Deep hole drill bit

Abstract

The present invention relates to a deep-hole drill bit, which includes a drill shank, a drill body and a drill tip. A cutting boss extending from a plurality of drill tips to the drill shank is arranged on the outer wall of the drill body. A chip fluting is arranged between two adjacent cutting bosses. A cutting edge is arranged at one end of the cutting boss located at the drill tip. The cutting edge includes a base, and a plurality of first cutting blocks in the shape of a frustum of a pyramid and a plurality of second cutting blocks in the shape of a frustum of a pyramid are arranged on the base. The height of the first cutting block is higher than that of the second cutting block, and the first cutting blocks and the second cutting blocks are arranged alternately. There is a spacing between the first cutting block and the adjacent second cutting block. By improving the cutting edge at the drill tip, the present invention changes the originally regularly shaped integral cutting edge into a discontinuous shape with uneven height. When the cutting edge performs cutting, the obtained chips are also discontinuous, that is, the width of the chips is reduced, the chips are more likely to break, the volume is also reduced, and it is easier to discharge through the chip fluting, thereby reducing the risk of chip fluting blockage.

Description

Technical Field

[0001] The present invention belongs to the field of cutting tools, and in particular, to a deep hole drill bit. Background Art

[0002] Deep hole drill bits are used for deep hole machining. Currently, the difficulties in deep hole machining are as follows: 1. During the drilling process, the temperature of the drill bit rises, and it is difficult to cool down, resulting in a decrease in the strength of the drill bit and a decrease in the drilling efficiency; 2. Due to the large depth of the hole, it is not easy to discharge the chips inside, and the chip discharge groove of the drill bit is prone to blockage; 3. The drill bit is too long and is prone to deformation, resulting in a large coaxiality error of the hole.

[0003] CN201310083911.0 discloses a deep hole double spiral internal cooling drill bit, and CN202011517042.4 discloses a gun drill structure that is beneficial to improving the cooling effect during deep hole machining. By arranging a cooling channel inside the drill bit, during drilling, the coolant flows along the cooling channel to the cutting edge, then enters the chip discharge groove, and finally flows out along the chip discharge groove, discharging the chips while achieving cooling.

[0004] Although this kind of drill bit has a good cooling effect and can promote chip discharge, the width of the chips cut by this kind of drill bit is relatively large, and it is still easy to block in the chip discharge groove. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a deep hole drill bit that can reduce the risk of chip blockage in the chip discharge groove and reduce the chip discharge difficulty.

[0006] To solve the above problems, the technical solution adopted by the present invention is: a deep hole drill bit, including a drill shank, a drill body, and a drill tip. A cutting boss extending from multiple drill tips to the drill shank is arranged on the outer wall of the drill body. A chip discharge groove is arranged between adjacent two cutting bosses. A cutting edge is arranged at one end of the cutting boss located at the drill tip.

[0007] The cutting edge includes a base. A plurality of first cutting blocks in the shape of a frustum of a pyramid and a plurality of second cutting blocks in the shape of a frustum of a pyramid are arranged on the base. The height of the first cutting block is higher than that of the second cutting block, and the first cutting blocks and the second cutting blocks are arranged alternately. There is a spacing between the first cutting block and the adjacent second cutting block.

[0008] Further, the base, the first cutting block, and the second cutting block are integrally formed.

[0009] Further, a support sleeve is fixedly arranged on the outer wall of the drill body. The cutting boss includes a first cutting boss and a second cutting boss. The first cutting boss and the second cutting boss are respectively located on both sides of the support sleeve. A connecting groove axially penetrating the support sleeve is arranged on the inner wall of the support sleeve. The chip discharge grooves on both sides of the support sleeve are communicated by the connecting groove.

