Positioning block for preventing drill bit from rotating, drill bit and machining method

Abstract

The invention relates to the technical field of machining equipment, and discloses a positioning block for preventing a drill bit from rotating, the drill bit and a machining method.The positioning block comprises a head-changing drill bit module, and a boss structure is arranged at the top of the head-changing drill bit module; the boss structure is a hexahedron structure and comprises a bottom surface, a top surface, two side surfaces and two end surfaces; wherein the bottom surface of the boss structure is arranged at the top of the head-changing drill bit module; the top face is of a plane structure, the two side faces are first stress faces, and the two end faces are second stress faces. The first stress surfaces are a pair of planes which are centrosymmetric to each other, and the second stress surfaces are a pair of involute curved surfaces which are centrosymmetric to each other. Relative rotation between the cutter body and the head-changing drill bit module is effectively prevented in the cutting process, blockage is avoided, and therefore the situation that chip removal is affected is avoided, and the stability of the machining quality is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of machining equipment, and in particular to a positioning block for preventing a drill bit from rotating, a drill bit thereof, and a machining method thereof. Background Art

[0002] In current drill grinding and cutting operations, in order to improve the applicability and ease of operation of the drill, a replaceable drill module design is widely used. This design enables the drill module to be quickly replaced according to different cutting requirements and material properties, thereby simplifying the drill replacement process and greatly improving work efficiency and flexibility.

[0003] However, although the replaceable drill bit module brings many advantages, in actual applications, since the drill bit module and the cutter body are mainly fixed by installation connection, when in a high-speed rotation environment, the connection between the drill bit module and the cutter body is not completely rigid, and the small gap and loose connection between the two will cause the two to rotate relative to each other under the action of centrifugal force and vibration, causing the drill bit's trajectory to deviate from the predetermined path during the cutting process, resulting in cutting deviation, increased roughness and other problems.

[0004] In addition, relative rotation may also cause the cutting edge to turn inside the cutter body, causing the drill chips to accumulate in the gap between the drill module and the cutter body, which in turn causes blockage. Blockage of drill chips not only affects the chip removal efficiency of the drill bit, but may also cause the drill bit to overheat and increase wear, thereby shortening the service life of the drill bit. In addition, blocked drill chips may also create additional resistance to the drilling process, further reducing drilling efficiency. Summary of the invention

[0005] The present invention aims to provide a positioning block for preventing a drill bit from rotating, a drill bit and a processing method thereof, so as to solve the problem that the existing replaceable drill bit module structure is prone to relative rotation when rotating at high speed, which is easy to cause blockage, thereby affecting the cutting accuracy and quality and shortening the service life of the drill bit.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a positioning block for preventing the drill bit from rotating, comprising a head-changing drill bit module, and a boss structure is provided on the top of the head-changing drill bit module; the boss structure is a hexahedral structure, comprising a bottom surface, a top surface, two side surfaces and two end surfaces; wherein the bottom surface of the boss structure is arranged at the top of the head-changing drill bit module; the top surface is a planar structure, the two side surfaces are first force-bearing surfaces, and the two end surfaces are second force-bearing surfaces; the first force-bearing surfaces are a pair of mutually centrally symmetrical planes, and the second force-bearing surfaces are a pair of mutually centrally symmetrical involute curved surfaces.

[0007] Furthermore, the height of the boss structure is 10% to 12.5% ​​of the drill bit diameter.

[0008] Furthermore, a positioning column is provided on the top surface of the boss structure.

[0009] Furthermore, the width of the pair of first force-bearing surfaces is 25% to 30% of the drill bit diameter; the parameter equation of the second force-bearing surface is:

[0010]

[0011] Where r is the radius of the involute base circle; d is the drill diameter, a and b are constants used to adjust the roll angle of the involute curve to adapt to the drill space, where a[10,12], b[5,6]; t is the independent variable of the equation, t(0,1].

