Double-layer casing section milling tool

Abstract

The invention discloses a double-layer sleeve section milling tool, relates to the technical field of sleeve forging and milling, and solves the technical problems that an existing device is low in forging and milling efficiency, cannot perform double-layer sleeve forging and milling, and is relatively short in service life. The forging and milling device comprises an upper body, a middle connector, a lower body and forging and milling assemblies, the two ends of the middle connector are connected with the upper body and the lower body correspondingly, the ends, away from the middle connector, of the upper body and the lower body are connected with the upper connector and the lower connector correspondingly, and the forging and milling assemblies are arranged in the upper body and / or the lower body; the piston rod is sleeved with a piston, the forging and milling assembly comprises a cutter body, a first guide block and a push block, the push block is detachably connected with the piston, the cutter body is provided with a multi-stage cutter head, the two ends of the cutter body are slidably connected with the first guide block and the push block respectively, the push block is pushed through the piston rod, the push block pushes the cutter body to move, and the forging and milling device has the advantages of being high in forging and milling efficiency, good in effect and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of casing forging milling, and particularly relates to a double-layer casing segment milling tool. BACKGROUND

[0002] Casing forging milling is a key technology for processing downhole casing in oil and gas engineering, and is mainly used for sidetracking, plugging or repairing operation of old wells, and the core thereof is to cut and mill double-layer casing at a predetermined position in the casing by using a special tool, so as to facilitate subsequent sidetracking or plugging operation.

[0003] The cutter head design of the currently used forging milling tool can only perform single-layer casing forging milling, and cannot realize efficient double-layer casing forging milling cutting, and the cutter body is subjected to large stress during tool rotation, which easily causes damage to the cutter body and affects the service life. SUMMARY

[0004] Therefore, the application provides a double-layer casing segment milling tool, and aims to solve the technical problem of low forging milling efficiency and short service life of the existing device.

[0005] To solve the above-mentioned technical problems, the technical scheme adopted by the application is as follows: A double-layer casing segment milling tool comprises an upper body, an intermediate joint, a lower body and a forging milling assembly, The intermediate joint is connected with the upper body and the lower body at two ends respectively, the upper body and the lower body are connected with an upper joint and a lower joint at one end away from the intermediate joint respectively, the forging milling assembly is arranged in the upper body and / or the lower body, one end of the forging milling assembly is connected with a piston rod, and the piston rod is sleeved with a piston, The forging milling assembly comprises a cutter body, a first guide block and a push block, the push block is detachably connected with the piston, a plurality of cutter heads are arranged on the cutter body, the cutter body is slidably connected with the first guide block and the push block at two ends respectively, and the push block is pushed to move the cutter body by the piston rod.

[0006] After the technical scheme is adopted, it should be noted that in the application, a nozzle is arranged in the bottom joint, throttling pressure is formed when fluid passes through the nozzle, the piston in the lower body is pushed up by the bypass hole of the piston rod to make the push block continuously push the cutter body to move outward, the cutter body is unfolded, throttling pressure is continued, the piston in the upper body is pushed up by the bypass hole of the piston rod in the upper body to push the cutter body to unfold and cut, the two ends of the cutter body will move relative to the first guide block and the push block respectively in this process, and the cutter body extends to the outside, and then the tool is rotated to cut the double-layer casing by the cutter head.

[0007] In addition, it needs to be pointed out that the multi-stage cutter head makes the cutter head toothed, thereby facilitating the guiding of chip discharge, in addition, the multi-stage cutter head can uniformly distribute the cutting force generated in the cutting process, and the multi-stage cutter head can be gradually inserted into the sleeve, thereby helping to enhance the cutting efficiency and prolong the service life of the cutter head.

[0008] As preferred, the cutter body is provided with three-stage cutter heads, the three-stage cutter heads are respectively first-stage cutter heads, second-stage cutter heads and third-stage cutter heads arranged from top to bottom, the first-stage cutter heads are provided with octagonal alloy blocks, and the second-stage cutter heads and the third-stage cutter heads are provided with quadrangular alloy blocks.