[0010] The outer diameter of the support sleeve is the same as that of the cutting boss; a plurality of receiving grooves are provided on the outer wall of the support sleeve, an active piece is provided in each receiving groove, a mounting hole is provided at the bottom of the receiving groove, a spring is provided in the mounting hole, one end of the active piece facing the drill tip is hinged to the receiving groove, and the middle of the active piece is fixedly connected to the spring; the active piece is arc-shaped, and when the active piece is completely located in the receiving groove, the outer wall of the active piece and the outer wall of the support sleeve are located on the same cylindrical surface.

[0011] Furthermore, lubricating grooves are provided on the outer walls of the support sleeve and the active piece, and an elastic oil storage layer is provided in the lubricating grooves.

[0012] Furthermore, there are 4 cutting bosses, which are evenly distributed around the drill body.

[0013] Furthermore, the first cutting boss is located between the support sleeve and the drill tip; the first cutting boss includes a pair of first active cutting bosses and a pair of first fixed cutting bosses, the second cutting boss includes a pair of second active cutting bosses and a pair of second fixed cutting bosses, and the first active cutting boss is connected to the second active cutting boss through a connecting section penetrating the support sleeve; an axially extending sliding groove is provided on the outer wall of the drill body, and the first active cutting boss and the second active cutting boss are located in the sliding groove and are slidably matched with the sliding groove; a regulating mechanism for controlling the axial positions of the first active cutting boss and the second active cutting boss is provided at one end of the drill handle where the second active cutting boss is located; during drilling, the axial positions of the first active cutting boss and the second active cutting boss are adjusted every once in a while, so that the cutting edges of the first active cutting boss and the first fixed cutting boss alternately drill holes.

[0014] Furthermore, the regulating mechanism includes a sliding sleeve provided on the drill body, a first cutting position screw hole and a second cutting position screw hole are provided on the outer wall of the drill body, a positioning screw is provided on the sliding sleeve, and the positioning screw is arranged inside the first cutting position screw hole or the second cutting position screw hole.

[0015] Furthermore, a cooling channel extending to the drill tip is provided inside the drill body, a liquid inlet is provided on the drill handle, one end of the cooling channel is connected to the liquid inlet, and the other end is connected to the chip discharge groove.

[0016] The beneficial effects of the present invention are as follows: By improving the cutting edge at the drill tip, the original integrally shaped cutting edge with regular shape is changed into a discontinuous shape with uneven height. When the cutting edge performs cutting, the obtained chips are also discontinuous, that is, the width of the chips is reduced, the chips are more likely to break, the volume is also reduced, and it is easier to be discharged through the chip discharge groove, thereby reducing the risk of blockage of the chip discharge groove.

[0017] The present invention is applicable to deep hole machining with a hole diameter of more than 30 mm and a depth of more than 400 mm. Description of the Drawings

[0018] Figure 1 is the overall front view sectional schematic diagram of the deep hole drill bit of the present invention;

[0019] Figure 2 is Figure 1 the enlarged schematic diagram of part A in

[0020] Figure 3 is Figure 1 the enlarged schematic diagram of part B in

[0021] Figure 4 is is Figure 3 the sectional schematic diagram of C-C in

[0022] Figure 5 is Figure 1 the sectional schematic diagram of E-E in

[0023] Figure 6 is Figure 1 the sectional schematic diagram of F-F in

[0024] Figure 7 is Figure 1 the enlarged schematic diagram of part D in

[0025] Reference Signs: 1 - drill shank; 11 - sliding sleeve; 12 - first cutting position screw hole; 13 - second cutting position screw hole; 14 - positioning screw; 2 - drill body; 22 - support sleeve; 23 - connecting groove; 24 - receiving groove; 25 - movable piece; 26 - mounting hole; 27 - spring; 28 - elastic oil storage layer; 212 - cooling channel; 213 - liquid inlet; 3 - drill tip; 4 - cutting boss; 41 - cutting edge; 411 - base; 412 - first cutting block; 413 - second cutting block; 414 - second cutting block; 42 - first cutting boss; 421 - first movable cutting boss; 422 - first fixed cutting boss; 423 - connecting section; 43 - second cutting boss; 431 - second movable cutting boss; 432 - second fixed cutting boss; 5 - chip removal groove. Detailed Description of the Invention

[0026] The present invention will be further described below in conjunction with the drawings and embodiments.

