CN108637407A - A kind of sectional tap - Google Patents

Abstract

A combined tap, including a tap working part, a tap handle and a nut; the working part of the tap is composed of a cutting part, a calibration part and a chip groove; the cutting part and the calibration part are distributed with threads, and the rake angle of the threads is 10°, the relief grinding amount of the cutting part is 5.5 mm, and the relief grinding amount of the calibration part is 0.1 mm; the taper of the working part of the tap is 0.08/100; the flank of the cutting part is cut with oil grooves. The design of the rake angle, the amount of relief grinding and the oil groove of the combined screw tap of the present invention increases the cutting strength and diameter stability of the screw tap. The length of the cutting part is 10-15 mm, and the cutting cone angle is 10-15°. The cutting load is reasonably distributed, which not only maintains the stability of the taper, but also increases the cutting capacity, and undertakes the functions of the first and second taps in the tap. . The taper of the working part of the tap and the design of the relief amount of the calibration part enable the calibration part to undertake the functions of the second tap and the third tap in the split tap.

Description

A combination tap

technical field

The invention relates to the technical field of large taps, in particular to a combined tap.

Background technique

Large-scale taps are mainly used in the production of large-scale mechanical equipment for power station construction, such as taps for machining M170 screw holes in cylinders of 600,000-kilowatt steam turbines. As the installed capacity of steam turbines continues to increase, the size of the connecting thread between the runner and the main shaft, the rotor arm and the blades will also increase. The processing of ultra-large machine taps with a diameter ranging from M140 to M180mm has become a key technology for steam turbines, and the corresponding dimensions The tap has exceeded the scope of market supply, and the company has to make its own according to the actual product.

Usually, when tapping internal threads with a pitch of 4 to 6 mm and a diameter of M140 to M180 mm, a group of two taps with one taper and two tapers or a group of three taps with one taper, two tapers and three tapers is used. , when tapping with split taps, the structure of each tap meets the requirements of each stage of head attack, second attack and fine calibration, but requires the operator to have high operating skills, change the taps many times, and after the front tap is tapped, the material processing Hardening makes it difficult to tap the next tap. In addition, the concentricity of multiple taps is out of tolerance, which is prone to chaotic taps and tooth shape thinning. However, if the single-tap tap with a conventional structure is used, chipping and edge chipping often occur in the working part of the tap, because when the tap is unscrewed, the cutting root falls under the back of the shovel of the previous tooth, and the extrusion of chips causes chipping along the cutting edge. , greatly reducing the life of the tap. Enterprises are in urgent need of a combination tap with strong cutting ability, which can undertake the functions of the first, second and third taps in the sub-tap, reasonably distribute the cutting load, and can not only maintain the sharpness and durability of the tap, but also the stability of the tap. , At the same time, it can also have sufficient chip capacity, and the chip removal usually ensures the quality of the processed thread.

The tap working part of the existing tap is integrated with the tap handle, but compared with the tap handle, the tap working part is prone to failure, and the service life of the handle is relatively strong. When the two are integrated, it is easy to cause the tap The waste of the handle increases the cost of the enterprise.

Contents of the invention

The purpose of the present invention is to provide a combination screw tap to solve the problems in the background technology.

The technical scheme of the present invention is as follows: a combined tap, characterized in that it includes a tap working part, a tap handle and a nut; the working part of the tap is composed of a cutting part, a calibration part and a chip pocket; the cutting part and the calibration Partially distributed with screw teeth, the rake angle of the screw teeth is 8-12°, the relief grinding amount of the cutting part is 5-6mm, and the relief grinding amount of the calibration part is 0.1-0.2mm; the taper of the working part of the tap is 0.08/100; the said The flank of the cutting part is cut with an oil groove; the chip groove is arranged along the axial direction.

Further, the flute row cross-sectional structure of the chip flute is divided into three parts, namely, a straight line segment, a second circular arc segment and a first circular arc segment; the straight line segment and the second circular arc segment are tangent to form a rake angle; the second The arc segment is tangent to the first arc segment to form a rear arc angle.

Further, the back angle β of the chip flute is 80-85°; the arc radius of the flute is R1/R2=3.13, wherein R1 is the radius of the first arc segment, and R2 is the radius of the second arc segment; The heart diameter D ₀ =0.68D, the length of the straight line segment forming the forward inclination angle h=2.5P, where P is the pitch; the groove angle μ is 20-30°.

Further, the screw pitch is 4-6mm, and the diameter of the working part of the tap is M140-M180mm.

Further, the length L of the cutting portion is 10-15 mm, and the cutting cone angle k is 10-15°.