[0009] After the technical scheme is adopted, it needs to be pointed out that the alloy blocks can strengthen the strength of the cutter head, improve the service life and cutting efficiency, in addition, the octagonal alloy is arranged on the uppermost first-stage cutter head, because the octagonal alloy has sharp corners, the resistance of the octagonal alloy when cutting into the sleeve is smaller, and the octagonal alloy mainly plays a cutting-in role, and the quadrangular alloy is arranged on the second-stage cutter heads and the third-stage cutter heads, which mainly plays a role of forging and milling chips.

[0010] As preferred, the first-stage cutter heads, the second-stage cutter heads and the third-stage cutter heads are each composed of a plurality of sub-cutter bodies, each of the sub-cutter bodies is provided with an inner inclination angle, the inner inclination angle gradually inclines to the inside of the cutter head from left to right, and the octagonal alloy blocks and the quadrangular alloy blocks are arranged on the surfaces of the corresponding inner inclination angles.

[0011] After the technical scheme is adopted, it needs to be pointed out that in the cutting process, the inner inclination angle and the inclined cutter head cooperate, thereby further enhancing the chip removal effect, in addition, the inner inclination angle makes each stage of the cutter head form a tooth shape in the transverse direction, thereby improving the cutting efficiency.

[0012] As preferred, the first-stage cutter heads, the second-stage cutter heads and the third-stage cutter heads are respectively provided with first forward inclination parts, second forward inclination parts and third forward inclination parts, and the first-stage cutter heads, the second-stage cutter heads and the third-stage cutter heads are provided with side inclination angles with the cutter body.

[0013] After the technical scheme is adopted, it needs to be pointed out that the first forward inclination part, the second forward inclination part and the third forward inclination part gradually increase, so as to be more beneficial to chip and reduce chip torsion, and at the same time, the deformation of the cutter body caused by excessive force is avoided, and the side inclination angle is to make it easier to break the chip when the chip is cut, thereby avoiding the chip wire causing the chip to be unable to be discharged.

[0014] As preferred, the push block is provided with two connecting holes near the side of the piston, the piston is provided with connecting rods corresponding to the connecting holes near the side of the push block, and the connecting rods and the connecting holes are provided with threads that can cooperate with each other, thereby realizing the detachable connection of the push block and the piston.

[0015] Preferably, the forging and milling assembly includes a first forging and milling assembly and a second forging and milling assembly, and the piston rod includes a first piston rod and a second piston rod. The first forging and milling assembly and the first piston rod are disposed in the upper body, and the second forging and milling assembly and the second piston rod are disposed in the lower body. Both the first forging and milling assembly and the second forging and milling assembly include three sets of cutter bodies, a first guide block, and a push block, with the three sets of cutter bodies, the first guide block, and the push block axially evenly distributed inside the upper body or the lower body.

[0016] After adopting this technical solution, it should be noted that pistons are provided on both the first and second piston rods. By sliding the pistons on the first and second piston rods, the tool bodies of the corresponding first and second forging and milling assemblies extend outward. The structures of the first and second forging and milling assemblies are the same and will not be described in detail. It should be noted that the second forging and milling assembly in the lower body mainly plays a role in straightening. Since there is a gap between the tool and the inner diameter of the sleeve, the second forging and milling assembly needs to extend to support the inner wall of the sleeve and prevent the tool from shaking inside the sleeve, thereby affecting the forging and milling.

[0017] Preferably, the upper body and the lower body are each provided with a circumferentially oriented cutting hole corresponding to the cutting tool, and the cutting tool, the first guide block, and the push block are all disposed within the cutting hole. The two ends of one side wall of the blade outlet are respectively provided with a first fixing groove and a second fixing groove. A first stop block and a second guide block are respectively threaded into the first fixing groove and the second fixing groove. One end of the blade body is slidably connected to the two guide blocks. The push block is located inside the second guide block and limits the push block. The first stop block limits the first guide block.

