CN103464842B - A kind of internal thread vibration-extrusion tapping technique - Google Patents

Abstract

An internal thread vibration extrusion tapping process, after the extrusion tap is aligned with the axis of the bottom hole on the workpiece, the axial vibration and the helical vibration in the same direction as the internal thread helix angle are superimposed separately or simultaneously, and then the extrusion tap starts The main rotary motion and axial feed, under the combined action of different vibration modes, complete the vibration extrusion tapping of the internal thread on the workpiece. Or the axial vibration and helical vibration are superimposed on the workpiece alone or at the same time, forming the instantaneous pulse impact of the extrusion tap on the workpiece material in the processing area and the repeated ironing effect of the extrusion tap and the surface of the workpiece material, and causing the extrusion tap and the workpiece material The instantaneous separation between the surfaces improves the plasticity of the material and improves the friction between the extrusion tap and the workpiece material. It has the advantages of high precision of internal thread forming, good surface quality, small tapping torque, no chips, high processing efficiency, and excellent material quality. Advantages of high utilization rate.

Description

A Vibratory Extrusion Tapping Process for Internal Threads

technical field

The invention belongs to the technical field of advanced material forming, and in particular relates to an internal thread vibration extrusion tapping process.

Background technique

With the development of modern manufacturing industry, the requirements for the processing quality of parts in aviation, aerospace, automobile, electrical, machinery manufacturing and other fields are increasing day by day. However, the widespread application of many new alloy materials and difficult-to-machine materials, such as high-strength stainless steel, high-temperature alloys, and titanium alloys, has increased the difficulty of processing parts, especially the widespread internal thread hole structure on parts.

Internal thread processing is one of the important processes of mechanical processing. It is generally arranged in the last few processes of parts processing. The quality of its processing will determine whether the parts are scrapped or not and the level of performance. At present, there are mainly the following types of internal thread processing technology: (1) Internal thread cutting and tapping process, which belongs to the category of tool cutting processing. Thread cutting by internal thread turning tools and taps on lathes, drilling machines, and tapping machines The tool realizes the processing of internal thread. Although this process is widely used, there are many problems, such as large tapping torque, severe tap wear, easy to break, low thread accuracy, high scrap rate, and chip generation, which is not conducive to the precision processing of parts; (2) The extrusion tapping process of the internal screw. The extrusion tapping process is based on the characteristics of plastic deformation and flow of the metal material under normal temperature after being stressed, and the internal thread hole is formed by extrusion taps on the bottom hole of the part. The internal thread processed by this process has the advantages of high thread precision, good surface quality, no metal fiber structure in the thread profile, and high connection strength. However, the tapping torque of this process is large, the production cost of the extrusion tap is high, and the extrusion tap is worn. Serious; (3) The internal thread milling process, which is also commonly known as "whirlwind thread milling", is a method of processing internal threads with a thread milling cutter. It is an advanced processing technology, especially on multi-axis CNC machine tools and machining centers. Got a lot of use. The internal thread milling process has high processing efficiency, light tap wear, full thread profile, and high connection strength. However, this process is limited by the structure of the milling cutter. It is difficult to process small-diameter internal thread holes, with poor precision and difficult processing quality. control; (4), internal thread vibration cutting and tapping process, which is based on the traditional internal thread cutting and tapping process, combined with the vibration cutting technology proposed by Japan in the 1960s, that is, in the traditional tapping rotary motion along the tap A controllable periodic vibration is superimposed in the direction of the helix angle, making the original continuous tapping process into a pulse, instantaneous and repetitive cutting process. This process reduces the tapping torque, improves the processing quality of the internal thread, and prolongs the service life of the tool. However, it produces chips, which still do not meet the high-precision production of parts, and the process cuts off the tooth-shaped metal fiber structure, and the connection strength is greatly weakened.

Contents of the invention

In order to overcome the disadvantages of the above-mentioned prior art, the purpose of the present invention is to provide an internal thread vibration extrusion tapping process, which solves the problems of low precision, chip generation, high reject rate, large tapping torque, and tap wear in the prior art process. Serious problems, low connection strength of internal thread, etc., but also has the advantages of high precision of internal thread, high connection strength, good surface quality, small tapping torque, small wear of extrusion tap, wide processing range, high material utilization rate, etc.

