Hybrid drill bit with high connection reliability of bit legs

Abstract

The invention discloses a hybrid drill bit with high bit leg connection reliability, which comprises a drill bit body provided with at least one bit leg, and is characterized in that the drill bit body is provided with a bit leg groove for placing the bit leg, and the horizontal section of the bit leg groove is in a dovetail groove shape; a mounting part is arranged at one end of the bit leg, and the shape of the mounting part is matched with that of the bit leg groove; the maximum width of the mounting part is smaller than the minimum width of the bit leg groove, so that a cushion groove is formed between one side of the mounting part and the side wall of the bit leg groove when the mounting part is mounted in the bit leg groove, and at least one cushion block is arranged in the cushion groove. The connection reliability between the bit leg and the drill bit body is high, and the service life of the drill bit is effectively prolonged.

Description

Technical Field

[0001] This invention relates to the field of hybrid drill bit technology. More specifically, this invention relates to a hybrid drill bit with high tooth-to-palm connection reliability. Background Technology

[0002] In existing technologies, hybrid drill bits are widely used due to their composite cutting structure of fixed blades and rolling cones, which offers advantages such as adaptability to various formations, high mechanical drilling speed, and large drilling footage. The die supporting the rolling cones is typically welded to the diamond drill bit body. Because the rolling cones and die are located on the outer edge of the drill bit, the drill bit core needs an internal flow channel for drilling fluid passage. This space constraint results in shallow weld depths and short lengths, leading to insufficient connection strength and low reliability between the die and the diamond drill bit body. In drilling companies that prioritize drilling efficiency and often employ reinforced drilling techniques, the connection strength between the die and the diamond drill bit body becomes severely insufficient, resulting in even lower reliability and increasing the risk of weld cracking and die falling into the well. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] To achieve these objectives and other advantages according to the present invention, a hybrid drill bit with high reliability of tooth-palm connection is provided. The hybrid drill bit includes a drill body, on which at least one tooth is provided. A tooth groove for placing the tooth is formed on the drill body, and the horizontal cross-section of the tooth groove is dovetail-shaped. One end of the tooth is a mounting portion, the shape of which matches the shape of the tooth groove. The maximum width of the mounting portion is less than the minimum width of the tooth groove, so that when the mounting portion is installed in the tooth groove, one side of it forms a pad groove with the sidewall of the tooth groove, and at least one pad is provided in the pad groove.

[0005] Preferably, the tooth groove has a right dovetail groove surface, a left dovetail groove surface, a front mating surface, and an upper mating surface; wherein the front mating surface is arranged perpendicular to the radial direction of the drill bit body, and the upper mating surface is arranged horizontally and perpendicular to the front mating surface; the right dovetail groove surface and the left dovetail groove surface are respectively arranged on both sides of the front mating surface and the upper mating surface, and the width of the tooth groove gradually increases from the outside to the inside along the radial direction of the drill bit body.

[0006] Preferably, the mounting portion has a right dovetail surface, a left dovetail surface, a front mating surface, and an upper mating surface that mate with the tooth groove; the minimum distance between the right dovetail surface and the left dovetail surface is greater than the maximum distance between the right dovetail surface and the left dovetail surface.

[0007] Preferably, the dovetail angle between the left dovetail groove surface and the front mating surface is 60° to 80°.

[0008] Preferably, the groove is located between the right dovetail groove surface and the right dovetail surface of the tooth palm, and the difference ΔL between the width of the groove and the width of the pad block is in the range of -0.5 to 1.0 mm.

[0009] Preferably, the number of pads is 1 to 10, and the multiple pads are stacked along the height direction of the pad groove.

[0010] Preferably, the sidewall of the drill bit body is provided with a drill bit body weld groove around the outer edge of the tooth groove; the tooth is provided with a tooth groove along the outer edge of the mounting part; when the tooth is installed in the tooth groove, the drill bit body weld groove and the tooth groove together form a welding space, and the welding space is filled with solder to form a weld, so that the mounting part of the tooth is welded to the drill bit body as a whole.

[0011] Preferably, the right dovetail groove surface and the left dovetail groove surface extend outward along the radial direction of the drill bit body to form a right side surface and a left side surface, respectively, and the length of the left side surface is greater than the length of the right side surface; the left dovetail groove surface of the tooth also extends outward along the radial direction of the drill bit body to form a left side surface of the tooth that matches the left side surface.

