Extrusion screw tap

Abstract

The utility model discloses an extrusion screw tap, which belongs to the field of screw taps and comprises a screw tap body. The tap handle is connected to one end of the tap main body; and each cone tooth unit comprises a plurality of ridges and a plurality of ridge backs which are arranged in a staggered mode, and the ridges of the cone tooth units are all spirally connected to the other end of the screw tap body, so that the ridge backs of the cone tooth units are all spirally connected to the other end of the screw tap body. The utility model has the technical effects that the contact points of the ridges and the workpiece are dispersed, so that the workpiece is not easy to deform when the wall thickness of the workpiece is relatively thin.

Description

Technical Field

[0001] The utility model relates to a tap, in particular to an extrusion tap. Background Art

[0002] Extrusion tap is a thread tool that uses the principle of metal plastic deformation to process internal threads. Extrusion tap extrusion of internal threads is a chipless processing technology, which is particularly suitable for materials such as copper alloys and aluminum alloys with low strength and good plasticity. It can also be used for materials with low hardness and high plasticity such as stainless steel and low carbon steel.

[0003] Chinese utility model patent, publication number: CN212704832U, publication date: 2021-03-16, discloses an extrusion tap, including a handle, a journal coaxially arranged at one end of the handle and a working end coaxially arranged at the end of the journal away from the handle; the working end includes a guide part coaxially arranged at one end of the journal; a plurality of tapered tooth units are arranged on the outer periphery of the guide part; the tapered tooth unit is a closed polygonal surface in the radial cross-section of the guide part; the tapered tooth unit includes a ridge back and a ridge protruding from the ridge back; the ridge back is surrounded by a circular ridge back line; the edge line of the part of the ridge protruding from the ridge back includes a first ridge line, a second ridge line and a third ridge line; the first ridge line and the third ridge line are symmetrically distributed with the diameter of the ridge back line as the center and are tangent to the ridge back line; the second ridge line is located between the first ridge line and the third ridge line and its two ends are respectively connected to the first ridge line and the third ridge line; the connection between the second ridge line and the first ridge line and the third ridge line is arc-shaped and transitions to form a circular arc part. This application has the effect of improving the wear resistance of the ridge and thus improving the service life of the extrusion tap. However, its disadvantage is that the contact points between the ridge and the workpiece are concentrated, and deformation is easy to occur when the wall thickness of the workpiece is thin. Utility Model Content

[0004] Purpose of the utility model: The purpose of the utility model is to provide an extrusion tap, the contact points between its ridges and the workpiece are dispersed, and it is not easy to deform when the wall thickness of the workpiece is thin.

[0005] Technical solution: An extrusion tap, comprising:

[0006] tap body;

[0007] A taper shank connected to one end of the tap body;

[0008] A plurality of cone tooth units, each of which comprises a plurality of ridges and a plurality of back edges arranged alternately with each other, wherein the plurality of ridges of the plurality of cone tooth units are all spirally connected to the other end of the tap body, so that the plurality of back edges of the plurality of cone tooth units are all spirally connected to the other end of the tap body.

[0009] Optionally, the ridge includes a root, a flank, and a crest that are connected in sequence. One end of the root away from the flank is connected to the other end of the tap body. The connection lines between the highest points of the root, the flank, and the crest and the center of the cross-section of the tap body are arranged in sequence along the circumferential direction of the tap body.

[0010] Optionally, the connection line between the highest point of the root and the center of the cross-section of the tap body is configured as a first connection line, the connection line between the highest point of the flank and the center of the cross-section of the tap body is configured as a second connection line, and the connection line between the highest point of the crest and the center of the cross-section of the tap body is configured as a third connection line. The first connection line, the second connection line, and the third connection line are arranged in sequence along the circumferential direction of the tap body.

[0011] Optionally, the first angle between the first connection line and the second connection line is greater than 0° and less than 5°, and the second angle between the second connection line and the third connection line is greater than 0° and less than 5°.

[0012] Optionally, a plurality of spiral cooling grooves are provided at the other end of the tap body.

[0013] Optionally, the plurality of spiral cooling grooves correspondingly cover a plurality of back ridges of the plurality of conical tooth units, and the number of the plurality of spiral cooling grooves is less than or equal to the number of the plurality of back ridges of the plurality of conical tooth units.

