CN114800629B

CN114800629B - PCB drill point

Info

Publication number: CN114800629B
Application number: CN202210395549.XA
Authority: CN
Inventors: 朱水生; 王正齐; 刘绪维; 王威; 吴淦鹏; 卢秀双
Original assignee: Guangdong Dingtai Hi Tech Co ltd
Current assignee: Guangdong Dingtai Hi Tech Co ltd
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2023-08-29
Anticipated expiration: 2042-04-14
Also published as: CN114800629A

Abstract

The invention belongs to the technical field of drill points, and discloses a PCB drill point. The PCB drill needle comprises a needle body, wherein one end of the needle body forms a drill point, the drill point comprises a chisel edge and two tip parts which are arranged in a central symmetry manner relative to the center of the chisel edge, and each tip part comprises a first rear cutter surface and a second rear cutter surface which are arranged in an included angle manner and connected with each other; in each tip, one side of the second rear cutter surface, which is close to the first rear cutter surface, is provided with a main cutting edge, and the main cutting edge extends from the circumcircle of the needle body to the axis of the needle body and extends to the endpoint of the intersection line of the first rear cutter surface and the second rear cutter surface, which is far away from the chisel edge. The PCB drill point can reduce the radial rake angle of the main cutting edge, reduce the abrasion speed of the main cutting edge, ensure the main cutting edge to be sharp, reduce the cutting resistance, ensure the effective core thickness by reserving the tip of the first rear cutter surface at the intersection of the two tip parts, improve the rigidity of the drill point, ensure the drill point not to be easy to break and prolong the service life of the drill point.

Description

PCB drill point

Technical Field

The invention relates to the technical field of drilling needles, in particular to a PCB drilling needle.

Background

The PCB, also called a printed circuit board or a printed wiring board, is an important electronic component, and is a support for electronic components, and is also a carrier for electrical interconnection of the electronic components. It is called a printed circuit board because it is made using electronic printing.

The PCB board is widely used in electronic products, before electronic components are mounted on the PCB board, the PCB drill in the prior art generally includes a needle body and a needle handle, the needle body is disposed at one end of the needle handle, one end of the needle body far away from the needle handle is provided with a cutting portion, as shown in fig. 1, the cutting portion includes a first back surface 100, a second back surface 200 and a chisel edge 300, and two sides of the chisel edge 300 include a first back surface 100 and a second back surface 200 respectively; the main cutting edge 110 is disposed at a side of the first relief surface 100 facing away from the second relief surface 200, the main cutting edge 110 has a high wear rate, the main cutting edge 110 has insufficient sharpness, which results in a slower cutting rate, and the needle body cannot be ensured to have a sufficient core thickness, and is poor in rigidity and easy to break.

Accordingly, there is a need for a PCB drill to solve the problems of the prior art.

Disclosure of Invention

The invention aims to provide a PCB drill needle, which can make a main cutting edge sharper, reduce the abrasion degree of the main cutting edge and improve the rigidity of a needle body.

To achieve the purpose, the invention adopts the following technical scheme:

the PCB drill needle comprises a needle body, wherein one end of the needle body forms a drill point, the drill point comprises a chisel edge and two tip parts which are arranged in a central symmetry mode relative to the center of the chisel edge, and each tip part comprises a first rear cutter surface and a second rear cutter surface which are arranged in an included angle mode and connected with each other;

in each tip, a main cutting edge is arranged on one side, close to the first rear cutter surface, of the second rear cutter surface, extends from a circumcircle of the needle body to the axis of the needle body and extends to an endpoint, far away from the chisel edge, of an intersection line of the first rear cutter surface and the second rear cutter surface.

Optionally, a minimum radial dimension of the first flank edge to the needle hub is not less than a minimum radial dimension of the second flank edge to the needle hub.

Optionally, each tip portion is provided with a first chip groove and a second chip groove which extend spirally around the axis of the needle body, the first chip grooves extend to the main cutting edge and the first flank, the second chip grooves extend to one side edge of the second flank, which is away from the first flank, and spiral boundaries of the two tip portions and the adjacent first chip grooves and the second chip grooves coincide.

Optionally, the maximum depth of the first chip groove is 0.05-0.475 times of the diameter of the circumcircle of the needle body.

Optionally, the maximum depth of the second chip groove is 0.15-0.475 times of the radius of the circumscribing circle of the needle body.

