Pagoda drill bit and switching combination structure thereof

Abstract

The utility model relates to the technical field of drill bits, in particular to a pagoda drill bit and a switching combination structure thereof, the drill bit comprises a drill body part, a limiting part and a hanging part which are sequentially arranged, the axial length of the limiting part extending along the direction of the rotation axis of the drill bit is L1, the axial length of the hanging part extending along the direction of the rotation axis of the drill bit is L2, and L1 is larger than L2; a plurality of limiting surfaces are uniformly distributed on the limiting part in the circumferential direction; on the section perpendicular to the rotation axis of the drill bit, the radius of the inscribed circle of the limiting face is r2, the radius of the circumscribed circle of the mounting part is r1, and r2 is larger than r1. The axial size and the radial size of the limiting part are both larger than those of the hanging part, the strength of the limiting part is higher, the hanging part only plays a role in preventing falling off, the size of the limiting part can be increased on the premise that the size of the clamping part arranged on the adapter is not increased, and therefore the drill handle is not prone to being broken.

Description

Technical Field

[0001] The utility model relates to the technical field of drill bits, in particular to a pagoda drill bit and its adapter combination structure. Background Art

[0002] The stepped drill bit, also known as the pagoda drill bit, can drill different hole diameters and is widely used in the processing fields of wood and metal sheets. In different usage scenarios, the stepped drill bit is connected to different driving mechanisms, such as an electric wrench, an electric drill, etc. Therefore, the shank of the stepped drill bit needs to have the ability to connect with these driving mechanisms. In one case, the stepped drill bit can be directly connected to the driving mechanism, and in another case, the stepped drill bit needs to be connected to the driving mechanism through an adapter.

[0003] Common pagoda drill bits in the prior art are as Figure 1 shown. Its drill shank is in the shape of a hexagonal prism, and an annular groove is provided on the hexagonal prism. The hexagonal prism-shaped shank of such a drill bit bears torque and also plays a role in hanging. Such a drill shank will be machined with a groove on the hexagonal prism. When such a drill shank is connected to an adapter, the prisms on both sides of the groove bear torque. At this time, because the groove is thinner, such a drill shank is prone to breakage at the groove.

[0004] Another example is as Figure 2 shown. The Chinese utility model patent with the publication number CN218926344U discloses a universal stepped drill bit and its combination structure, and an electric tool, including a drill shank and a stepped drill body. The drill shank includes: a clamping section, which is arranged at the tail end of the drill body, and the side of the clamping section has a plurality of clamping surfaces for clamping and fixing; a threaded section axially extends at the tail end of the clamping section, and an external thread is formed on the side.

[0005] In the above prior art, the drill shank is provided with a clamping section and a threaded section. When it needs to be connected to an adapter, it is connected through the threaded section. When it needs to be connected to a chuck, it is connected through the clamping section. That is, when connected to an adapter, only the threaded section is utilized, and the clamping section cannot be utilized. However, when the threaded section of the drill shank is connected to the adapter, a tool is needed to assist in tightening, and the threads are also prone to slipping, damage, etc. Content of the Utility Model

[0006] To solve the problems of easy breakage and damage of the existing drill shanks, the purpose of the present utility model is to provide a pagoda drill bit and its adapter combination structure.

[0007] The technical solution provided by the present utility model is as follows:

[0008] In the first aspect, a pagoda drill bit, the drill bit includes a drill body part, a limiting part, and a hanging part arranged in sequence; wherein, the drill body part, the limiting part, and the hanging part are coaxially arranged, and the limiting part and the hanging part are jointly and cooperatively connected to an adapter;

[0009] When the drill bit is cooperatively connected with the adapter, the mounting part is used to prevent the drill bit from falling off the adapter, and the limiting part is used to prevent the drill bit from rotating relative to the adapter;

[0010] The axial length of the limiting part extending along the rotary axis direction of the drill bit is L1, and the axial length of the mounting part extending along the rotary axis direction of the drill bit is L2, where L1 > L2, and the difference between L1 and L2 is 0.3 - 10 mm;

[0011] The limiting part is circumferentially provided with a plurality of limiting surfaces; in a cross-section perpendicular to the rotary axis of the drill bit, the radius of the inscribed circle of the limiting surface is r2, and the radius of the circumscribed circle of the mounting part is r1, where r2 > r1, and the difference between r2 and r1 is 0.1 - 5.0 mm.

[0012] As an optional technical solution of the first aspect, the value range of L2 is 8 - 25 mm, and the value range of r1 is 3 - 10 mm.

[0013] As an optional technical solution of the first aspect, the mounting part includes a first mounting section, a clamping groove, and a second mounting section arranged in sequence;

[0014] Wherein:

[0015] The second mounting section is connected to the limiting part;

[0016] The clamping groove is used to connect with the clamping part provided on the adapter.

[0017] Optionally, the distance between the clamping groove and the end face of the first mounting section is L3, where L3 is 3 - 15 mm.

[0018] Further, the clamping groove is an annular groove; the distance between the bottom of the clamping groove and the rotary axis of the drill bit is r3, where r3 = (0.5 - 0.9)r1.

[0019] Optionally, both the first mounting section and the second mounting section are straight prisms, and the side surfaces of the two straight prisms are adapted to each other, and the side surfaces of each straight prism are also adapted to the limiting surfaces.

[0020] Optionally, both the first mounting section and the second mounting section are cylinders.