[0012] The present invention has at least the following beneficial effects: The hybrid drill bit with high tooth-to-hand connection reliability provided by this invention features a dovetail-shaped inner wall surface of the tooth groove, the wall surface of the mounting part in contact with the tooth groove and the pad, and the pad itself, which bear the majority of the thrust when the tooth is subjected to an outward thrust along the radial direction of the drill bit body. This significantly reduces the load on the weld, resulting in high connection reliability between the tooth and the drill bit body and effectively improving the service life of the drill bit. Furthermore, because the load on the weld is very small, the weld depth can be reduced, the amount of solder used can be decreased, and the manufacturing cost of the drill bit can be lowered.

[0013] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the hybrid drill bit described in this invention; Figure 2 This is a schematic diagram showing the installation position of the pad block in the hybrid drill bit of the present invention; Figure 3 This is a schematic diagram of the tooth groove in the hybrid drill bit of the present invention; Figure 4This is a schematic diagram of the horizontal cross-section of the hybrid drill bit described in this invention; Figure 5 for Figure 4 Enlarged view of a portion of point A in the middle; Figure 6 This is a schematic diagram of the structure of the right dovetail face of the tooth in the hybrid drill bit of the present invention; Figure 7 This is a schematic diagram of the structure of the left dovetail face of the tooth in the hybrid drill bit of the present invention; Figure 8 This is a schematic diagram of the horizontal cross-section of the mounting portion in the hybrid drill bit of the present invention; Figure 9 This is a schematic diagram of the structure of the pad block described in this invention; Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0016] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship when the hybrid drill bit is used. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0017] like Figures 1 to 9 As shown, the present invention provides a hybrid drill bit with high reliability of tooth-palm connection. The hybrid drill bit includes a drill body 1, on which at least one tooth 2 is provided. A tooth groove 120 for placing the tooth 2 is formed on the drill body 1. The horizontal cross-section of the tooth groove 120 is dovetail-shaped. One end of the tooth 2 is a mounting part, the shape of which matches the shape of the tooth groove. The maximum width of the mounting part is less than the minimum width of the tooth groove 120, so that when the mounting part is installed in the tooth groove 120, one side of it forms a pad groove 10 between itself and the side wall of the tooth groove. At least one pad block 5 is provided in the pad groove 10.

[0018] In this technical solution, refer to Figure 1 and Figure 2The drill bit body 2 is equipped with cutter wings 4 and nozzles 8. The cutter wings 4 are divided from the inside out into an inner cone, a nose, a shoulder, and a diameter-maintaining section. Fixed cutting teeth 9, which are diamond composite sheets, are installed on each part of the cutter wings 4. Figure 3 As shown, the toothed groove 120 and the toothed cone groove 110 are formed between at least one pair of adjacent blades 4; a toothed 2 is installed in the toothed groove 120, and the mounting part of the toothed 2 is welded to the drill body 1. A journal is provided at the other end of the toothed 2, and a toothed cone 6 is fitted onto the journal through the inner hole of the toothed cone and axially locked by a steel ball. The toothed cone 6 is located in the toothed cone groove 110, and toothed cone cutting teeth 7 are installed on the toothed cone 6. Figure 3 and Figure 4 As shown, the horizontal cross-section of the tooth groove 120 is dovetail-shaped. One end of the toothed wheel 2, which is inserted into the tooth groove 120, is a mounting part, which also has a dovetail-shaped horizontal cross-section, but its size is different from that of the tooth groove 120. This allows a gap to be formed between one side of the toothed wheel 2 and the inner wall of the tooth groove 120, i.e., the pad groove 10, providing installation space for the pad block 5. The other side of the toothed wheel 2 is in contact with the inner wall of the tooth groove 120. When the toothed wheel 6 and the toothed wheel 2 are subjected to an outward thrust along the radial direction of the drill bit body 1, the dovetail-shaped inner wall of the tooth groove 120, the wall surface of the mounting part that contacts the tooth groove 120 and the pad block 5, and the pad block 5 bear most of the thrust, thereby significantly reducing the load borne by the weld 3, thus ensuring a high connection reliability between the toothed wheel 2 and the drill bit body 1. Furthermore, since the load borne by the weld is very small, the weld depth can be reduced, the amount of solder used can be decreased, and the manufacturing cost of the drill bit can be lowered. The spacer 5 allows for fine-tuning of the position of the toothed joint 2 within the toothed joint groove 120, achieving precise control over the position of the toothed joint 2. The spacer 5 can also absorb and compensate for accumulated manufacturing tolerances between the toothed joint 2 and the toothed joint groove 120. In addition, if the toothed joint 2 and the toothed joint groove 120 are in rigid contact, stress will concentrate at several high points in the contact area, easily leading to fatigue cracks. The spacer 5 allows the toothed joint 2 to transfer the load more smoothly and evenly to a larger toothed joint groove contact surface, avoiding stress concentration and improving the overall structural load-bearing capacity and fatigue resistance.

