CN112975007A

CN112975007A - Machine screw tap of high accuracy screw processing

Info

Publication number: CN112975007A
Application number: CN202110240494.0A
Authority: CN
Inventors: 陈里; 杨金利; 刘文举; 刘传金
Original assignee: Sichuan Tianhu Tools Manufacturing Co ltd
Current assignee: Sichuan Tianhu Tools Manufacturing Co ltd
Priority date: 2021-03-04
Filing date: 2021-03-04
Publication date: 2021-06-18

Abstract

The invention discloses a machine screw tap for high-precision screw hole machining, which comprises: a guide post (1) and a tap body (2); the tap body (2) comprises a cutting cone (3) and a tap handle (4); the guide post (1) comprises a guide post guiding outer cylinder (7), a guide post positioning outer cylinder (8), a guide post locking bolt (9) and a guide post inner hexagon (10); the guide post (1) is connected with a screw tap locking screw hole (6) of the screw tap main body (2) through a guide post locking bolt (9). By adopting the structure, the invention has the advantages of more convenient on-site processing alignment, high processing efficiency and high coaxiality of processed screw holes, and reduces the risks of tipping of the screw tap and tooth decay of the screw hole caused by poor centering and easy vibration in the processing process of a common screw tap, thereby improving the cost performance of the screw tap and obtaining the high-precision screw hole processing quality.

Description

Machine screw tap of high accuracy screw processing

Technical Field

The invention relates to the field of screw taps, in particular to a machine screw tap for high-precision screw hole machining.

Background

Tap tapping is widely applied to mechanical processing, and the following defects exist in the traditional tap tapping;

1. the tap is not provided with a screw hole positioning and guiding structure, cutting is directly participated by a cutting cone, the tap is mainly aligned by the experience and the skill of an operator when the initial positioning is found, and the coaxiality of a bottom hole of the screw hole and the tap cannot be guaranteed; in the tapping process, due to the fact that no guide structure exists, stress is not stable in the tapping process, vibration is easy to occur, and the risk of tipping of the screw tap and tooth decay of the screw hole is caused. Especially when the rocker drill is used for machining, the machine tool lacks position precision guarantee and completely depends on manual skill, and the quality of a machined screw hole is not easy to guarantee.

2. The bottom hole tolerance of the standard thread is large, the precision is low, the processing technology and the precision are different, and even if the screw tap is made into an integral screw tap with a guide structure, the high-quality screw hole cannot be easily obtained due to the large gap of the guide pillar. For example, in the case of a thread with a national standard 6H accuracy, when the thread pitch is 2, the small-diameter tolerance is (0, + 0.375), so that it is difficult to position the guide post of the standard tap with a small clearance and high accuracy with a large tolerance.

3. Common screw has through-hole and blind hole, and the length in hole differs, and the preparation integral screw tap of taking the guide pillar is difficult to adapt to different processing environment, and integral consumptive material is more, and the economic nature is not high.

Therefore, the screw tap of the traditional structure is difficult to align, the cutting is not stable in the screw tap machining process, the tipping of the screw tap and the rotten teeth of the screw hole are easily caused, the machining precision of the screw hole is low, the machining efficiency of the screw tap is low, and the economical efficiency is poor.

The utility model with the patent number of CN2055759 discloses an anti-skew screw tap, and in the scheme, the guide pillar can not be changed, and application scope is less, and the economic nature is not high.

Disclosure of Invention

The invention mainly aims to provide a machine screw tap for high-precision screw hole machining, and aims to achieve the purposes of guiding tapping, stable machining process and high screw hole machining precision by replacing a guide pillar.

In order to achieve the above object, the present invention provides a machine tap for high-precision screw hole machining, comprising: a guide post and a tap body; the tap body comprises a cutting cone and a tap shank; the cutting cone is fixedly arranged at one end of the handle part of the screw tap; the end face of the cutting cone is also provided with a screw tap positioning hole and a screw tap locking screw hole; the guide pillar comprises a guide pillar guiding outer cylinder, a guide pillar positioning outer cylinder, a guide pillar locking bolt and a guide pillar inner hexagon; the inner hexagon of the guide post is arranged at the center of the section of one end of the guide post guide outer cylinder; the guide post positioning outer cylinder is arranged on the section of the other end of the guide post guiding outer cylinder; the end part of the guide post positioning outer cylinder is connected with a guide post locking bolt; the guide pillar is connected with a screw tap locking screw hole of the screw tap main body through a guide pillar locking bolt.