[0021] In the second aspect, a pagoda drill bit, the drill bit includes a drill body part, a limiting part, and a mounting part arranged in sequence; wherein, the drill body part, the limiting part, and the mounting part are coaxially arranged, and the limiting part and the mounting part are jointly connected to the adapter;

[0022] The mounting part is provided with a circumferential annular card slot for clamping the beads on the adapter to limit the movement of the drill bit along its axial direction; the limiting part has a plurality of equally spaced limiting surfaces in the circumferential direction for limiting the rotation of the drill bit relative to the adapter.

[0023] The axial length of the limiting part extending along the rotary axis of the drill bit is L1, and the axial length of the mounting part extending along the rotary axis of the drill bit is L2, where L1 > L2, and the radial dimension of the limiting part is greater than the radial dimension of the mounting part.

[0024] As an optional technical solution of the second aspect, the mounting part is cylindrical, and the card slot is arranged at the middle position of its axis; the limiting part is evenly distributed with three or five or six limiting surfaces in the circumferential direction.

[0025] As an optional technical solution of the first aspect or the second aspect, a step is provided on the end face of the limiting part close to the drill body part.

[0026] In the cross-section perpendicular to the rotary axis of the drill bit, the radius of the outer circle of the step is r5, and the radius of the circumscribed circle of the limiting surface is r4.

[0027] Among them, r5 > r4, and the difference between r5 and r4 is 0.2 - 2.0 mm.

[0028] As an optional technical solution of the first aspect or the second aspect, a transition surface is provided between adjacent limiting surfaces, and this transition surface is an arc surface or a rectangular surface.

[0029] As an optional technical solution of the first aspect or the second aspect, the drill body part is conical, the radial dimension of the drill body part increases sequentially from the tip to the drill tail direction, and the radial dimension of the drill tail is greater than the radial dimension of the step.

[0030] The drill body part is provided with a plurality of symmetrically arranged chip removal grooves.

[0031] In the third aspect, a combined structure of a pagoda drill bit and an adapter includes the pagoda drill bit in any one of the technical solutions of the first aspect or the second aspect.

[0032] It further includes an adapter, which includes a connecting column and a sleeve sleeved on the connecting column, and the sleeve can reciprocate along the axial direction of the connecting column.

[0033] The adapter further includes a limiting mechanism for preventing the sleeve from falling off the connecting column.

[0034] One end of the connecting column is provided with a wrench slot for inserting the output shaft of an electric wrench.

[0035] The other end of the connecting column is provided with a drill handle slot, which includes a limiting slot and a mounting slot. Among them, the mounting slot is adapted to the mounting part, and the limiting slot is adapted to the limiting part; when the limiting part is located in the limiting slot, the pagoda drill bit cannot rotate relative to the connecting column;

[0036] The connecting column is provided with a first through groove communicating with the mounting slot, and a first ball is installed in this first through groove;

[0037] The connecting column is also provided with a second through groove communicating with the wrench slot, and a second ball is installed in this second through groove;

[0038] The connecting column and the sleeve are connected by a spring; the elastic force of this spring makes the sleeve in the first position;

[0039] When the sleeve is in the first position, the sleeve simultaneously abuts against the first ball and the second ball, and the first ball and the second ball can be inserted into the mounting slot and the wrench slot respectively;

[0040] When overcoming the elastic force of the spring to move the sleeve axially along the connecting column to the second position, the sleeve does not abut against the first ball and the second ball, and the first ball and the second ball can respectively withdraw from the mounting slot and the wrench slot.

[0041] As an optional technical solution of the third aspect, a stepped surface is provided on the outer wall of the connecting column, and the inner wall of the sleeve is adapted to the stepped surface;

[0042] The limiting mechanism includes a clamp, which is installed at one end of the connecting column close to the pagoda drill bit; a limiting boss adapted to the clamp is provided on the inner wall of the sleeve;

[0043] When the sleeve is in the first position, the limiting boss abuts against the clamp;

[0044] When the sleeve is in the second position, the stepped surface abuts against the inner wall of the sleeve.

[0045] As an optional technical solution of the third aspect, a first boss is provided on the inner wall of the sleeve, and a first avoidance groove is provided on the side of the first boss close to the pagoda drill bit;

[0046] A second boss is also provided on the inner wall of the sleeve, and a second avoidance groove is provided on the side of the second boss close to the pagoda drill bit;

[0047] When the sleeve is in the first position, the first boss abuts against the first ball, and the second boss abuts against the second ball;

[0048] When the sleeve is in the second position, the first avoidance groove is aligned with the first ball, and the second avoidance groove is aligned with the second ball.

[0049] As an optional technical solution of the third aspect, a receiving cavity is formed between the step surface and the first boss, and the spring is installed in the receiving cavity, with two ends of the spring respectively abutting against the step surface and the first boss.

[0050] As an optional technical solution of the third aspect, a positioning groove is provided at one end of the inner wall of the sleeve away from the pagoda drill bit; a positioning boss is provided at one end of the connecting column away from the pagoda drill bit, and the positioning boss is located in the positioning groove;

[0051] When the sleeve is at the second position, the positioning boss abuts against the bottom of the positioning slide groove.

[0052] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

[0053] When the pagoda drill bit of the utility model needs to be connected to an adapter, the limiting part and the mounting part provided on the drill bit are both connected to the adapter at the same time, wherein the mounting part plays a role in preventing the drill bit from falling off the adapter, and the limiting part can limit the drill bit so that it will not rotate relative to the adapter. Under the joint action of the mounting part and the limiting part, the drill bit is firmly connected to the adapter. The axial and radial dimensions of the limiting part of the utility model are both larger than the mounting part, and the mounting part only plays a role in preventing it from falling off and does not bear torque. Since the overall structure of the limiting part is not damaged, the overall strength of the limiting part is relatively high, and the drill shank is not prone to breakage. At the same time, the center of gravity of the drill bit is more centered, and the drill bit is more stable when rotating.