Optionally, the minimum radial width of the needle body is the core thickness, and the width of the first chip groove is 0.5-1 times of the core thickness.

Optionally, the depth of the first junk slot gradually decreases in a direction of the needle body axially away from the drill tip.

Optionally, the depth of the second junk slot gradually decreases in a direction of the needle body axially away from the drill tip.

Optionally, the included angle of the two second relief surfaces is a point angle α, and the point angle α is 105 ° -170 °.

Optionally, the needle body further includes a base surface, the base surface is a surface which is formed by intersecting lines of the first flank surface and the second flank surface and forms a first preset included angle beta with the end surface of the needle body, the degree of the first preset included angle beta is (180 ° - α)/2, the included angle between the first flank surface and the base surface is a first flank angle gamma, the included angle between the second flank surface and the base surface is a second flank angle delta, and the first flank angle gamma is greater than 0 ° and less than delta, or the first flank angle gamma is greater than-60 ° and less than 0 °.

The invention has the beneficial effects that:

the PCB drill point that this embodiment provided, with the main cutting edge setting on the second back face, the main cutting edge is by the axial center of circumscribing circle to the needle body and be close to one side extension of first back face, make the radial rake angle of main cutting edge reduce, can reduce the wearing and tearing speed of main cutting edge, guarantee to have sharp main cutting edge, reduce the resistance of cutting, and along the radial of the needle body, the main cutting edge compares first back face and is close to the circumscribing circle, thereby can guarantee the size of first back face along first back face and second back face range direction, guaranteed effective core thickness, can increase the rigidity of drill point, make the drill point be difficult to fracture, improve the life of drill point.

Drawings

FIG. 1 is a schematic view of a prior art PCB drill point;

FIG. 2 is a schematic view of a needle according to an embodiment of the present invention;

FIG. 3 is a schematic view of a needle body according to an embodiment of the present invention in another view;

FIG. 4 is a schematic view of a needle body according to a second embodiment of the present invention;

fig. 5 is a schematic structural view of a needle body according to a second embodiment of the present invention under another view angle.

In the figure:

100. a first relief surface; 110. a main cutting edge; 200. a second relief surface; 300. a chisel edge;

1. a needle body; 11. a drill tip; 111. a first relief surface; 112. a second relief surface; 1121. a main cutting edge; 113. a chisel edge; 12. a first junk slot; 13. and a second junk slot.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are orientation or positional relationships based on those shown in the drawings, merely for convenience of description and simplicity of operation, and do not indicate or imply that the apparatus 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 invention. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for distinguishing between them.

Example 1

As shown in fig. 2, the present embodiment provides a PCB drill, including a needle body 1, a drill tip 11 is formed at one end of the needle body 1, the drill tip 11 includes a chisel edge 113 and two tips disposed in central symmetry with respect to a midpoint of the chisel edge 113, each tip includes a first flank 111 and a second flank 112, the first flank 111 and the second flank 112 are connected and disposed at an included angle, in each tip, a main cutting edge 1121 is disposed on a side of the second flank 112 near the first flank 111, and the main cutting edge 1121 extends from a circumcircle of the needle body 1 to an axis of the needle body 1 and extends to an end point of an intersection line of the first flank 111 and the second flank 112, which is far away from the chisel edge 113. The main cutting edge 1121 is arranged on the second flank 112, the main cutting edge 1121 extends from an circumscribed circle to the axis of the needle body 1 and to one side close to the first flank 111, so that the radial rake angle of the main cutting edge 1121 is reduced, the abrasion speed of the main cutting edge 1121 can be reduced, the sharp main cutting edge 1121 is ensured, the cutting resistance is reduced, and the main cutting edge 1121 is closer to the circumscribed circle than the first flank 111 along the radial direction of the needle body 1, thereby ensuring the size of the first flank 111 along the arrangement direction of the first flank 111 and the second flank 112, ensuring the effective core thickness, being capable of increasing the rigidity of the drill needle, ensuring that the drill needle is not easy to break and prolonging the service life of the drill needle.

Further, the intersection of the first flank 111 and the second flank 112, which are respectively located at the two tips, forms a pointed structure, which is beneficial to further ensuring the effective core thickness, thereby increasing the rigidity of the drill. Here, the effective core thickness is the minimum radial width of the needle body 1.

