deep hole drill

Abstract

The application provides a deep hole drill, comprising a drill body, the drill body comprising a drill section, the drill section comprising a drill core, a cutting edge being formed at a drill tip of the drill core, the drill section further comprising a plurality of blade strips spirally arranged along an axial direction of the drill core, a flow groove being configured on a guide surface of at least part of the blade strips, and a cooling liquid channel being formed in the drill section and capable of guiding the cooling liquid to the drill tip. The application increases the contact area between the cooling liquid and the blade strips, realizes efficient cooling and heat dissipation of the blade strips, eliminates the occurrence of thermal cracking caused by high temperature generated by the cutting edge, further eliminates the occurrence of tool failure and product scrapping caused by thermal cracking, and improves the drilling efficiency of the deep hole drill.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of drilling tool design, and particularly relates to a deep hole drill. BACKGROUND

[0002] In the modern mechanical processing industry, mold processing is an indispensable part of the manufacturing industry. In the mold manufacturing process, the inner cooling hole and the top pin hole of the mold must be deep hole processed. The traditional gun drill cannot meet the pursuit of processing efficiency in modern mold processing. Therefore, it is urgent to apply deep hole drills (the drilling depth is generally greater than 5 times the diameter of the drill bit) to mold processing.

[0003] Hole processing is carried out in a closed or semi-closed state, with a large processing allowance and the real-time cutting condition of the tool cannot be observed. The processing technology is difficult, which mainly reflects that the cutting area temperature is high, the cutting heat is not easy to transfer; the chip removal path is long, and the chip is difficult to discharge; the process system is poor in rigidity, and vibration is easy to occur during drilling; due to high temperature and high pressure in the drilling area, the drill tip is easy to wear. Especially in the drilling process, the inner part of the blade belt of the drilling part for guiding the drill body is extremely easy to produce thermal cracks under the action of high temperature, thereby causing tool failure, product scrap and reducing the drilling efficiency of the deep hole drill. SUMMARY

[0004] Therefore, the present application provides a deep hole drill, which can overcome the technical problem that the inner part of the blade belt of the deep hole drill is extremely easy to produce thermal cracks under the action of high temperature, thereby causing tool failure, product scrap and reducing the drilling efficiency of the deep hole drill.

[0005] In order to solve the above problems, the present application provides a deep hole drill, which comprises a drill body, the drill body comprises a drilling section, the drilling section comprises a drill core, a cutting edge is formed at a drill tip of the drill core, the drilling section further comprises a plurality of blade belts spirally arranged along the axial direction of the drill core, a flow passage is formed on the guide surface of at least part of the blade belts, and a cooling liquid channel is formed in the drilling section to guide the cooling liquid to the drill tip.

[0006] In some embodiments, the blade belt has a first side surface and a second side surface connected with the guide surface thereof, the flow passage penetrates through the first side surface and the second side surface, the blade belt intersects with the cutting edge at point A, a tangent line of the cutting edge passing through the point A is a first tangent line, and the penetration direction of the flow passage is parallel to the first tangent line; and / or, the cutting edge has m pieces, the blade belt has 2m pieces, the m pieces are respectively connected with the cutting edge as a first blade belt, and each flow passage is formed on the first blade belt.

[0007] In some embodiments, on any one of the land bands, the flow grooves are arranged at n along the axial direction of the drill core, and the minimum distance between the groove wall of the flow groove closest to the drill tip and the cutting edge is I, I = 0.0264*n 2 + 0.073*H, wherein H is the width of the land band.

[0008] In some embodiments, on the same land band, the distance between two adjacent flow grooves increases along the direction away from the drill tip.

[0009] In some embodiments, the distance between the i-th flow groove and the (i-1)-th flow groove is (0.5+0.25i)H, i is a natural number not less than 2.

[0010] In some embodiments, the flow grooves are V-shaped grooves, the groove depth of the flow grooves is E, E = 0.6mm~0.12mm; and / or, the groove wall surface of the flow groove near the side of the drill tip has an inclination angle F, F = 30°~40°.