[0012] Since the boss structure is arranged in a narrow inner cavity and the interacting contact surfaces have the characteristics of thin walls, in order to ensure that the first force-bearing surface can generate a thrust force to balance the cutting force when relative rotation occurs, thereby reducing the relative rotation and ensuring that it can be installed in the inner cavity and achieve a certain strength, the geometric shape of the boss structure is constrained by the second force-bearing surface. For example, different base circle radii r and different a and b parameters will affect the length of the first force-bearing surface. When the involute equation is determined, the overall "arc length" of the involute surface is determined by the width of the first force-bearing surface; the arc angle of the second force-bearing surface can be adjusted according to the parametric equation and design.

[0013] At the same time, the present solution also provides a drill bit that prevents the drill bit from rotating, which is applied to the above-mentioned positioning block, including a cutter body, a head-changing drill bit module is provided at the bottom end of the cutter body; a positioning block is provided at the top of the head-changing drill bit module; an inwardly recessed limit groove is provided at the bottom of the cutter body; and the positioning block is arranged in the limit groove.

[0014] Furthermore, the limit groove is a step groove, including a first step groove, a second step groove and a third step groove; the bottom surface of the first step groove is in contact with the top surface of the boss structure, and the inner side surface of the second step groove is arranged on the outside of the second force-bearing surface and the first force-bearing surface, and there is a certain gap; the third step groove is clamped with the middle part of the head-changing drill module.

[0015] Furthermore, a docking hole recessed inwardly is provided in the middle of the first step groove, and the positioning column is arranged in the docking hole.

[0016] Furthermore, the height of the second step groove is consistent with the height of the boss structure; the inner side surface of the second step groove includes a first limiting surface corresponding to the first force-bearing surface, and a second limiting surface corresponding to the second force-bearing surface.

[0017] At the same time, the present invention also provides a drill bit processing method for preventing the drill bit from rotating, which is applied to the above-mentioned drill bit and includes the following steps:

[0018] Step 1, install the head-changing drill module in the limiting groove of the cutter body, so that the positioning column is located in the docking hole, and the positioning block corresponds to the first step groove and the second step groove;

[0019] Step 2, using a replaceable drill module to process the workpiece; when the cutter body and the module rotate relative to each other, the first force-bearing surface and the second force-bearing surface contact the cutter body in turn, and generate relative forces to offset the cutting rotational force.

[0020] Furthermore, when relative rotation occurs, the first force-bearing surface first contacts the first limit surface and generates a relatively reverse thrust force to balance the current cutting force; when the cutting force is too large and the rotation reaches a critical point, the second force-bearing surface will contact the second limit surface and generate friction to balance the current cutting force.

[0021] The principles and advantages of this solution are:

[0022] Without changing the structure of the tool and the replaceable drill module, this solution cleverly sets a positioning block on the top of the drill module, so that the drill module can be directly installed in the inner cavity of the tool, strengthening the limiting effect while effectively transmitting torque. And taking into account the thin-walled characteristics of the tool, a double-stage limiting structure is adopted to realize a two-stage limiting mechanism, which effectively prevents the relative rotation between the tool body and the replaceable drill module during the cutting process, improves the torque strength of the overall structure, and avoids blockage and affects chip removal. Even in a high-speed rotating operating environment, the tool can prevent the problems of low drilling efficiency and precision loss caused by relative rotation, thereby ensuring the stability of product quality and greatly reducing the need for rework, which not only reduces labor intensity but also effectively controls production costs. At the same time, this solution can also be applied to the processing of various replaceable tool modules to improve applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic structural diagram of a positioning block for preventing a drill bit from rotating according to the present invention.

[0024] Figure 2 The figure is a top view of the positioning block for preventing the drill bit from rotating according to the present invention.

[0025] Figure 3 The present invention is a schematic structural diagram of a drill bit for preventing the drill bit from rotating.

[0026] Figure 4 The present invention is a schematic diagram of the cutter body structure of a drill bit that prevents the drill bit from rotating.

[0027] Figure 5 for Figure 4 A schematic diagram of the enlarged local structure of part A in the middle.