[0018] After adopting this technical solution, it should be noted that the function of the first stop block is to fix the first guide block, preventing it from moving along with the tool body during movement and preventing it from vibrating during rotation, which could damage the tool head or tool body, reduce its service life, and increase operating costs, thereby improving the stability and forging efficiency during operation. In addition, the second guide block has two functions: first, to limit the push plate by connecting the second guide block to the upper or lower body; second, there is a sliding connection between the tool body and the second guide block. It should be noted that the push plate and the side wall of the tool body are in abutting relationship. When the push plate pushes the tool body, the tool body will move relative to the push plate, driving the tool body to move. Simply put, the push block plays the role of pushing the tool body to move, while the sliding connection between the tool body and the second guide block plays a guiding role, making the movement of the tool body more stable. Furthermore, it should be noted that bolts are provided on the first stop block and the second guide block, and threaded holes are provided in the corresponding first fixing groove and second fixing groove. The first stop block and the second guide block can be detachably connected by the cooperation of the bolts and the threaded holes.

[0019] Preferably, the first stop block is provided with a limiting platform on the side near the first guide block, the first guide block has a through hole, the side wall of the knife outlet hole has a first positioning groove, and the limiting platform passes through the through hole and is placed in the first positioning groove.

[0020] After adopting this technical solution, it should be noted that after the first stop is fixed by bolts and threaded holes, the limiting platform is placed in the first positioning groove through the through hole, so as to limit the first guide block in the knife hole.

[0021] Preferably, the second guide block has a boss and a guide rail on the upper end of the side near the cutter body, the push block is located below the boss, and the cutter body is slidably connected to the second guide block through the guide rail.

[0022] Preferably, the blade body is provided with a second guide groove and a third guide groove at both ends, the first stop is provided with a first guide groove, the first guide groove and the second guide groove are slidably engaged, and the third guide groove and the guide rail are slidably engaged.

[0023] Preferably, the blade body has an inclined portion on one side of the third guide groove, the inclined portion is located at the lower end of the third guide groove, and the inclined portion is in the opposite direction to the inclination direction of the third guide groove. The front end of the push block fits into the inclined portion, and the inclination direction of the front end of the push block is in the opposite direction to the inclination direction of the second guide groove.

[0024] After adopting this technical solution, it should be noted that the boss and the surface of the second guide block form a height difference. The boss limits the push block so that the push block can only move along the axial direction of the piston rod. In this invention, the inclination directions of the second guide groove and the third guide groove are consistent, and the inclination directions of the first guide groove and the guide rail are respectively opposite to the second guide groove and the third guide groove.

[0025] Preferably, the first guide block is provided with a second positioning groove on the side near the blade body. The second positioning groove is connected to the first guide groove, and a second stop is provided in the second positioning groove.

[0026] After adopting this technical solution, it should be noted that when the cutter body moves upward along the first guide groove, the movement of the cutter body will be restricted by the obstruction of the second stop to prevent the cutter body from falling off.

[0027] Working principle of the invention: As the fluid passes through the nozzle in the lower body, it creates throttling and pressure buildup. The fluid then pushes the piston inside the lower body upwards through the bypass hole of the piston rod, causing the pusher block to continuously push the cutter body outwards, thus unfolding the cutter body. Continuing to throttle and build up pressure, the fluid pushes the piston inside the upper body through the bypass hole of the piston rod, further unfolding the cutter body for cutting. During this process, both ends of the cutter body move relative to the first guide block and the pusher block respectively, until the cutter body extends to the outside. Afterwards, the tool rotates, cutting the double-layered sleeve through the cutter head.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention provides a double-layer sleeve section milling tool, which sets up a multi-stage cutter head so that the cutter head is toothed, thereby facilitating the discharge of chips. In addition, the multi-stage cutter head can be evenly distributed on the cutting force generated during the cutting process. The multi-stage cutter head can be gradually connected into the sleeve, which helps to enhance the cutting efficiency and extend the cutter head life.

