Back boring tool and back boring method

Abstract

The present invention discloses a reverse boring tool, which relates to the field of cutting tools. The reverse boring tool is suitable for passing through the avoidance hole and processing a reverse boring hole coaxial with the avoidance hole on the workpiece. The reverse boring tool comprises a tool holder, a tool holder and a blade. The tool holder is connected to the tool holder, and the blade is fixed to the tool holder. The blade is provided with a plurality of blades, and the plurality of blades are evenly spaced and arranged at the outer edge of the tool holder, and the plurality of blades are arranged in an arc shape with the central axis of the tool holder as the center. The tool holder is suitable for rotating along the central axis and revolving around the central axis of the avoidance hole under the drive of a machine tool, and the plurality of blades sequentially contact the surface to be processed for cutting to form a reverse boring hole. The present invention is provided with a plurality of blades, and the plurality of blades continuously cut when the reverse boring tool rotates, thereby improving the processing efficiency.

Description

Technical Field

[0001] The invention relates to the field of cutting tools, and in particular to a back boring tool and a back boring method. Background Art

[0002] Due to the limitation of working environment, some large workpieces need to be processed by back boring. For example, when processing the cylinder head of a steam turbine, the back boring tool passes through the through hole on the cylinder head of the steam turbine and cuts on the other side of the cylinder head to back bore a countersunk hole coaxial with the through hole.

[0003] In the prior art, the back boring tool is driven by the machine tool to rotate relative to the workpiece, thereby cutting the workpiece. The Chinese invention patent with publication number CN118720192A discloses a non-standard eccentric back boring tool and a back boring method, wherein the back boring tool comprises a tool handle, a tool body, a tool rod and a tool holder, the tool handle is connected to the machine tool, the tool rod is connected to the tool holder, a boring tool is arranged on the tool holder, and the tool handle drives the tool body, the tool rod and the tool holder to rotate, so that the boring tool performs a boring operation on the workpiece.

[0004] In the above-mentioned reverse boring tool, only one blade is arranged on the reverse boring tool, and the cutting amount of the blade is limited each time the tool handle rotates, and the workpiece processing rate is low, so there is room for improvement. Summary of the invention

[0005] The purpose of the present invention is to provide a back boring tool, which is provided with a plurality of blades. When the back boring tool rotates, the plurality of blades cut continuously, thereby improving the processing efficiency.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] According to a first aspect of the present invention, a back boring tool is provided for back boring of a workpiece, wherein the workpiece is provided with an avoidance hole for the back boring tool to pass through, the back boring tool is suitable for passing through the avoidance hole and processing a back boring hole coaxial with the avoidance hole on the workpiece, the back boring tool comprises a tool holder, a tool holder and a blade, the tool holder is connected to the tool holder, and the blade is fixed to the tool holder;

[0008] There are multiple blades, which are evenly spaced and arranged on the outer edge of the tool holder, and are arranged in an arc shape with the central axis of the tool handle as the center; the tool handle is suitable for rotating along the central axis and revolving around the central axis of the avoidance hole under the drive of the machine tool, and the multiple blades are contacted with the surface to be processed in turn for cutting to form a back boring hole.

[0009] In this scheme, after the back boring tool passes through the avoidance hole, the back boring operation is performed on the other side of the workpiece (the side away from the machine tool) to reduce the limitation of the workpiece shape on the boring operation. Among them, the tool handle of the back boring tool is connected to the machine tool, and the machine tool can drive the tool handle to rotate and revolve, thereby driving the multiple blades on the tool holder to rotate around the center axis of the tool handle and revolve around the center axis of the avoidance hole. Since the multiple blades are arranged along the arc with the center axis of the tool handle as the center, when the tool handle rotates, the movement trajectory of the blade relative to the center axis of the tool handle is circular, and at the same time, the tool handle revolves around the center axis of the avoidance hole. The movement trajectory of the blade is the superposition of the rotation circle and the revolution circle of the blade. After the back boring cutting, the surface to be processed forms a circular surface that is inscribed in the rotation circle of the blade and coaxial with the avoidance hole, thereby realizing the back boring of a through hole coaxial with the avoidance hole on the workpiece. When the back boring tool is used to back bore a workpiece, since the blade not only rotates but also revolves, the processing radius of the blade is the sum of the rotation circle radius and the revolving circle radius, so that when the back boring tool can pass through the avoidance hole, the radius of the back boring hole that can be processed by the back boring tool can be larger than the radius of the avoidance hole, reducing the restrictions when the back boring tool is used, and the radius of the back boring hole can be adjusted by adjusting the radius of the blade's revolving circle. Among them, multiple blades are arranged on the tool holder, and by adjusting the speed of the blade's self-rotation and revolving, the multiple blades can contact the surface to be processed in turn for cutting when the back boring tool rotates, so that the multiple blades cut the surface to be processed when the tool holder rotates one circle, thereby improving the efficiency of the back boring process.