[0014] Optionally, when the spiral directions of the plurality of ridges and the plurality of back ridges of the plurality of conical tooth units are both left-handed, the first spiral angle is greater than 0° and less than 50°; when the spiral directions of the plurality of ridges and the plurality of back ridges of the plurality of conical tooth units are both right-handed, the second spiral angle is greater than 0° and less than 50°.

[0015] Optionally, the plurality of conical tooth units are configured as a plurality of extrusion cones and a plurality of calibration cones that are all connected to the other end of the tap body, and the plurality of extrusion cones are located at one end of the plurality of calibration cones away from the shank.

[0016] Optionally, along the direction from the plurality of calibration cones to the shank, the radial dimensions of the plurality of extrusion cones gradually increase.

[0017] Optionally, a coating is provided on each of the plurality of conical tooth units.

[0018] Beneficial effects: Since the multiple ridges of several conical tooth units are all helically connected to the other end of the tap body, so that the multiple back ridges of several conical tooth units are all helically connected to the other end of the tap body, which is equivalent to that the contact points between the multiple ridges of several conical tooth units and the workpiece are in a spiral shape, facilitating the dispersion of the contact points between the multiple ridges of several conical tooth units and the workpiece, thereby making the stress uniformity of the workpiece good, preventing stress concentration of the workpiece, and it is not easy to deform when the wall thickness of the workpiece is relatively thin. Description of the Drawings

[0019] Figure 1 Isometric view of the extrusion tap according to Embodiment 1 of the present utility model;

[0020] Figure 2 Figure 1 Partial view of A in;

[0021] Figure 3 Radial cross-sectional view of the extrusion tap according to Embodiment 1 of the present utility model;

[0022] Figure 4 Is Figure 3 Partial view of B in;

[0023] Figure 5 Schematic structural view of the extrusion tap according to Embodiment 1 of the present utility model with left-handed ridges;

[0024] Figure 6 Schematic structural view one of the extrusion tap according to Embodiment 1 of the present utility model with right-handed ridges;

[0025] Figure 7 Schematic structural view two of the extrusion tap according to Embodiment 1 of the present utility model with right-handed ridges;

[0026] Figure 8 Isometric partial view of the extrusion tap according to Embodiment 1 of the present utility model;

[0027] In the figure: 1, tap body; 2, taper shank; 3, conical tooth unit; 31, ridge; 311, tooth root; 312, tooth flank; 313, tooth tip; 32, back ridge; 301, extrusion cone; 302, calibration cone; 41, first connecting line; 42, second connecting line; 43, third connecting line; 5, spiral cooling groove. Detailed Description of the Invention

[0028] In order to make the technical solutions of the present utility model clearer, the following further describes the present utility model in detail with reference to the drawings and specific embodiments.

[0029] Embodiment 1

[0030] As Figure 1 , 3As well as 8, this embodiment provides an extrusion tap, including: a tap body 1; a taper shank 2 connected to one end of the tap body 1; a plurality of taper tooth units 3, and the taper tooth unit 3 includes a plurality of ridges 31 and a plurality of flanks 32 arranged alternately. The plurality of ridges 31 of the plurality of taper tooth units 3 are all helically connected to the other end of the tap body 1, so that the plurality of flanks 32 of the plurality of taper tooth units 3 are all helically connected to the other end of the tap body 1.

[0031] Specifically, the tap body 1 is used to carry the taper shank 2, the plurality of ridges 31 and the plurality of flanks 32 of the plurality of taper tooth units 3, etc.; the taper shank 2 is used to cooperate with relevant tapping equipment, so as to facilitate the cooperation between the extrusion tap of the present application and the relevant tapping equipment. Among them, the taper shank 2 can be a triangular shank, a hexagonal shank, etc.; the plurality of taper tooth units 3 are arranged in sequence along the axial direction of the tap body 1, and each taper tooth unit 3 includes a plurality of ridges 31 and a plurality of flanks 32. The ridge 31 is used for extrusion or calibration, and the flank 32 is used to connect adjacent ridges 31. Since the plurality of ridges 31 of the plurality of taper tooth units 3 are all helically connected to the other end of the tap body 1, so that the plurality of flanks 32 of the plurality of taper tooth units 3 are all helically connected to the other end of the tap body 1, it is equivalent that the contact points between the plurality of ridges 31 of the plurality of taper tooth units 3 and the workpiece are in a spiral shape, which is convenient for dispersing the contact points between the plurality of ridges 31 of the plurality of taper tooth units 3 and the workpiece, so that the stress uniformity of the workpiece is good, preventing stress concentration of the workpiece, and it is not easy to deform when the wall thickness of the workpiece is relatively thin.