[0054] The pagoda drill bit adapter combination structure of the utility model uses one sleeve to control two clamping beads at the same time, and the adapter, the electric wrench, and the pagoda drill bit can be disassembled or installed at the same time by axially moving the sleeve, which is more convenient and quick to use. In addition, since only one sleeve can control two clamping beads at the same time, the overall axial stroke of the sleeve is short, and the overall axial length of the adapter is appropriate, which is conducive to reducing the shaking caused by the rotation of the adapter and the pagoda drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic diagram of a drill bit in the prior art;

[0056] Figure 2 It is a schematic diagram of a drill bit in the prior art;

[0057] Figure 3 This is a schematic diagram of the structure of a pagoda drill bit in one embodiment of the present application;

[0058] Figure 4 This is a schematic diagram of the structure of a pagoda drill bit after the drill body is removed in one embodiment of the present application;

[0059] Figure 5 This is a side view of a pagoda drill bit after the drill body is removed in one embodiment of the present application;

[0060] Figure 6 This is a cross-sectional view of a reducing adapter in an embodiment of the present application;

[0061] Figure 7 This is a schematic connection diagram of a step drill bit and a reducing adapter in an embodiment of the present application.

[0062] Explanation of the reference numerals in the schematic diagram:

[0063] Drill body part 101, transition surface 102, first cylindrical section 103, clamping groove 104, limiting surface 105, second cylindrical section 106, step 107;

[0064] Sleeve 201, first boss 202, first relief groove 203, limiting boss 204, accommodating cavity 205, positioning sliding groove 206, second relief groove 207, second boss 208;

[0065] Connecting column 301, hanging slot 302, first through slot 303, limiting slot 304, spring 305, step surface 306, second through slot 307, positioning boss 308, wrench slot 309;

[0066] First detent ball 401, second detent ball 402, clamp 403. Specific embodiments

[0067] To further understand the content of the present invention, the present invention will be described in detail with reference to the accompanying drawings and embodiments.

[0068] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of clear narration and are not used to limit the scope of implementation. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope that the present invention can implement.

[0069] The present invention provides a step drill bit, as Figure 3As shown, in one embodiment, the drill bit includes a drill body portion 101, a limiting portion, and a mounting portion arranged in sequence. The drill body portion 101, the limiting portion, and the mounting portion are coaxially arranged. Here, the coaxial arrangement means that when the drill bit is driven to rotate for drilling, the rotation axes of the three are coincident. When this drill bit needs to be connected to a swivel joint, the limiting portion and the mounting portion of this drill bit are connected to the swivel joint simultaneously, rather than only one of them being connected to the swivel joint. Specifically, when the drill bit is connected to the swivel joint in a mating manner, the mounting portion is only used to prevent the drill bit from falling off the swivel joint and does not bear torque, while the limiting portion is used to prevent the drill bit from rotating relative to the swivel joint, and at this time the limiting portion bears torque.

[0070] As Figure 1 shown in the existing drill bit, the drill shank bears both the mounting function and the torque. Figure 1 The drill shank in is in the shape of a hexagonal prism, and a card slot is provided on the hexagonal prism. When this drill shank is connected to the swivel joint, the card slot cooperates with the swivel joint to prevent the drill bit from falling off, and the prism surface of the prism plays a role in restricting the rotation of the drill bit relative to the swivel joint. In this existing solution, the prism surfaces on both sides of the card slot play a role in restricting the rotation of the drill bit. Since the swivel joint is provided with a mechanism that cooperates with the card slot to play a mounting role, the torques received by the prisms on both sides of the card slot are different. And the card slot causes the prism not to extend smoothly along the axis, and the strength of the prism at the card slot will decrease. When the torques received by the prisms on both sides of the card slot are different, the drill shank will break.

[0071] As Figure 2 shown in the existing drill bit, the threaded section and the clamping section cannot be utilized simultaneously. That is, when it needs to be connected to the swivel joint, only the threaded section is connected to the swivel joint. At this time, the threaded section not only plays the role of mounting the drill bit but also bears torque. However, when only the threaded section is connected to the swivel joint, on the one hand, auxiliary tools are needed to help tighten during installation, and on the other hand, the threads are easily damaged during use, such as slipping or breaking of the shank.

[0072] In this embodiment, by making both the mounting portion and the limiting portion connected to the swivel joint simultaneously, the mounting portion and the limiting portion undertake different functions respectively. This can make the mounting portion smaller in size, so that the installation position of the clamping mechanism in the swivel joint does not need to be farther away from the axis, that is, the size of the swivel joint does not need to be increased. And it can make the mounting portion not bear torque and avoid its damage. At the same time, it can make the limiting portion, which needs to bear torque, larger in size, and make the prism surface of the limiting portion extend smoothly, thereby improving the strength of the limiting portion and making the drill shank not easily break.