Optionally, the minimum radial dimension from the edge of the first clearance surface 111 to the axis of the needle body 1 is not smaller than the minimum radial dimension from the edge of the second clearance surface 112 to the axis of the needle body 1, so that the needle body 1 has an inscribed circle with the minimum radial dimension from the edge of the second clearance surface 112 to the axis of the needle body 1 as a radius, and the core thickness is not smaller than the diameter of the inscribed circle, thereby further ensuring the core thickness of the PCB drill needle, improving the rigidity of the needle body 1, reducing the occurrence of needle breakage, and improving the service life of the PCB drill needle.

Preferably, as shown in fig. 3, each tip portion of the needle body 1 is provided with a first chip groove 12 and a second chip groove 13 extending spirally around the axis of the needle body 1, the first chip groove 12 extends to the main cutting edge 1121 and the first flank 111, the second chip groove 13 extends to one side edge of the second flank 112 facing away from the first flank 111, and spiral boundaries of the adjacent first chip groove 12 and second chip groove 13 respectively located at the two tip portions coincide. In the process of cutting the PCB drill point, chips are preferentially discharged from the first chip groove 12, when the first chip groove 12 is full of chips, the chips gradually move to the second chip groove 13, and the cutting is subjected to shearing force at a transition position, so that the long-strip chips are extruded and discharged, the long-strip chips are prevented from being wound on the drill point to cause broken pins, the chip discharging capability of the PCB drill point is improved, the chips are timely discharged from a drilled hole, friction between the chips and a hole wall is reduced, the roughness of the hole wall is reduced, and the processing quality is improved.

During actual machining, the width of the first junk slot 12 may extend from the circumscribed circle to the second flank 112 of the opposite side tip; the width of the second flutes 13 may also extend to the first relief surface 111 of the opposite side tip.

Alternatively, as shown in fig. 3, the maximum depth of the first junk slot 12 is 0.05-0.475 times, for example 0.1 times, 0.2 times, 0.3 times, or 0.45 times the diameter of the circumcircle of the needle body 11. The maximum depth of the first chip groove 12 in this embodiment is preferably 0.3 times of the diameter of the circumcircle of the needle body 11, so that the chip capacity and chip removal function of the first chip groove 12 are ensured, the core thickness of the needle body 1 is ensured, and the strength of the needle body 1 is improved.

Alternatively, as shown in fig. 3, the maximum depth of the second junk slot 13 is 0.15-0.475 times, for example 0.2 times, 0.3 times or 0.45 times, the radius of the circumcircle of the needle body 1. The maximum depth of the second chip groove 13 in this embodiment is preferably 0.3 times of the radius of the circumscribing circle of the needle body 1, so as to further improve the chip holding capacity and chip removing capacity of the needle body 1, and simultaneously ensure that the chips can be hinged and broken by shearing force at the junction of the first flank 111 and the second flank 112, become short strip cutting and are discharged, reduce the abrasion of the chips to the hole wall, improve the processing quality of the hole wall, and prevent the strip chips from winding on the drill needle to cause broken needles.

Alternatively, the width of the first junk slots 12 is 0.5-1 times, e.g., 0.55 times, 0.6 times, 0.7 times, 0.8 times, or 0.9 times the core thickness. The core thickness is the shortest distance between two first flutes 12. In this embodiment, the width of the first junk slot 12 is preferably 0.55 times of the core thickness, so that the core thickness of the needle body 1 is ensured, and the strength of the needle body 1 is improved, thereby further improving the chip removing capacity of the whole chip containing space of the needle body 11 and the first junk slot 12.

Preferably, the first chip grooves 12 and the second chip grooves 13 corresponding to the same tip are arranged at intervals to form a land. In this embodiment, through setting up the width of first chip groove 12 and second chip groove 13 for distance between first chip groove 12 and the second chip groove 13 is shorter, does not need to set up limit sword structure, has saved the process of processing, has improved the machining efficiency to the PCB drill point, can also reduce the area of contact of needle body 1 and drilling pore wall at the in-process of PCB drill point drilling, reduces the heat that needle body 1 and pore wall friction produced, reduces the burning erosion of high temperature to the pore wall, improves the quality of processing.