[0019] In another technical solution, refer to Figure 3 and Figure 4The tooth groove 120 has a right dovetail groove surface 123, a left dovetail groove surface 125, a front mating surface 121, and an upper mating surface 124; wherein the front mating surface 121 is arranged perpendicular to the radial direction of the drill bit body 1, and the upper mating surface 125 is arranged horizontally and perpendicular to the front mating surface 121; the right dovetail groove surface 123 and the left dovetail groove surface 125 are respectively arranged on both sides of the front mating surface 121 and the upper mating surface 124, and the width of the tooth groove 120 gradually increases from the outside to the inside along the radial direction of the drill bit body 1.

[0020] Furthermore, referring to Figures 6-8 The mounting part has a right dovetail surface 21, a left dovetail surface 26, a front mating surface 22, and an upper mating surface 23 that mate with the tooth groove 120; the minimum distance D2 between the right dovetail surface 123 and the left dovetail surface 125 is greater than the maximum distance D1 between the right dovetail surface 21 and the left dovetail surface 26.

[0021] like Figure 2 and Figure 4 As shown, when the toothed palm 2 is assembled in the toothed palm groove 120, the left dovetail surface 26 of the toothed palm is in contact with the left dovetail groove surface 125, the front mating surface 22 of the toothed palm is in contact with the front mating surface 121, and the upper mating surface 23 of the toothed palm is in contact with the upper mating surface 124; at this time, there is a gap between the right dovetail surface 21 of the toothed palm and the right dovetail groove surface 123, forming the pad groove 10. The left dovetail groove surface 125 and the right dovetail groove surface 123 are inclined relative to the front mating surface 121. When the toothed plate 2 is subjected to an outward thrust along the radial direction of the drill bit, the left dovetail groove surface 26, the right dovetail groove surface 21, the pad block 5, the left dovetail groove surface 125, and the right dovetail groove surface 123 bear most of the thrust, thereby significantly reducing the load borne by the weld. When the toothed plate 2 is subjected to a counter-torque from the formation, the side of the dovetail groove acts as a shear key. When the torque attempts to rotate the toothed plate 2, the force will act directly on the side, and its shear resistance is much stronger than that of a simple vertical plane. This ensures that the torque can be efficiently and reliably transmitted from the toothed plate 2 to the drill bit body 1, preventing fretting wear or structural damage caused by poor torque transmission.

[0022] Furthermore, in order to achieve better technical results, the dovetail angle β between the left dovetail groove surface 125 and the front mating surface 121 is 60° to 80°.

[0023] In another technical solution, refer to Figure 5 and Figure 9The groove 10 is located between the right dovetail groove surface 123 and the right dovetail surface 21 of the toothed palm. The difference ΔL=KH between the width K of the groove 10 and the width H of the pad 5 ranges from -0.5 to 1.0 mm. Appropriate fit tolerances facilitate the quick installation of the pad 5 and ensure precise control of the position of the pad 5 on the toothed palm 2. Preferably, the pad is rectangular in shape, and to facilitate insertion into the groove 10, the pad 5 also has a pointed tip.

[0024] Furthermore, the number of the pads 5 is 1 to 10, and multiple pads 5 are stacked along the height direction of the pad groove 10. (Refer to...) Figure 2 When multiple pads 5 are set, the pads 5 of the corresponding size can be flexibly selected according to the size of the pad groove at different positions, thereby further improving the stability of the tooth palm 2.

[0025] In another technical solution, the sidewall of the drill body 1 is provided with a drill body weld groove 130 along the outer edge of the tooth groove 120; the tooth 2 is provided with a tooth weld groove along the outer edge of the mounting part; when the tooth 2 is installed in the tooth groove 120, the drill body weld groove 130 and the tooth weld groove together form a welding space, and the welding space is filled with solder to form a weld 3, so that the mounting part of the tooth 2 is welded to the drill body 1 as a whole.

[0026] Furthermore, the right dovetail groove surface 123 and the left dovetail groove surface 125 extend outward along the radial direction of the drill bit body 1 to form a right side surface 122 and a left side surface 126, respectively, and the length of the left side surface 126 is greater than the length of the right side surface 122; the tooth palm left dovetail surface 26 also extends outward along the radial direction of the drill bit body 1 to form a tooth palm left side surface 25 that mates with the left side surface 126.