Preferably, the cutting cone is further provided with a calibration structure and a chip groove; the calibration structures are uniformly distributed on the outer wall of the cutting cone; the chip groove is arranged at the section of the cutting cone.

Preferably, the tail of the tap shank is square.

Preferably, the groove type of the tap is a straight groove.

Preferably, the groove of the tap is a spiral groove structure.

Preferably, the guide pillar guide outer cylinder adopts a pure cylindrical surface, does not have a groove and has a smooth surface.

Preferably, the end face of the guide pillar is of an inner hexagonal structure and is assembled and disassembled by an inner hexagonal wrench.

The invention has the main advantages that:

1. the guide pillar is added as tapping positioning guide, so that the tapping and centering of the tap on site are very convenient, and the tapping process is more stable;

2. the guide pillar outer cylinder adopts a pure cylindrical surface, does not have a groove, has a smooth surface, is matched with the threaded bottom hole of the processed part smoothly, and does not scratch the threaded bottom hole;

3. the guide post can be detached and replaced to adapt to threaded bottom holes with different diameters and lengths, and the actual fit clearance between the guide post and the bottom hole is reduced, so that the optimal tapping guide effect is obtained;

4. by adopting the structure, the on-site processing alignment is more convenient, the processing efficiency is high, the processed screw hole coaxiality is high, the risks of tipping of the screw tap and decayed teeth of the screw hole due to poor centering and easy vibration in the processing process of the common screw tap are reduced, the cost performance of the screw tap is improved, and the high-precision screw hole processing quality is obtained.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the connection between the guide post and the tap mounting portion of the present invention;

FIG. 3 is a view of the profile of the guide post of the present invention;

FIG. 4 is an assembly view of the guide post and tap of the present invention.

The reference numbers illustrate:

1-guide pillar, 2-tap body, 3-cutting cone, 4-tap handle, 5-tap positioning hole, 6-tap locking screw hole, 7-guide pillar guiding outer cylinder, 8-guide pillar positioning outer cylinder, 9-guide pillar locking bolt, 10-guide pillar inner hexagon, 11-calibration structure, 12-chip pocket, D-guide pillar guiding outer cylinder 7 diameter and L-guide pillar guiding length.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

The invention provides an embodiment, and referring to fig. 1, fig. 1 is a schematic structural diagram of the invention.

As shown in fig. 1, the present embodiment is a machine tap for high-precision screw hole machining, which mainly includes a guide post 1, a tap body 2, a cutting cone 3, and a tap shank 4.

The tap body 2 comprises a cutting cone 3 and a tap shank 4; the cutting cone 3 is fixedly arranged at one end of the tap handle 4; the guide post 1 is connected with the tap body 2 through a bolt.

As shown in fig. 2, fig. 2 is a schematic view of the connection between the guide post and the tap assembly according to the present invention.

In this embodiment, unlike the conventional machine tap, the present invention adds a guide post 1 that can be attached and detached and replaced. During the use, an inner hexagonal wrench is adopted to stretch into an inner hexagonal 10 of the guide column, the guide column 1 is installed in a screw tap end hole to be connected, the outer cylinder 8 for positioning the guide column and the screw tap positioning hole 5 are in clearance fit (the fit precision of H7/H6 can be achieved) to achieve radial positioning of the guide column 1 and the screw tap main body 2, and the guide column 1 is rotated through the inner hexagonal wrench, and the guide column locking bolt 9 and the screw tap locking screw hole 6 are in tight fit to lock the guide column 1 and the screw tap.

As shown in fig. 3, fig. 3 is an outline view of the guide post of the present invention.