[0032] Further, as Figure 2 and 4 , the ridge 31 includes a tooth root 311, a tooth flank 312 and a tooth tip 313 connected in sequence. One end of the tooth root 311 away from the tooth flank 312 is connected to the other end of the tap body 1. The connection lines between the highest points of the tooth root 311, the tooth flank 312 and the tooth tip 313 and the center of the cross-section of the tap body 1 are arranged in sequence along the circumferential direction of the tap body 1.

[0033] Specifically, the tooth root 311 is used to machine the minor diameter of the threaded hole, the tooth flank 312 is used to machine the middle diameter of the threaded hole, and the tooth tip 313 is used to machine the major diameter of the threaded hole; since the connection lines between the highest points of the tooth root 311, the tooth flank 312 and the tooth tip 313 and the center of the cross-section of the tap body 1 are arranged in sequence along the circumferential direction, that is, the connection lines between the highest points of the tooth root 311, the tooth flank 312 and the tooth tip 313 and the center of the cross-section of the tap body 1 do not coincide, it is convenient for the contact points between the plurality of ridges 31 of the plurality of taper tooth units 3 and the workpiece to be in a spiral shape, which is convenient for dispersing the contact points between the plurality of ridges 31 of the plurality of taper tooth units 3 and the workpiece, so that the stress uniformity of the workpiece is good, preventing stress concentration of the workpiece, and it is not easy to deform when the wall thickness of the workpiece is relatively thin.

[0034] Further, as Figure 4, the connecting line between the highest point of the tooth root 311 and the center of the cross-section of the tap body 1 is configured as the first connecting line 41, the connecting line between the highest point of the tooth flank 312 and the center of the cross-section of the tap body 1 is configured as the second connecting line 42, and the connecting line between the highest point of the tooth crest 313 and the center of the cross-section of the tap body 1 is configured as the third connecting line 43. The first connecting line 41, the second connecting line 42, and the third connecting line 43 are arranged in sequence along the circumferential direction of the tap body 1.

[0035] Specifically, the length of the first connecting line 41 is less than the length of the second connecting line 42, and the length of the second connecting line 42 is less than the length of the third connecting line 43, which is convenient for the tooth root 311 to be used for machining the minor diameter of the threaded hole, the tooth flank 312 to be used for machining the middle diameter of the threaded hole, and the tooth crest 313 to be used for machining the major diameter of the threaded hole; since the first connecting line 41, the second connecting line 42, and the third connecting line 43 are arranged in sequence along the circumferential direction of the tap body 1, it is convenient for the first connecting line 41, the second connecting line 42, and the third connecting line 43 not to coincide, so that the contact points of the multiple ridges 31 of the plurality of tapered tooth units 3 and the workpiece are in a spiral shape, and it is convenient for the contact points of the multiple ridges 31 of the plurality of tapered tooth units 3 and the workpiece to be dispersed, so that the stress uniformity of the workpiece is good, preventing stress concentration of the workpiece, and the workpiece is not likely to deform when the wall thickness of the workpiece is relatively thin.

[0036] Furthermore, as Figure 4 , the first angle α1 between the first connecting line 41 and the second connecting line 42 is greater than 0° and less than 5°, and the second angle α2 between the second connecting line 42 and the third connecting line 43 is greater than 0° and less than 5°. Specifically, the first angle α1 can be specifically 2°, 3°, or 4°, etc. If the first angle α1 is too small, it will cause the first connecting line 41 and the second connecting line 42 to almost coincide, resulting in stress concentration of the workpiece. If the first angle α1 is too large, it will cause the total number of ridges 31 to be small, resulting in poor extrusion performance of the extrusion tap of the present application; if the second angle α2 is too small, it will cause the second connecting line 42 and the third connecting line 43 to almost coincide, resulting in stress concentration of the workpiece. If the second angle α2 is too large, it will cause the total number of ridges 31 to be small, resulting in poor extrusion performance of the extrusion tap of the present application.