[0028] Figure 6The present invention is a schematic cross-sectional structural diagram of a drill body and a drill bit installation state for preventing the drill bit from rotating.

[0029] Figure 7 The present invention is a schematic diagram of the force-bearing structure of the first stage of limiting the drill bit in the drill bit processing method for preventing the drill bit from rotating.

[0030] Figure 8 The present invention is a schematic diagram of the force bearing structure of the second stage of limiting the drill bit in the drill bit processing method for preventing the drill bit from rotating. DETAILED DESCRIPTION

[0031] The following is further described in detail through specific implementation methods:

[0032] Marked in the accompanying drawings are: cutter body 1, head-changing drill module 2, positioning block 3, protrusion structure 4, bottom surface 5, top surface 6, side surface 7, end surface 8, positioning column 9, limiting groove 10, first step groove 11, second step groove 12, third step groove 13, docking hole 14, card slot 15, first force-bearing surface b, second force-bearing surface a, first limiting surface b', second limiting surface a'.

[0033] The positioning block 3 for preventing the drill bit from rotating in this embodiment is provided with a protruding block structure 4 on the top of the head-changing drill bit module 2, and adopts a double-stage limiting structure to gradually increase the anti-torsion capacity of the overall structure, thereby reducing the relative rotation between the drill bit module and the cutter body, and ensuring the stability and accuracy of the drilling operation. Figure 1 As shown, the head-changing drill module 2 includes a cutter head that is spiral in shape as a whole, and a positioning block 3 is arranged above the cutter head. The positioning block 3 includes a convex block structure 4 arranged on the top of the head-changing drill module 2 for limiting and transmitting torque. Among them, the convex block structure 4 is a hexahedral structure, including a bottom surface 5, a top surface 6, two side surfaces 7 and two end surfaces 8. Among them, the bottom surface 5 of the convex block structure 4 is directly formed on the top of the head-changing drill module, and its top surface is set as a plane structure. The overall height of the convex block structure 4 is 10% to 12.5% ​​of the drill diameter. If the drill diameter is 20mm, then the corresponding boss structure 4 has a height of 2mm to 2.5mm, which can ensure that the strength of the limiting boss increases proportionally with the increase of the drill diameter. In this embodiment, a positioning column 9 is also integrally formed on the top surface of the boss structure 4, and the diameter of the positioning column 9 is set to 2-2.5mm and the height is set to 2.5-3mm for stable installation.

[0034] In this embodiment, as shown in the attached Figure 2 As shown, the two side surfaces 7 are the first force-bearing surfaces located on both sides of the bump structure 4, denoted as surface b, which are a pair of planar structures that are centrally symmetrical to each other. In this embodiment, the width of a pair of first force-bearing surfaces is 25% to 30% of the drill bit diameter. For example, if the drill bit diameter is 20 mm, then the corresponding width of the first force-bearing surface is 5 mm to 6 mm.

[0035] The two end faces 8 are the second force-bearing surfaces located at both ends of the bump structure 4, denoted as a surface, and are a pair of involute curved surfaces whose cross sections are centrally symmetrical to each other. That is, in this embodiment, the cross-sectional shape of the second force-bearing surface is an involute with two base circle radii of the same size but different rolling angles, that is, involutes that are equidistant from each other. In this embodiment, the involute parameter equation of the cross section of the second force-bearing surface is:

[0036]

[0037] Wherein r is the radius of the involute base circle. In this embodiment, the value range of r can be designed within 7% to 7.5% of the drill diameter; d is the drill diameter; a and b are constants used to adjust the roll angle of the involute curve to adapt to the drill space, where a[10,12] and b[5,6]; t is the independent variable of the equation, t(0,1].

[0038] The arc length of the involute curve is determined by the parameter equation of the second force-bearing surface and the width of the first force-bearing surface.

