A telescopic self-locking conversion drilling and tapping integrated drill bit and use method thereof

Abstract

The present invention discloses a telescopic self-locking conversion drilling and tapping integrated drill bit and a method of using the same, which belongs to the field of cutting tools, and includes a tool bar, the tool bar having a first fitting surface, and an end of the tool bar located on the first fitting surface is provided with a socket and two positioning grooves, wherein the socket is located on the central axis of the tool bar, and the two positioning grooves are mirror-imaged with respect to the socket. The telescopic self-locking conversion drilling and tapping integrated drill bit of the present invention and a method of using the same, by providing a connecting portion and a tool head, the tool head is aligned with the end of the connecting portion away from the tool bar, and the upper end face of the tool head is fitted with the first locking surface, so that the tool head can be avoided from being directly assembled with the tool bar. In essence, the connecting portion is equivalent to providing a relief to the tool bar, and the tool bar will not be directly damaged, thereby replacing the entire tool bar, and the increase in production costs can increase the service life of the drill bar on the drill bit.

Description

Technical Field

[0001] The invention belongs to the field of cutting tools, and in particular relates to a telescopic self-locking conversion drilling and tapping integrated drill bit and a use method thereof. Background Art

[0002] Drilling is a widely used process in cutting. The drill bits used in drilling are usually made of carbide, which is prone to wear during the drilling process. In order to facilitate the replacement of the drill bit without removing the drill body from the shank or the main shaft of the frame, in order to save the working hours of drilling, users generally use telescopic self-locking conversion drill bits to facilitate and quickly replace the drill bits.

[0003] In the prior art, when a telescopic self-locking convertible drill bit is replaced, the user generally uses a wrench to remove the worn and scrapped cutter head, and then installs the intact cutter head onto the cutter bar, so as to save costs and quickly replace the drill bit. For example, a replaceable head drill bit disclosed in the patent application publication number (CN115026332A) includes a cutter bar and a cutter head detachably connected to the cutter bar, the cutter bar includes a hand-held portion and a limiting portion coaxially connected, the cutter head includes a docking portion adapted to center the limiting portion and a locking portion adapted to lock the limiting portion, the central axis of the docking portion coincides with the central axis I of the cutter head; the limiting portion includes a handle and a locking portion adapted to lock the limiting portion, the central axis of the docking portion coincides with the central axis I of the cutter head; the limiting portion includes a handle and a locking portion adapted to lock the limiting portion. The centering block connected to the handheld part has a centering groove matched with the docking part at one end of the centering block away from the handheld part. However, there are certain limitations. When drilling on a jig or a grinder, the cutter head is often greatly worn. When a new cutter head is installed on a drill rod, the cutter head and the drill rod are directly assembled. However, when a wrench is used to install the cutter head on the drill rod for a long time, a large torque is used each time the screw is turned, which is undoubtedly a damage to the drill bit and the drill rod. It is easy to cause thread slippage or unstable connection on the drill rod of the drill bit, so the drill rod on the drill bit needs to be replaced, which will increase the production cost. It is urgent to improve this problem. Summary of the invention

[0004] In response to one or more of the above defects or improvement needs in the prior art, the present invention provides a telescopic self-locking conversion drilling and tapping integrated drill bit and a method of using the same, which has the advantages of easy replacement of the cutter head and a long service life of the drill bit rod.

[0005] To achieve the above-mentioned object, the present invention provides a telescopic self-locking conversion drilling and tapping integrated drill bit and a method for using the same, which comprises a tool bar, the tool bar having a first fitting surface, an end of the tool bar located on the first fitting surface is provided with a plug hole and two positioning grooves, wherein the plug hole is located on the central axis of the tool bar, and the two positioning grooves are distributed in a mirror image with respect to the plug hole;

[0006] A connecting portion, wherein the connecting portion has a connecting drill rod, the connecting drill rod is detachably connected to one end of the tool rod having a first fitting surface, and the connecting drill rod is coaxially arranged with the tool rod, and the end of the connecting drill rod away from the tool rod is downwardly provided with a notch along the central axis direction of the connecting drill rod, the notch is an irregular cylindrical shape, and the part of the connecting drill rod located in the notch forms a first locking surface, a second locking surface and a third locking surface, a screw hole is provided at one end of the connecting drill rod located in the notch, and the screw hole passes through the first locking surface, a positioning rod is fixed in the screw hole, a first screw rod adapted to the jack is fixed on one side of the connecting drill rod close to the tool rod, and an insert block adapted to the positioning groove is also fixed on one side of the connecting drill rod close to the tool rod; and