[0010] Furthermore, when the tool handle rotates once, the cutting tracks of the plurality of blades on the surface to be processed are continuously connected to form an arc with the center of the avoidance hole as the center.

[0011] In this solution, the cutting trajectories of multiple blades are continuous during one rotation of the tool holder, so that the surface to be processed is smooth and continuous after back boring, which is convenient for further processing.

[0012] Furthermore, the counter-boring hole is circular, the diameter of the counter-boring hole is larger than the diameter of the avoidance hole, and the distance from the blade to the center axis of the shank is smaller than the diameter of the avoidance hole.

[0013] In this solution, the distance between the blade and the center axis of the tool handle is smaller than the diameter of the avoidance hole, so that the back boring tool can pass through the avoidance hole.

[0014] Furthermore, the cutting depth of each blade is defined as r, the cutting length of each blade is defined as L, the radius of the surface to be processed of the back boring hole is defined as R, the angular velocity of the rotation of the tool holder is defined as ω1, the angular velocity of the revolution of the tool holder is defined as ω2, and the angle between two adjacent blades is defined as θ, wherein ω1 / ω2=θ(R+r) / L.

[0015] In this scheme, the radius of the surface to be processed is R, and the cutting depth of the blade is r. Then, the distance from the surface to be processed to the center axis of the avoidance hole after cutting is (R+r), and the arc length of each cutting of the blade is L, and the corresponding center angle is (L / (R+r)). The angle between two adjacent blades is θ, the angular velocity of the rotation of the tool handle is ω1, and the angular velocity of the revolution of the blade is ω2. When the tool handle rotates by an angle of θ, the previous blade completes the cutting, and the next blade rotates to contact the surface to be processed. The tool handle revolves by an angle of (ω2θ / ω1). Since ω1 / ω2=θ(R+r) / L, that is, the tool handle revolves by an angle of (L / (R+r)), the blade in contact with the surface to be processed just rotates by the arc length L, thereby realizing continuous cutting of the surface to be processed by multiple blades.

[0016] Furthermore, the rotation direction of the tool handle is opposite to the revolution direction.

[0017] In this solution, the rotation direction of the tool holder is opposite to the revolution direction. Therefore, when the cutting depth of the blade is too large or the force between the blade and the workpiece is too large, causing the blade to get stuck, the tool holder can rotate in the opposite direction to disengage the blade from the stuck part, reducing the risk of blade breakage.

[0018] Furthermore, a plurality of mounting grooves are formed on one side of the tool holder facing the tool handle, and the blades are fixedly mounted in the mounting grooves in a one-to-one correspondence, and the cutting edges of the blades protrude from the mounting grooves in a direction away from the tool holder.

[0019] In this solution, the blades are fixed in the installation slots one by one, and the blades are limited by the installation slots, which facilitates the positioning and installation of multiple blades.

[0020] Furthermore, the blade is inclined in a radially outward direction toward the direction approaching the handle.

[0021] In this solution, the blade is inclined in a radially outward direction toward the direction close to the tool handle, so that an angle is formed between the blade and the surface to be processed of the workpiece, which facilitates the blade to cut into the surface to be processed.

[0022] Furthermore, a slag discharge groove is provided on the blade, the slag discharge groove extends axially along the tool holder, and the edge of the slag discharge groove extends to the cutting edge of the blade.

[0023] In this solution, a slag groove is provided on the blade, and the edge of the slag groove is connected to the blade, so that the iron chips cut by the blade can be accommodated in the slag groove and thrown out when the blade rotates, avoiding the iron chips from being stuck between the blade and the surface to be processed and affecting the normal cutting work of the blade.