[0011] In some embodiments, the drill core comprises an axial front section and an axial rear section arranged continuously along the axial direction thereof, wherein the axial front section is a constant-diameter section, the axial rear section is a tapered section with a diameter gradually decreasing along the side away from the drill tip, and each of the flow grooves is formed on the land band corresponding to the axial front section.

[0012] In some embodiments, the axial length of the constant-diameter section is L1, the diameter is d, L1 = 2.5D~3D, and / or d = 0.25D~0.4D, wherein D is the outer diameter of the drill section.

[0013] In some embodiments, the axial length of the inverted tapered section is L2, the taper of the inverted tapered section is T, and the axial length L2 and the taper T satisfy the following formula:

[0014]

[0015] In some embodiments, the top angle of the drill tip is A, 137°≤A≤147°, the relief angle of the drill tip is B, 9°≤B≤15°, and the helix angle of the land band is C, 27°≤C≤29°; and / or, the deep hole drill further comprises a shank section and a clearance section between the shank section and the drill section.

[0016] In some embodiments, A = 138°, B = 8.5°, and C = 27.5°.

[0017] The deep hole drill provided by the present application has the following beneficial effects:

[0018] The flow groove is arranged on the guide surface of the blade band, and during the drilling process of the deep hole drill, the cooling liquid enters the deep hole bottom position, that is, the drill tip area, to cool and dissipate heat of the drill tip area, and the cooling liquid can also flow through the flow groove, thereby increasing the contact area of the cooling liquid and the blade band, so that efficient cooling and heat dissipation of the blade band are realized, and the occurrence of thermal cracks of the blade band due to high temperature generated by the cutting edge is effectively prevented, thereby preventing tool failure and product scrap caused by thermal cracks, and improving the drilling efficiency of the deep hole drill;

[0019] On the one hand, the flow groove is arranged on the first blade band connected with the cutting edge, which can effectively reduce the probability of thermal cracks of the blade band connected with the cutting edge due to heat conduction of the cutting edge, and on the other hand, the flow groove is not arranged on the blade band not connected with the cutting edge, because thermal cracks hardly occur on this part of the blade band, and the rigidity of the whole guide part is ensured at the same time.

[0020] By arranging the through extension direction of the flow groove parallel to the first switching surface, the same grinding angle can be used when machining the cutting edge of the deep hole drill and each flow groove, that is, only different grinding tools need to be replaced without adjusting the clamping angle of the grinding tool, which can significantly improve the machining efficiency.

[0021] For the same blade band, the more the number of flow grooves arranged on the guide surface thereof is, the greater the minimum distance I of the flow groove closest to the drill tip is, and vice versa. In this way, the balance between the number of flow grooves 1141 and the width of the blade band 114 can be ensured, and the reasonable selection of the parameters of the deep hole drill is guided, thereby reducing the design difficulty.

[0022] The distance between the two adjacent flow grooves becomes larger and larger along the direction away from the drill tip, that is, becomes smaller and smaller along the direction close to the drill tip, which can preferentially ensure efficient cooling of the blade band close to the drill tip area and prevent thermal cracks from occurring at this position.

[0023] The flow groove is a V-shaped groove, and the groove depth and the inclination angle of the groove wall are limited, which can guide the cooling liquid at the drill tip to the back of the blade band, increase the contact area of the blade band and the cooling liquid, and further improve the cooling effect of the blade band.

[0024] On the one hand, the flow grooves are formed on the corresponding blade bands of the constant diameter section, which can ensure the structural rigidity of the constant diameter section while achieving the cooling effect of the blade bands, and ensure the stability of the drilling section during drilling. Since the drill bit is used for drilling during drilling, the diameter of the corresponding constant diameter section is greater than the diameter of the tapered section, so that the mass center is close to the drill bit while ensuring sufficient working strength, which can ensure that the blade band can play a better supporting role during drilling. On the other hand, the axial rear section is designed as a tapered section that tapers away from the drill bit side. As the core thickness gradually decreases, the natural frequency of the deep hole drill gradually increases, so the frequency causing tool resonance needs to be higher, and the stability of the deep hole drill is higher. At the same time, the tapered diameter section also makes the space of the chip groove larger and larger away from the drill bit, so that the cutting chip can be discharged more smoothly, reducing the risk of deep hole drill breakage.