Optionally, the helical angles of the first junk slots 12 and the second junk slots 13 are the same, and the helical angles of the first junk slots 12 and the second junk slots 13 are both 30 ° -55 °. For example, 40 °, 45 ° or 50 °. Specifically, in this embodiment, the helix angle of the first flute 12 gradually increases along the direction of the needle body 1 toward the needle shank, for example, the helix angle of the first flute 12 near the drill tip 11 is defined as a front helix angle, the angle of the front helix angle is 40 °, the helix angle of the first flute 12 near the needle shank portion is defined as a rear helix angle, the angle of the rear helix angle is 50 °, and by gradually increasing the helix angles of the first flute 12 and the second flute 13, the discharge of broken chips and chips can be facilitated, the roughness of the hole wall is reduced, and the processing quality of the hole wall is further improved. In other embodiments, the spiral angles of the first chip groove 12 and the second chip groove 13 may be 45 °, i.e. the spiral angles of the first chip groove 12 and the second chip groove 13 are unchanged along the direction of the needle body 1 towards the needle handle, which is also beneficial to chip breaking and cutting discharge, and reduces the roughness of the hole wall, thereby improving the processing quality from the hole wall.

Optionally, the depth of the first junk slot 12 gradually decreases along the direction of the needle body 1 toward the needle handle, and the depth of the second junk slot 13 gradually decreases along the direction of the needle body 1 toward the needle handle, and it is understood that the gradual decrease of the depths of the first junk slot 12 and the second junk slot 13 makes the distance between the two first junk slots 12 gradually increase along the direction of the needle body 11 toward the needle handle, and the distance between the two second junk slots 13 gradually increases along the direction of the needle body 1 toward the needle handle, so that the toughness and strength of the needle body 1 can be further improved.

Optionally, the needle body 1 and the needle handle of the PCB drill needle are both made of hard alloy materials, and the hard alloy has the advantages of high hardness, wear resistance, high strength and good toughness, so that the service life of the PCB drill needle can be prolonged.

Optionally, the drill point 11 further comprises a point angle α, the angle of the two second relief surfaces 112 being the point angle α, the angle of the point angle α being 105 ° -170 °, for example the point angle α may be 110 °, 120 °, 130 °, 140 °, 150 ° or 160 °, in this embodiment the angle of the point angle α being 150 °, which ensures that the needle 11 has a sharp main cutting edge 1121.

Optionally, the needle body 1 further includes a base surface, the base surface is a surface which is made by intersecting lines of the first flank surface 111 and the second flank surface 112 and forms a first preset included angle β with the end surface of the needle body 1, the end surface of the needle body 1 is a plane which passes through the drill point and is perpendicular to the central axis of the needle body 1, the first preset included angle β has a degree of (180 ° - α)/2, the included angle between the first flank surface 111 and the base surface is a first flank angle γ, the included angle between the second flank surface 112 and the base surface is a second flank angle δ, the first flank angle γ is greater than 0 ° and less than δ, the degree of the first flank angle is greater than 0 ° and less than the angle of the second flank angle, so that the main cutting edge 1121 on the second flank surface 112 can be ensured to be sharper, and meanwhile, the wear speed of the first flank surface 111 and the second flank surface 112 can be reduced, and the service life of the PCB drill needle can be further improved.

TABLE 1

TABLE 2

Machine tool equipment	Drilling machine
		Rotational speed	160kr/min
Number of holes	2500Hit
		Feed amount	1.62m/min
Knife retracting speed	25.2m/min

TABLE 3 Table 3

As shown in the above table, table 1 is the parameters of the PCB drill provided in this example, table 2 is the processing conditions, the drill in table 1 is mounted on the drilling machine provided in table 2, and the board with the thickness of 12mm is drilled under the processing conditions in table 2, so as to obtain the experimental data in table 3, wherein the control group is the structure of the existing PCB drill.

In the actual processing process, the larger the value of CPK is, the better the processing quality of the hole wall is shown, and from the experimental data in Table 3, the three groups of data in the experimental group can obviously show that the value of CPK of the PCB drill point provided by the embodiment after processing is obviously larger than the value of CPK of the PCB drill point in the control group, so that the stability of the PCB drill point provided by the embodiment in the processing process is strong, and the experimental results in the experimental group and the control group show that the phenomena of wire winding and hole plugging of the PCB drill point structure provided by the embodiment are obviously improved. Therefore, it is enough to explain that the needle body 1 is provided with the first chip groove 12 and the second chip groove 13 which extend spirally side by side, the spiral boundaries of the first chip groove 12 and the second chip groove 13 are coincident, so that chips can be ensured to be discharged from the first chip groove 12 preferentially in the cutting process of the PCB drill, when the chips are fully accumulated in the first chip groove 12, the chips gradually move to the second chip groove 13, and the cutting is subjected to the shearing force at the transition position, so that the long-strip chips are extruded and discharged, the broken needle caused by winding the long-strip chips on the drill is prevented, the roughness of the hole wall is reduced, the processing quality is improved, the chip discharging capability of the PCB drill is improved, and the service life of the drill is prolonged.

