CN211564765U

CN211564765U - Progressive screw tap

Info

Publication number: CN211564765U
Application number: CN202020173061.9U
Authority: CN
Inventors: 唐景康
Original assignee: Hunan Qixin Precision Tools Co ltd
Current assignee: Hunan Qixin Precision Tools Co ltd
Priority date: 2020-02-14
Filing date: 2020-02-14
Publication date: 2020-09-25
Anticipated expiration: 2030-02-14

Abstract

The utility model discloses a progressive screw tap, which is provided with a screw tap body, wherein the screw tap body is provided with a thread section, and the thread section is provided with a cutting thread section and a calibration thread section which are arranged from front to back in the axial direction; wherein the thread section comprises a plurality of thread ridges which are spaced in the axial direction and are spirally arranged and a root which is formed between the adjacent thread ridges, and the diameter h1 of the root is constant; the thread ridges of the cutting thread section are trapezoidal in axial cross section, and the outer diameter h21 of the thread ridges of the cutting thread section gradually increases from front to back in the spiral direction until the outer diameter h22 of the thread ridges of the calibration thread section is equal. The utility model discloses more rational distribution cutting allowance, the smear metal is thinner, and the shape symmetry curls more easily and the chip removal reduces the tipping probably, finally reaches the life who improves cutting speed, extension screw tap.

Description

Progressive screw tap

Technical Field

The utility model relates to a progressive screw tap.

Background

At present, a cutting tap is a general tool for machining threaded holes, and a typical structure of a general cutting tap is shown in fig. 1, wherein the cutting tap is a main cutting edge of a tool, is responsible for a main workload of cutting to form a tooth form, and is the most important working part of the tap. The existing tap cutting conical forms mostly adopt the bevel angle type as shown in figures 1 and 2, and the bevel angle type mainly has two defects: 1. the machining allowance is unreasonable, the teeth close to the bottom of the teeth have high strength and small machining allowance, and the teeth close to the top of the teeth have low strength and large machining allowance. 2. The cutting layer is large in thickness, asymmetric in shape and small in chip curl, and chip removal is not facilitated.

Disclosure of Invention

The utility model aims to solve the technical problem that overcome prior art's defect, provide a formula screw tap advances one by one, its more rational distribution cutting surplus, the smear metal is thinner, and the shape symmetry curls more easily and the chip removal reduces the tipping probably, finally reaches improvement cutting speed, prolongs the life of screw tap.

The utility model provides a technical scheme that above-mentioned technical problem took is: a progressive tap having a tap body with a threaded section having a cutting thread section and a calibration thread section axially displaced from a forward to a rearward direction; wherein the content of the first and second substances,

the thread section comprises a plurality of thread ridges which are spaced in the axial direction and are spirally arranged and a root formed between the adjacent thread ridges, and the diameter h1 of the root is constant;

the thread ridges of the cutting thread section are trapezoidal in axial cross section, and the outer diameter h21 of the thread ridges of the cutting thread section gradually increases from front to back in the spiral direction until the outer diameter h22 of the thread ridges of the calibration thread section is equal.

Further, the cone body is provided with chip flutes at intervals in the circumferential direction.

Further, the chip flutes are provided with three or four in the circumferential direction.

Further, the outer diameters h21 of the thread ridges of the cutting thread segments are the same in increments that gradually increase from front to back in the spiral direction.

Further, the tap body also has a shank axially rearward of the threaded section.

Further, a square head part is arranged at the rear end of the handle part.

After the technical scheme is adopted, the utility model discloses a progressive screw tap, its cutting thread section's screw thread is trapezium structure on the cross-section of axle, and the external diameter h21 of cutting thread section's screw thread is by preceding gradual increase progressively backward until with the external diameter h22 of calibration thread section's screw thread equals, such structure setting, make under the screw tap of same effective diameter, the cutting layer thickness of cutting thread section reduces to some extent, and the external diameter of screw thread is little (cutting thread section's anterior segment), the machining allowance is big, backward more, the machining allowance is degressive, thereby more rational distribution the cutting allowance, the smear metal curls more easily and discharges, reduce the tipping possibility, finally reach and improve cutting speed, the life of extension screw tap.

Drawings

FIG. 1 is a block diagram of a prior art tap;

FIG. 2 is a left side view of FIG. 1;

FIG. 3 is a cutting edge profile of the tap of FIG. 1;

FIG. 4 is a profile of the thickness and the margin of a cutting layer after using the tap of FIG. 1;

fig. 5 is a perspective view of the tap with three flutes according to the present invention;

fig. 6 is a schematic structural view of the screw tap with three flutes according to the present invention;

FIG. 7 is a left side view of FIG. 6;

fig. 8 is a cutting edge profile of the four flute tap of the present invention;

fig. 9 is a distribution diagram of the thickness of the cutting layer and the allowance after the tap in fig. 8 is used.

Detailed Description

In order that the present invention may be more readily and clearly understood, the following detailed description of the present invention is provided in connection with the accompanying drawings.