[0073] Specifically, in this solution, the axial length of the limiting portion extending along the drill bit rotation axis is L1, and the axial length of the mounting portion extending along the drill bit rotation axis is L2, where L1 > L2. The limiting portion is circumferentially provided with a plurality of limiting surfaces 105. In a cross-section perpendicular to the drill bit rotation axis, the radius of the inscribed circle of the limiting surface 105 is r2, and the radius of the circumscribed circle of the mounting portion is r1, where r2 > r1. That is, in this embodiment, both the axial dimension and the radial dimension of the limiting portion are larger than those of the mounting portion, and the limiting portion has higher strength. The mounting portion only plays a role in preventing detachment. On the premise of keeping the size of the engaging portion provided on the adapter unchanged, the size of the limiting portion can be increased, so that the drill shank is not prone to breakage. At the same time, the center of gravity of this drill bit is more centered, and the running stability of the drill bit is higher.

[0074] For the limiting portion, in an alternative embodiment, as Figure 5 shown, the limiting portion is circumferentially provided with at least three limiting surfaces 105. For example, the limiting surface 105 can be provided with three, and one end of the limiting surface 105 extends to the end surface of the limiting portion close to the mounting portion. Let the end of the limiting surface 105 facing away from the drill body portion 101 extend to the end surface of the limiting portion close to the mounting portion. In this way, when connecting the drill bit to the adapter, after inserting the mounting portion into the adapter, the limiting portion can be directly inserted into the corresponding slot provided in the adapter, and the slot wall can also be in close contact with the outer surface of the limiting portion.

[0075] As an alternative embodiment, the value range of L2 is 8 - 25 mm, such as 8.2 mm, or 10 mm, or 23 mm, etc. The value range of r1 is 3 - 10 mm, such as 3.2 mm, or 5.5 mm, or 9.8 mm, etc. The difference between r2 and r1 is 0.1 - 5.0 mm, such as the value of r2 minus the value of r1 is 0.2 mm, or the value of r2 minus the value of r1 is 1.45 mm, or the value of r2 minus the value of r1 is 4.8 mm, etc.

[0076] A pagoda drill bit, the drill bit includes a drill body portion 101, a limiting portion, and a mounting portion provided in sequence; wherein, the drill body portion 101, the limiting portion, and the mounting portion are coaxially arranged, and the limiting portion and the mounting portion are jointly connected to the adapter. The mounting portion is provided with a circumferential annular slot 104, and the annular slot 104 is used to engage with the beads on the adapter to limit the movement of the drill bit along its axis. The so-called limiting the movement of the drill bit along the axis does not mean that the drill bit cannot move along the axis at all. There is a surplus space in the slot 104. After the beads are engaged in the slot 104, the drill bit can still undergo a slight displacement along the axis.

[0077] As an alternative solution, the mounting portion is cylindrical, and the slot 104 is provided at the middle position in its axial direction.

[0078] The limiting portion has a plurality of limiting surfaces 105 evenly spaced in the circumferential direction, which are used to limit the rotation of the drill bit relative to the adapter. For example, three, five or six limiting surfaces 105 can be evenly spaced in the circumferential direction on the limiting portion.

[0079] The axial length of the limiting portion extending along the drill bit rotation axis is L1, and the axial length of the mounting portion extending along the drill bit rotation axis is L2, wherein L1>L2, and the radial dimension of the limiting portion is greater than the radial dimension of the mounting portion.

[0080] When the drill bit is connected to the adapter, the mounting part is only used to limit the movement of the drill bit along its axis, and the limiting part is used to limit the rotation of the drill bit relative to the adapter, that is, only the limiting part bears the torque. The radial dimension of the limiting part is larger than the radial dimension of the mounting part.

[0081] Since the mounting part is only used to prevent the drill bit from falling off the adapter and does not bear torque, while the limiting part is used to bear torque, the size of the mounting part can be appropriately reduced, while the size of the limiting part can be appropriately increased to improve the structural strength of the limiting part. By appropriately increasing the size of the limiting part, the center of gravity of the drill bit can also be lowered (because the limiting part is located below the mounting part when drilling), thereby improving the stability of the drill bit when rotating and drilling.

[0082] As for the mounting part, as a specific implementation scheme, it includes a first mounting section 103, a card slot 104, and a second mounting section 106 which are arranged in sequence, wherein the second mounting section 106 is connected to the limiting part, and the card slot 104 is used to connect with the card connection part provided on the adapter.

[0083] As an optional implementation scheme, the difference between L1 and L2 is 0.3 to 10 mm. For example, it can be 0.8 mm, or 1.9 mm, or 8.5 mm, or 10 mm, etc. In this scheme, the distance between the slot 104 and the end face of the first mounting section 103 is L3, where L3 is 3 to 15 mm, for example, it can be 3 mm, or 12 mm, or 15 mm, etc. Since the total length of the adapter is often fixed, when the mounting portion only assumes the anti-falling function, the axial length of the mounting portion can be minimized. At this time, the position of the slot 104 can be as close to the drill shank end as possible (the end face of the first mounting section 103 away from the slot 104). When the position of the slot 104 moves toward the drill shank end, the axial length of the mounting portion is reduced accordingly. Under the premise that the total length of the drill shank is fixed, the length of the limit portion can be increased, and the radial dimension of the limit portion can also be increased, so that the limit portion is stronger and less likely to break the shank.

[0084] The length of the second mounting section 106 is not significantly smaller than the length of the first mounting section 103, that is, the length of the second mounting section 106 is equal to the length of the first mounting section 103, and the length of the second mounting section 106 can also be made greater than the length of the first mounting section 103. In this way, when the drill bit is drilling, the center of gravity of the drill bit will be lower (because the second mounting section 106 is located below the first mounting section 103 when drilling), and the stability of the drill bit is better.