[0027] like Figure 3 , Figure 5 and Figure 6As shown, the drill bit body weld groove includes: a right drill bit body weld groove 131 disposed on the outer edge of the right side face 122, and a left drill bit body weld groove 133 disposed on the outer edge of the left side face. A circumferential drill bit body weld groove 132 is formed between the right drill bit body weld groove 131 and the left drill bit body weld groove 133 to connect the two and form a drill bit body weld groove 130. The toothed plate weld groove includes: a right toothed plate weld groove 27 disposed on the outer edge of the right dovetail face 21 of the toothed plate, and a left toothed plate weld groove 24 disposed on the outer side of the outer boundary line of the left toothed plate face 25. The toothed plate mating surface 23 connects the right toothed plate weld groove 27 and the left toothed plate weld groove 24 to form the toothed plate weld groove. Furthermore, considering that a spacer 5 is provided between the right dovetail groove surface 123 and the right dovetail surface 21 of the toothed joint, and the welding area where the right branch of the weld is located includes the large end face 51 of the spacer 5, if the left side surface 126 and the right side surface 122 of the toothed joint 120 are symmetrically arranged with equal lengths, the widths of the left and right branches of the weld 3 will not be equal. This will lead to unequal welding shrinkage on the left and right sides of the weld 3, causing cracks to form inside the weld 3. To solve this problem, and to make the widths of the left and right branches of the weld 3 approximately equal, the length of the left side surface 126 is set to be greater than the length of the right side surface 122, referring to... Figure 4 The tooth groove 120 is asymmetrically arranged on the left and right sides.

[0028] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A hybrid drill bit with high reliability of tooth-palm connection, the hybrid drill bit comprising a drill body, wherein at least one tooth-palm is provided on the drill body, characterized in that, The drill bit body has a tooth groove for placing the tooth plate, and the horizontal cross-section of the tooth groove is dovetail-shaped; one end of the tooth plate is a mounting part, and the shape of the mounting part matches the shape of the tooth groove; the maximum width of the mounting part is less than the minimum width of the tooth groove, so that when the mounting part is installed in the tooth groove, one side of it forms a pad groove with the side wall of the tooth groove, and at least one pad block is provided in the pad groove.

2. The hybrid drill bit with high reliability of tooth-palm connection as described in claim 1, characterized in that, The tooth groove has a right dovetail groove surface, a left dovetail groove surface, a front mating surface, and an upper mating surface; wherein the front mating surface is arranged perpendicular to the radial direction of the drill bit body, and the upper mating surface is arranged horizontally and perpendicular to the front mating surface; the right dovetail groove surface and the left dovetail groove surface are respectively arranged on both sides of the front mating surface and the upper mating surface, and the width of the tooth groove gradually increases from the outside to the inside along the radial direction of the drill bit body.

3. The hybrid drill bit with high reliability of tooth-palm connection as described in claim 2, characterized in that, The mounting part has a right dovetail surface, a left dovetail surface, a front mating surface, and an upper mating surface that mate with the tooth groove; the minimum distance between the right dovetail surface and the left dovetail surface is greater than the maximum distance between the right dovetail surface and the left dovetail surface.

4. The hybrid drill bit with high reliability of tooth-palm connection as described in claim 2, characterized in that, The dovetail angle between the left dovetail groove surface and the front mating surface is 60° to 80°.

5. The hybrid drill bit with high reliability of tooth-palm connection as described in claim 3, characterized in that, The groove is located between the right dovetail groove surface and the right dovetail surface of the tooth palm, and the difference ΔL between the width of the groove and the width of the pad block ranges from -0.5 to 1.0 mm.

6. The hybrid drill bit with high tooth-palm connection reliability as described in claim 5, characterized in that, The number of pads is 1 to 10, and multiple pads are stacked along the height direction of the pad groove.

7. The hybrid drill bit with high reliability of tooth-palm connection as described in claim 3, characterized in that, The drill bit body has a drill bit body weld groove on its side wall around the outer edge of the tooth groove; the tooth has a tooth groove along the outer edge of the mounting part; when the tooth is installed in the tooth groove, the drill bit body weld groove and the tooth groove together form a welding space, and the welding space is filled with solder to form a weld, so that the mounting part of the tooth is welded to the drill bit body as one piece.

8. The hybrid drill bit with high reliability of tooth-palm connection as described in claim 7, characterized in that, The right dovetail groove and the left dovetail groove extend outward along the radial direction of the drill bit body to form a right side face and a left side face, respectively, with the length of the left side face being greater than the length of the right side face; the left dovetail groove of the tooth also extends outward along the radial direction of the drill bit body to form a left side face of the tooth that matches the left side face.

Images