Research On Improving The Cutter Design Of Auto Transmission Gear

For an enterprise, the biggest role of tooling system is to reduce cost. With the new technology of tooling system ,efficient processing can be achieved and the cost of using machine be effectively reduced.So to speak, tooling system contribute a lot to improve the economic benefit of a company.Therefore, an enterprise wants to improve the craft level, product quality, the first job they need to do is to design and manufacture of best tool, continuous improvement and innovation. Practice proves that put a little investment on it, get a big profit.Most of gear cutting tools are complex. In recent years, with the high requirements to gear's performance, the new kinds of gear cutting continous to arise. Meanwhile, there are many technical problems still need to be solved. In the process of graduation design topic, combined with the highlight problems at my company, I chose the topic "the research of improving the design of auto transmission gears tools"as the research content of graduation design and try to improve and innovate the cutting tool engineerings which are being study or still not solved in domestic. The research results to improve the manufacturing level of gear cutter in domestic and promote the new technology has good economic significance and social benefits. The content includes the following three aspects:Currently,to reduce the auto weight, automobile manufacturing enterprises in the world are trying to reduce transmission weight. One of the common method is to reduce axial dimensions of gearbox, remove the clearance groove of the contraction tooth of synchronizer sleeve, so the method of machining process can't be applied. At present, an advanced method appeared abroad called inflation crowded method, this method has high efficiency and precision. The current inflation crowded method introduced by my company is not reasonable in design and localization cutter life is unstable which bring a lot of trouble to production. This article puts forward a new kind of design method to improve the design theory ,overcome the technical problems of the original structure ,raise the precision of cutting tools ,extend the cutter life and create a favorable condition for promoting the new technology of manufacturing engaged tooth and contracted tooth of the synchronzier's sleeve.At present,the world car industry manufacture gears by shaving process mostly as its high efficiency. Shaving process has its congenital defect process that is easy to generate concave during production. To ensure the accuracy of gear profile ,shaving cutter must be corrected its flank shape. Correcting shaver flank shape is a complex technology and is also an important basic technical work in gear industry. So groping and accumulating a method of correcting shaver flank shape is that gear manufacturing enterprises are dedicated to explore a technical work. In this article ,through using computer technology and the advantage of drawing process and simulating the engagement of shaving cutter and workpiece, then put forward a new method to determine the shaping curve of the cutter. The method is simple, accurate and intuitive .With the method applied, can get intended target, overcom the blindness, improve the success chance of shaver grinding rate so that can provide a guarantee supply to production.Refer to the given shape curve by the method, the work of correcting cutter flank shape greatly reduced,the cutter durability increased by 10% ~ 50%.Therefore the targets of reducing the cost of cutter the production cost can be achieved.With the development of science and technology, use requirements increasing, the demand to reduce gear noise becomes stronger and stronger. The major cause for noise is the bump burr, especially the tooth burr after shaving. Bump generally occurs in the transverse tooth profile and addendum circle. The rejection rates caused by bump and burr tend to be among 10-60%, therefore deburring is increasingly attached importance instead of a complementary process like past time. The preventive measures in gear production include two points: On the one hand strengthen the process management, increase the location appliance to prevent the bump occurred; the other hand, take measures to reduce the bump, the burr on the noise. Currently, the main idea to eliminate burrs and knocking on the noise is prior to machine chamfer for tooth profile, avoid burrs bumped hurt the tooth, so as to burrs bumped involve meshing to affect noise. Gear profile extrusion edge process is the best method of tooth profile chamfering, machine tools used in the process 20 years ago has achieved domestically, but for domestic chamfering tool, only simple tools can be produced domestically, which can't give full play to squeeze edge technology. Full functional chamfering tool also relies on imports, to some extent, affect the tooth profile extrusion edge technology popularized. This paper presents a design method of chamfering tool and manufacturing process, according to the mean provided, chamfering tool cutter can reach the level of imports, thereby provides favorable conditions for extrusion edge technology to promote tooth profile in the domestic.