[0027] The deep hole drill bit of the present invention, as Figures 1 to 7 shown, includes a drill shank 1, a drill body 2 and a drill tip 3. A cutting boss 4 extending from a plurality of drill tips 3 to the drill shank 1 is provided on the outer wall of the drill body 2. A chip removal groove 5 is provided between adjacent cutting bosses 4. A cutting edge 41 is provided at one end of the cutting boss 4 located at the drill tip 3.

[0028] Among them, the drill shank 1 is used to connect with the main shaft of the drilling equipment. The drill body 2 is the main body of the drill bit, and the drill tip 3 is the front end of the drill body 2. The cutting boss 4 is used to cut the part to complete the drilling process. The cutting edge 41 is used to contact the bottom of the hole to be machined, playing the main role in drilling. The cutting bosses 4 in other parts play the role of auxiliary positioning and improving stability.

[0029] The traditional cutting edge 41 is an integrally formed cutting edge with a relatively regular shape. The cut chips are continuous, with a relatively large width and volume, and are not easy to discharge, resulting in a high risk of blockage in the chip fluting 5.

[0030] In the present invention, as Figure 2 shown, the cutting edge 41 includes a base 411. A plurality of frustum-shaped first cutting blocks 412 and a plurality of frustum-shaped second cutting blocks 413 are arranged on the base 411. The height of the first cutting blocks 412 is higher than that of the second cutting blocks 413, and the first cutting blocks 412 and the second cutting blocks 413 are arranged alternately. There is a spacing 414 between the first cutting block 412 and the adjacent second cutting block 413.

[0031] In the present invention, the first cutting blocks 412 and the second cutting blocks 413 with different heights are arranged on the base 411, and there is a spacing 414 between the first cutting block 412 and the adjacent second cutting block 413. The first cutting blocks 412 and the second cutting blocks 413 are not continuous, so the cut chips are also discontinuous. Therefore, the width of the chips is smaller, the chips are more likely to break, the volume is also reduced, and it is easier to discharge through the chip fluting, thereby reducing the risk of blockage in the chip fluting.

[0032] The base 411, the first cutting blocks 412 and the second cutting blocks 413 are integrally formed, with high overall strength. The base 411, the first cutting blocks 412 and the second cutting blocks 413 are made of wear-resistant materials to improve the service life and ensure the drilling accuracy.

[0033] When drilling deep holes, the length of the drill bit itself is large and it is easy to deform, resulting in lower machining accuracy, and the stability of the drill bit is poor and it is easy to break. In order to improve the stability of the drill bit during the drilling process, as Figure 1 、 Figure 3 and Figure 4 shown, in the present invention, a cylindrical support sleeve 22 is fixedly arranged on the outer wall of the drill body 2, and the support sleeve 22 is located at the middle position of the drill body 2. The cutting boss 4 includes a first cutting boss 42 and a second cutting boss 43, and the first cutting boss 42 and the second cutting boss 43 are respectively located on both sides of the support sleeve 22. A connecting groove 23 axially penetrating the support sleeve 22 is arranged on the inner wall of the support sleeve 22. The chip flutings 5 on both sides of the support sleeve 22 are communicated by the connecting groove 23, which does not affect the normal chip discharge.