[0085] Regarding the shape of the slot 104, in one embodiment, the slot 104 is an annular slot. If the slot 104 is an annular slot, the mounting portion as a whole is a rotating body, and during the rotation of the drill bit, the mounting portion being a rotating body is conducive to improving the stability of the drill bit rotation. In addition, if the slot 104 is an annular slot, there is no need to consider the alignment of the slot 104.

[0086] The spacing between the bottom of the slot 104 and the axis of rotation of the drill bit is r3, wherein r3 = (0.5-0.9) r1, such as r3 = 0.52r1, or r3 = 0.45r1, or r3 = 0.7r1, etc., that is, the depth of the slot 104 should not be too shallow, because if it is too shallow, the clamping part is easy to be separated from the slot 104, causing the drill bit to fall off, and if it is too deep, the clamping part needs to have a longer stroke, which will cause the width of the adapter to be larger. In an optional embodiment, the value range of r3 can be 5.8-6.1 mm, such as 5.85 mm, or 5.90 mm, or 5.95 mm, etc.

[0087] As for the shapes of the first mounting section 103 and the second mounting section 106, in one embodiment, the first mounting section 103 and the second mounting section 106 are both right prisms, such as hexagonal prisms, and the side surfaces of the two right prisms are matched, and the side surfaces of each right prism are also matched with the limiting surface 105, so that when the mounting part is inserted into the slot provided in the adapter, the limiting part will also correspond to the slot provided in the adapter for the limiting part to be inserted, and the shape of the mounting part can also play a guiding role. In this embodiment, the shape of the outer side surface of the mounting part can also be a column with a similar shape to the outer side surface of the limiting part, and the mounting part can also play a guiding role.

[0088] Regarding the shapes of the first mounting section 103 and the second mounting section 106, in another embodiment, the first mounting section 103 and the second mounting section 106 are both cylindrical. In this embodiment, since the first mounting section 103 and the second mounting section 106 are both cylindrical, when inserting the mounting portion into the corresponding slot provided in the adapter, there is no need to rotate the drill bit to adjust the angle, and the mounting portion can be directly inserted into the adapter, which makes it more convenient and quick to install the drill bit, thereby improving the installation speed.

[0089] When inserting the mounting part into the adapter, the first mounting section 103 is first inserted into the slot provided in the adapter, and then the second mounting section 106 enters the slot provided in the adapter, so that the mounting part can be directly inserted into the adapter, improving the installation speed. To improve the stability of the drill bit, in this solution, the radius of the cylinder of the second mounting section 106 is not less than the radius of the cylinder of the first mounting section 103. If the radius of the cylinder of the second mounting section 106 is less than the radius of the cylinder of the first mounting section 103, after the drill bit is installed in place, the inner diameter of the slot corresponding to the installation position of the second mounting section 106 will be greater than the radius of the cylinder of the second mounting section 106. At this time, the outer surface of the second mounting section 106 does not adhere to the inner wall of the slot corresponding to its installation position, so the mounting part is not installed stably enough and may be deflected, which may cause the drill bit to shake when the drill bit rotates and drills. Preferably, the radii of the first mounting section 103 and the second mounting section 106 are equal, and the inner diameters of the slots corresponding to the installation positions of the first mounting section 103 and the second mounting section 106 are also equal. In this way, when the first mounting section 103 is first inserted into the slot corresponding to the installation position of the second mounting section 106, the axis of the drill bit's rotation line coincides with the axis of the slot of the adapter. At this time, the mounting part and the limiting part can be directly pushed into the adapter without further adjusting the angle.

[0090] In one embodiment, as Figures 3-5 shown, a step 107 is provided on the end face of the limiting part close to the drill body part 101. And in the cross-section perpendicular to the rotation axis of the drill bit, the outer circle radius of the step 107 is r5, and the outer circle radius of the limiting surface 105 is r4. Among them, r5>r4, and the difference between r5 and r4 is 0.2-2.0 mm. For example, the value of r5 minus the value of r4 is 0.2 mm, or the value of r5 minus the value of r4 is 0.6 mm, or the value of r5 minus the value of r4 is 1.2 mm, or the value of r5 minus the value of r4 is 1.45 mm, or the value of r5 minus the value of r4 is 2 mm, etc. In this embodiment, the radial dimension of the step is larger than the part provided with the limiting surface 105. Through this step 107, the adapter can be prevented from directly contacting the drill body part 101, and the radial dimension of this step 107 is larger than the slot provided in the adapter, so that the adapter can be prevented from colliding with the end face of the drill body part 101, thereby preventing end face damage.

[0091] A transition surface 102 is provided between adjacent limiting surfaces 105, and this transition surface 102 is an arc surface or a rectangular surface. In Figures 3-5 it, the transition surface is an arc surface, and the central angle range of the limiting surface 105 corresponding to the outer circle is 20°-60°, so that the limiting surface 105 has enough surface area to be clamped or limited.

[0092] For the drill body part 101, in one embodiment, the drill body part 101 is a stepped drill bit, i.e., a stepped drill, which is conical. The radial dimension of the drill body part 101 increases successively from the tip towards the drill tail direction, and the radial dimension of the drill tail is larger than that of the step 107. The limiting part and the mounting part are successively arranged at the tail end of the drill body part 101. The stepped structure of the drill body part 101 forms machining surfaces with different diameters. A plurality of symmetrically arranged chip discharge grooves are provided on the drill body part 101 for discharging waste chips during drilling. The chip discharge grooves can be 2 or 3, and can be straight groove-shaped or spiral-shaped. The chip discharge grooves are relatively mature in the prior art and will not be elaborated and limited here.

