CN209773658U - Novel screw tap - Google Patents

Abstract

The utility model belongs to the technical field of thread machining tools, and discloses a novel screw tap, which is provided with a cone, wherein the front end of the cone is integrally provided with a nose cone, the nose cone is provided with 5-8 cutting edges, and the position of the nose cone is provided with a front end groove; the rear end of the front end groove is communicated with the front end straight groove. The screw tap has a front end groove, so that chips can be removed conveniently, and the problem that the surface quality is poor due to the fact that scrap iron is wound on the screw tap and the thread is small in diameter during machining is solved. By grinding a proper main deflection angle, the cutting cone length is prolonged to more than 5 threads, so that the cutting force of each thread is decomposed, and the service life of the screw tap is prolonged. The angle of the front end groove and the front angle are reasonably grinded, so that the sharpness and the firmness of the screw tap are ensured, the rotating speed of a machine tool during machining is improved, and the production efficiency is ensured.

Description

Novel screw tap

Technical Field

The utility model belongs to the technical field of the thread machining cutter, especially, relate to a novel screw tap.

Background

The stainless steel nut thread machining method comprises the steps of turning, milling and tapping, a special tapping machine is used for tapping, a nut clamping tool is arranged on a workbench, a screw tap is fixed on a machine head, center and equipment parameters are adjusted, the tapping machine can tap and withdraw at one time, the whole tapping process is completed, a check nut (SPL) is machined and fastened before the straight-groove screw tap is changed, the method is operated, the machining efficiency is low, the cost is high, and the machining quantity of single screw taps is small.

The processing of the Shibilio pine nut has the following characteristics:

The Shibija (SPL) locknut made of stainless steel materials has the advantages of simple structure, good locking performance, reusability (having the locking performance of a self-locking nut) and the like, and is widely applied to connection and assembly of various machines and parts.

1. the Shibija thread has reverse direction, and the Shibija thread can be prevented from loosening by the fact that the tapping direction of a tap is consistent with the bolt selecting direction in general, and the tap is marked as BT type. Under special conditions, the screw tap cannot be driven in from the screwing-in direction of the bolt and can only be driven in from the opposite direction, and the screw thread driven by the TT-shaped screw tap can be used for preventing looseness.

2. The tapping of stainless steel materials is more difficult than the tapping of common steel materials, and the phenomena that the tap is seized in the thread, the thread is broken or broken, the surface of the thread is not smooth, the groove is formed, the size is out of tolerance, the thread is broken irregularly, the tap is abraded seriously and the like often occur. Therefore, the corresponding technical measures are adopted to solve the problem when the stainless steel threads are tapped.

3. When stainless steel threads are tapped, the phenomenon of tooth expansion is serious, and a tap is easy to be seized in a hole, so that a thread bottom hole is properly enlarged and the requirement on size consistency is high.

currently, the current state of the art commonly used in the industry is such that:

Taking the machining specification of M14 for an example of a schobenzone loose nut, the material is stainless steel 316L.

The first scheme is as follows: the method is directly finished by one-step processing of a straight-groove screw tap. Because the screw tap groove type is not convenient for chip removal, iron fillings can twine on the screw tap, can cause the thread finish not enough because iron fillings friction hole after the tapping, can not satisfy the technological quality requirement, and about every screw tap can only process 150, manufacturing cost is too high.

Scheme II: the method is completed by adopting a straight-groove screw tap through one-time tapping and two-time tapping. A tapping cone is transformed by an M14 common tap, the major diameter of the tap is ground, the diameter is ensured to be 13.05 mm, and about 300 taps can be machined by one tapping cone. However, after the tap with the large diameter ground is used for tapping, the burrs at the two ends of the inner hole are large, the orifice has accumulated chips and has defects, and if the tapping force is too small, the over-cutting phenomenon can be caused. Meanwhile, the cutting allowance is reduced during secondary tapping, the cutting force is small during tap machining, the abrasion is slow, each tap can machine about 450 parts, but the problem that the tap is difficult to align the teeth exists during machining, the teeth are not perpendicular or the screwing depth is insufficient, and the defects of over-cutting, double teeth, rough tooth side and insufficient smoothness and the like can occur when the tap is not operated properly.

in summary, the problems of the prior art are as follows:

(1) The straight-groove screw tap is adopted for processing, the screw tap groove type is not convenient for chip removal, the processing quality is low, and the service life of the screw tap is short.