Further, the end of the working part of the tap is provided with a notch, the inside of the working part of the tap is provided with a through hole, the end of the handle of the tap is provided with threads, and the middle part is provided with a limit driving arm. The position is limited by the slot at the end of the working part of the tap, and fixed by the nut. There is a stepped hole at the end of the working part of the tap.

Compared with the prior art, the beneficial effects of the present invention are as follows:

The invention provides a large-diameter high-strength combined tap, which is characterized in that the diameter of the tap is M140-M180mm, the rake angle of the thread of the cutting part of the tap is 8-12°, the relief amount of the cutting part is 5-6mm, and the flank cutting With an oil groove, the relief angle of this structure is not too large, which ensures the cutting strength of the tap, and at the same time ensures the centering stability of the combined tap and the accuracy of the screw hole diameter; Oil is used to reduce the friction between the flank and workpiece.

The length L of the cutting part of the tap is 10-15 mm, and the cutting taper angle k is 10-15°. The cutting load can be distributed reasonably, which can not only ensure the stability of the tap, but also increase the cutting capacity of the tap. Functions of cones and bicones. The taper of the working part of the tap is 0.08/100, and the relief grinding amount of the calibration part is 0.1-0.2mm, so that the calibration part undertakes the functions of two taps and three taps in the divided tap.

The cross-sectional structure of the flute row of the tap chip flute is composed of the forward angle and the rear arc angle. The rake angle β of the above-mentioned chip flute is 80-85°, the groove arc radius R1/R2=3.13, the heart diameter D0=0.68D, the length of the straight line segment forming the rake angle h=2.5P, and the groove angle μ is 20 ~30°, with the best ratio between the back angle and each line segment, there is enough chip holding capacity; when the tap is cutting, the rake angle makes the cutting form a spiral shape; No jamming, smooth and timely withdrawal; in this way, the tap will not or rarely cause chipping during the tapping and withdrawal process.

The inside of the working part of the tap is provided with a through hole, and the front end has a stepped hole to provide space for the nut. The rear end of the working part of the tap is also provided with a slot for limiting and driving rotation in the circumferential direction of the tap. The end of the tap handle is provided with a thread, and the middle part is provided with a limit drive arm. The tap working part of the combined tap and the tap handle are limited by a slot and fixed by a nut. The installation is convenient and the limit drive is reliable.

The tap working part of the combined tap is more likely to fail than the tap handle, so the split design of the tap working part and the tap handle makes it possible to reuse the handle and improve the economic benefits of the enterprise.

The invention has reasonable structure, high tapping precision and efficiency, good wear resistance, long service life and high practical economy.

Description of drawings

Fig. 1 is the three-dimensional schematic diagram of a kind of combined screw tap of the present invention;

Fig. 2 is a side view of a combination screw tap of the present invention;

Fig. 3 is the front view of a kind of combined screw tap of the present invention;

Fig. 4 is the situation of helical chips produced when a combination tap of the present invention is tapping threads;

Fig. 5 is a schematic diagram of iron filings whirling when a combined tap of the present invention is withdrawn;

Fig. 6 is a groove diagram of a combination tap of the present invention.

Among them: 1-tap working part, 2-tap handle, 3-nut, 11-cutting part, 12-calibration part, 13-chip groove, 14-end, 15-straight line segment, 16-second arc segment , 17-the first arc section, 18 oil grooves.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments and accompanying drawings, so as to help understand the content of the present invention.

As shown in FIG. 1 and FIG. 3 , a combination tap of the present invention includes a tap working part 1 , a tap handle 2 and a nut 3 . The tap working part 1 is composed of a cutting part 11 , a calibration part 12 and a chip pocket 13 . The cutting part 11 and the calibration part 12 are distributed with screw teeth, the rake angle γ of the screw teeth is 10°, the relief grinding amount δ of the cutting part is 5.5mm, and the flank face of the cutting part is cut with an oil groove 18, which can increase the Cutting strength and diameter stability, that is, to ensure the cutting strength of the tap, and at the same time the relief angle is not too large, to ensure the centering stability of the combined tap, so as to ensure the dimensional accuracy of the screw hole. The oil storage reduces the friction between the flank and the workpiece. The taper of the working part 1 of the tap is 0.08/100, and the relief grinding amount of the calibration part of the tap is 0.1mm, so that the calibration part undertakes the functions of two taps and three taps in the split tap, making the load distribution more reasonable.

As shown in Figure 2, the length L of the cutting part 11 is 12mm, and the cutting taper angle k is 12°, so that the cutting load can be reasonably distributed, which can not only keep the stability of the tap into the tap, but also increase the cutting capacity of the tap, and bear the burden. The function of the first cone and the second cone in the taper.

As shown in FIG. 3 , the chip flutes 13 are arranged axially, and the number of flutes is 8; the screw teeth are distributed on both sides of the chip flutes 13 , and the chip flutes 13 extend to the end 14 of the tap working part 1 .

