CN102581574A

CN102581574A - Method for machining inner gear rings

Info

Publication number: CN102581574A
Application number: CN2012100735583A
Authority: CN
Inventors: 江国辉
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-03-20
Filing date: 2012-03-20
Publication date: 2012-07-18

Abstract

The invention discloses a method for machining inner gear rings. The method includes steps of forging, normalizing, rough lathing, finish lathing, gear shaping, carburizing, pressure quenching and shot blasting. By the aid of the method, surface hardness, core structure and depth of a hardened layer of a gear ring are improved, machining cost is lowered, deformation of the gear ring is avoided assuredly, accordingly, the service life of the gear ring is prolonged, and the load capacity of a vehicle is enhanced.

Description

A kind of processing method of ring gear

Technical field

The present invention relates to a kind of processing method of ring gear.

Background technology

The automobile synchronizer gear ring is one of important spare part in the automobile variable speed mechanism, and its crudy, structure, service life etc. directly have influence on the cruising of automobile and driver and crew's personal safety, and Domestic Automotive Industry is started late, and its heat treatment technics is comparatively backward; Picture adopts the technology processing ring gear of ionic nitriding, can not satisfy the requirement of present automobile, and medium carbon alloy steels such as 40Cr are adopted in gear ring processing usually; Earlier rough turn, modified again, after carry out fine finishining; Carry out nitrogenize then, do to prevent the gear ring distortion like this, but its case hardness is low; Hardened layer is shallow, and processing cost is high, presses for a kind of method now and solves these difficult problems.

Summary of the invention

The invention provides a kind of processing method of ring gear, the gear ring that this method is made can improve case hardness, centre hardness, hardened-depth, cut down finished cost, and can guarantee the gear ring size again.

The present invention has adopted following technical scheme: a kind of processing method of ring gear, and it may further comprise the steps: step 1, forging, select low-carbon alloy steel for use, reserve surplus, forging and molding according to drawing requirement; Step 2, normalizing are adopted the isothermal normalizing technology to eliminate and are forged the harmful structure that produces, and make even tissue; Step 3, rough turn is removed a large amount of surpluses, and cylindrical, hole, end face are carried out preliminarily forming; Step 4, finish turning are shaped cylindrical, hole, end face, seam according to the specification requirement finish turning; Step 5, gear shaping are with the tooth Profile Machining moulding of ring gear; Step 6, carburizing through the multipurpose furnace carburizing, guarantee that carburized layer is between 0.6-1.0mm; Step 7, pressure are quenched, and with the workpiece heating, move to press on the press again and quench; Step 8, ball blast carry out ball blast with the workpiece that it is good that pressure is quenched, and surperficial non-martensite is removed in the clean surface, obtains finished product.

Normalizing temperature is 920-930 ℃ in the said normalizing process, and isothermal temperature is 600-650 ℃, and hardness is 160-200HBW after the isothermal normalizing; Said pressure is quenched in the process workpiece is quenched pressing after being heated to the 840-860 degree on the rotary hearth furnace.

The present invention has following beneficial effect: the gear ring that the present invention makes had both improved case hardness, core structure, hardened-depth, had cut down finished cost, and can guarantee the gear ring distortion again, thereby improve the service life of gear ring and the load-carrying ability of car.

Description of drawings

Fig. 1 is a process chart of the present invention.

The specific embodiment

As shown in Figure 1, the invention provides a kind of processing method of ring gear, it may further comprise the steps: step 1, forge, select low-carbon alloy steel 20CrMnTiH material for use, reserve surplus, forging and molding according to drawing requirement; Step 2, the isothermal normalizing technology is adopted in normalizing, and normalizing temperature is at 920-930 ℃, and isothermal temperature 600-650 ℃, hardness 160-200HBW after the isothermal normalizing, and can eliminate the harmful structure of forging generation, and make even tissue; Step 3, rough turn, remove a large amount of surpluses, cylindrical, hole, end face are carried out preliminarily forming; Step 4, finish turning is shaped cylindrical, hole, end face, seam according to the specification requirement finish turning; Step 5, gear shaping, with the tooth Profile Machining moulding of ring gear, profile accuracy guarantees within 8 grades; Step 6, carburizing through the multipurpose furnace carburizing, guarantees that carburized layer is between 0.6-1.0mm; Step 7, pressure is quenched, and workpiece is heated to the 840-860 degree on rotary hearth furnace, moves to press on the press to quench again, and can reduce distortion like this, and profile of tooth can guarantee within 9 grades; Step 8, ball blast carries out ball blast with the workpiece that it is good that pressure is quenched, and surperficial non-martensite is removed in the clean surface, can increase the service life of gear ring like this.

Claims

1. the processing method of a ring gear is characterized in that it may further comprise the steps:

Low-carbon alloy steel is selected in step 1, forging for use, reserves surplus, forging and molding according to drawing requirement;

Step 2, normalizing are adopted the isothermal normalizing technology to eliminate and are forged the harmful structure that produces, and make even tissue;

Step 3, rough turn is removed a large amount of surpluses, and cylindrical, hole, end face are carried out preliminarily forming;

Step 4, finish turning are shaped cylindrical, hole, end face, seam according to the specification requirement finish turning;

Step 5, gear shaping are with the tooth Profile Machining moulding of ring gear;

Step 6, carburizing through the multipurpose furnace carburizing, guarantee that carburized layer is between 0.6-1.0mm;

Step 7, pressure are quenched, and with the workpiece heating, move to press on the press again and quench;

Step 8, ball blast carry out ball blast with the workpiece that it is good that pressure is quenched, and surperficial non-martensite is removed in the clean surface, obtains finished product.

2. the processing method of a kind of ring gear according to claim 1 is characterized in that normalizing temperature is 920-930 ℃ in the said normalizing process, and isothermal temperature is 600-650 ℃, and hardness is 160-200HBW after the isothermal normalizing.

3. the processing method of a kind of ring gear according to claim 1 is characterized in that said pressure is quenched in the process workpiece is quenched pressing after being heated to the 840-860 degree on the rotary hearth furnace.