[0039] Since the boss structure 4 is arranged in a narrow inner cavity and the interacting contact surfaces have the characteristics of thin walls, in order to ensure that the first force-bearing surface can generate a thrust force to balance the cutting force when relative rotation occurs, thereby reducing the relative rotation, and ensuring that it can be installed in the inner cavity and achieve a certain strength, the geometric shape of the boss structure 4 is constrained by the second force-bearing surface for the overall length. If the base circle radius r is different and the a and b parameters are different, the length of the first force-bearing surface will be affected. When the involute equation is determined, the overall "arc length" of the involute surface is determined by the width of the first force-bearing surface.

[0040] The corresponding force-bearing surface of the second force-bearing surface in the cutter body is also an involute. The cross-sectional shape of the second force-bearing surface of the drill bit and the cross-sectional shape of the second force-bearing surface of the cutter body are two involutes with the same base circle radius but different rolling angles, that is, involutes that are equidistant from each other. When one of the curves rotates around the center, there must be a certain rotation angle that makes the two curves coincide. Then, when the second force-bearing surface of the cutter body and the second force-bearing surface of the drill bit contact and coincide, friction will be generated at the contact point, and this friction will provide additional limiting force. According to the characteristics of the involute, when the two curved surfaces completely overlap, theoretically every point of the curved surfaces contacts each other and generates friction. In order to ensure the stable installation of the boss structure 4 and to ensure the effect of balancing the cutting force and effectively reduce the relative rotation phenomenon, the spacing between the two involutes is 0.18mm to 0.22mm.

[0041] At the same time, in this embodiment, a drill bit for preventing the drill bit from rotating is also provided, which is applied to the above positioning block. Figure 3 As shown, it comprises a cutter body 1, and a head-changing drill module 2 is installed and connected at the bottom end of the cutter body 1. A positioning block 3 in this solution is arranged on the top of the head-changing drill module 2.

[0042] As attached Figure 4 As shown, a limiting groove 10 recessed inwardly is provided at the bottom of the blade body 1. When connected, the positioning block 3 extends into the limiting groove 10 of the blade body 1 and is positioned and connected through the positioning column 9.

[0043] As attached Figure 5 As shown, in this embodiment, the limiting groove 10 is a step groove, including a first step groove 11, a second step groove 12 and a third step groove 13. Among them, the first step groove 11 is located at the top of the limiting groove 10, and the shape of the first step groove 11 corresponds to the shape of the boss structure 4. After connection, its bottom surface fits with the top surface of the boss structure 4. And an inwardly recessed docking hole 14 is opened in the middle of the first step groove 11, so that the positioning column 9 can be placed in the docking hole 14 after connection, thereby realizing the positioning connection between the cutter body 1 and the head-changing drill module 2.

[0044] The second step groove 12 is located below the first step groove 11, and the height of the second step groove 12 is consistent with the height of the boss structure 4. After the connection, the inner side of the second step groove 12 is located outside the second force-bearing surface and the first force-bearing surface, and there is a certain gap between the first force-bearing surface and the second force-bearing surface. Figure 6 As shown. In this embodiment, the inner side surface of the second step groove 12 includes a first limiting surface corresponding to the first force-bearing surface b, denoted as b'; and a second limiting surface corresponding to the second force-bearing surface a, denoted as a'. In this embodiment, the first limiting surface is a centrally symmetrical planar structure, and the second limiting surface is a centrally symmetrical involute curved surface.

[0045] As attached Figure 5 As shown, the third step groove 13 is arranged below the second step groove 12, and a clamping groove 15 is also provided between the third step groove 13 and the second step groove 12. The third step groove 13 and the clamping groove 15 are clamped with the middle part of the head-changing drill module 2, so that the head-changing drill module 2 is installed on the bottom end of the cutter body 1.