As shown in fig. 5 to 7, a progressive tap has a tap body having a threaded section with a cutting thread section 10 and a calibration thread section 20 arranged axially from front to rear; wherein the content of the first and second substances,

the thread section comprises a plurality of thread ridges 100 which are spaced in the axial direction and are spirally arranged and a root 200 which is formed between the adjacent thread ridges 100, wherein the diameter h1 of the root 200 is constant;

as shown in fig. 7, the thread ridge 100 of the cutting thread section 10 has a trapezoidal structure in axial cross section, and the outer diameter h21 of the thread ridge 100 of the cutting thread section 10 gradually increases from front to back in the spiral direction until it is equal to the outer diameter h22 of the thread ridge 100 of the calibration thread section 20.

As shown in fig. 5, 6 and 7, the tap body is provided with chip flutes 300 at intervals in the circumferential direction thereof.

The chip flutes 300 are provided with three or four in the circumferential direction, but are not limited thereto; a, B, C, D in fig. 2, 3, and 8 each represent a corresponding chip flute 300.

The outer diameter h21 of the thread ridge 100 of the cutting thread segment 10 is the same in increasing amount gradually from front to back in the spiral direction.

As shown in fig. 5, the tap body also has a shank portion 30 located axially rearward of the threaded segments.

The rear end of the handle 30 may be provided with a square head.

Taking a four-flute tap for machining a common thread as an example, the cutting taper length, i.e., the ineffective teeth, are all 2.5 pitches (the first complete teeth in fig. 3 and 8 are all the third teeth of the B flute). Fig. 1 and 2 show a conventional beveled type tap with four flutes, fig. 8 being a cutting edge profile of the progressive tap in the present embodiment (A, B, C, D indicates four flutes of the tap), fig. 4 being a profile of the thickness of a cutting layer and a margin after using the tap in fig. 1, and fig. 9 being a profile of the thickness of a cutting layer and a margin after using the tap in fig. 8. From fig. 3 and 8, it can be seen that the thread start position, the incomplete thread length and the number of teeth participating in cutting are completely the same (14 in all). Fig. 4 and 9 are corresponding respective fig. 3 and 8, all superimposed with the cut tooth form. Comparing fig. 4 and fig. 9, it is clear that the cutting layer thickness 1 of fig. 4 is greater than the cutting layer thickness 2 of fig. 9, 1 ═ 1.2 × 2 calculated by example. In FIG. 4, the shape of the cutting layer is an asymmetric quadrangle, and in FIG. 9, the shape of the cutting layer is a symmetric isosceles trapezoid

The cutting allowance of the

threads

1, 2, 3 and 4 close to the root is small in fig. 4, the machining allowance of the

threads

1, 2, 3 and 4 close to the root is much larger in fig. 9, and the allowance is gradually decreased from 5 to 14.

From the analysis, the progressive screw tap in the embodiment has the advantages that the cutting allowance is more reasonably distributed, the cutting chip is thinner, the shape is symmetrical, the curling and the chip removal are easier, the possibility of edge breaking is reduced, the cutting speed is finally improved, and the service life of the screw tap is prolonged.

The above-mentioned embodiments further explain in detail the technical problems, technical solutions and advantages solved by the present invention, and it should be understood that the above only is a specific embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

In the description of the present invention, it is to be understood that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, and do not indicate or imply that the equipment or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the product of the present invention is used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhang" and the like do not imply that the components are required to be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the present disclosure, unless otherwise expressly stated or limited, the first feature may comprise both the first and second features directly contacting each other, and also may comprise the first and second features not being directly contacting each other but being in contact with each other by means of further features between them. Also, the first feature being above, on or above the second feature includes the first feature being directly above and obliquely above the second feature, or merely means that the first feature is at a higher level than the second feature. A first feature that underlies, and underlies a second feature includes a first feature that is directly under and obliquely under a second feature, or simply means that the first feature is at a lesser level than the second feature.

Claims

1. A progressive tap characterized by a tap body having a threaded tap body with a threaded section having a cutting thread section (10) and a calibration thread section (20) arranged axially from front to back; wherein the content of the first and second substances,

the thread section comprises a plurality of thread ridges (100) which are spaced in the axial direction and are spirally arranged and a root (200) formed between the adjacent thread ridges (100), and the diameter h1 of the root (200) is constant;

the thread ridge (100) of the cutting thread section (10) is in a trapezoidal structure in the axial cross section, and the outer diameter h21 of the thread ridge (100) of the cutting thread section (10) gradually increases from front to back in the spiral direction until the outer diameter h22 of the thread ridge (100) of the calibration thread section (20) is equal.

2. The progressive tap according to claim 1,

the tap body is provided with chip flutes (300) at intervals in the circumferential direction thereof.

3. The progressive tap according to claim 2,

the chip flutes (300) are provided with three or four in the circumferential direction.

4. The progressive tap according to claim 1,

the outer diameter h21 of the thread ridge (100) of the cutting thread section (10) is the same in increasing amount gradually from front to back in the spiral direction.

5. The progressive tap according to claim 1,

the tap body also has a shank (30) located axially rearward of the threaded section.

6. The progressive tap according to claim 5,

the rear end of the handle part (30) is provided with a square head part.