Example two

As shown in fig. 4 to 5, the difference between the PCB drill provided in this embodiment and the first embodiment is that the included angle between the first flank 111 and the base surface of the PCB drill in this embodiment is greater than-60 ° and less than 0 °, and the main cutting edge 1121 is disposed on the second flank 112, where the radial rake angle of the main cutting edge 1121 is reduced, so that the wear speed of the main cutting edge 1121 can be reduced, the sharp main cutting edge 1121 is ensured, the cutting resistance is reduced, and the tip of the first flank 111 is reserved at the intersection of the two tips, so that the effective core thickness is ensured, the rigidity of the drill can be increased, the drill is not easy to break, and the service life of the drill is prolonged.

It is to be understood that the above examples of the present invention are provided for clarity of illustration only and are not limiting of the embodiments of the present invention. Various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of the invention. It is not necessary here nor is it exhaustive of all embodiments. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the invention are desired to be protected by the following claims.

Claims

1. A PCB drill point, comprising a needle body (1), wherein one end of the needle body (1) forms a drill point (11), and the drill point is characterized in that the drill point (11) comprises a chisel edge (113) and two tip parts which are arranged in a central symmetry way relative to the center of the chisel edge (113), and each tip part comprises a first rear tool face (111) and a second rear tool face (112) which are arranged in an included angle way and are connected with each other;

in each tip portion, a main cutting edge (1121) is arranged on one side, close to the first rear cutter surface (111), of the second rear cutter surface (112), and the main cutting edge (1121) extends from a circumcircle of the needle body (1) to the axis of the needle body (1) and extends to an endpoint, far away from the chisel edge (113), of an intersection line of the first rear cutter surface (111) and the second rear cutter surface (112).

2. The PCB drill point according to claim 1, characterized in that the minimum radial dimension of the edge of the first flank (111) to the axial centre of the needle body (1) is not smaller than the minimum radial dimension of the edge of the second flank (112) to the axial centre of the needle body (1).

3. The PCB drill point according to claim 1, characterized in that the needle body (1) is provided with a first chip groove (12) and a second chip groove (13) corresponding to each tip portion, which extend helically around the axis of the needle body (1), the first chip groove (12) extending to the main cutting edge (1121) and the first flank (111), the second chip groove (13) extending to a side edge of the second flank (112) facing away from the first flank (111), the helical boundaries of the adjacent first chip groove (12) and second chip groove (13) being coincident with each other at two tip portions.

4. A PCB drill point according to claim 3, characterized in that the maximum depth of the first junk slot (12) is 0.05-0.475 times the diameter of the circumcircle of the needle body (1).

5. A PCB drill according to claim 3, characterized in that the maximum depth of the second junk slot (13) is 0.15-0.475 times the radius of the circumscribing circle of the needle body (1).

6. A PCB drill according to claim 3, characterized in that the minimum radial width of the needle body (1) is the core thickness and the width of the first junk slots (12) is 0.5-1 times the core thickness.

7. A PCB drill point according to claim 3, characterized in that the depth of the first junk slots (12) decreases gradually in the axial direction of the needle body (1) in a direction away from the drill point (11).

8. A PCB drill point according to claim 7, characterized in that the depth of the second junk slots (13) decreases gradually in the axial direction of the needle body (1) in a direction away from the drill point (11).

9. A PCB drill point according to claim 1, characterized in that the angle between the two second flank surfaces (112) is a point angle α, which is 105 ° -170 °.

10. The PCB drill point of claim 9, wherein the needle body (1) further comprises a base surface, the base surface being a surface forming a first preset angle β with the end surface of the needle body (1) through an intersection line of the first flank surface (111) and the second flank surface (112), the first preset angle β having a degree of (180 ° - α)/2, the first flank surface (111) having a first flank angle γ with the base surface, the second flank surface (112) having a second flank angle δ with the base surface, the first flank angle γ being greater than 0 ° and less than δ, or the first flank angle γ being greater than-60 ° and less than 0 °.