As shown in Figures 3 and 6, the groove row cross-sectional structure of the chip flute 13 is divided into three parts, that is, the straight line segment 15, namely the AB segment; the second circular arc segment 16, namely the BC segment; and the first circular arc segment 17, that is, the CD segment; the straight line segment 15 and the second arc segment 16 are tangent to form a forward angle, which is used to calibrate cutting; the second arc segment 16 and the first arc segment 17 are tangent to form a rear arc angle, which is used to accommodate Spin iron filings. The back angle β of the chip pocket 13 is 82°. Groove arc radius R1/R2=3.13, wherein R1=30mm is the radius of the first arc segment 17, R2=9.58mm is the radius of the second arc segment 16. Heart diameter D ₀ =0.68D, wherein D ₀ =60mm, D=88.24mm. The length of the straight line segment 15 forming the forward rake angle is h=2.5P=12.5, wherein P=5mm is the pitch; the groove angle μ is 25°.

As shown in Figures 4 and 5, the back angle of the chip flute 13 and each line segment are matched with an optimal ratio to have sufficient chip capacity. When the tap is cutting, the forward inclination angle makes the cutting form a spiral shape; when the tap is withdrawing, the back arc angle does not scrape, so that the chips will not be jammed, and the chips will come out smoothly and in time; in this way, the tap will not or very little during the tapping and withdrawal process Chipping occurs.

As shown in Figures 1 and 2, the tap working part 1 has a through hole inside, and a stepped hole at the front end to provide space for the nut. The rear end 14 of the tap working part 1 is provided with a slot for limiting and rotating the tap in the circumferential direction. The end of the tap handle 2 is provided with a thread, and the middle part is provided with a limit driving arm. The tap working part 1 and the tap handle 2 of the combined tap are limited by the slot 14 at the end and fixed by the nut 3, which is convenient for installation , Reliable limit drive.

The tap working part of the combined tap is more likely to fail than the tap handle, so the split design of the tap working part and the tap handle makes it possible to reuse the handle and improve the economic benefits of the enterprise.

The combined tap uses W6Mo5Cr4V2-4 high-speed steel as raw material, which increases the strength and cutting ability of the tap, solves the problems of tap chipping and early wear during processing, reduces the labor intensity of workers, and improves processing efficiency and Machining accuracy, proven by cutting to create high economic value.

It will be apparent to those skilled in the art that the invention is not limited to the details of the above-described exemplary embodiments, but that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Accordingly, the embodiments should be regarded in all points of view as exemplary and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and it is therefore intended that the scope of the invention be defined by the appended claims rather than by the foregoing description. All changes within the meaning and range of equivalents of the elements are embraced in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims (7)

1. a kind of sectional tap, it is characterised in that：Including screw tap working portion, tap handle and nut；The screw tap work department That divides is made of cutting tip, calibrated section and chip pocket；Thread, thread anterior angle is distributed in the cutting tip and calibrated section It it is 8~12 °, cutting tip relief grinding amount is 5~6mm, 0.1~0.2mm of calibrated section relief grinding amount；The cone of the screw tap working portion Degree is 0.08/100；The flank of the cutting tip cuts with oil groove；The chip pocket is axially disposed.

2. sectional tap according to claim 1, it is characterised in that：The slot row cross-sectional structure of the chip pocket is three Divide, i.e. straightway, the second arc section and the first arc section；Straightway and the tangent composition top rake of the second arc section；Second circular arc Arc angle after section and the tangent composition of the first arc section.

3. sectional tap according to claim 2, it is characterised in that：The knife spine angle beta of the chip pocket is 80~85 °；Slot Shape arc radius R1/R2=3.13, wherein R1 are the radius of the first arc section, and R2 is the radius of the second arc section；Heart diameter D₀= 0.68D, constitutes the length of straigh line h=2.5P of top rake, and wherein P is screw pitch；Flute profile angle μ is 20~30 °.

4. sectional tap according to claim 3, it is characterised in that：The screw pitch is 4~6mm, the screw tap work department A diameter of M140~the M180mm divided.

5. sectional tap according to claim 4, it is characterised in that：The length L of the cutting tip is 10~15mm, is cut It is 10~15 ° to cut cone angle k.

6. sectional tap according to claim 5, it is characterised in that：It states and opens up through-hole inside screw tap working portion, it is described The end of screw tap working portion offers flat recess mouth, and tap handle end set has screw thread, middle part to be equipped with limit actuating arm；Institute It states screw tap working portion to be limited by the end flat recess mouth of screw tap working portion with tap handle, and is carried out by nut It is fixed.

7. sectional tap according to claim 6, it is characterised in that：There is stepped hole in the end of the screw tap working portion.