[0037] Furthermore, as Figure 1 and 3 , it further includes a plurality of spiral cooling grooves 5 provided at the other end of the tap body 1. Specifically, the spiral cooling grooves 5 are used to match the spirally arranged ridges 31 and the ridge backs 32 and are used for the coolant to flow through, which is convenient for the extrusion tap of the present application to achieve external cooling.

[0038] Furthermore, as Figure 1 and 3, a plurality of spiral cooling grooves 5 correspondingly cover a plurality of ridge backs 32 of a plurality of taper tooth units 3, and the number of the plurality of spiral cooling grooves 5 is less than or equal to the number of the plurality of ridge backs 32 of the plurality of taper tooth units 3. Specifically, the plurality of ridge backs 32 are used to carry the plurality of spiral cooling grooves 5, preventing the plurality of spiral cooling grooves 5 from affecting the strength of the plurality of ridge crests 31, thereby preventing the extrusion performance of the extrusion tap of the present application from deteriorating; when the number of the plurality of spiral cooling grooves 5 is less than the number of the plurality of ridge backs 32, it is equivalent to not providing spiral cooling grooves 5 on some of the ridge backs 32. When the number of the plurality of spiral cooling grooves 5 is equal to the number of the plurality of ridge backs 32, it is equivalent to providing one spiral cooling groove 5 on each ridge back 32. The number of the plurality of spiral cooling grooves 5 should not be greater than the number of the plurality of ridge backs 32, otherwise some of the spiral cooling grooves 5 need to be provided on the ridge crests 31, resulting in the deterioration of the strength of the ridge crests 31, and further resulting in the deterioration of the extrusion performance of the extrusion tap of the present application.

[0039] Further, as Figures 5 - 7 , when the spiral directions of the plurality of ridge crests 31 and the plurality of ridge backs 32 of the plurality of taper tooth units 3 are both left-handed, the first spiral angle ω1 is greater than 0° and less than 50°; when the spiral directions of the plurality of ridge crests 31 and the plurality of ridge backs 32 of the plurality of taper tooth units 3 are both right-handed, the second spiral angle ω2 is greater than 0° and less than 50°.

[0040] Specifically, the first spiral angle ω1 can specifically be 10°, 30° or 40°, etc. If the first spiral angle ω1 is too small, it will cause the plurality of ridge crests 31 and the plurality of ridge backs 32 of the plurality of taper tooth units 3 to be almost linearly arranged, resulting in the concentration of the contact points between the plurality of ridge crests 31 of the plurality of taper tooth units 3 and the workpiece, and the workpiece is prone to deformation when the wall thickness of the workpiece is thin. If the first spiral angle ω1 is too large, it will cause the total number of the plurality of ridge crests 31 of the plurality of taper tooth units 3 to be small, resulting in the deterioration of the extrusion performance of the extrusion tap of the present application; if the second spiral angle ω2 is too small, it will cause the plurality of ridge crests 31 and the plurality of ridge backs 32 of the plurality of taper tooth units 3 to be almost linearly arranged, resulting in the concentration of the contact points between the plurality of ridge crests 31 of the plurality of taper tooth units 3 and the workpiece, and the workpiece is prone to deformation when the wall thickness of the workpiece is thin. If the second spiral angle ω2 is too large, it will cause the total number of the plurality of ridge crests 31 of the plurality of taper tooth units 3 to be small, resulting in the deterioration of the extrusion performance of the extrusion tap of the present application.

[0041] Further, as Figure 1 and 5-7, a plurality of taper tooth units 3 are configured as a plurality of extrusion cones 301 and a plurality of calibration cones 302 that are all connected to the other end of the tap body 1. The plurality of extrusion cones 301 are located at one end of the plurality of calibration cones 302 away from the taper shank 2. Specifically, the plurality of extrusion cones 301 are used for machining internal threads; the plurality of calibration cones 302 are used for calibrating the machined internal threads to facilitate increasing the machining accuracy of the completed internal threads; since the plurality of extrusion cones 301 are located at one end of the plurality of calibration cones 302 away from the taper shank 2, it is convenient to make the extrusion tap of the present application first extrude and then calibrate during tapping.