[0025] The optimized deep hole drill improves the tool life by 13%, and the drilling efficiency is 20 times higher than that of the traditional gun drill. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. The drawings in the following description are only exemplary, and those skilled in the art can also obtain other implementation drawings according to the provided drawings without creative labor.

[0027] Figure 1 is the overall structure schematic diagram of the deep hole drill in the embodiment of the present application;

[0028] Figure 2 is the longitudinal section view of the deep hole drill in Figure 1 ;

[0029] Figure 3 is the overall structure schematic diagram of the deep hole drill in Figure 1 from another perspective;

[0030] Figure 4 is the section view of A-A in Figure 3 ;

[0031] Figure 5 is the section view of B-B in Figure 3 ;

[0032] Figure 6 is the partial structure schematic diagram of the deep hole drill in Figure 1 ;

[0033] Figure 7 is the relief angle schematic diagram of the deep hole drill in Figure 1 ;

[0034] Figure 8 is Figure 1 another partial structure diagram of the deep hole drill in

[0035] Figure 9 is Figure 1 still another partial structure diagram of the deep hole drill in

[0036] Figure 10 is Figure 9 a partial enlarged view of A in

[0037] Reference signs are:

[0038] 11, drilling section; 111, drill core; 112, drill tip; 113, cutting edge; 114, land; 1141, flow-through recess; 115, coolant channel; 116, gash face; 117, chip flute; 12, shank section; 13, clearance section. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work under the premise, belong to the scope of protection of the present application.

[0040] In the description of the present application, it should be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship is usually based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0041] For purposes of the description hereinafter, spatial relations terms, such as "above", "below", "upper", "lower", and the like, can be used with respect to the device or feature under discussion. Such spatially relative terms are intended to encompass different orientations of the device or feature in use or operation in addition to the orientation depicted in the figures. For example, if the device depicted in the figures is turned over, the device or features depicted as above other devices or features could then be oriented below the other devices or features. Accordingly, the exemplary terms "above" and "below" can encompass both orientations of above and below. The device or features can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0042] In addition, it should be pointed out that the use of the terms "first", "second" and the like in connection with various elements is merely intended for convenience of description and is in no way intended to limit the scope of the application, unless otherwise indicated.

[0043] Referring to Figures 1 to 10 As shown, according to the embodiment of the present application, a deep hole drill (the ratio of the drilling depth to the diameter of the drill bit is 30 times or more) is provided, which comprises a drill body (not shown in the figure), the drill body comprising a drilling section 11, it can be understood that in the specific use process, the drilling section 11 will participate in the formation of the hole, the drilling section 11 comprises a drill core 111, a cutting edge 113 (i.e. the main cutting edge, which is used to cut the corresponding area of the cutting object and further form the hole body) is formed at the drill tip 112 of the drill core 111, the drilling section 11 further comprises a plurality of blade strips 114 spirally arranged along the axial direction of the drill core 111, in the use process, the blade strips 114 abut against the inner wall of the formed hole to realize the support of the drill body, ensure the drilling feeding direction and ensure the stability of the drill body, at least part of the guide surface (not shown in the figure) of the blade strips 114 is provided with a flow groove 1141, the drilling section 11 is formed with a cooling liquid channel 115 capable of guiding the cooling liquid to the drill tip 112.

[0044] In the technical scheme, the flow groove 1141 is arranged on the guide surface of the blade band 114. During the drilling process of the deep hole drill, the cooling liquid enters the deep hole bottom position, i.e., the drill tip 112 area, through the cooling liquid channel 115, and cools and dissipates heat for the drill tip 112 area. Meanwhile, the cooling liquid can also flow through the flow groove 1141, thereby increasing the contact area between the cooling liquid and the blade band 114, and achieving efficient cooling and heat dissipation for the blade band 114. Therefore, the thermal cracks caused by high temperature of the blade band 114 due to the cutting edge 113 can be effectively prevented, and the tool failure and product scrapping caused by the thermal cracks can be effectively prevented, thereby improving the drilling efficiency of the deep hole drill.