[0093] In one embodiment, the present utility model also proposes a stepped drill bit adapter combination structure, which includes the stepped drill bit in any of the above embodiments, and also includes an adapter, as Figure 7 shown. After connecting the stepped drill bit to the adapter, and then connecting the adapter to an electric wrench, it can be realized that the electric wrench drives the adapter to drive the stepped drill bit to rotate.

[0094] As Figure 6 shown, the adapter includes a connecting column 301 and a sleeve 201 sleeved on the connecting column 301. The sleeve 201 can reciprocate axially along the connecting column 301. The output shaft of the electric wrench, the connecting column 301, the sleeve 301, and the stepped drill bit are all coaxially arranged.

[0095] Specifically, one end of the connecting column 301 is provided with a wrench slot 309 for the output shaft of the electric wrench to be inserted. After the output shaft is inserted into the wrench slot 309, the connecting column 301 cannot rotate relative to the output shaft, and the output shaft can drive the connecting column 301 to rotate together. The other end of the connecting column 301 is provided with a drill shank slot, which includes a limiting slot 304 and a mounting slot 302. Among them, the mounting slot 302 is adapted to the mounting part, and the limiting slot 304 is adapted to the limiting part. In this way, when the limiting part is located in the limiting slot 304, the stepped drill bit cannot rotate relative to the connecting column 301, and the output shaft can drive the connecting column 301 and the stepped drill bit to rotate together.

[0096] In order to prevent the sleeve 201 from falling off the connecting column 301, the adapter further includes a limiting mechanism, and the sleeve 201 can be prevented from falling off the connecting column 301 through this limiting mechanism.

[0097] When the electric wrench drives the adapter to drive the stepped drill bit to rotate, in order to prevent the adapter from detaching from the output shaft of the electric wrench and also to prevent the stepped drill bit from separating from the adapter. In one solution, the connecting column 301 is provided with a first through groove 303 communicating with the mounting slot 302, and a first ball 401 is installed in this first through groove 303. The connecting column 301 is also provided with a second through groove 307 communicating with the wrench slot 309, and a second ball 402 is installed in this second through groove 307.

[0098] When the sleeve 201 is in the first position, the sleeve 201 abuts against the first detent ball 401 and the second detent ball 402 simultaneously. The first detent ball 401 and the second detent ball 402 can be inserted into the mounting slot 302 and the wrench slot 309 respectively. At this time, a part of the first detent ball 401 is clamped into the card slot 104, and a part of the second detent ball 402 is clamped into the jack provided on the output shaft of the electric wrench, so that the tower drill bit will not be separated from the connecting column 301, and the connecting column 301 will not be separated from the output shaft of the electric wrench either.

[0099] As an alternative embodiment, the connecting column 301 and the sleeve 201 are connected by a spring 305, and the sleeve 201 is in the first position by the elastic force of the spring 305. At this time, one side of the sleeve 201 is subject to the elastic force of the spring 305, and the other side is limited by the limiting mechanism, so that the sleeve 201 can be kept in the first position.

[0100] When overcoming the elastic force of the spring 305 to move the sleeve 201 axially along the connecting column 301 to the second position, at this time the sleeve 201 does not abut against the first detent ball 401 and the second detent ball 402, and the first detent ball 401 and the second detent ball 402 can withdraw from the mounting slot 302 and the wrench slot 309 respectively. At this time, the tower drill bit can be separated from the connecting column 301, and the connecting column 301 can also be separated from the output shaft of the electric wrench.

[0101] For the limiting mechanism, in one embodiment, the outer wall of the connecting column 301 is provided with a step surface 306. The connecting column 301 can have a larger diameter in one section and a smaller diameter in another section, so as to form the step surface 306. The inner wall of the sleeve 201 is adapted to the step surface 306, that is, it can be considered that the inner wall of the sleeve 201 also forms another step surface.

[0102] The limiting mechanism includes a clamp 403, which is installed at one end of the connecting column 301 close to the tower drill bit. The inner wall of the sleeve 201 is provided with a limiting boss 204 adapted to the clamp 403. When the sleeve 201 is in the first position, the limiting boss 204 abuts against the clamp 403, and at this time the sleeve 201 cannot move further in the direction of the tower drill bit; when the sleeve 201 is in the second position, the step surface 306 abuts against the inner wall of the sleeve 201, and at this time the sleeve 201 cannot move further in the direction away from the tower drill bit.

[0103] There is a distance between the clamp 403 and the end face of the connecting column 301 close to the tower drill bit. When the sleeve 201 is in the first position, this distance allows the user's fingers to clamp, so that the sleeve 201 can be pushed to the second position. In order to increase the friction, knurling can be processed on this outer surface.

[0104] In an alternative scheme, the clamp 403 is detachable. At this time, when the clamp 403 is removed, the sleeve 201 can be separated from the connecting column 301.

[0105] As an alternative embodiment, a first boss 202 is provided on the inner wall of the sleeve 201, and a first relief groove 203 is provided on the side of the first boss 202 close to the pagoda drill bit. A second boss 208 is also provided on the inner wall of the sleeve 201, and a second relief groove 207 is provided on the side of the second boss 208 close to the pagoda drill bit. The first boss 202, the first relief groove 203, the second boss 208, and the second relief groove 207 can all be annular.