[0034] The outer diameter of the support sleeve 22 is consistent with the outer diameter of the cutting boss 4, that is, the outer diameter of the support sleeve 22 is adapted to the diameter of the deep hole drilled by the drill bit, and the outer wall of the support sleeve 22 can fit against the inner wall of the deep hole. A plurality of receiving grooves 24 are provided on the outer wall of the support sleeve 22, and the number of receiving grooves 24 can be four. An active piece 25 is arranged in each receiving groove 24, a through hole 26 extending to the bearing 21 is arranged at the bottom of the receiving groove 24, a spring 27 is arranged in the through hole 26, one end of the active piece 25 facing the drill tip 3 is hinged to the receiving groove 24, and the middle part of the active piece 25 is fixedly connected to the spring 27; the active piece 25 is arc-shaped, and when the active piece 25 is completely located in the receiving groove 24, the outer wall of the active piece 25 and the outer wall of the support sleeve 22 are located on the same cylindrical surface.

[0035] When the drilling depth is small, the support sleeve 22 is located outside the hole, the spring 27 is at its normal length, at this time the active piece 25 is in an inclined state, and the main body is located outside the receiving groove 24. When drilling to a certain depth and the support sleeve 22 starts to enter the drilled hole, the hole opening squeezes the active piece 25, pushing the active piece 25 to rotate towards the inside of the receiving groove 24, the spring 27 is compressed to generate elastic force, and the elastic force is transmitted to the active piece 25, prompting the active piece 25 to tightly adhere to the inner wall of the drilled hole. At this time, the active piece 25 and the support sleeve 22 can support and position the drill body 2, improve the stability of the drill body 2, prevent the drill body 2 from deforming, and ensure the drilling accuracy. After the drilling is completed, the drill bit withdraws from the drilled hole, the spring 27 elongates and resets, and the active piece 25 rotates outside the receiving groove 24 again.

[0036] The support sleeve 22 and the active piece 25 rotate with the drill body 2, and there is friction with the inner wall of the hole, increasing the drilling resistance. In order to reduce the friction force, in the present invention, lubricating grooves are provided on the outer walls of the support sleeve 22 and the active piece 25, and an elastic oil storage layer 28 is arranged in the lubricating grooves. The elastic oil storage layer 28 can be a common flexible liquid-absorbing material such as sponge, which can absorb and store a certain amount of lubricating oil. The volume of the elastic oil storage layer 28 in the soft state is larger than the volume of the lubricating groove, so that a part of the elastic oil storage layer 28 extends outside the lubricating groove. When the support sleeve 22 and the active piece 25 enter the hole, the elastic oil storage layer 28 contacts the hole wall and is squeezed, and the absorbed lubricating oil is extruded and adhered to the hole wall, playing a role in lubrication and reducing the frictional resistance.

[0037] In the present invention, there are four cutting bosses 4, and they are evenly distributed around the drill body 2. In addition, the number of cutting bosses 4 can also be two, three, etc. The cutting bosses 4 can be in the traditional spiral shape or in a straight line shape.