[0045] In some embodiments, the cutting edges 113 have m pieces, and the blade bands 114 have 2m pieces, where each piece of the cutting edges 113 is connected to a piece of the blade bands 114 as a first blade band (not labeled in the figure) in one-to-one correspondence, and each flow groove 1141 is arranged on the first blade band. In a specific embodiment of the present application, the cutting edges 113 have two pieces (i.e., m=2), and the blade bands 114 have four pieces. Two of the blade bands 114 are connected to the cutting edges 113, and the other two are not connected to the cutting edges 113. The cutting edges 113 are symmetrically distributed at the drill tip 112, and the four blade bands 114 are uniformly and spacedly arranged around the circumference of the drill core 111. It can be understood that each cutting edge 113 and the corresponding gash surface 116 (i.e., the surface between the rake face and the chip flute 117) form a chip flute 117, and the first blade band simultaneously serves as one of the guide surfaces of the chip flute 117.

[0046] In the technical scheme, on the one hand, the flow groove 1141 is arranged on the first blade band connected to the cutting edge 113, which can effectively reduce the probability of thermal cracks of the blade band 114 connected to the cutting edge 113 due to heat conduction of the cutting edge 113. On the other hand, the flow groove 1141 is not arranged on the blade band 114 not connected to the cutting edge 113, because the thermal cracks hardly occur on this part of the blade band 114, and the rigidity of the overall guide part is ensured.

[0047] Specifically referring to Figure 1 As shown in the figure, the deep hole drill further includes a shank section 12 and a clearance section 13 between the shank section 12 and the drilling section 11. The shank section 12 is used to be fixedly connected to a driving device such as a machine tool. The clearance section 13 can effectively avoid interference and collision during machining of a complex structure part and reserve space for chip removal under the condition of ensuring the strength of the tool.

[0048] In some embodiments, the land 114 has a first side (specifically, for example, the side close to the chip flute 117) and a second side (specifically, for example, the side away from the chip flute 117) connected with the guide surface thereof, and the flow-through groove 1141 penetrates through the first side and the second side, so that the coolant can flow smoothly from one side of the land 114 to the other side, ensuring efficient cooling of the land 114 by the coolant, and the land 114 intersects with the cutting edge 113 at point A (see Figure 8 The tangent line of the cutting edge 113 passing through the point A is a first tangent line, and the penetration and extension direction of the flow-through groove 1141 is parallel to the first tangent line. The extension direction is also the grinding feed direction of the grinding tool when the flow-through groove 1141 is ground.

[0049] In this technical solution, by arranging the penetration and extension direction of the flow-through groove 1141 parallel to the first tangent line, the same grinding angle can be used when machining the cutting edge of the deep hole drill and each flow-through groove 1141, that is, only different grinding tools need to be replaced without adjusting the clamping angle of the grinding tool, which can significantly improve the machining efficiency.

[0050] Specifically referring to Figure 8 In some embodiments, on any one of the lands 114, the flow-through grooves 1141 are arranged at intervals along the axial direction of the drill core 111, and the minimum distance between the groove wall of the flow-through groove 1141 closest to the drill tip 112 and the cutting edge 113 is I, I = 0.0264*n 2 + 0.073*H, where H is the width of the land 114.

[0051] In this technical solution, for the same land 114, the more the number of flow-through grooves 1141 arranged on the guide surface, the greater the minimum distance I of the flow-through groove 1141 closest to the drill tip 112, and vice versa. In this way, the balance between the number of flow-through grooves 1141 and the width of the land 114 can be ensured, thereby guiding the reasonable selection of the parameters of the deep hole drill and reducing the design difficulty.

[0052] In some embodiments, on the same land 114, the distance between two adjacent flow-through grooves 1141 increases along the direction away from the drill tip 112, and specifically, the distance between the ith flow-through groove 1141 and the (i-1)th flow-through groove 1141 is (0.5+0.25i)H, where i is a natural number not less than 2.