[0029] 2. The present invention provides a double-layer sleeve section milling tool, which strengthens the tool head, improves service life and cutting efficiency by setting an octagonal alloy block on the first-stage tool head and a quadrangular alloy block on the second-stage and third-stage tool heads.

[0030] 3. The present invention provides a double-layer sleeve section milling tool, which, by setting an inclination angle and setting a side tilting part and a forward tilting part on the cutter head, enhances the chip removal effect by cooperating with the inclination angle and the tilted cutter head during the cutting process. In addition, the inclination angle makes each stage of the cutter head form a tooth shape in the transverse direction, thereby improving the cutting efficiency.

[0031] 4. The present invention provides a double-layer sleeve section milling tool, which, by setting a second stop, restricts the movement of the cutter body as it moves upward along the first guide groove, thereby preventing the cutter body from falling off. Attached Figure Description

[0032] The present invention will be described by way of example and with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the structure of the first forging and milling assembly of the present invention; Figure 4 This is a schematic diagram of the blade body structure of the present invention; Figure 5 This is a schematic diagram of the blade structure according to one embodiment of the present invention; Figure 6 This is a top view of the blade body of the present invention; Figure 7This is a side view of the blade body of the present invention; Figure 8 This is an exploded view of the structure of the first forging and milling assembly of the present invention; Figure 9 This is a diagram showing the connection between the blade body, the first guide block, and the first stop block of the present invention. Figure 10 This is a structural diagram of the first stop block and the first guide block of the present invention; Figure 11 This is a schematic diagram of the second guide block structure of the present invention; Figure 12 This is a schematic diagram of the present invention with the first forging and milling assembly and the second forging and milling assembly removed.

[0033] Figure label: 1-Upper connector, 2-Upper body, 201-Tool outlet hole, 202-First fixing groove, 203-Second fixing groove, 204-First positioning groove, 3-Intermediate connector, 4-Lower connector, 5-Lower body, 6-Bottom connector, 7-First forging and milling assembly, 701-Tool body, 702-Tool head, 7021-First-stage tool head, 7022-Second-stage tool head, 7023-Third-stage tool head, 703-First guide block, 704-Push block, 8-Second forging and milling assembly, 9-First piston rod 10-Second piston rod, 11-Piston, 12-First stop, 1201-Limiting platform, 13-Second guide block, 14-First guide groove, 15-Second positioning groove, 16-Through hole, 17-Second stop, 18-Second guide groove, 19-Third guide groove, 20-Inclined part, 21-Connecting hole, 22-Connecting rod, 23-Boss, 24-Limiting platform, 25-Guide rail, 26-Octagonal alloy block, 27-Four-corner alloy block, 28-Inward tilt angle, 29-Nozzle. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0035] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility product is in use. They are only for the convenience of describing this application 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 application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] The following is combined Figures 1-12 The present invention will be described in detail below. Example 1

[0037] A double-layer sleeve segment milling tool, such as Figures 1-10 As shown, it includes an upper body 2, an intermediate joint 3, a lower body 4, and a forging and milling assembly. The intermediate joint 3 is connected to the upper body 2 and the lower body 4 at both ends, respectively. The ends of the upper body 2 and the lower body 4 away from the intermediate joint 3 are connected to the upper joint 1 and the lower joint 5, respectively. The forging and milling assembly is provided inside the upper body 2 and / or the lower body 4. One end of the forging and milling assembly is connected to a piston rod, and a piston 11 is sleeved on the piston rod. The forging and milling assembly includes a cutter body 701, a first guide block 703, and a pusher block 704. The pusher block 704 is detachably connected to the piston 11. The cutter body 701 is provided with multi-stage cutter heads 702. Both ends of the cutter body 701 are slidably connected to the first guide block 703 and the pusher block 704, respectively. The piston rod pushes the pusher block 704, which in turn pushes the cutter body 701 to move.