[0038] During drilling, the cutting edge 41 is subjected to the greatest cutting force, generates heat fastest, and is also the most easily worn part. In order to slow down the wear of the cutting edge 41, ensure sufficient heat dissipation of the cutting edge 41, and improve the working life of the cutting edge 41, in the present invention, as Figure 1 、 Figure 3, Figure 4 , Figure 5 and Figure 6 As shown, the first cutting boss 42 is located between the support sleeve 22 and the drill tip 3; the first cutting boss 42 includes a pair of first movable cutting bosses 421 and a pair of first fixed cutting bosses 422, the second cutting boss 43 includes a pair of second movable cutting bosses 431 and a pair of second fixed cutting bosses 432, the first movable cutting boss 421 is connected to the second movable cutting boss 431 through a connecting section 423 penetrating the support sleeve 22, and the first fixed cutting boss 422 and the second fixed cutting boss 432 are fixedly installed on the drill body 2. An axially extending chute is provided on the outer wall of the drill body 2, and the chute can be a dovetail chute. The first movable cutting boss 421 and the second movable cutting boss 431 are located in the chute and are slidably engaged with the chute, so that the first movable cutting boss 421 and the second movable cutting boss 431 can slide along the chute to adjust the axial position. The second movable cutting boss 431 is provided with an adjusting mechanism for controlling the axial positions of the first movable cutting boss 421 and the second movable cutting boss 431 at one end of the drill handle 1. During drilling, the axial positions of the first movable cutting boss 421 and the second movable cutting boss 431 are adjusted every once in a while, so that the cutting edges 41 of the first movable cutting boss 421 and the first fixed cutting boss 422 drill holes alternately. Specifically, the adjusting mechanism can be used to drive the first movable cutting boss 421 and the second movable cutting boss 431 to slide towards the drill handle 1, so that the cutting edge 41 of the first movable cutting boss 421 is located behind the cutting edge 41 of the first fixed cutting boss 422. At this time, the cutting edge 41 of the first fixed cutting boss 422 drills the hole, while the cutting edge 41 of the first movable cutting boss 421 is in a rest state; after a period of time, the drilling is paused, the drilling equipment drives the drill bit as a whole to move outwards by an appropriate distance, and the adjusting mechanism is used to drive the first movable cutting boss 421 and the second movable cutting boss 431 to slide towards the drill tip 3, so that the cutting edge 41 of the first movable cutting boss 421 is located in front of the cutting edge 41 of the first fixed cutting boss 422. At this time, the cutting edge 41 of the first movable cutting boss 421 contacts the bottom of the hole and continues to drill the hole, while the cutting edge 41 of the first fixed cutting boss 422 does not contact the bottom of the hole and is in a rest state. In the present invention, the two cutting bosses 4 are divided into two pairs, and the two pairs of cutting bosses 4 drill holes and rest alternately, which can effectively prevent the temperature of the cutting edge 41 from being too high and the strength from being reduced, and improve the working life of the cutting edge 41.

[0039] In the present invention, the adjusting mechanism is as Figure 7As shown in the figure, it includes a sliding sleeve 11 arranged on the drill body 2, and the second movable cutting boss 431 is fixedly connected to the sliding sleeve 11; a first cutting position screw hole 12 and a second cutting position screw hole 13 are arranged on the outer wall of the drill body 2, and a positioning screw 14 is arranged on the sliding sleeve 11, and the positioning screw 14 is arranged inside the first cutting position screw hole 12 or the second cutting position screw hole 13. When the positioning screw 14 cooperates with the first cutting position screw hole 12, the cutting edge 41 of the first fixed cutting boss 422 works, and when the positioning screw 14 cooperates with the second cutting position screw hole 13, the cutting edge 41 of the first movable cutting boss 421 works.

[0040] A cooling channel 212 extending to the drill tip 3 is arranged inside the drill body 2, a liquid inlet 213 is arranged on the drill handle 1, one end of the cooling channel 212 is connected to the liquid inlet 213, and the other end is connected to the chip removal groove 5. During drilling, the coolant is introduced into the cooling channel 212 through the liquid inlet 213, the coolant flows through the cooling channel 212 to the drill tip 3 and enters the chip removal groove 5, and finally is discharged along the chip removal groove 5 to cool the cutting edge 41 and promote chip removal at the same time.

[0041] The present invention is applicable to deep hole machining with a hole diameter of more than 30 mm and a depth of more than 400 mm.