(2) The straight-groove screw tap is adopted for processing, so that the cutting speed is low, the cost is high, and the processing efficiency is influenced.

(3) By adopting the one-tapping and two-tapping scheme, the service life of the screw tap is prolonged, but the problem that the screw tap is difficult to tap in the two-tapping process exists, the processing quality is not high, and the requirement on the skill of a worker is high.

(4) The problem of cost and efficiency is solved by adopting a first tapping scheme and a second tapping scheme, but the method needs to be improved, the key parameters of the screw tap are properly adjusted by combining weak links in the processing, and finally the effect of completing two times of processing by one-time tapping is achieved.

Disclosure of Invention

To the problem that prior art exists, the utility model provides a novel screw tap. The advantages of the two screw taps are summarized by extracting the processing advantages of the straight-slot screw tap and the tip screw tap, the advantages of the two screw taps are concentrated on one screw tap in the grinding process of the screw tap, the processing effects of the two screw taps are achieved simultaneously, certain adjustment is performed on the cutting angle of the screw tap through the difference of equipment and processing materials, and the processing effect of 2-3 times that of a common screw tap is achieved.

The utility model is realized in such a way, the novel screw tap is provided with a cone, the front end of the cone is integrally provided with a head cone, the head cone is provided with 5-8 cutting edges, the position of the head cone is provided with a front end groove, and the angle, the size and the shape of the head cone are properly adjusted, so that the cutting force is small, the chip removal is convenient, the small diameter of a friction thread is avoided, and the technological requirements are met;

Through experimental verification, the key parameters for manufacturing the nose cone are controlled in the following ranges: as shown in fig. 3, the main deflection angle range K is 5 ° to 9 °, i.e., the intersection line angle generated when the cutting edge and the tip groove are polished; the angle range beta of the chip groove is 5-10 degrees, and R is 2.5 mm; the front angle range is delta is 4-9 degrees, R is 1.2mm, and the front angle range is the position of the front end groove, so that the design requirement can be met, and the ideal processing effect is achieved.

the rear end of the front end groove is communicated with the front end straight groove, the straight groove is designed according to the diameter of scrap iron cut by the front end groove, the single-side grinding depth of the straight groove is 2-4 times of the thread pitch, the width of the single-edge scrap removal groove is 1/4-1/2, the straight groove can contain the scrap iron and can ensure that lubricating oil can fully flow through the straight groove, so that the cutting heat is reduced, the service life of the screw tap is indirectly ensured, the cutting parameters are effectively improved, and the production efficiency is improved.

Adopt this novel screw tap, improve the three processing methods of realization scheme on the basis of aforementioned traditional technology (scheme one, scheme two), adopt this novel screw tap to attack promptly, attack with former straight flute screw tap two, in the screw thread processing experiment that the processing specification is M14's the must japanning loose nut, the material is stainless steel 316L, compares traditional technology and obtains following data:

Table 1 comparison of processing schemes

Through the comparison of the three processing schemes, the novel screw tap can be obtained, and the production efficiency and the product quality can be greatly improved when the novel screw tap is processed.

in summary, the advantages and positive effects of the invention are:

Firstly, the screw tap should have the tip groove, the chip removal of being convenient for, solve the processing process iron fillings winding screw tap and friction screw thread path, lead to the problem of surface quality difference.

secondly, the cutting taper length is prolonged to be more than 5 thread lengths by grinding a proper main deflection angle, so that the cutting force of each thread is decomposed, and the service life of the screw tap is prolonged.

Thirdly, the angles of the chip grooves and the front angles are reasonably grinded, so that the sharpness of the screw tap is ensured, the rotating speed of a machine tool during machining is improved, and the production efficiency is ensured.

Only 150 single taps are processed before improvement, the cost of the single tap is 3.09 yuan, and the production efficiency is 1 time; after the first improvement, 375 taps are finished on average by a single tap, and the total tap cost of a single product is 2.11 yuan, and the production efficiency is 1.4 times; after the second improvement, 825 taps are finished by average single tap, the total tap cost of single products is 1.31 yuan, and the production efficiency is 3.1 times.

The novel screw tap solves the problems of low thread processing quality and short service life of the screw tap in the traditional screw tap processing.

Drawings

Fig. 1 is a schematic structural diagram of a novel screw tap provided by an embodiment of the present invention;

Fig. 2 is an assembly view of the novel tap provided by the embodiment of the invention;

Fig. 3 is a cross-sectional view of the novel tap provided by the embodiment of the invention;

In the figure: 1. a front end groove; 2. a vertebral body; 3. a nose cone and a chip groove; 4. a cutting edge; 5. the front end is a straight groove.