[0038] The push block 704 has two connecting holes 21 on the side near the piston 11. The piston 11 has a connecting rod 22 corresponding to the connecting holes 21 on the side near the push block 704. The connecting rod 22 and the connecting holes 21 are provided with threads that can cooperate with each other, thereby realizing the detachable connection between the push block 704 and the piston 11.

[0039] The forging and milling assembly includes a first forging and milling assembly 7 and a second forging and milling assembly 8, and the piston rod includes a first piston rod 9 and a second piston rod 10. The first forging and milling assembly 7 and the first piston rod 9 are disposed within the upper body 2, and the second forging and milling assembly 8 and the second piston rod 10 are disposed within the lower body 4. Both the first forging and milling assembly 7 and the second forging and milling assembly 8 include three sets of cutter bodies 701, first guide blocks 703 and push blocks 704, which are axially evenly distributed inside the upper body 2 or the lower body 4.

[0040] like Figures 8-12 As shown, the upper body 2 and the lower body 4 are respectively provided with circumferentially oriented cutting holes 201 corresponding to the cutting body 701. The cutting body 701, the first guide block 703, and the push block 704 are all disposed within the cutting holes 201. The two ends of one side wall of the blade hole 201 are respectively provided with a first fixing groove 202 and a second fixing groove 203. A first stop block 12 and a second guide block 13 are respectively threaded into the first fixing groove 202 and the second fixing groove 203. One end of the blade body 701 is slidably connected to the second guide block 13. The push block 704 is provided inside the second guide block 13 and limits the push block 704. The first stop block 12 limits the first guide block 703.

[0041] The first stop block 12 is provided with a limiting platform 1201 on the side near the first guide block 703. The first guide block 703 has a through hole 16. The side wall of the knife outlet hole 201 has a first positioning groove 204. The limiting platform 1201 passes through the through hole 16 and is placed in the first positioning groove 204.

[0042] The second guide block 13 has a boss 23 and a guide rail 25 on the upper end of the side near the blade body 701. The push block 704 is located below the boss 23. The blade body 701 is slidably connected to the second guide block 13 through the guide rail 25.

[0043] The blade body 701 is provided with a second guide groove 18 and a third guide groove 19 at both ends, and the first stop block 12 is provided with a first guide groove 14. The first guide groove 14 and the second guide groove 18 are slidably engaged, and the third guide groove 19 and the guide rail 25 are slidably engaged.

[0044] The blade body 701 is provided with an inclined portion 20 on one side of the third guide groove 19. The inclined portion 20 is located at the lower end of the third guide groove 19, and the inclined direction of the inclined portion 20 is opposite to that of the third guide groove 19. The front end of the push block 704 fits into the inclined portion 20, and the inclined direction of the front end of the push block 704 is opposite to that of the second guide groove 18.

[0045] In this embodiment, under external pressure, the piston 11 moves along the piston rod, causing the pusher block 704 to push the cutter body 701 to move outward continuously. During this process, the two ends of the cutter body 701 will move relative to the first guide block 703 and the pusher block 704 respectively until the cutter body 701 extends to the outside. Then the tool rotates and cuts the double-layer sleeve through the cutter head 702. The multi-stage cutter head makes the cutter head 702 toothed, which is conducive to guiding the chips out. In addition, the multi-stage cutter head can be evenly distributed on the cutting force generated during the cutting process. The multi-stage cutter head can be gradually connected into the sleeve, which helps to enhance the cutting efficiency and extend the life of the cutter head 702. Furthermore, the first stop block 12 serves to fix the first guide block 703, preventing it from moving along with the cutter body 701 and preventing it from vibrating during rotation, which could damage the cutter head 702 or the cutter body 701, reducing its service life and increasing operating costs, thereby improving working stability and forging efficiency. In addition, the second guide block 13 has two functions: first, to limit the push plate by connecting the second guide block 13 to the upper body 2 or the lower body 4; second, the cutter body 701 and the second guide block 13 have a sliding connection, and the second guide block 13 guides the movement of the cutter body 701. Example 2