In order to achieve the above object, the technical scheme that the present invention takes is:

An internal thread vibration extrusion tapping process, comprising the following steps:

a) After the extrusion tap 1 is aligned with the axis of the bottom hole on the workpiece 2, the axial vibration and the helical vibration in the same direction as the helix angle of the internal thread are superimposed separately or simultaneously. The vibration frequency ranges from 10Hz to 20kHz and the amplitude range is 0.005mm ~0.1mm, and the vibration modes include the following eight types: ①, Extrusion tap 1 alone axial vibration; ②, Extrusion tap 1 alone spiral vibration; ③, workpiece 2 separate axial vibration; ④, workpiece 2 separate spiral vibration; ⑤, extrusion tap 1 axial vibration, workpiece 2 helical vibration; ⑥, extrusion tap 1 helical vibration, workpiece 2 axial vibration; ⑦, extrusion tap 1 simultaneous axial vibration and helical vibration; ⑧, workpiece 2 simultaneous axial vibration Directional vibration and spiral vibration;

b) Extrusion tap 1 starts the main rotation movement and feeds axially, and under the compound action of any of the above vibration modes, the vibration extrusion tapping of the internal thread on the workpiece 2 is completed.

The present invention has the following advantages:

On the basis of the traditional internal thread extrusion tapping process, axial vibration and helical vibration are superimposed on the extrusion tap or the workpiece separately or simultaneously to form the instantaneous pulse impact of the extrusion tap on the workpiece material in the processing area and the extrusion tap and the workpiece. The repeated ironing effect on the surface of the workpiece material will cause instant separation between the extrusion tap and the surface of the workpiece material, which is conducive to the entry of the lubricating liquid into the processing area, thereby improving the plastic properties of the material and improving the friction between the extrusion tap and the workpiece material situation. Therefore, it has the advantages of high precision of internal thread forming, good surface quality, small tapping torque, no chips, high processing efficiency and high material utilization rate.

Description of drawings

Fig. 1 is a schematic diagram of vibration mode ① of the present invention.

Fig. 2 is a schematic diagram of vibration mode ② of the present invention.

Fig. 3 is a schematic diagram of vibration mode ③ of the present invention.

Fig. 4 is a schematic diagram of vibration mode ④ of the present invention.

Fig. 5 is a schematic diagram of vibration mode ⑤ of the present invention.

Fig. 6 is a schematic diagram of vibration mode ⑥ of the present invention.

Fig. 7 is a schematic diagram of vibration mode ⑦ of the present invention.

Fig. 8 is a schematic diagram of vibration mode ⑧ of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

An internal thread vibration extrusion tapping process, comprising the following steps:

a) After the extrusion tap 1 is aligned with the axis of the bottom hole on the workpiece 2, the axial vibration and the helical vibration in the same direction as the helix angle of the internal thread are superimposed separately or simultaneously. The vibration frequency ranges from 10Hz to 20kHz and the amplitude range is 0.005mm ~0.1mm, and the vibration modes include the following eight types: ①, refer to Figure 1, extrusion tap 1 alone axial vibration; ②, refer to Figure 2, extrusion tap 1 alone spiral vibration; ③, refer to Figure 3, workpiece 2 alone Axial vibration; ④, refer to Figure 4, workpiece 2 spiral vibration alone; ⑤, refer to Figure 5, extrusion tap 1 axial vibration, workpiece 2 spiral vibration; ⑥, refer to Figure 6, extrusion tap 1 spiral vibration, workpiece 2 Axial vibration; ⑦, referring to Figure 7, extrusion tap 1 has axial vibration and helical vibration at the same time; ⑧, referring to Figure 8, workpiece 2 is simultaneously axially and helically vibrating;

b) Extrusion tap 1 starts the main rotation movement and feeds axially, and under the compound action of any of the above vibration modes, the vibration extrusion tapping of the internal thread on the workpiece 2 is completed.

Claims (1)

1. an internal thread vibration-extrusion tapping technique, is characterized in that, comprise the following steps:

A) after the bottom outlet axial alignment, on thread forming tap (1) with workpiece (2), superpose axial vibration and the spiral vibrating identical with internal thread lead angle direction individually or simultaneously, vibration frequency range 10Hz ~ 20kHz, amplitude range 0.005mm ~ 0.1mm, 1., thread forming tap (1) separately axial vibration wherein mode of vibration comprises following eight kinds:; 2., thread forming tap (1) spiral vibrating separately; 3., workpiece (2) axial vibration separately; 4., workpiece (2) spiral vibrating separately; 5., thread forming tap (1) axial vibration, workpiece (2) spiral vibrating; 6., thread forming tap (1) spiral vibrating, workpiece (2) axial vibration; 7., thread forming tap (1) axial vibration simultaneously and spiral vibrating; 8., workpiece (2) axial vibration simultaneously and spiral vibrating;

B), thread forming tap (1) starts principal rotating motion axial feed, taking under any one mode of vibration compound action above, completing the vibration-extrusion tapping at the upper internal thread of workpiece (2).