[0042] Further, as Figure 1 and 5 -7, along the direction from the plurality of calibration cones 302 to the taper shank 2, the radial dimensions of the plurality of extrusion cones 301 gradually increase. Specifically, since the radial dimensions of the plurality of extrusion cones 301 gradually increase, it is convenient to make the extrusion tap of the present application gradually cooperate with the inner hole of the workpiece during tapping, and the cooperation has good transitional properties.

[0043] Further, as Figure 1 , a coating is provided on each of the plurality of taper tooth units 3. Specifically, the coating is used to increase the strength of the plurality of taper tooth units 3, thereby increasing the service life of the plurality of taper tooth units 3. The coating can be a TiCN coating, a TiAlN coating or a TiN coating, etc.; among them, the TiCN coating, that is, the titanium carbonitride coating, facilitates making the plurality of taper tooth units 3 have advantages such as high hardness and low friction coefficient; the TiAlN coating, that is, the titanium aluminum nitride coating, facilitates making the plurality of taper tooth units 3 have advantages such as high hardness, low friction coefficient, strong bonding force and excellent thermal stability; the TiN coating, that is, the titanium nitride coating, facilitates making the plurality of taper tooth units 3 have advantages such as high wear resistance and low friction coefficient.

[0044] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. An extrusion tap, characterized in that, Comprising: Tap body; A taper shank connected to one end of the tap body; A number of tap tooth units, each tap tooth unit including a plurality of ridges and a plurality of flanks arranged alternately, and the plurality of ridges of the number of tap tooth units are all helically connected to the other end of the tap body, so that the plurality of flanks of the number of tap tooth units are all helically connected to the other end of the tap body.

2. The extrusion tap according to claim 1, wherein The ridge includes a tooth root, a tooth flank and a tooth tip connected in sequence. One end of the tooth root away from the tooth flank is connected to the other end of the tap body. The connecting lines of the highest points of the tooth root, the tooth flank and the tooth tip to the center of the cross-section of the tap body are arranged in sequence along the circumferential direction of the tap body.

3. The extrusion tap according to claim 2, characterized in that, The connecting line of the highest point of the tooth root and the center of the cross-section of the tap body is configured as a first connecting line, the connecting line of the highest point of the tooth flank and the center of the cross-section of the tap body is configured as a second connecting line, and the connecting line of the highest point of the tooth tip and the center of the cross-section of the tap body is configured as a third connecting line. The first connecting line, the second connecting line and the third connecting line are arranged in sequence along the circumferential direction of the tap body.

4. The extrusion tap according to claim 3, characterized in that, The first angle between the first connecting line and the second connecting line is greater than 0° and less than 5°, and the second angle between the second connecting line and the third connecting line is greater than 0° and less than 5°.

5. A fluted tap according to any one of claims 1 to 4, characterized in that, It further includes a number of spiral cooling grooves provided at the other end of the tap body.

6. The extrusion tap according to claim 5, characterized in that, The number of the spiral cooling grooves correspondingly covers the plurality of flanks of the number of tap tooth units, and the number of the spiral cooling grooves is less than or equal to the number of the plurality of flanks of the number of tap tooth units.

7. A kind of extrusion tap according to any one of claims 1-4, characterized in that, When the spiral directions of the plurality of ridges and the plurality of flanks of the number of tap tooth units are all left-handed, the first helix angle is greater than 0° and less than 50°; when the spiral directions of the plurality of ridges and the plurality of flanks of the number of tap tooth units are all right-handed, the second helix angle is greater than 0° and less than 50°.

8. A tapping screw according to any one of claims 1-4, characterized in that, The number of tap tooth units is configured as a plurality of extrusion taps and a plurality of calibration taps all connected to the other end of the tap body, and the plurality of extrusion taps are located at one end of the plurality of calibration taps away from the taper shank.

9. A extrusion tap according to claim 8, characterized in that, Along the direction from the plurality of calibration taps to the taper shank, the radial dimensions of the plurality of extrusion taps gradually increase.

10. A extrusion tap according to any one of claims 1-4, characterized in that, Coatings are provided on the number of tap tooth units.

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