CN215787269U

CN215787269U - Screw tap assembly

Info

Publication number: CN215787269U
Application number: CN202122083430.2U
Authority: CN
Inventors: 刘大禹; 刘健飞
Original assignee: Changchun Up Optotech Co ltd
Current assignee: Changchun Up Optotech Co ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2022-02-11
Anticipated expiration: 2031-08-31

Abstract

A screw tap assembly comprises a first screw tap, wherein the first screw tap sequentially comprises a first threaded part, a first guide part and a first handle part; the width of the blade back of the first thread part is 0 mm; the number of the complete thread part of the first thread part is 2-5; the diameter of the first guide part is larger than or equal to that of the bottom hole to be processed. The utility model reduces the number of teeth participating in cutting, so that the cutting resistance is reduced, the processing is easy, the cutting edge is changed into a sharp acute angle, and even if the screw tap is broken, the screw tap is easy to clean and break due to the small number of teeth.

Description

Screw tap assembly

Technical Field

The utility model relates to the field of thread machining, in particular to a screw tap assembly.

Background

The screw tap is a tool for processing internal threads, but the cutting resistance of the internal threads of the titanium alloy material parts processed by the common screw tap is very large, and the screw tap is broken frequently during tapping. The existing relief grinding mode of the relief grinding screw tap relief angle obtains good processing effect, but needs a special machine tool, and the cost is 10 times of that of a common screw tap. For example, the chinese utility model patent with the application number CN201220317716.0, application date of 2012, 7 and 3, and application name of "screw tap suitable for numerical control machining of titanium alloy" is that the angle of the relief angle of the tool face of the screw tap is 25 to 45 degrees, and the width of the ground back of the blade is 0.3 to 0.6 mm.

SUMMERY OF THE UTILITY MODEL

The utility model provides a low-cost screw tap assembly for solving the problems. In order to achieve the purpose, the utility model adopts the following specific technical scheme:

a tap assembly comprising a first tap;

the first screw tap comprises a first thread part, a first guide part and a first handle part in sequence;

the width of the blade back of the first thread part is 0 mm;

the number of the complete thread part of the first thread part is 2-5;

the diameter of the first guide part is larger than or equal to that of a bottom hole to be machined.

Further, the screw tap assembly further comprises a second screw tap, and the second screw tap sequentially comprises a second threaded part, a second guide part and a second handle part;

the number of the complete thread part of the second thread part is 2-5;

the diameter of the second guide part is larger than or equal to that of the bottom hole.

Further, the diameter of the first guide portion is not more than 0.05mm compared with the diameter of the bottom hole.

Further, the diameter of the second guide portion is not more than 0.05mm compared with the diameter of the bottom hole.

Furthermore, the end part of the first thread part is provided with a tip.

Furthermore, the end part of the second thread part is provided with a tip.

Furthermore, the end part of the second thread part is provided with a guide post, and the diameter of the guide post is equal to or smaller than that of the bottom hole.

The utility model can obtain the following technical effects:

the screw tap assembly provided by the utility model can be reformed into a screw tap for titanium alloy by using a common screw tap or a waste screw tap, so that the cost is reduced, and the cutting resistance is very small; the cutting resistance is reduced and the processing is easy because the number of teeth participating in cutting is reduced; due to the small number of teeth, even if the screw tap is broken, the broken screw is easy to clean.

Drawings

FIG. 1 is a front view of a prior art tap;

FIG. 2 is a side view schematic of a prior art tap;

FIG. 3 is a front view of a first tap according to the present disclosure;

FIG. 4 is a side view of a first tap according to the present disclosure;

FIG. 5 is a front view of a second tap according to the present disclosure;

FIG. 6 is a side view schematic illustration of a second tap disclosed herein;

fig. 7 is a front view schematically illustrating another second tap according to the present disclosure.

Reference numerals:

1. a first screw tap; 11. a first threaded portion; 12. a first guide portion; 13. a first handle; 2. a second screw tap; 20. a guide post; 21. a second threaded portion; 22. a second guide portion; 23. a second handle; 6. cutting edges; 7. a concentric relief surface; 8. and (4) a rear angle.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not to be construed as limiting the utility model.