[0046] The difference between this embodiment and Embodiment 1 is that, as Figure 4 , Figure 5 , Figure 7 As shown, the cutter body 701 is provided with three levels of cutter heads, namely, a first-level cutter head 7021, a second-level cutter head 7022, and a third-level cutter head 7023 arranged from top to bottom. The first-level cutter head 7021 is provided with an octagonal alloy block 26, and the second-level cutter head 7022 and the third-level cutter head 7023 are provided with square alloy blocks 27.

[0047] In this embodiment, the alloy block can strengthen the strength of the cutter head 702, improve its service life and cutting efficiency. In addition, an octagonal alloy is provided on the top-level first-stage cutter head 7021 because the octagonal alloy has sharp corners, which reduces the resistance when cutting into the sleeve and mainly plays the role of cutting in. On the second-stage cutter head 7022 and the third-stage cutter head 7023, a square alloy is provided, which mainly plays the role of forging and milling chips. Example 3

[0048] The difference between this embodiment and Embodiment 2 is that, as Figure 4 , Figure 7As shown, the first-stage cutter head 7021, the second-stage cutter head 7022, and the third-stage cutter head 7023 are all composed of several sub-cutter heads. Each sub-cutter head is provided with a side tilt angle 28. The side tilt angle 28 gradually tilts inward from left to right towards the cutter head 702. The octagonal alloy block 26 and the quadrangular alloy block 27 are both provided on the surface of the corresponding side tilt angle 28.

[0049] In this embodiment, the alloy block can strengthen the strength of the cutting head 702, improve its service life and cutting efficiency. During the cutting process, the side tilt angle 28 and the inclined cutting head 702 work together to further enhance the chip removal effect. In addition, the side tilt angle 28 causes each stage of the cutting head 702 to form teeth in the transverse direction, thereby improving the cutting efficiency.

[0050] In this embodiment, during the cutting process, the tilt angle 28 and the inclined cutter head 702 work together to further enhance the chip removal effect, while making it easier to break chips during cutting, preventing the iron chips from forming filaments that cannot be removed. Furthermore, the tilt angle 28 causes each stage of the cutter head 702 to form teeth in the transverse direction, thereby improving cutting efficiency. Additionally, as... Figure 7 As shown, the roll angle 28 is represented by the γ angle, which is 3°. Example 4

[0051] The difference between this embodiment and embodiment 3 is that, as Figure 4 , Figure 6 As shown, the first-stage cutter head 7021, the second-stage cutter head 7022, and the third-stage cutter head 7023 are respectively provided with a first forward-tilting part, a second forward-tilting part, and a third forward-tilting part, and the first-stage cutter head 7021, the second-stage cutter head 7022, and the third-stage cutter head 7023 are provided with an inward tilt angle between them and the cutter body 701.

[0052] In this embodiment, the first forward tilt, the second forward tilt, and the third forward tilt increase in size sequentially to facilitate chip cutting and reduce chip torque, while avoiding excessive force on the tool body 701 and causing deformation of the tool body 701. The inclination angle is for installing the alloy block and forming a cutting edge at the front end of the alloy block after installation. It should be noted that the inclination angle is represented by β and is fixed at 90° for installing the alloy block. In addition, such as Figure 4 , Figure 6 As shown, the first forward tilting portion, the second forward tilting portion, and the third forward tilting portion are represented by α1, α2, and α3, respectively. In this embodiment, α1, α2, and α3 are 19°, 22°, and 25°, respectively, so as to form sequential cutting. When the first-stage cutter head 7021 wears out, the second-stage cutter head 7022 can then perform cutting. As shown in Table 1 below, it illustrates the influence of different combinations of α1, α2, and α3 on the performance of the cutter body 701.