[0106] When the sleeve 201 is in the first position, the first boss 202 abuts against the first detent ball 401, and the second boss 208 abuts against the second detent ball 402. The first detent ball 401 and the second detent ball 402 can respectively insert into the mounting groove 302 and the wrench slot 309. At this time, a part of the first detent ball 401 is stuck in the card slot 104, and a part of the second detent ball 402 is stuck in the jack provided on the output shaft of the electric wrench, so that the pagoda drill bit will not be separated from the connecting column 301, and the connecting column 301 will not be separated from the output shaft of the electric wrench.

[0107] When the sleeve 201 is in the second position, the first relief groove 203 is aligned with the first detent ball 401, and the second relief groove 207 is aligned with the second detent ball 402. The first detent ball 401 and the second detent ball 402 lose the block. When the pagoda drill bit is pulled out, the first detent ball 401 can withdraw from the card slot 104. When the output shaft is pulled out, the second detent ball 402 can withdraw from the infusion jack provided on the output shaft of the electric wrench.

[0108] Regarding the installation method of the spring 305, in one embodiment, a receiving cavity 205 is formed between the stepped surface 306 and the first boss 202. This receiving cavity 205 is located between the sleeve 201 and the connecting column 301. The spring 305 is installed in the receiving cavity 205. The spring 305 can be a helical spring sleeved on the connecting column 301. Both ends of the spring 305 abut against the stepped surface 306 and the first boss 202 respectively. The elastic force of the spring 305 can abut against one end of the sleeve 201, and the other end of the sleeve 201 is abutted by the clamp 403, so that the sleeve 201 is in the first position. Only when the sleeve 201 is pushed in the direction away from the pagoda drill bit, the spring 305 is compressed, and the sleeve 201 can move to the second position.

[0109] As an alternative embodiment, a positioning chute 206 is provided at one end of the inner wall of the sleeve 201 away from the pagoda drill bit, and a positioning boss 308 is provided at one end of the connecting column 301 away from the pagoda drill bit. The positioning boss 308 is located in this positioning chute 206. The length of the positioning chute 206 can be set such that when the sleeve 201 is pushed until the positioning boss 308 abuts against the bottom of the positioning chute 206, the sleeve 201 is in the second position at this time. On the other hand, by providing the positioning boss 308 and the positioning chute 206, it can also prevent the sleeve 201 from detaching from the side of the connecting column 301 away from the pagoda drill bit.

[0110] The above has schematically described the present utility model and its implementation manners. This description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present utility model, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the creation of the present utility model, design similar structural manners and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present utility model.

Claims

1. A pagoda drill bit, characterized in that: The drill bit includes a drill body part (101), a limiting part, and a mounting part arranged in sequence; wherein, the drill body part (101), the limiting part, and the mounting part are coaxially arranged, and the limiting part and the mounting part are jointly connected with a swivel joint; When the drill bit is connected with the swivel joint, the mounting part is used to prevent the drill bit from falling off the swivel joint, and the limiting part is used to prevent the drill bit from rotating relative to the swivel joint; The axial length of the limiting part extending along the rotary axis direction of the drill bit is L1, and the axial length of the mounting part extending along the rotary axis direction of the drill bit is L2, wherein, L1 > L2, and the difference between L1 and L2 is 0.3 - 10 mm; A plurality of limiting surfaces (105) are evenly distributed in the circumferential direction on the limiting part; in a cross-section perpendicular to the rotary axis of the drill bit, the radius of the inscribed circle of the limiting surface (105) is r2, and the radius of the circumscribed circle of the mounting part is r1, wherein, r2 > r1, and the difference between r2 and r1 is 0.1 - 5.0 mm.

2. The pagoda drill bit according to claim 1, characterized in that: The value range of the axial length L2 of the mounting part extending along the rotary axis direction of the drill bit is 8 - 25 mm.

3. The pagoda drill bit according to claim 1, characterized in that: The value range of the radius r1 of the circumscribed circle of the mounting part is 3 - 10 mm.

4. The pagoda drill bit according to claim 1, characterized in that: The mounting part includes a first mounting section (103), a clamping groove (104), and a second mounting section (106) arranged in sequence; Wherein: The second mounting section (106) is connected to the limiting part; The clamping groove (104) is used to connect with the clamping part provided on the swivel joint.

5. The pagoda drill bit according to claim 4, characterized in that: The distance between the clamping groove (104) and the end face of the first mounting section (103) is L3, wherein L3 is 3 - 15 mm.

6. The pagoda drill bit according to claim 5, characterized in that: The clamping groove (104) is an annular groove; The distance between the bottom of the clamping groove (104) and the rotary axis of the drill bit is r3, wherein, r3 = (0.5 - 0.9)r1.

7. The pagoda drill bit according to claim 4, characterized in that: Both the first mounting section (103) and the second mounting section (106) are straight prisms, and the side surfaces of the two straight prisms are adapted to each other, and the side surfaces of each straight prism are also adapted to the limiting surface (105).

8. The pagoda drill bit according to claim 4, wherein: Both the first mounting section (103) and the second mounting section (106) are cylinders.

9. A pagoda drill bit, characterized in that: The drill bit includes a drill body part (101), a limiting part, and a mounting part arranged in sequence; wherein, the drill body part (101), the limiting part, and the mounting part are coaxially arranged, and the limiting part and the mounting part are jointly connected with a swivel joint; The mounting part is provided with a clamping groove (104) for clamping into the clamping beads on the swivel joint to limit the movement of the drill bit along its axis direction; the limiting part has a plurality of equally spaced limiting surfaces (105) in the circumferential direction for restricting the rotation of the drill bit relative to the swivel joint; The axial length of the limiting part extending along the drill bit rotation axis is L1, and the axial length of the mounting part extending along the drill bit rotation axis is L2. Among them, L1 > L2, and the radial dimension of the limiting part is greater than the radial dimension of the mounting part.