[0007] A cutter head, wherein the cutter head is detachably connected to a notch provided in the connecting drill rod, and the cutter head is coaxially arranged with the connecting drill rod, the cutter head has a spiral cutting edge, a second chip removal groove is provided in the spiral cutting edge, the cutter head also has a cutting tip, a second screw rod matched with a screw hole is fixedly provided on one side of the cutter head close to the notch of the connecting drill rod, a positioning hole for a positioning rod to penetrate is provided on one side of the second screw rod close to the notch of the connecting drill rod, and an abutment block is fixedly provided on the outer circumferential surface of the cutter head;

[0008] Among them, the second locking surface and the third locking surface are both perpendicular to the first locking surface, and the second locking surface intersects with the third locking surface, and the angle of intersection between the second locking surface and the third locking surface is greater than twenty degrees and less than fifty degrees, and the first locking surface, the second locking surface and the third locking surface together form an area for the abutment block to be engaged.

[0009] As a further improvement of the present invention, the cross-sectional area of ​​the notch formed in the connecting drill rod is larger than the cross-sectional area of ​​the cutter head.

[0010] As a further improvement of the present invention, a clamping groove is further provided on the outer circumferential surface of the knife rod.

[0011] As a further improvement of the present invention, a first chip removal groove is further provided on the outer circumferential surface of one end of the connecting portion away from the tool rod.

[0012] As a further improvement of the present invention, the positioning groove is in an arc shape, the inserting block is also in an arc shape, and the size of the positioning groove is the same as that of the inserting block.

[0013] As a further improvement of the present invention, the depth of the screw hole is twice the length of the positioning rod.

[0014] As a further improvement of the present invention, the depth of the positioning hole is the same as the length of the positioning rod, and the caliber of the positioning hole is the same as the caliber of the positioning rod.

[0015] Another technical problem to be solved by the present invention is to provide a method for using a telescopic self-locking conversion drilling and tapping integrated drill bit, comprising the following steps:

[0016] S1: First, place the connection part on the upper end surface of the knife rod so that the connection part and the knife rod are coaxially placed, rotate the first screw into the insertion hole, and when the insert block contacts the positioning groove, continue to rotate the first screw, and the insert block rotates in the positioning groove to complete the assembly of the connection part and the knife rod;

[0017] S2: Align the cutter head with the end of the connecting portion away from the cutter rod, rotate the second screw rod and insert it into the insertion hole. When the positioning rod contacts the positioning hole, continue to rotate the second screw rod so that the positioning rod is completely inserted into the positioning hole. When the positioning rod is completely inserted into the positioning hole, the abutment block is stuck in the first locking surface. In the area formed by the second locking surface and the third locking surface, the upper end surface of the cutter head is in contact with the first locking surface.

[0018] In general, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

[0019] The telescopic self-locking conversion drilling and tapping integrated drill bit of the present invention and the use method thereof, by providing a connecting portion and a cutter head, the cutter head is aligned with the end of the connecting portion away from the cutter rod, the second screw rod is rotated and inserted into the insertion hole, and when the positioning rod contacts the positioning hole, the second screw rod is continuously rotated so that the positioning rod is completely inserted into the positioning hole. When the positioning rod is completely inserted into the positioning hole, the abutment block is simultaneously stuck in the first locking surface, and in the area formed by the second locking surface and the third locking surface, the upper end surface of the cutter head is in contact with the first locking surface, so that the cutter head can be avoided from being directly assembled with the cutter rod. In essence, the connecting portion is equivalent to It has a relief effect on the tool rod and will not cause the tool rod to be directly damaged, thereby replacing the entire tool rod and causing an increase in production costs, which can increase the service life of the drill rod on the drill bit. At the same time, the second screw is rotated and inserted into the socket, and the second screw is rotated to make the positioning rod completely penetrate into the positioning hole. When the positioning rod is completely penetrated into the positioning hole, the abutment block is stuck on the first locking surface. The area formed by the second locking surface and the third locking surface can make the connection between the tool head and the connecting part more stable, and it can be more convenient to replace the tool head. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the integrated drilling and tapping drill bit of the present invention;

[0021] Figure 2 An exploded view of the integrated drilling and tapping drill bit of the present invention;

[0022] Figure 3 It is a structural schematic diagram of the knife bar of the present invention;

[0023] Figure 4 A top view of the knife bar of the present invention;

[0024] Figure 5 It is a structural schematic diagram of the connecting portion of the present invention.