[0053] Table 1

[0054] In this embodiment, the preferred angles between α1, α2, and α3 and the horizontal plane are 19°, 22°, and 25°, respectively. The magnitudes of these angles reflect the lifespan of the cutting head. Specifically, taking α1 as an example, since the β angle is a fixed value of 90°, the smaller the angle of α1, the larger the contact area between the tip of the alloy block and the sleeve during cutting after the alloy block is installed, resulting in greater resistance and lower cutting efficiency. Conversely, the larger the angle of α1, the smaller and then larger the contact area between the tip of the alloy block and the sleeve, potentially even causing the tip of the alloy block to be perpendicular to the inner wall of the sleeve. This can accelerate wear on the tip of the alloy block and reduce its lifespan. Therefore, an excessively large angle of α1 or... If the angle is too small, it will affect the contact area with the sleeve, causing changes in torque. The larger the torque, the greater the resistance experienced by the cutter body 701. Therefore, as shown in Table 1 above, when α1 is 19° and 20°, the torque experienced by the cutter body 701 is comparable. However, when the angle is 20°, the tip of the alloy block becomes more perpendicular to the inside of the sleeve, making the tip of the alloy block more prone to breakage and reducing its lifespan. When the angle is less than 19°, the contact area between the tip of the alloy block and the sleeve decreases, while the side of the alloy block gradually contacts the sleeve, increasing friction and thus increasing resistance, resulting in a significant decrease in lifespan. In addition, when α2 and α3 are 22° and 25° respectively, the lifespan of the cutter body 701 is the highest and the torque experienced by the cutter body 701 is the lowest. Example 5

[0055] The difference between this embodiment and embodiment 3 is that, as Figure 10 As shown, the first guide block 703 is also provided with a second positioning groove 15 on the side near the blade body 701. The second positioning groove 15 is connected to the first guide groove 14, and a second stop block 17 is provided in the second positioning groove 15.

[0056] In this embodiment, as the blade 701 moves upward along the first guide groove 14, the movement of the blade 701 is restricted by the second stop 17 to prevent the blade 701 from falling off.

[0057] Working principle of the invention: When the fluid passes through the nozzle 29 in the lower body 4, it forms a throttling and pressure buildup. The fluid pushes the piston 11 inside the lower body 4 upward through the bypass hole 16 of the piston rod, thereby causing the push block 704 to push the cutter body 701 outward continuously, causing the cutter body 701 to unfold. Continuing to throttle and pressure buildup, the fluid pushes the piston 11 inside the upper body 2 through the bypass hole 16 of the piston rod, which in turn pushes the cutter body 701 to unfold and cut. During this process, the two ends of the cutter body 701 will move relative to the first guide block 703 and the push block 704 respectively, until the cutter body 701 extends to the outside. After that, the tool rotates, and the cutter head 702 cuts the double-layer sleeve.

[0058] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A double-layer sleeve segment milling tool, characterized in that, Includes an upper body (2), an intermediate joint (3), a lower body (4), and a forging and milling assembly. The upper body (2) and the lower body (4) are respectively connected to the two ends of the intermediate joint (3). The upper body (2) and the lower body (4) are respectively connected to the upper joint (1) and the lower joint (5) at the ends away from the intermediate joint (3). The forging and milling assembly is provided inside the upper body (2) and / or the lower body (4). One end of the forging and milling assembly is connected to a piston rod, and a piston (11) is sleeved on the piston rod. The forging and milling assembly includes a cutter body (701), a first guide block (703), and a pusher block (704). The pusher block (704) is detachably connected to the piston (11). The cutter body (701) is provided with multi-stage cutter heads (702). The two ends of the cutter body (701) are slidably connected to the first guide block (703) and the pusher block (704) respectively. The piston rod pushes the pusher block (704) and causes the pusher block (704) to push the cutter body (701) to move.