[0024] According to a second aspect of the present invention, a back boring method is provided, which is implemented by the back boring tool as described above, and is characterized in that the back boring method comprises the following steps:

[0025] S1, a back boring tool passes through a avoidance hole on a workpiece, and the back boring tool is connected to a machine tool;

[0026] S2. Adjust the position of the back boring tool so that the blade of the back boring tool contacts the surface to be processed;

[0027] S3, the machine tool drives the tool handle of the back boring tool to rotate, and at the same time drives the back boring tool to revolve around the central axis of the avoidance hole, so that multiple blades of the back boring tool contact the surface to be processed in turn for cutting;

[0028] S4, after a layer of the surface to be processed is cut, the revolution radius of the tool holder is increased so that the blade can contact and cut the surface to be processed after the cutting when the tool holder rotates;

[0029] S5, repeating the above steps S3-S4 until the diameter of the surface to be processed reaches the required back boring diameter;

[0030] S6. Stop the tool holder from rotating and pull the counter boring tool out of the avoidance hole.

[0031] In this scheme, when the back-boring tool is used to back-boring a workpiece, the back-boring tool passes through the avoidance hole, and the tool handle of the back-boring tool is connected to the machine tool so as to be driven to rotate by the machine tool. After the blade reaches the other side of the avoidance hole, the machine tool drives the tool handle to move so that the center axis of the tool handle is offset from the center axis of the avoidance hole until the blade can contact the surface to be processed when it rotates. At this time, the machine tool drives the tool handle to rotate and revolve, and multiple blades continuously cut the surface to be processed. After cutting a layer of the surface to be processed, the radius of the blade's revolution can be increased by adjusting the machine tool, so that the blade can cut the next layer of the surface to be processed after cutting. Repeat the above operation, cut the surface to be processed layer by layer, until the diameter of the back-boring hole is processed to the required diameter, then stop rotating the tool handle and pull the back-boring tool out of the avoidance hole to complete the back-boring operation. The method can realize back boring processing on the to-be-machined surface of the workpiece on the side of the avoidance hole away from the machine tool, and can adjust the diameter of the back boring hole to be machined, and the size of the back boring hole is not limited by the avoidance hole.

[0032] Further, the cutting depth of each blade is defined as r, the cutting length of each blade is defined as L, the radius of the surface to be processed of the back boring hole is defined as R, and the angle between two adjacent blades is defined as θ;

[0033] S3 includes the following steps:

[0034] S31, the tool holder rotates by an angle of θ and simultaneously revolves by an angle of L / (R+r). After the blade currently in contact with the surface to be processed on the tool holder cuts a length of L on the surface to be processed, the next blade contacts the surface to be processed;

[0035] S32, repeat S31 until the last blade on the tool holder completes cutting the surface to be processed;

[0036] S33, the tool handle stops revolving until the tool handle rotates until the first blade contacts the surface to be processed, and then returns to step S31;

[0037] S34: After the tool handle has made one revolution, execute step S4.

[0038] In this scheme, when the blade continuously cuts the same layer of the surface to be processed, the tool holder rotates by an angle of θ and revolves by an angle of L / (R+r) at the same time, so that the blade continuously cuts on the surface to be processed, that is, the part cut by the previous blade is continuous with the part cut by the next blade, so that after the tool holder rotates one circle, multiple blades cut a continuous arc groove on the surface to be processed. After the last blade on the tool holder rotates by an angle of θ to complete the cutting, the tool holder stops revolving and waits for the tool holder to rotate until the first blade contacts the surface to be processed, that is, the tool holder completes one rotation from the first blade cutting. At this time, the tool holder revolves and rotates synchronously for the next cutting, so that the arc grooves cut by multiple blades are connected in sequence each time the tool holder rotates one circle. Repeat the above operation until the tool holder rotates several circles and the tool holder revolves one circle, and the cutting of a whole layer of the surface to be processed is completed.