[0025] Figure 6 It is a structural schematic diagram of the connection part of the present invention viewed from another angle;

[0026] Figure 7 It is a structural schematic diagram of the cutter head of the present invention;

[0027] Figure 8 It is a schematic diagram of the structure of the present invention when viewed from the bottom of the cutter head.

[0028] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0029] 1. knife bar; 11. card slot; 12. first fitting surface; 13. positioning slot; 14. plug hole;

[0030] 2. Connecting part; 21. Connecting drill rod; 22. First locking surface; 23. Second locking surface; 24. Third locking surface; 25. Screw hole; 26. Positioning rod; 27. First chip removal groove; 28. Insert block; 29. ​​First screw rod;

[0031] 3. Cutter head; 31. Spiral cutting edge; 32. Second chip removal groove; 33. Cutter tip; 34. Second screw rod; 35. Positioning hole; 36. Abutment block. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the embodiment, Figure 1-8 Provided is a telescopic self-locking conversion drilling and tapping integrated drill bit, in the present invention Figure 1 It is a schematic diagram of the overall structure of the integrated drilling and tapping drill bit of the present invention; Figure 2 An exploded view of the integrated drilling and tapping drill bit of the present invention; Figure 3 It is a structural schematic diagram of the knife bar of the present invention; Figure 4 A top view of the knife bar of the present invention; Figure 5 It is a structural schematic diagram of the connecting portion of the present invention. Figure 6 It is a structural schematic diagram of the connection part of the present invention viewed from another angle; Figure 7It is a structural schematic diagram of the cutter head of the present invention; Figure 8 The present invention is a schematic structural diagram when viewed from the bottom of the cutter head. The drilling and tapping integrated drill bit comprises a cutter bar 1, the upper section of the cutter bar 1 is columnar, the lower section of the cutter bar 1 is twisted, the cutter bar 1 has a first fitting surface 12, and one end of the cutter bar 1 located on the first fitting surface 12 is provided with a plug hole 14 and two positioning grooves 13, wherein the plug hole 14 is located on the central axis of the cutter bar 1, and the two positioning grooves 13 are mirror-displayed about the plug hole 14; a connecting portion 2, the connecting portion 2 has a connecting drill rod 21, and the connecting drill rod 21 is detachably connected to one end of the cutter bar 1 having the first fitting surface 12 The end of the connecting drill rod 21 is coaxially arranged with the cutter bar 1. A notch is provided downwardly along the central axis direction of the connecting drill rod 21 at one end away from the cutter bar 1. The notch is an irregular cylindrical shape. The part of the connecting drill rod 21 located in the notch forms a first locking surface 22, a second locking surface 23 and a third locking surface 24. A screw hole 25 is provided at one end of the connecting drill rod 21 located in the notch, and the screw hole 25 passes through the first locking surface 22. A positioning rod 26 is fixed in the screw hole 25. A side surface of the connecting drill rod 21 close to the cutter bar 1 is fixedly provided with a locking rod 26 that is compatible with the jack. 14, a first screw 29 adapted to the drill rod 21, a plug block 28 adapted to the positioning groove 13 is fixedly provided on one side of the connecting drill rod 21 close to the tool rod 1; a cutter head 3, the cutter head 3 is detachably connected to the notch arranged in the connecting drill rod 21, and the cutter head 3 is coaxially arranged with the connecting drill rod 21, the cutter head 3 has a spiral cutting edge 31, a second chip removal groove 32 is also provided in the spiral cutting edge 31, the cutter head 3 also has a cutting tip 33, and a second screw 34 adapted to the screw hole 25 is fixedly provided on one side of the cutter head 3 close to the notch of the connecting drill rod 21, and the second screw A positioning hole 35 for the positioning rod 26 to pass through is provided on one side surface 34 close to the notch of the connecting drill rod 21, and a contact block 36 is also fixed on the outer circumferential surface of the cutter head 3; wherein the second locking surface 23 and the third locking surface 24 are both perpendicular to the first locking surface 22, and the second locking surface 23 intersects with the third locking surface 24, and the angle of intersection between the second locking surface 23 and the third locking surface 24 is greater than twenty degrees and less than fifty degrees, and the first locking surface 22, the second locking surface 23 and the third locking surface 24 together enclose an area for the contact block 36 to be engaged.