10. The pagoda drill bit according to claim 9, characterized in that: The mounting part is cylindrical, and a circumferential annular slot (104) is provided on the mounting part; the slot (104) is provided at a position close to the middle in the axial direction thereof; the limiting part is evenly distributed with three or five or six limiting surfaces (105) in the circumferential direction.

11. The pagoda drill bit according to any one of claims 1-10, characterized in that: A step (107) is provided on the end surface of the limiting part on the side close to the drill body part (101); In a cross-section perpendicular to the drill bit rotation axis, the radius of the outer circle of the step (107) is r5, and the radius of the circumscribed circle of the limiting surface (105) is r4; Among them, r5 > r4, and the difference between r5 and r4 is 0.2-2 mm.

12. The pagoda drill bit according to claim 11, characterized in that: The drill body part (101) is conical, and the radial dimension of the drill body part (101) increases sequentially from the tip to the drill tail direction, and the radial dimension of the drill tail is greater than the radial dimension of the step (107); The drill body part (101) is provided with a plurality of symmetrically arranged chip removal grooves.

13. A pagoda drill bit adapter combination structure, characterized in that: It includes the pagoda drill bit according to any one of claims 1-12; It further includes an adapter, and this adapter includes a connecting column (301) and a sleeve (201) sleeved on the connecting column (301), and the sleeve (201) can reciprocate along the axial direction of the connecting column (301); One end of the connecting column (301) is provided with a wrench slot (309), and this wrench slot (309) is used for the output shaft of the electric wrench to be inserted; the other end of the connecting column (301) is provided with a drill shank slot, and this drill shank slot includes a limiting slot (304) and a mounting slot (302), among which, the mounting slot (302) is adapted to the mounting part, and the limiting slot (304) is adapted to the limiting part; when the limiting part is located in the limiting slot (304), the pagoda drill bit cannot rotate relative to the connecting column (301); Moving the sleeve (201) can unlock and pull out the drill bit.

14. The pagoda drill bit adapter combination structure according to claim 13, characterized in that: The adapter further includes a limiting mechanism, and this limiting mechanism is used to prevent the sleeve (201) from falling off the connecting column (301); The connecting column (301) is provided with a first through groove (303) communicating with the mounting slot (302), and a first ball (401) is installed in this first through groove (303); The connecting column (301) is further provided with a second through groove (307) communicating with the wrench slot (309), and a second ball (402) is installed in this second through groove (307); The connecting column (301) is connected to the sleeve (201) through a spring (305); the elastic force of this spring (305) makes the sleeve (201) in the first position; When the sleeve (201) is in the first position, the sleeve (201) abuts against the first ball (401) and the second ball (402) simultaneously, and the first ball (401) and the second ball (402) can be inserted into the mounting slot (302) and the wrench slot (309) respectively; When overcoming the elastic force of the spring (305) to axially move the sleeve (201) along the connecting column (301) to the second position, the sleeve (201) does not abut against the first ball (401) and the second ball (402), and the first ball (401) and the second ball (402) can withdraw from the mounting slot (302) and the wrench slot (309) respectively.

15. The combination structure for adapter of a pagoda drill bit according to claim 14, wherein: A stepped surface (306) is provided on the outer wall of the connecting column (301), and the inner wall of the sleeve (201) is adapted to the stepped surface (306); The limiting mechanism includes a clamp (403), and this clamp (403) is installed at one end of the connecting column (301) close to the pagoda drill bit; a limiting boss (204) adapted to the clamp (403) is provided on the inner wall of the sleeve (201); When the sleeve (201) is in the first position, the limiting boss (204) abuts against the clamp (403); When the sleeve (201) is in the second position, the stepped surface (306) abuts against the inner wall of the sleeve (201).

16. The combination structure for adapter of a pagoda drill bit according to claim 15, wherein: A first boss (202) is provided on the inner wall of the sleeve (201), and a first relief groove (203) is provided on one side of the first boss (202) close to the pagoda drill bit; A second boss (208) is further provided on the inner wall of the sleeve (201), and a second relief groove (207) is provided on one side of the second boss (208) close to the pagoda drill bit; When the sleeve (201) is in the first position, the first boss (202) abuts against the first ball (401), and the second boss (208) abuts against the second ball (402); When the sleeve (201) is in the second position, the first relief groove (203) is aligned with the first ball (401), and the second relief groove (207) is aligned with the second ball (402).

17. The combination structure for adapter of a pagoda drill bit according to claim 16, wherein: An accommodation cavity (205) is formed between the stepped surface (306) and the first boss (202), the spring (305) is installed in the accommodation cavity (205), and both ends of the spring (305) abut against the stepped surface (306) and the first boss (202) respectively.

18. The combination structure for adapter of a pagoda drill bit according to claim 13, wherein: A positioning chute (206) is provided at one end of the inner wall of the sleeve (201) away from the pagoda drill bit; a positioning boss (308) is provided at one end of the connecting column (301) away from the pagoda drill bit, and the positioning boss (308) is located in this positioning chute (206); When the sleeve (201) is in the second position, the positioning boss (308) abuts against the bottom of the positioning chute (206).

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