2. A double-layer sleeve segment milling tool according to claim 1, characterized in that, The blade body (701) is provided with three levels of blade heads (702). The three levels of blade heads (702) are respectively a first-level blade head (7021), a second-level blade head (7022), and a third-level blade head (7023) arranged from top to bottom. An octagonal alloy block (26) is provided on the first-level blade head (7021), and a quadrangular alloy block (27) is provided on the second-level blade head (702) and the third-level blade head (702).

3. A double-layer sleeve segment milling tool according to claim 2, characterized in that, The first-level cutter head (7021), the second-level cutter head (7022), and the third-level cutter head (7023) are all composed of several sub-cutter bodies. Each sub-cutter head is provided with a side tilt angle (28). The side tilt angle (28) gradually tilts inward from left to right towards the cutter head (702). The octagonal alloy block (26) and the quadrangular alloy block (27) are both provided on the surface of the corresponding side tilt angle (28).

4. A double-layer sleeve segment milling tool according to claim 2, characterized in that, The first-stage cutter head (7021), the second-stage cutter head (7022), and the third-stage cutter head (7023) are respectively provided with a first forward tilting part, a second forward tilting part, and a third forward tilting part, and the first-stage cutter head (7021), the second-stage cutter head (7022), and the third-stage cutter head (7023) are provided with a side tilting angle with the cutter body (701).

5. A double-layer sleeve segment milling tool according to any one of claims 1-4, characterized in that, The forging and milling assembly includes a first forging and milling assembly (7) and a second forging and milling assembly (8), and the piston rod includes a first piston rod (9) and a second piston rod (10). The first forging and milling assembly (7) and the first piston rod (9) are located inside the upper body (2), and the second forging and milling assembly (8) and the second piston rod (10) are located inside the lower body (4). The first forging and milling assembly (7) and the second forging and milling assembly (8) each include three sets of cutter bodies (701), a first guide block (703) and a push block (704), and the three sets of cutter bodies (701), the first guide block (703) and the push block (704) are axially evenly distributed inside the upper body (2) or the lower body (4).

6. A double-layer sleeve segment milling tool according to any one of claims 1-4, characterized in that, The upper body (2) and the lower body (4) are respectively provided with circumferentially circumferentially openings for cutting holes (201) corresponding to the cutting body (701). The cutting body (701), the first guide block (703) and the push block (704) are all disposed in the cutting holes (201). The two ends of one side wall of the blade hole (201) are respectively provided with a first fixing groove (202) and a second fixing groove (203). The first fixing groove (202) and the second fixing groove (203) are respectively threadedly connected with a first stop block (12) and a second guide block (13). One end of the blade body (701) is slidably connected to the two guide blocks. The push block (704) is located inside the second guide block (13) and limits the push block (704). The first stop block (12) limits the first guide block (703).

7. A double-layer sleeve segment milling tool according to claim 6, characterized in that, The first stop block (12) is provided with a limiting platform (1201) on the side near the first guide block (703). The first guide block (703) has a through hole (16). The side wall of the knife hole (201) has a first positioning groove (204). The limiting platform (1201) passes through the through hole (16) and is placed in the first positioning groove (204).

8. A double-layer sleeve segment milling tool according to claim 6, characterized in that, The second guide block (13) has a boss (23) and a guide rail (25) on the upper end of the side near the blade body (701). The push block (704) is located below the boss (23). The blade body (701) is slidably connected to the second guide block (13) through the guide rail (25).

9. A double-layer sleeve segment milling tool according to claim 6, characterized in that, The blade body (701) is provided with a second guide groove (18) and a third guide groove (19) at both ends, and the first stop block (12) is provided with a first guide groove (14). The first guide groove (14) and the second guide groove (18) are slidably engaged, and the third guide groove (19) and the guide rail (25) are slidably engaged.

10. A double-layer sleeve segment milling tool according to claim 9, characterized in that, The first guide block (703) is provided with a second positioning groove (15) on the side near the blade body (701). The second positioning groove (15) is connected to the first guide groove (14). A second stop block (17) is provided in the second positioning groove (15).

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