[0034] In this embodiment, the assembly and specific use of the tool bar 1, the connecting part 2, and the cutter head 3 are further described. First, the tool bar 1 is installed on the spindle of the milling machine, or the tool bar 1 is installed on the cutter head of the milling machine. After the assembly of the tool bar 1 is completed, the connecting part 2 is placed on the upper end surface of the tool bar 1 so that the connecting part 2 and the tool bar 1 are coaxially placed. The first screw 29 is rotated into the insertion hole 14. When the insert block 28 contacts the positioning groove 13, the first screw 29 is continued to be rotated, and the insert block 28 is rotated in the positioning groove 13 to complete the assembly of the connecting part 2 and the tool bar 1. Finally, Align the cutter head 3 with the end of the connecting portion 2 away from the cutter rod 1, rotate the second screw 34 and insert it into the insertion hole 14. When the positioning rod 26 contacts the positioning hole 35, continue to rotate the second screw 34 so that the positioning rod 26 is completely inserted into the positioning hole 35. When the positioning rod 26 is completely inserted into the positioning hole 35, the abutment block 36 is stuck in the area formed by the first locking surface 22, the second locking surface 23 and the third locking surface 24. The upper end surface of the cutter head 3 is in contact with the first locking surface 22, and the assembly of the cutter rod 1, the connecting portion 2 and the cutter head 3 is completed. By providing the connecting portion 2, it is possible to avoid the cutter head 3 being directly assembled with the cutter rod 1, and it is possible to avoid the long-term use of a wrench to install the cutter head on the drill rod. Since a large torque force is used for each screwing, this is undoubtedly a damage to the drill rod, and it is easy to cause thread slippage or unstable connection on the drill rod of the drill. In essence, the connecting portion 2 is equivalent to a buffer for the cutter rod 1. It should be noted here that the buffer provided by the connecting portion 2 to the cutter rod 1 can be understood as that when the connecting portion 2 is damaged, the connecting portion 2 can be directly replaced without The tool rod 1 needs to be replaced as a whole, which saves production costs. At the same time, the second screw 34 is rotated and inserted into the socket 14. The second screw 34 is rotated so that the positioning rod 26 is completely inserted into the positioning hole 35. When the positioning rod 26 is completely inserted into the positioning hole 35, the abutment block 36 is stuck in the area formed by the first locking surface 22, the second locking surface 23 and the third locking surface 24, so that the tool head 3 can be more stably assembled on the connecting part 2, and the tool head 3 can be replaced more conveniently, and the drilling work can be carried out on the drill bit as a whole.

[0035] In some embodiments, in order to make the cutter head 3 and the connecting part 2 closer, the cross-sectional area of ​​the notch opened in the connecting drill rod 21 is larger than the cross-sectional area of ​​the cutter head 3, which can facilitate the cutter head 3 to be assembled into the notch of the connecting drill rod 21.

[0036] In some embodiments, in order to facilitate the overall assembly of the tool rod 1 to the spindle or cutter disc of the milling machine, a slot 11 is further provided on the outer circumferential surface of the tool rod 1. The slot 11 can facilitate the user to use a wrench to screw the slot 11 onto the spindle or cutter disc.

[0037] In some embodiments, in order to facilitate the drill bit to better discharge drilling debris, a first chip discharge groove 27 is further provided on the outer circumferential surface of the end of the connecting portion 2 away from the tool rod 1.

[0038] In some embodiments, in order to further enhance the stability of the connection between the connecting portion 2 and the shank 1 , the positioning groove 13 is arc-shaped, the shape of the insert block 28 is also arc-shaped, and the size of the positioning groove 13 is the same as that of the insert block 28 .