[0046] At the same time, in this embodiment, a drill processing method for preventing the drill from rotating is also provided. In this embodiment, the positioning block and the drill can also be applied to other modular tool products with replaceable heads. In this embodiment, the use of the positioning block and the drill is used as an example for explanation, including the following steps:

[0047] S1, as attached Figure 3 As shown, the head-changing drill module 2 is installed in the limiting groove 10 of the cutter body 1, the positioning column 9 is located in the docking hole 14, and the positioning block 3 corresponds to the first step groove 11 and the second step groove 12. The first limiting surface b' of the second step groove 12 corresponds to the first force-bearing surface b of the positioning block 3, and the second limiting surface a' corresponds to the second force-bearing surface a.

[0048] In this embodiment, the positioning block 3 is set in the inner cavity of the cutter body 1 with a narrow space, and the interacting contact surface has the characteristic of thin wall, so two sections of force-bearing surfaces are set to form a double-section limit. The relationship between the first limit surface and the second limit surface is designed, considering the principle and characteristics of the centering ability of the original structure, and the limit surface is set to passive torsion resistance, that is, when the drill bit is pre-tightened and not subjected to the cutting force, the first limit surface and the second limit surface are both in an "idle" state, that is, they are not in contact with any surface, that is, there is a certain gap between the first force-bearing surface and the second force-bearing surface, so as to ensure the centering ability of the original structure of the drill bit interface.

[0049] S2, using a replaceable drill module to process the workpiece; when the cutter body and the module rotate relative to each other, the first force-bearing surface and the second force-bearing surface contact the cutter body in turn, and generate relative forces to offset the cutting rotational force.

[0050] When the drill bit rotates at high speed and is subjected to cutting force, there is a tendency for relative movement between the drill head module 2 and the cutter body 1. When the cutting force is greater than the static friction between the drill head module 2 and the cutter body 1, a slight relative rotation is allowed between the drill head module and the cutter body 1.

[0051] When the rotation reaches the initial point of the first limit surface, the first limit occurs. At this time, the first force surface b first contacts the first limit surface b'. At this time, only the first force surface b contacts the first limit surface b', and the first limit surface acts as the limit. The second limit surface a' is empty, that is, no contact and no force is generated. At this time, the force condition of the positioning block 3 is as shown in the attached figure. Figure 7 As shown, the first limiting surface will generate a relatively reverse thrust force F 止 Under the action of the thrust force, the drill module is subjected to a pair of forces of equal magnitude and opposite direction to balance the current cutting force, thereby preventing the drill module and the cutter body 1 from rotating relative to each other.

[0052] When the cutting force of the drill bit continues to increase and the cutting force is greater than the static friction of the system, the head-changing drill bit module 2 will continue to rotate relatively inside the cutter body 1. When the rotation reaches a critical point, the first limit surface b' will undergo elastic deformation, causing the first stage of limit to fail, that is, plastic deformation occurs but the first force surface does not break, so there is still force, and the drill bit will continue to rotate relatively. When the rotation angle is too large, the relative rotation reaches the starting point of the second stage of limit, causing the second limit surface a' to contact the second force surface a, generating friction, and generating the second stage of limit. The friction force increases the limit force, and double-stage limit is achieved on the basis of the first stage of limit, achieving the effect of double limit and increasing the torsion resistance of the overall structure. In this embodiment, when the second stage of limit occurs, friction force dF will be generated. 摩, and according to the characteristics of the involute, that is, the normal line of any point on the involute is tangent to the base circle, it is easy to infer that the direction of the friction force on any point on the a surface is perpendicular to the normal of the point. The force state analysis is shown in the attached figure. Figure 8 As shown, F 摩 =∫dF 摩 , hold the drill module again to balance the current cutting force and prevent failure, thereby effectively ensuring the stability between the cutter body 1 and the head-changing drill module 2, reducing the risk of relative rotation and improving the accuracy of the drill.

