ground out of the tolerance range, the scars cannot be eliminated, and it will result in defective products, and the quality cannot be guaranteed, so it is necessary to propose improvements