[0039] In some embodiments, in order to prevent the positioning hole 35 from directly contacting the positioning rod 26 when inserted into the screw hole 25 , the depth of the screw hole 25 is twice the length of the positioning rod 26 .

[0040] In some embodiments, the depth of the positioning hole 35 is the same as the length of the positioning rod 26 , and the diameter of the positioning hole 35 is the same as the diameter of the positioning rod 26 .

[0041] Another technical problem to be solved by the present invention is to provide a method for using a telescopic self-locking conversion drilling and tapping integrated drill bit, comprising the following steps:

[0042] Step 1: First, place the connection part 2 on the upper end surface of the knife bar 1 so that the connection part 2 and the knife bar 1 are coaxially placed, rotate the first screw 29 into the insertion hole 14, and when the insert block 28 contacts the positioning groove 13, continue to rotate the first screw 29, and the insert block 28 rotates in the positioning groove 13 to complete the assembly of the connection part 2 and the knife bar 1;

[0043] Step 2: Align the cutter head 3 with the end of the connecting portion 2 away from the cutter rod 1, rotate the second screw 34 and insert it into the insertion hole 14. When the positioning rod 26 contacts the positioning hole 35, continue to rotate the second screw 34 so that the positioning rod 26 is completely inserted into the positioning hole 35. When the positioning rod 26 is completely inserted into the positioning hole 35, the abutment block 36 is stuck in the area formed by the first locking surface 22, the second locking surface 23 and the third locking surface 24, and the upper end surface of the cutter head 3 is in contact with the first locking surface 22.

[0044] In summary, by setting the connecting portion 2 and the cutter head 3, the cutter head 3 is aligned with the end of the connecting portion 2 away from the cutter rod 1, and the second screw 34 is rotated and inserted into the insertion hole 14. When the positioning rod 26 contacts the positioning hole 35, the second screw 34 is continued to be rotated so that the positioning rod 26 is completely inserted into the positioning hole 35. When the positioning rod 26 is completely inserted into the positioning hole 35, the abutment block 36 is stuck in the area formed by the first locking surface 22, the second locking surface 23 and the third locking surface 24. The upper end surface of the cutter head 3 is in contact with the first locking surface 22, which can avoid the cutter head 3 being directly assembled with the cutter rod 1, and can avoid the use of a wrench for a long time to install the cutter head on the drill rod. Since a large torque force is used for each screw installation, this will undoubtedly affect the drill bit. The drill rod is a kind of damage, and it is easy to cause thread slippage or unstable connection on the drill rod of the drill bit. In essence, the connecting part 2 is equivalent to a relief for the tool rod 1, and will not allow the tool rod 1 to be directly damaged. The entire tool rod 1 will not be replaced, which will increase the production cost, and it can be more convenient to replace the cutter head 3. At the same time, the second screw 34 is rotated and inserted into the socket 14. The second screw 34 is rotated so that the positioning rod 26 is completely inserted into the positioning hole 35. When the positioning rod 26 is completely inserted into the positioning hole 35, the abutment block 36 is stuck in the first locking surface 22. The area formed by the second locking surface 23 and the third locking surface 24 can make the connection between the cutter head 3 and the connecting part 2 more stable.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A telescopic self-locking conversion drilling and tapping integrated drill bit, characterized in that: include A knife rod (1), the knife rod (1) having a first fitting surface (12), an end of the knife rod (1) located on the first fitting surface (12) being provided with an insertion hole (14) and two positioning grooves (13), wherein the insertion hole (14) is located on the central axis of the knife rod (1), and the two positioning grooves (13) are distributed in a mirror image with respect to the insertion hole (14); The connecting portion (2) comprises a connecting drill rod (21), the connecting drill rod (21) being detachably connected to one end of the knife rod (1) having a first fitting surface (12), and the connecting drill rod (21) being coaxially arranged with the knife rod (1), and the end of the connecting drill rod (21) away from the knife rod (1) having a notch downwardly formed along the central axis direction of the connecting drill rod (21), the notch being an irregular cylindrical shape, and the portion of the connecting drill rod (21) located in the notch forming a first locking surface (22), a second locking surface (22) and a second locking surface (22). a locking surface (23) and a third locking surface (24); a screw hole (25) is formed at one end of the connecting drill rod (21) located in the notch, and the screw hole (25) passes through the first locking surface (22); a positioning rod (26) is fixedly arranged in the screw hole (25); a first screw rod (29) adapted to the insertion hole (14) is fixedly arranged on one side of the connecting drill rod (21) close to the cutter rod (1); and an insert block (28) adapted to the positioning groove (13) is also fixedly arranged on one side of the connecting drill rod (21) close to the cutter rod (1); and A cutter head (3), the cutter head (3) being detachably connected to a notch provided in the connecting drill rod (21), and the cutter head (3) being coaxially arranged with the connecting drill rod (21), the cutter head (3) having a spiral cutting edge (31), a second chip removal groove (32) being provided in the spiral cutting edge (31), the cutter head (3) also having a cutting tip (33), a second screw rod (34) cooperating with the screw hole (25) being fixedly provided on one side of the cutter head (3) close to the notch of the connecting drill rod (21), a positioning hole (35) for a positioning rod (26) to penetrate is provided on one side of the second screw rod (34) close to the notch of the connecting drill rod (21), and an abutment block (36) is fixedly provided on the outer circumferential surface of the cutter head (3); The second locking surface (23) and the third locking surface (24) are both perpendicular to the first locking surface (22), and the second locking surface (23) and the third locking surface (24) intersect each other, and the angle between the second locking surface (23) and the third locking surface (24) is greater than twenty degrees and less than fifty degrees, and the first locking surface (22), the second locking surface (23) and the third locking surface (24) together enclose an area for engaging the abutment block (36).

