Method and device for machining cracking groove for connecting rod

Abstract

A method and a device for machining a cracking groove for a connecting rod, wherein a drive pulley (72) is rotated under the driving action of a rotatingly driving source (68) installed in a body (14) to transmit the rotatingly driving force of the drive pulley (72) to a driven pulley (74) through a drive force transmission belt (76) so as to rotate a groove machining part (24) integrally connected to the driven pulley (74). In the groove machining part (24), a spindle (34) integrally connected to the driven pulley (74) is rotatably supported on a support part (32), and a metal saw (36) having a plurality of blade parts (54) on the outer peripheral surface thereof is installed on the holding part (48) of the spindle (34). A first groove (88) of roughly V-shape in cross section is formed in the large end hole (20) of a connecting rod (18) by inserting the metal saw (36) into the large end hole (20) of the connecting rod, and a second groove (90) of roughly V-shape in cross section which is symmetrical with the first groove (88) is formed in the connecting rod (18) at a position opposed to the first groove (88) with respect to the axis of the connecting rod.

Description

technical field [0001] The present invention relates to a method and a device for processing a fracture groove for a connecting rod. The method and device for processing a fracture groove for a connecting rod are formed, for example, on the inner peripheral surface of the large end hole of the connecting rod after the connecting rod constituting the vehicle engine is integrally formed. A breaking groove for splitting the connecting rod into a cover part and a rod part is formed on the top. Background technique [0002] Conventionally, a crankshaft and a piston of a vehicle engine are connected by a connecting rod (hereinafter simply referred to as a connecting rod), and a rotational driving force of the crankshaft is transmitted to the piston. [0003] The connecting rod is provided with a bearing on the inner peripheral surface of the large end hole formed at the large end portion on the one end side to pivotally support the journal of the crankshaft, and a small end hole f...

AI Technical Summary

Problems solved by technology

However, in the broaching edge of the above-mentioned tool, since it is difficult to form the fracture-promoting groove in an acute-angled substantially V-shape, it is necessary to increase the impact when the connecting rod is divided into the shaft portion and the cover portion by the fracture-promoting groove. load, and it is difficult to effectively split the above-mentioned connecting rods reliably and equally

[0009] In addition, in the cutting method performed with throwaway inserts, etc., since the inner peripheral surface of the large end hole of the connecting rod is intermittently cut by the plurality of inserts, the tops of the cutting edges of the plurality of inserts are worn, and thus In the process of grooving, it is difficult to process the groove angle into an acute angle, and the degree of stress concentration at the time of fracture becomes lower

[0010] In addition, in the case of forming the groove for promoting fracture by laser processing, a large-scale processing device is required, and the investment cost required for the processing device is huge.

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