Detailed Description

In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to fig. 1 to 3.

the novel screw tap is provided with a cone, the front end of the cone is integrally provided with a nose cone, the nose cone is provided with 5-8 cutting edges, and the rear side of the nose cone is provided with a chip groove;

The front end of the chip groove is communicated with the front end groove.

Further, the main deflection angle K of the nose cone is 5 ° -9 °, the chip groove angle β is 5 ° -10 °, R is 2.5mm, the rake angle range is δ is 4 ° -9 °, and R is 1.2 mm.

This novel screw tap replaces the straight flute screw tap of using in traditional mode one is attacked, can effectual improvement work efficiency, improve the quality of processing product, improve the life of screw tap, reduction in production cost.

The utility model is realized in such a way that a straight flute screw tap of the original processing nut is ground to obtain a tip screw tap, the tip screw tap is adopted for head tapping, and the chip discharge mode of the tip screw tap avoids chips from interfering the surface of the formed thread, so that the thread quality is greatly improved; meanwhile, compared with spiral-fluted taps, the cutting speed can be generally increased by more than 50%, and the processing efficiency is greatly improved; in addition, the spiral point tap generally has 5-8 cutting edges, further reducing the cutting amount per tooth, thereby improving the service life of the tap.

The novel screw tap is made of superhard high-speed steel, the main deflection angle K of the nose cone is 5-9 degrees, the angle beta of a chip groove is 5-10 degrees, R is 2.5mm, the front angle delta is 4-9 degrees, R is 1.2mm, and the groove length is larger than or equal to the cutting cone length plus 2 buttons.

This novel little circular arc first end groove of screw tap area chamfer, reinforcing screw tap wearability makes the iron fillings of cutting out convolute tighter, avoids the fish tail nut hole to cause the roughness discrepancy.

This novel screw tap low-angle owner declination cooperation is greater than 5P cutting edge length, makes the iron fillings that the cutting produced thinner, and single iron fillings are thinner to reduce the cutting force, strengthened the life-span of screw tap.

The novel screw tap can use the machine tool rotating speed and the screw tap feeding speed which are higher than those of a straight-groove screw tap in machining, and the production efficiency can be improved.

The length of the main cutting edge of the novel screw tap is more than 5 threading teeth (more than 5P). The length of the main cutting edge of the tap is increased to more than 5P, so that the durability of the tap is improved.

The main deflection angle range of the conical head cone of the novel screw tap is that K is 5-9 degrees, the cutting edge is long in a matched mode, so that scrap iron generated by cutting is thinner, and single scrap iron is thinner, so that the cutting force is reduced, and the service life of the screw tap is prolonged.

The angle range of the novel tap chip groove is beta which is 5 degrees to 10 degrees, the angle range of the front angle is delta which is 4 degrees to 9 degrees, the chamfered small arc end groove enhances the wear resistance of the tap, the cut scrap iron is wound more tightly, and the roughness out-of-tolerance caused by scratching the inner hole of the nut is avoided.

This novel screw tap groove length is greater than or equal to cutting awl length +2 and detains, and the screw tap is sharper, and the cutting power is littleer, improves the surface quality of product after being cut.

The novel screw tap can be used for tapping of common metal materials and is more suitable for tapping operation of metal materials difficult to cut.

The novel screw tap can be applied to machining of threaded holes from M5 to M100.

the above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all the modifications and equivalents of the technical spirit of the present invention to any simple modifications of the above embodiments are within the scope of the technical solution of the present invention.

Claims (4)

1. The novel screw tap is characterized in that the novel screw tap is provided with a cone, the front end of the cone is integrally provided with a nose cone, 5-8 cutting edges are arranged on the nose cone, and chip grooves are formed between chip cones on the rear side of the nose cone;

the front end of the chip groove is communicated with the front end groove;

the main deflection angle range K of the nose cone is 5-9 degrees, the angle range beta of the chip groove is 5-10 degrees, R is 2.5mm, the front angle range delta is 4-9 degrees, and R is 1.2 mm.

2. a novel tap according to claim 1 wherein said chip taper is greater than 5 threading lengths.

3. The novel tap according to claim 1 wherein said leading end flute is a chamfered circular arc flute configuration.

4. A novel tap according to claim 1 wherein said leading flute has a flute length greater than the length of the cutting cone.