[0053] In this technical solution, the distance between two adjacent flow grooves 1141 increases as it moves away from the drill tip 112, and decreases as it moves closer to the drill tip 112. This ensures efficient cooling of the cutting edge 114 near the drill tip 112 and prevents thermal cracks from forming there.

[0054] See details Figure 10 As shown, in some embodiments, the flow groove 1141 is a V-shaped groove, the groove depth of the flow groove 1141 is E, E = 0.6mm to 0.12mm; the inclination angle of the groove wall surface of the flow groove 1141 near the drill tip 112 is F, F = 30° to 40°.

[0055] In this technical solution, the flow groove 1141 is a V-shaped groove, and its depth and the inclination angle of the groove wall are limited. This effectively guides the coolant at the drill tip 112 to the back of the cutting edge 114, increasing the contact area between the cutting edge 114 and the coolant, and further improving the cooling effect on the cutting edge 114. In addition, the flow groove 1141 is a V-shaped groove, which has a simple structure and is easy to process. Furthermore, because the V-shaped groove has a large opening size and a small bottom size, and the opening faces the hole wall, it can achieve flow cooling while ensuring the rigidity of the cutting edge 114 as much as possible.

[0056] In some embodiments, the drill core 111 includes an axially continuous front section (i.e., ...) along its axial direction. Figure 2 The interval represented by L1) and the axial rear segment (i.e. Figure 2 The interval represented by L2 is defined as follows: the axial front section is a constant diameter section (i.e., the diameter of the drill core 111 remains constant along the axial direction within this interval), and the axial rear section is a tapered section whose diameter gradually decreases along the side away from the drill tip 112 (i.e., the diameter becomes smaller and smaller). Each of the flow grooves 1141 is formed on each of the cutting edges 114 corresponding to the axial front section.

[0057] In the technical solution, on one hand, each flow groove 1141 is formed on the corresponding blade band 114 of the constant diameter section, which can ensure the cooling effect of the blade band 114 and the structural rigidity of the constant diameter section, thereby ensuring the stability of the drilling section 11 during drilling. Since the drill bit 112 is used for drilling during drilling, the diameter of the constant diameter section is greater than that of the tapered section, so that the mass center is close to the drill bit 112, which can ensure that the blade band 114 can play a better supporting role during drilling. On the other hand, the axial rear section is designed as a tapered section that gradually shrinks away from the drill bit 112. As the thickness of the core gradually decreases, the natural frequency of the deep hole drill gradually increases, so that the frequency causing tool resonance needs to be higher, and the stability of the deep hole drill is higher. In addition, the tapered section with gradually decreasing diameter makes the space of the chip flute 117 larger away from the drill bit 112, so that the cutting chip can be discharged more smoothly, thereby reducing the risk of drill breakage.

[0058] In a specific embodiment, the axial length of the constant diameter section is L1, and the diameter is d, L1 = 2.5D-3D. It is verified by experiments that the drilling vibration is lower when L1 is within the above range, and the vibration is relatively high when L1 is higher or lower than the above range. And / or, d = 0.25D-0.4D, preferably 0.3D. It is verified by experiments that the drilling vibration is lower when d is within the above range, and the vibration is relatively high when d is higher or lower than the above range. Wherein, D is the outer diameter of the drilling section 11.

[0059] In some embodiments, the axial length of the inverted tapered section is L2, and the taper of the inverted tapered section is T, the axial length L2 and the taper T satisfy the following formula:

[0060]

[0061] In the technical solution, by limiting T, L2 and L1, T can be within a reasonable range, which can ensure the overall rigidity of the deep hole drill while reducing the vibration during drilling.

[0062] In some embodiments, the top angle of the drill bit 112 is A, 137°≤A≤147°, preferably A = 138°, to prevent excessive axial force; the relief angle of the drill bit 112 is B, 9°≤B≤15°, preferably B = 8.5°. It is verified that when B is less than 9°, drilling will interfere, resulting in tool breakage, and when B is greater than 15°, the strength of the drill bit will be reduced; the helix angle of the blade band 114 is C, 27°≤C≤29°, preferably C = 27.5°. It is verified by experiments that when the helix angle C is lower than 27° or higher than 29°, the axial force of the deep hole drill will increase, the drilling temperature will increase, and the tool life will be reduced.