[0039] In summary, the present invention has the following beneficial effects:

[0040] In the present invention, the handle of the back boring tool is connected to the machine tool, and the machine tool can drive the handle to rotate and revolve, thereby driving the multiple blades on the tool holder to rotate around the center axis of the handle and revolve around the center axis of the avoidance hole. When the back boring tool is used to perform back boring operations on the workpiece, since the blade revolves in addition to rotating, the radius of the back boring hole that can be processed by the back boring tool can be larger than the radius of the avoidance hole when the back boring tool can pass through the avoidance hole, thereby reducing the restrictions on the use of the back boring tool, and the radius of the back boring hole can be adjusted by adjusting the radius of the blade's revolving circle. Among them, multiple blades are arranged on the tool holder, and by adjusting the speed of the blade's rotation and revolution, the multiple blades can be in contact with the surface to be processed in turn for cutting when the back boring tool rotates, so that the multiple blades cut the surface to be processed when the handle rotates one circle, thereby improving the efficiency of the back boring process. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the vertical cross-sectional structure of a workpiece at the avoidance hole according to an embodiment of the present invention.

[0042] Figure 2 It is a schematic diagram of the three-dimensional structure of a reverse boring tool according to an embodiment of the present invention.

[0043] Figure 3 It is a schematic diagram of the front structural view of a reverse boring tool according to an embodiment of the present invention.

[0044] Figure 4 It is a schematic diagram of the three-dimensional structure of a tool holder and a blade according to an embodiment of the present invention.

[0045] Figure 5 It is a schematic diagram of the exploded structure of a tool holder and a blade according to an embodiment of the present invention.

[0046] Figure 6 It is a schematic diagram of the three-dimensional structure of a blade according to an embodiment of the present invention.

[0047] Figure 7 It is a schematic diagram of the front view of the tool holder and the blade according to one embodiment of the present invention.

[0048] Figure 8 It is a schematic diagram of a back boring tool passing through an avoidance hole to perform a back boring operation according to an embodiment of the present invention.

[0049] Fig. 9 It is a schematic diagram of a first blade cutting a surface to be processed according to an embodiment of the present invention.

[0050] Fig.10 It is a schematic diagram of a second blade cutting a surface to be processed according to an embodiment of the present invention.

[0051] Fig.11 It is a schematic diagram of a third blade cutting a surface to be processed according to an embodiment of the present invention.

[0052] Fig.12 It is a schematic diagram of a fourth blade cutting a surface to be processed according to an embodiment of the present invention.

[0053] In the figure:

[0054] 1000, counter boring tool; 100, tool handle; 200, tool holder; 210, mounting groove; 220, clearance space; 230, circular guide groove; 240, limit block; 300, blade; 301, first blade; 302, second blade; 303, third blade; 304, fourth blade; 310, limit groove; 320, chamfered surface; 330, slag groove; 400, shock absorber; 2000, workpiece; 2100, avoidance hole; 2200, counter boring hole. DETAILED DESCRIPTION

[0055] The present invention will be further described below in conjunction with the accompanying drawings.

[0056] This embodiment discloses a reverse boring tool 1000, referring to Figure 1The back boring tool 1000 of this embodiment is used for back boring processing of the workpiece 2000, and is specifically described by taking the turbine cylinder as an example. During the processing, it is necessary to process a circular avoidance hole 2100 on the workpiece 2000 (turbine cylinder), and to process a countersink coaxial with the avoidance hole 2100. Since one side of the workpiece 2000 is a horizontal center dividing surface, and the other side is an irregularly raised special-shaped surface, it is more convenient to process when the machine tool is set on one side of the horizontal center dividing surface. Therefore, when processing the countersink, it is necessary to use the back boring tool 1000 to pass through the avoidance hole 2100 to perform back boring processing on the countersink. When the back boring tool 1000 of this embodiment performs the back boring operation, the back boring tool 1000 passes through the avoidance hole 2100 and then performs the back boring operation on the other side of the workpiece 2000 (the side away from the machine tool) to reduce the restrictions on the boring operation caused by the shape of the workpiece 2000.

[0057] Reference Figure 2 and Figure 3 The back boring tool 1000 includes a tool handle 100, a tool holder 200 and a blade 300. The tool handle 100 is cylindrical in shape as a whole, and a shock absorber 400 is built into the tool handle 100. The shock absorber 400 buffers the impact of the back boring tool 1000 during operation, thereby improving the service life of the back boring tool 1000. The tool handle 100 is connected to the base of the machine tool, and the machine tool can drive the base to rotate around the central axis of the avoidance hole 2100, and the base can drive the tool handle 100 to rotate around the central axis of the tool handle 100. The tool holder 200 is connected to the tool handle 100, and the blade 300 is fixed to the tool holder 200. Thus, the machine tool can drive the back boring tool 1000 to rotate around the center axis of the tool holder 100 and revolve around the center axis of the avoidance hole 2100, thereby driving the blade 300 on the tool holder 200 to rotate around the center axis of the tool holder 100 and revolve around the center axis of the avoidance hole 2100.