[0053] In this embodiment, a positioning block 3 structure is set on the top of the head-changing drill module 2, and the positioning block 3 is set in the inner cavity at the bottom of the cutter body, so as to increase the limit and transmit torque without changing the external structure of the tool, ensuring the original centering ability of the drill structure. In combination with the thin-walled characteristics of the contact surface, the boss structure 4 is set as a double-stage limit mode, and the two-stage limit structure is used to prevent the relative rotation of the cutter body 1 and the head-changing drill module 2, thereby increasing the torsion resistance of the overall structure, thereby avoiding relative rotation under high-speed rotation, causing the cutting edge to turn to the inside of the cutter body, causing blockage of chip removal, thereby affecting cutting efficiency and precision, ensuring product quality, reducing the amount of rework, effectively reducing labor intensity, and reducing production costs.

[0054] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A positioning block to prevent the drill bit from rotating, characterized in that: It includes a head-changing drill bit module, and a boss structure is provided on the top of the head-changing drill bit module; the boss structure is a hexahedral structure, including a bottom surface, a top surface, two side surfaces and two end surfaces; the bottom surface of the boss structure is arranged on the top of the head-changing drill bit module; the top surface is a plane structure, the two side surfaces are first force-bearing surfaces, and the two end surfaces are second force-bearing surfaces; the first force-bearing surfaces are a pair of mutually centrally symmetrical planes, and the second force-bearing surfaces are a pair of mutually centrally symmetrical involute curved surfaces.

2. The positioning block for preventing the drill bit from rotating according to claim 1, characterized in that: The height of the boss structure is 10% to 12.5% ​​of the drill bit diameter.

3. The positioning block for preventing the drill bit from rotating according to claim 1, characterized in that: A positioning column is arranged on the top surface of the boss structure.

4. The positioning block for preventing the drill bit from rotating according to claim 1, characterized in that: The width of a pair of first force-bearing surfaces is 25% to 30% of the drill bit diameter; the parameter equation of the second force-bearing surface is: Where r is the radius of the involute base circle; d is the drill diameter; a and b are constants used to adjust the roll angle of the involute curve, where a[10,12] and b[5,6]; t is the independent variable of the equation, t(0,1].

5. A drill bit that prevents the drill bit from rotating, characterized in that: The positioning block used in any one of claims 1-4 comprises a cutter body, a head-changing drill module is provided at the bottom end of the cutter body; a positioning block is provided at the top of the head-changing drill module; an inwardly recessed limiting groove is provided at the bottom of the cutter body; and the positioning block is arranged in the limiting groove.

6. The drill bit for preventing the drill bit from rotating according to claim 5, characterized in that: The limiting groove is a step groove, including a first step groove, a second step groove and a third step groove; the bottom surface of the first step groove is in contact with the top surface of the boss structure, and the inner side surface of the second step groove is arranged on the outer side of the second force-bearing surface and the first force-bearing surface, and there is a certain gap; the third step groove is clamped with the middle part of the head-changing drill module.

7. The drill bit for preventing the drill bit from rotating according to claim 5, characterized in that: A docking hole recessed inwardly is provided in the middle of the first step groove, and the positioning column is arranged in the docking hole.

8. The drill bit for preventing the drill bit from rotating according to claim 6, characterized in that: The height of the second step groove is consistent with the height of the boss structure; the inner side surface of the second step groove includes a first limiting surface corresponding to the first force-bearing surface, and a second limiting surface corresponding to the second force-bearing surface.

9. A drill bit processing method for preventing the drill bit from rotating as claimed in any one of claims 5 to 8, characterized in that: The following steps are included: Step 1, install the head-changing drill module in the limiting groove of the cutter body, so that the positioning column is located in the docking hole, and the positioning block corresponds to the first step groove and the second step groove; Step 2, using a replaceable drill module to process the workpiece; when the cutter body and the module rotate relative to each other, the first force-bearing surface and the second force-bearing surface contact the cutter body in turn, and generate relative forces to offset the cutting rotational force.

10. The drill bit processing method for preventing the drill bit from rotating according to claim 9, characterized in that: When relative rotation occurs, the first force-bearing surface first contacts the first limit surface and generates a relatively opposite thrust force to balance the current cutting force; when the cutting force is too large and the rotation reaches a critical point, the second force-bearing surface will contact the second limit surface and generate friction to balance the current cutting force.

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