[0042] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A deep hole drill, comprising a drill shank (1), a drill body (2) and a drill tip (3), wherein the outer wall of the drill body (2) is provided with a cutting boss (4) extending from a plurality of drill tips (3) to the drill shank (1), a chip removal groove (5) is provided between two adjacent cutting bosses (4), and a cutting edge (41) is provided at one end of the cutting boss (4) located at the drill tip (3), characterized in that: The cutting edge (41) comprises a base (411), on which a plurality of first cutting blocks (412) in the form of a prism and a plurality of second cutting blocks (413) in the form of a prism are arranged, the height of the first cutting blocks (412) being higher than the height of the second cutting blocks (413), the first cutting blocks (412) and the second cutting blocks (413) being arranged alternately, and a spacing (414) being provided between the first cutting blocks (412) and adjacent second cutting blocks (413); A support sleeve (22) is fixedly provided on the outer wall of the drill body (2), and the cutting boss (4) comprises a first cutting boss (42) and a second cutting boss (43), wherein the first cutting boss (42) and the second cutting boss (43) are respectively located on two sides of the support sleeve (22); The first cutting boss (42) is located between the support sleeve (22) and the drill tip (3); the first cutting boss (42) includes a pair of first movable cutting bosses (421) and a pair of first fixed cutting bosses (422); the second cutting boss (43) includes a pair of second movable cutting bosses (431) and a pair of second fixed cutting bosses (432); the first movable cutting boss (421) is connected to the second movable cutting boss (431) via a connecting section (423) that passes through the support sleeve (22); an axially extending sliding groove is provided on the outer wall of the drill body (2); The first movable cutting boss (421) and the second movable cutting boss (431) are located in the slide groove and are slidably matched with the slide groove; the second movable cutting boss (431) is located at one end of the drill shank (1) and is provided with an adjustment mechanism for controlling the axial position of the first movable cutting boss (421) and the second movable cutting boss (431); when drilling, the axial position of the first movable cutting boss (421) and the second movable cutting boss (431) is adjusted at regular intervals so that the cutting edges (41) of the first movable cutting boss (421) and the first fixed cutting boss (422) drill holes alternately.

2. The deep hole drill bit according to claim 1, characterized in that: The base (411), the first cutting block (412) and the second cutting block (413) are integrally formed.

3. The deep hole drill bit according to claim 1, characterized in that: The inner wall of the support sleeve (22) is provided with a connecting groove (23) which axially penetrates the support sleeve (22), and the chip removal grooves (5) on both sides of the support sleeve (22) are connected by the connecting groove (23); The outer diameter of the support sleeve (22) is consistent with the outer diameter of the cutting boss (4); the outer wall of the support sleeve (22) is provided with a plurality of accommodating grooves (24), each of the accommodating grooves (24) is provided with a movable piece (25), the bottom of the accommodating groove (24) is provided with a mounting hole (26), a spring (27) is provided in the mounting hole (26), one end of the movable piece (25) facing the drill tip (3) is hinged to the accommodating groove (24), and the middle part of the movable piece (25) is fixedly connected to the spring (27); the movable piece (25) is arc-shaped, and when the movable piece (25) is completely in the accommodating groove (24), the outer wall of the movable piece (25) and the outer wall of the support sleeve (22) are located on the same cylindrical surface.

4. The deep hole drill bit according to claim 3, characterized in that: The outer walls of the support sleeve (22) and the movable sheet (25) are provided with lubrication grooves, and an elastic oil storage layer (28) is provided in the lubrication grooves.

5. The deep hole drill bit according to claim 3, characterized in that: There are four cutting bosses (4), which are evenly distributed around the drill body (2).

6. The deep hole drill bit according to claim 5, characterized in that: The adjustment mechanism comprises a sliding sleeve (11) arranged on the drill body (2), and the second movable cutting boss (431) is fixedly connected to the sliding sleeve (11); the outer wall of the drill body (2) is provided with a first cutting position screw hole (12) and a second cutting position screw hole (13), and the sliding sleeve (11) is provided with a positioning screw (14), and the positioning screw (14) is arranged inside the first cutting position screw hole (12) or the second cutting position screw hole (13).

7. The deep hole drill according to any one of claims 1 to 6, characterized in that: A cooling channel (212) extending to the drill tip (3) is provided inside the drill body (2), a liquid inlet (213) is provided on the drill shank (1), one end of the cooling channel (212) is connected to the liquid inlet (213), and the other end is connected to the chip removal groove (5).

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