Extrusion tap

Abstract

The utility model provides a kind of extrusion tap, it is related to tap technical field, including blade part, blade part includes the cutting edge with several blade zone, at least part blade zone in cutting edge is provided with at least two extrusion points;Extrusion point on the same blade zone is different in the height in radial direction, last extrusion point height in advancing direction is highest, and / or, the angle of tooth profile angle of extrusion point on the same blade zone is different, the angle of tooth profile angle of last extrusion point in advancing direction is maximum;By setting at least two extrusion points on blade zone, the plastic deformation of material does not start from a point, makes deformation more reasonable in distribution on circumference and axial direction, reduces stress concentration, reduces initial cutting force peak value, torque and axial force curve is more gentle, improves thread quality and consistency;And can also disperse wear, prolong tap life, improve the stability of processing.

Description

Technical Field

[0001] This utility model relates to the field of tap technology, and in particular to a forming tap. Background Technology

[0002] An extrusion tap is a tool that forms threads by plastically deforming (extruding) metal, causing it to flow and fill the grooves of the tap's thread. When the tap is screwed into a pre-drilled hole, the extrusion point contacts the hole wall, applying extrusion pressure to the metal surrounding the hole wall. Under this pressure, the hole wall metal undergoes plastic deformation, guiding the extruded metal to flow along the contour and helical direction of the extrusion ridges, filling the "valley" space of the tap's thread profile. As the tap rotates forward, the extruded metal eventually solidifies, forming an internal thread profile corresponding to the tap's thread profile. During the extrusion process, the surface metal of the thread undergoes plastic deformation and work hardening.

[0003] Traditional forming taps have only one forming point per cutting edge width (e.g., Figure 5 The tap relies on the extrusion point (extrusion point 1) to plastically deform (extrude) the workpiece to form a standard internal thread. However, with only one extrusion point (extrusion point 1), the uneven flow of metal material increases during extrusion, the peak torque is high at the initial cut, the ellipticity problem may occur in the starting section of the thread, and the wear at the extrusion point is more concentrated, leading to thread quality problems and reduced tap life. In order to address the above defects, this application is proposed. Utility Model Content

[0004] The purpose of this invention is to provide a forming tap that reduces stress concentration by designing multiple forming points on each cutting edge, making the torque and axial force curves smoother, improving thread quality and consistency, dispersing wear, and extending tap life.

[0005] To solve the above problems, this utility model provides an extrusion tap, including a cutting edge, the cutting edge including a cutting edge having a plurality of cutting edges, and at least two extrusion points are provided on at least a portion of the cutting edges;

[0006] The extrusion points on the same cutting edge have different radial heights, with the last extrusion point in the advancing direction having the highest height, and / or the tooth profile angles of the extrusion points on the same cutting edge are different, with the last extrusion point in the advancing direction having the largest tooth profile angle. This is used to reduce extrusion pressure and improve the wear resistance of the tap.

[0007] The standard tooth shape is formed at the last compression point.

[0008] This structure, based on the forming tap, increases the number of extrusion points in the tap inlet. When the tap is screwed into a pre-drilled hole, the thread forming process is carried out in stages, dispersing the extrusion force on the tap and reducing wear at the extrusion points. This reduces torque and increases tap life. During cutting, not all teeth bear the maximum extrusion resistance simultaneously; instead, the torque is distributed across multiple stages, and the thread profile gradually changes from non-standard to standard. This decomposition of the thread forming steps reduces the torque experienced by the tap at any given moment, decreasing the risk of tap wear and breakage, improving chip guidance, optimizing tap alignment, reducing the risk of thread misalignment and tapping errors, and improving thread quality.

[0009] According to one embodiment of the present invention, the height of each extrusion point on the same blade increases sequentially.

[0010] According to one embodiment of the present invention, the height increase value of each extrusion point on the blade is a fixed value, that is, the height increase value of each extrusion point is the same compared to the previous extrusion point, such as X mm.

[0011] According to one embodiment of the present invention, the tooth angle of each extrusion point 12 on the same blade 13 increases sequentially.

[0012] According to one embodiment of the present invention, the increase value of the tooth profile angle of each extrusion point on the blade is a fixed value, that is, the increase value of the tooth profile angle of each extrusion point compared with the previous extrusion point is the same, such as 10°.

[0013] According to one embodiment of the present invention, multiple extrusion points are evenly distributed on the circumferential position of the blade.

[0014] According to one embodiment of the present invention, the extrusion amount of a single extrusion point on the same blade is 1 / n of the standard extrusion amount, where n is the number of extrusion points set on the blade.

[0015] According to one embodiment of the present invention, the extrusion tap further includes a shank connected to the cutting edge. The shank is the shank of a cutting tool used in machining and is a general-purpose shank.

[0016] According to one embodiment of the present invention, each cutting edge has at least two compression points.

[0017] According to one embodiment of the present invention, the number of extrusion points on each blade is 2 to 4, preferably 3.

[0018] The beneficial effects of this invention are as follows: by setting at least two extrusion points on the cutting edge, the plastic deformation of the material does not start from a single point, resulting in a more reasonable distribution of deformation circumferentially and axially. This reduces stress concentration, lowers the initial cutting force peak, ensures smoother start-up, and produces flatter torque and axial force curves, improving thread quality and consistency, resulting in a fuller tooth profile, smoother surface, and better initial section quality. It also reduces the tap's sensitivity to orifice quality, making tap insertion smoother. Furthermore, it improves the machining capabilities of thin-walled parts and difficult-to-machine materials, reducing deformation and defects; and it also disperses wear, extends tap life, and improves machining stability. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a schematic diagram of the overall structure of the extrusion tap in this scheme;

[0021] Figure 2 This is a schematic diagram of the cross-sectional structure of the cutting edge;

[0022] Figure 3 This is an enlarged schematic diagram of the cutting edge.