[0063] The optimized deep hole drill, tool life is improved by 13%, drilling efficiency compared with traditional gun drill highest increase 20 times.

[0064] Those skilled in the art will readily understand that the advantageous technical features of the above-mentioned modes can be freely combined and superimposed without conflict.

[0065] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and variations can also be made, which should be considered as the protection scope of the present application.

Claims

1. A deep hole drill, characterized in that, The system includes a drill body, which includes a drilling section (11), a drill core (111), and a cutting edge (113) formed at the drill tip (112) of the drill core (111). The drilling section (11) also includes multiple cutting edges (114) spirally arranged along the axial direction of the drill core (111). At least a portion of the cutting edges (114) have flow grooves (1141) formed on their guide surfaces. A coolant channel (115) is formed within the drilling section (11) to guide coolant to the drill tip (112). On any one of the cutting edges (114), n flow grooves (1141) are spaced n times along the axial direction of the drill core (111), and the minimum distance between the groove wall of the flow groove (1141) closest to the drill tip (112) and the cutting edge (113) is I, where I = 0.0264 * n. 2 +0.073*H, where H is the width of the cutting edge (114).

2. The deep hole drill according to claim 1, characterized in that, The cutting edge (114) has a first side surface and a second side surface connected to its guide surface. The flow groove (1141) passes through the first side surface and the second side surface. The cutting edge (114) intersects the cutting edge (113) at point A. The tangent line passing through point A and tangent to the cutting edge (113) is the first tangent line. The through extension direction of the flow groove (1141) is parallel to the first tangent line. And / or, the cutting edge (113) has m segments, and the cutting edge (114) has 2m segments, wherein the m segments are connected one by one with each cutting edge (113) to form the cutting edge (114) as the first cutting edge. Each flow groove (1141) is constructed on the first cutting edge.

3. The deep hole drill according to claim 1, characterized in that, On the same cutting edge (114), the spacing between two adjacent flow grooves (1141) increases in the direction away from the drill tip (112).

4. The deep hole drill according to claim 3, characterized in that, The distance between the flow groove (1141) described in the i-th clause and the flow groove (1141) described in the (i-1)-th clause is (0.5+0.25i)H, where i is a natural number not less than 2.

5. The deep hole drill according to claim 1, characterized in that, The flow groove (1141) is a V-shaped groove, and the groove depth of the flow groove (1141) is E, E=0.6mm~0.12mm; and / or, the inclination angle of the groove wall surface of the flow groove (1141) near the drill tip (112) is F, F=30°~40°.

6. The deep hole drill according to claim 1, characterized in that, The drill core (111) includes an axial front section and an axial rear section continuously arranged along its axial direction, wherein the axial front section is a constant diameter section and the axial rear section is a tapered section whose diameter gradually decreases along the side away from the drill tip (112), and each of the flow grooves (1141) is formed on each of the cutting edges (114) corresponding to the axial front section.

7. The deep hole drill according to claim 6, characterized in that, The axial length of the equal diameter section is L1 and the diameter is d, where L1 = 2.5D to 3D and / or d = 0.25D to 0.4D, and D is the outer diameter of the drilling section (11).

8. The deep hole drill according to claim 7, characterized in that, The axial length of the inverted cone segment is L2, and the taper of the inverted cone segment is T. The axial length L2 and the taper T satisfy the following formula: 。 9. The deep hole drill according to claim 1, characterized in that, The apex angle of the drill tip (112) is A, 137°≤A≤147°, the back angle of the drill tip (112) is B, 9°≤B≤15°, the helix angle of the cutting edge (114) is C, 27°≤C≤29°; and / or, the deep hole drill further includes a shank section (12) and a clearance section (13) located between the shank section (12) and the drilling section (11).

10. The deep hole drill according to claim 9, characterized in that, A=138°, B=8.5°, C=27.5°.

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