The tap body 2 is only one, but the replaceable guide column 1 can be one or more, the diameter D and the length L of the guide column guide outer cylinder 7 can be designed into specifications with different sizes (designed independently by manufacturers or customized according to user requirements), and the replaceable guide column can be flexibly selected on the use site. For the selection of the diameter of the guide pillar guide excircle D, the radial positioning with higher precision can be realized only by selecting a specification (recommended to be matched according to 7-level tolerance) which is close to and slightly smaller than the size of the machined screw hole according to the actual size of the machined screw hole. For the selection of the length L of the guide pillar guide outer cylinder 7, whether a processed screw hole is a through hole or a blind hole is mainly considered, and for the through hole, the length L of the screw hole can be 0.5-1 time of that of the screw hole; for the blind hole, processing is carried out in a single branch or in a group mode, if the tool withdrawal distance is smaller than 3 times of the thread pitch, the guide pillar 1 is not installed on the fine cone in principle, if the tool withdrawal distance is larger than 3 times of the thread pitch, the length L can be selected according to 1-2 times of the thread pitch, and if the blind hole is a coarse cone processed in a group mode, the length L can be selected according to 2-3 times of the thread pitch.

As shown in fig. 4, fig. 4 is an assembly view of the guide post and tap of the present invention.

In the present embodiment, by the above-mentioned embodiment, the operator selects the guide post 1 having the guide diameter D and the length L corresponding to the workpiece, and assembles the guide post 1 and the tap into a whole, thereby performing the tapping operation. During machine tapping, at first stretch into the excircle D of guide pillar by the alignment of processing thread bottom hole, realize the screw automatically, the lathe main shaft rotates, thread tapper centre gripping screw tap stalk portion 4, the square head structure transmission moment of torsion through screw tap stalk portion 4, under the guide effect of guide post, rotary motion and axial feed are done to the screw tap, cutting cone 3 gets into the screw and participates in the cutting, calibration structure 11 scrapes the light correction to the screw hole, realize steady leading-in tapping process promptly, the chip pocket and the chip removal effect of iron fillings are realized to screw tap chip pocket 12. When the through hole is machined, the screw tap calibration structure 11 completely passes through the screw hole, and the whole screw hole machining is completed; when the blind hole is machined, when the tapping stroke reaches the preset machining depth, the screw tap reversely rotates to withdraw from the screw hole, and the whole screw hole is machined.

The structures, functions, and connections disclosed herein may be implemented in other ways. For example, the embodiments described above are illustrative only, e.g.; the groove type of the screw tap is shown as a straight groove, and the screw tap can be designed into a spiral groove structure and scrap iron back row for screw holes with poor chip removal, such as blind holes, deep holes and the like. In addition, functional components in the embodiments herein may be integrated into one functional component, or each functional component may exist alone physically, or two or more functional components may be integrated into one functional component.

Claims

1. The utility model provides a machine screw tap of high accuracy screw processing which characterized in that includes: a guide post (1) and a tap body (2); the tap body (2) comprises a cutting cone (3) and a tap handle (4); the cutting cone (3) is fixedly arranged at one end of the tap handle (4); the end face of the cutting cone (3) is also provided with a screw tap positioning hole (5) and a screw tap locking screw hole (6); the guide post (1) comprises a guide post guiding outer cylinder (7), a guide post positioning outer cylinder (8), a guide post locking bolt (9) and a guide post inner hexagon (10); the guide post inner hexagon (10) is arranged at the center of the section of one end of the guide post guide outer cylinder (7); the guide post positioning outer cylinder (8) is arranged on the section of the other end of the guide post guiding outer cylinder (7); the end part of the guide post positioning outer cylinder (8) is connected with a guide post locking bolt (9); the guide post (1) is connected with a screw tap locking screw hole (6) of the screw tap main body (2) through a guide post locking bolt (9).

2. A machine tap for high precision screw hole machining according to claim 1, characterized in that said cutting cone (3) is further provided with a calibration structure (11) and a chip flute (12); the calibration structures (11) are uniformly distributed on the outer wall of the cutting cone (3); the chip groove (12) is arranged at the section of the cutting cone (3).

3. A machine tap for high precision tapping according to claim 1 wherein the tail of the tap shank (4) is square-headed.

4. A machine tap for high-precision screw hole machining according to claim 1, wherein the groove type of said tap is a straight groove.

5. A machine tap for screw hole machining with high accuracy as set forth in claim 1, wherein the groove shape of said tap is provided in a spiral groove structure.

6. A machine tap for high precision tapping according to claim 1 wherein said guide post guiding outer cylinder (7) is a pure cylindrical surface, without grooves, with smooth surface.

7. The machine tap for machining threaded holes with high precision according to claim 1, characterized in that the end face of the guide post (1) adopts an inner hexagonal structure and is assembled and disassembled by an inner hexagonal wrench.