Fig. 3 to 4 show the main structure of a first tap 1 of the present invention, the first tap 1 including a first threaded portion 11, a first guide portion 12, and a first shank portion 13 in this order. The first thread portion 11 is used for machining threads on a bottom hole to be machined, the first guide portion 12 is used for guiding the first tap 1, and the first shank portion 13 is clamped and mounted on a tool of a special driving tap by a clamping tool.

The width of the blade back of the first thread part 11 is 0mm, namely the cutting edge is acute, the cutting edge is sharp so as to provide cutting force to the maximum extent, the width of the blade back is 0.3-0.6mm different from that of the prior art, the width is not reserved, namely, the sharp cutting edge is adopted, namely, the length of a 0-degree rear angle part of the first thread part 11 of the screw tap, which is connected with the cutting edge, is 0mm, so that the grinding is facilitated, the width of the blade back does not need to be controlled, the rear angle is directly ground until the cutting edge is ground, and the machining precision is reduced; the number of the full thread portion of the first thread part 11 is 2-5. The first thread part 11 has a minimum contact with the bottom hole, and the machining resistance is reduced to the maximum. Meanwhile, the number of teeth is reduced, and the processing resistance is further reduced. The problem of poor guidance due to less contact between the pilot hole and the first threaded portion 11 is solved by the first guide portion 12 described later. Be connected with the chip groove between two blades, provide accommodation space for the sweeps.

Preferably, the end of the first threaded part 11 is further provided with a tip, and for a small-diameter tap, the tip is added to facilitate the centering. The structure of the tip is known in the art and will not be described in detail herein.

The diameter of the first guide part 12 is larger than or equal to that of the bottom hole to be machined, so that after the first screw tap 1 is placed in the bottom hole, the first guide part 12 is in contact with the bottom hole, and the guide effect on the first screw tap 1 is achieved. However, if the diameter of the first guide portion is too large than the bottom hole, the first guide portion and the bottom hole are difficult to move, and therefore the diameter is not too large. Preferably, the diameter of the first guide part 12 varies from 0 to 0.05mm compared to the diameter of the bottom hole. For example, to machine a thread having a bottom hole of M6 with a diameter of 5.0mm, the diameter of the first guide 12 varies within the range of 5-5.05 mm.

The resistance is reduced to the greatest extent through first screw thread portion 11 and the direction is guaranteed through first guide portion 12, and especially for processing the bottom hole of minor diameter, the machining precision is improved. The tap can reduce the contact area between the tap and a workpiece, has small cutting torque and light and quick cutting, and can averagely prolong the service life of the tap by several times. The diameter of the first guide portion 12 is larger than that of the bottom hole, further preventing the tap from being broken.

The end of the first handle 13 has a square head, and is fixedly connected with a universal clamp, which is the prior art and will not be described herein.

As shown in fig. 1-2, which are structural schematic views of prior art taps, the tap for straight fluted machines includes a tip, a threaded portion, and a shank. The thread part is divided into a cutting part and a complete thread part from the length direction, the outer contour of the thread of the cutting part is conical, and the corresponding thread is an incomplete thread. Compared with the prior art, the conventional method for machining the M6 thread with the bottom hole with the diameter of 5mm has the advantages that the length of the thread part is about 25 teeth generally, and the number of teeth of the complete thread part is about 20 teeth generally. The axial cross section of screw thread portion has the multiunit screw tap blade, is formed with the recess that the whole section is the circular arc between two sets of adjacent screw tap blades, and the recess has formed the chip removal mouth, and the both ends of circular arc form anterior angle and relief angle 8 respectively, connect through concentric back knife face 7 between anterior angle and the relief angle 8, and blade 6 is formed through the curve that forms the anterior angle and the curve of concentric back knife face 8'. The length of the 0 ° relief angle portion of the first threaded portion 11 of the tap contacting the cutting edge is 0mm, that is, the length of the concentric relief surface is 0 mm.