2. The telescopic self-locking conversion drilling and tapping integrated drill bit according to claim 1, characterized in that: The cross-sectional area of ​​the notch formed in the connecting drill rod (21) is larger than the cross-sectional area of ​​the cutter head (3).

3. The telescopic self-locking conversion drilling and tapping integrated drill bit according to claim 1, characterized in that: A clamping groove (11) is also provided on the outer circumferential surface of the knife rod (1).

4. The telescopic self-locking conversion drilling and tapping integrated drill bit according to claim 1, characterized in that: A first chip removal groove (27) is also provided on the outer circumferential surface of one end of the connecting portion (2) away from the tool rod (1).

5. The telescopic self-locking conversion drilling and tapping integrated drill bit according to claim 1, characterized in that: The positioning groove (13) is in an arc shape, the insert block (28) is also in an arc shape, and the size of the positioning groove (13) is the same as that of the insert block (28).

6. The telescopic self-locking conversion drilling and tapping integrated drill bit according to claim 1, characterized in that: The hole depth of the screw hole (25) is twice the length of the positioning rod (26).

7. The telescopic self-locking conversion drilling and tapping integrated drill bit according to claim 1, characterized in that: The depth of the positioning hole (35) is the same as the length of the positioning rod (26), and the caliber of the positioning hole (35) is the same as the caliber of the positioning rod (26).

8. The method for using the telescopic self-locking conversion drilling and tapping integrated drill bit according to any one of claims 1 to 7, characterized in that: S1: firstly, the connection part (2) is placed on the upper end surface of the knife rod (1) so that the connection part (2) and the knife rod (1) are coaxially placed, and the first screw rod (29) is rotated into the insertion hole (14). When the insert block (28) contacts the positioning groove (13), the first screw rod (29) is continuously rotated, and the insert block (28) is rotated in the positioning groove (13), thereby completing the assembly of the connection part (2) and the knife rod (1); S2: Align the cutter head (3) with the end of the connecting portion (2) away from the cutter rod (1), rotate the second screw rod (34) and insert it into the insertion hole (14); when the positioning rod (26) contacts the positioning hole (35), continue to rotate the second screw rod (34) so ​​that the positioning rod (26) is completely inserted into the positioning hole (35); when the positioning rod (26) is completely inserted into the positioning hole (35), the abutment block (36) is stuck in the first locking surface (22), and the area formed by the second locking surface (23) and the third locking surface (24), and the upper end surface of the cutter head (3) is in contact with the first locking surface (22).

Images