[0023] Figure 4 A schematic diagram showing the tooth profile angle at different extrusion points along the cutting edge;

[0024] Figure 5 A schematic diagram of a traditional extrusion tap with one extrusion point;

[0025] In the diagram: blade 1, cutting edge 11, extrusion point 12, extrusion point one 121, extrusion point two 122, extrusion point three 123, blade band 13, handle 2. Detailed Implementation

[0026] The following description is only intended to disclose the present invention so that those skilled in the art can implement it. The embodiments in the following description are merely examples, and those skilled in the art will conceive of other obvious modifications. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other solutions that do not depart from the spirit and scope of the present invention.

[0027] Example 1:

[0028] A type of extrusion tap, such as Figure 1 It includes a cutting edge 1 and a shank 2 connected to the cutting edge 1. The shank is the shank of a cutting tool used in machining and is a general-purpose shank.

[0029] like Figure 1 The cutting edge 1 includes a cutting edge 11 with a plurality of cutting edges 13, such as Figure 2At least two pressing points 12 are provided on at least part or all of the cutting edge 13.

[0030] The number of pressing points 12 on each blade 13 is 2 to 4. In this embodiment, it is preferred to set 3. Figure 3 Multiple extrusion points 12 are evenly distributed on the circumferential position of the blade 13.

[0031] The following three settings can be selected for extrusion point 12:

[0032] A: The radial height of the extrusion points 12 on the same cutting edge 13 increases sequentially (either by one or not by one), with the last extrusion point having the highest height;

[0033] B: The tooth profile angles of the extrusion points 12 on the same cutting edge 13 increase sequentially (either increasing one by one or not increasing one by one is acceptable), such as Figure 4 The tooth profile angle is the largest at the last compression point;

[0034] C: The radial height of the extrusion points 12 on the same cutting edge 13 increases sequentially, and the tooth angle of the extrusion points 12 on the same cutting edge 13 increases sequentially.

[0035] Along the direction of the cutting cone's advance, the last extrusion point constitutes the main extrusion tooth, and the last extrusion point on each cutting edge 13 is the standard tooth profile.

[0036] Optionally, the height increase value of each extrusion point 12 on the blade 13 can be a fixed value or a non-fixed value. In this embodiment, a fixed value is preferred, that is, the height increase value of each extrusion point is the same compared to the previous extrusion point, such as X mm.

[0037] Optionally, the increase in the tooth angle of each extrusion point 12 on the blade 13 can be a fixed value or a non-fixed value. In this embodiment, a fixed value is preferred, that is, the increase in the tooth angle of each extrusion point is the same as that of the previous extrusion point, such as 10°. The tooth angles of extrusion point 121, extrusion point 222, and extrusion point 323 are γ40°, α50°, and β60°, respectively.

[0038] Optionally, the extrusion amount of a single extrusion point 12 on the same blade 13 may be the same or different. In this embodiment, it is preferred that the extrusion amount is the same, that is, the extrusion amount of a single extrusion point 12 on the same blade 13 is 1 / n of the standard extrusion amount, where n is the number of extrusion points 12 set on the blade 13.

[0039] This structure, based on the forming tap, increases the number of extrusion points in the tap inlet. When the tap is screwed into a pre-drilled hole, the thread forming process is carried out in stages, dispersing the extrusion force on the tap and reducing wear at the extrusion points. This reduces torque and increases tap life. During cutting, not all teeth bear the maximum extrusion resistance simultaneously; instead, the torque is distributed across multiple stages, and the thread profile gradually changes from non-standard to standard. This decomposition of the thread forming steps reduces the torque experienced by the tap at any given moment, decreasing the risk of tap wear and breakage, improving chip guidance, optimizing tap alignment, reducing the risk of thread misalignment and tapping errors, and improving thread quality.

[0040] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been shown and explained in the embodiments. Without departing from the stated principles, the implementation of the present invention may have any variations and modifications.

Claims

1. A forming tap, characterized in that: Includes a cutting edge (1), the cutting edge (1) includes a cutting edge (11) having a plurality of cutting edges (13), at least a portion of the cutting edges (11) having at least two pressing points (12). The extrusion points (12) on the same cutting edge (13) have different heights in the radial direction, with the last extrusion point (12) in the advancing direction having the highest height, and / or the tooth angles of the extrusion points (12) on the same cutting edge (13) are different, with the last extrusion point (12) in the advancing direction having the largest tooth angle.

2. The forming tap according to claim 1, characterized in that: The height of each extrusion point (12) on the same blade (13) increases sequentially.

3. The forming tap according to claim 2, characterized in that: The height increase of each extrusion point (12) on the blade (13) is a fixed value.

4. The forming tap according to any one of claims 1-3, characterized in that: The tooth angle of each extrusion point (12) on the same cutting edge (13) increases sequentially.

5. The forming tap according to claim 4, characterized in that: The tooth angle increase value of each extrusion point (12) on the blade (13) is a fixed value.

6. The forming tap according to claim 1, characterized in that: Multiple extrusion points (12) are evenly distributed on the circumferential position of the blade (13).

7. The forming tap according to claim 1, characterized in that: The extrusion amount of a single extrusion point (12) on the same blade (13) is 1 / n of the standard extrusion amount, where n is the number of extrusion points (12) set on the blade (13).

8. The forming tap according to claim 1, characterized in that: The extrusion tap also includes a shank (2) connected to the cutting edge (1).

9. The forming tap according to claim 1, characterized in that: Each cutting edge (13) in the cutting edge (11) is provided with at least two pressing points (12).

10. The forming tap according to claim 1, characterized in that: The number of compression points (12) set on each blade (13) is 2 to 4.

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