The utility model can be modified by a straight flute machine by a screw tap, a part of cutting edges of a thread part close to a handle part are ground by a tool grinder, and are changed into a first guide part 13, wherein the size of the cutting edges is equal to or larger than the size of the bottom diameter of the screw tap; and for the rest threads, manually grinding the relief angle of the tap until the concentric relief surface is also relief-ground, so that the ground back edge width is 0mm, and further reducing the cutting resistance. It is noted that the first tap 1 is a relief of the relief angle and a reduction of the number of full threads without changing the other structure of the prior art threaded portion, which may not have an incomplete bolt, and is only schematically explained here with a straight fluted machine tap.

When the thread-cutting machine is used, a first screw tap 1 is used for machining threads on a bottom hole, and then a second screw tap in the field is used for shaping and further removing tool scraps. Taps that accomplish reshaping and further cutting are common taps in the art, but the second tap 12 below is preferred.

The tap assembly further comprises a second tap 2. as shown in fig. 5-6, the second tap 2 comprises in sequence a second threaded portion 21 for scraping and truing, a second guide portion 22 for guiding the tap and a second shank portion 23 for holding the tap.

The number of the complete thread portions of the second thread part 21 is 2 to 5, and the second tap 2 is similarly double tapped along the path of the first tap 1, so that the double tapping accuracy is high.

Wherein, the diameter of the second guiding part 22 is larger than or equal to the bottom diameter of the second thread part 21, and the change range of the diameter of the second guiding part 22 compared with the diameter of the second thread part 21 is 0-0.05 mm. The structure and function of the second guide portion 22 are similar to those of the first guide portion 12 described above, and will not be described in detail here.

Preferably, the end of the second threaded portion 21 is provided with a tip.

Preferably, as shown in fig. 7, the second tap is a blind-hole tap, and no tip is provided at the end of the second threaded portion 21.

Preferably, the end of the second threaded portion 21 is provided with a guide post 20, the diameter of which is required to play a guiding role and is smaller than or equal to the diameter of the bottom hole. Preferably, the diameter of the guide post is less than 0.01-0.04mm of the diameter of the bottom hole, so that the second tap 2 can be rapidly inserted into the bottom hole. The guide post 20 may be conical with varying diameter or cylindrical with constant diameter,

the second screw tap 2 can be manufactured by using a waste screw tap by a two-screw method, the front and rear threads of the threaded part of the screw tap for the straight fluted machine are respectively ground to the bottom diameter of the screw tap by using a tool grinder to become a guide, and finally the screw hole is trimmed.

The method for tapping, namely machining the threaded hole by using the tap assembly comprises the following steps:

s1, roughly machining the threaded bottom hole by using the first screw tap 1;

and S2, performing scraping, cutting, finishing and trimming on the machined threaded bottom hole by using the second screw tap 2.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A tap assembly, characterized by a first tap (1);

the first tap (1) comprises a first thread part (11), a first guide part (12) and a first shank part (13) in sequence;

the width of the blade back of the first thread part (11) is 0 mm;

the number of the complete thread part of the first thread part (11) is 2-5;

the diameter of the first guide part (12) is larger than or equal to the diameter of a bottom hole to be processed.

2. A tap assembly according to claim 1, further comprising a second tap (2), said second tap (2) comprising in sequence a second threaded portion (21), a second guide portion (22) and a second shank portion (23);

the number of the complete thread part of the second thread part (21) is 2-5;

the diameter of the second guide portion (22) is greater than or equal to the diameter of the bottom hole.

3. A tap assembly according to claim 2, wherein the diameter of said first guide portion (12) is no more than 0.05mm compared to the diameter of said bottom hole.

4. A tap assembly according to claim 2, wherein the diameter of said second guide portion (22) is no greater than 0.05mm compared to the diameter of said bottom hole.

5. A tap assembly according to claim 2, wherein the end of said first threaded portion (11) is provided with a point.

6. A tap assembly according to claim 2, wherein the end of said second threaded portion (21) is provided with a point.

7. A tap assembly according to claim 2, wherein the end of the second threaded portion (21) is provided with a guide post (20), the diameter of the guide post (20) being equal to or smaller than the diameter of the bottom hole.

8. A tap assembly according to claim 1, wherein the diameter of said first guide portion (12) is no more than 0.05mm compared to the diameter of said bottom hole.

9. A tap assembly according to claim 1, wherein the end of said first threaded portion (11) is provided with a point.