[0058] The tool holder 200 is fixedly connected to the end of the tool handle 100 away from the machine tool. The tool holder 200 is fan-shaped as a whole, so that the blade 300 can be driven to move in a circular motion after the blade 300 is installed.

[0059] Reference Figures 4 to 5 A mounting groove 210 is provided on the knife holder 200 on one side facing the knife handle 100, and the blade 300 is fixedly installed in the mounting groove 210. In this embodiment, a plurality of blades 300 are provided, and a plurality of corresponding mounting grooves 210 for the blades 300 are provided on the knife holder 200. The blades 300 are fixedly installed in the mounting grooves 210 one by one, and the blades of the blades 300 protrude from the mounting grooves 210 in a direction away from the knife holder 200. The blades 300 are limited by the mounting grooves 210, so that the positioning and installation of the plurality of blades 300 are facilitated.

[0060] In this embodiment, a plurality of mounting grooves 210 are distributed in an arc shape along the outer edge of the tool holder 200, the intervals between the plurality of mounting grooves 210 are equal, and the arc where the plurality of mounting grooves 210 are located takes the central axis of the tool holder 100 as the center, thereby making it possible for a plurality of blades 300 to be evenly spaced and arranged on the outer edge of the tool holder 200, and the plurality of blades 300 to be arranged in an arc shape taking the central axis of the tool holder 100 as the center, thereby facilitating the plurality of blades 300 to contact the surface to be processed in turn for cutting to form a counter-boring hole 2200 when the tool holder 100 rotates.

[0061] Since multiple blades 300 are arranged along an arc with the central axis of the tool handle 100 as the center, when the tool handle 100 rotates, the movement trajectory of the blade 300 relative to the central axis of the tool handle 100 is circular. At the same time, the tool handle 100 revolves around the central axis of the avoidance hole 2100, and the movement trajectory of the blade 300 is the superposition of the rotation circle and the revolution circle of the blade 300. After back boring, the surface to be machined forms a circular surface that is inscribed in the rotation circle of the blade 300 and coaxial with the avoidance hole 2100, thereby realizing back boring a through hole coaxial with the avoidance hole 2100 on the workpiece 2000.

[0062] When the back-boring tool 1000 is used to perform a back-boring 2200 operation on the workpiece 2000, since the blade 300 is not only rotating but also revolving, the processing radius of the blade 300 is the sum of the radius of the rotation circle and the radius of the revolution circle. Therefore, when the back-boring tool 1000 can pass through the avoidance hole 2100, the radius of the back-boring hole 2200 that can be processed by the back-boring tool 1000 can be larger than the radius of the avoidance hole 2100, thereby reducing the restrictions on the use of the back-boring tool 1000, and the radius of the back-boring hole 2200 can be adjusted by adjusting the radius of the revolution circle of the blade 300. Among them, multiple blades 300 are arranged on the tool holder 200. By adjusting the speed of rotation and revolution of the blades 300, the multiple blades 300 can contact the surface to be processed in turn for cutting when the back boring tool 1000 rotates. Therefore, when the tool holder 100 rotates one circle, the multiple blades 300 cut the surface to be processed, thereby improving the back boring processing efficiency.

[0063] Reference Figure 5 and Figure 6 The bottom wall of the installation slot 210 is provided with a stopper 240, and a stopper groove 310 is provided on the side of the bottom wall of the blade 300 facing the installation slot 210. The stopper 240 is matched with the stopper groove 310, so that the stopper 240 is inserted into the stopper groove 310 to further stop the blade 300, so that the blade 300 is firmly and reliably connected to the tool holder 200.

[0064] The blade 300 and the blade holder 200 may be fixedly connected by welding, bolt connection or the like.

[0065] Reference Figures 4 to 6The width of the mounting groove 210 is greater than the width of the blade 300. The blade 300 is close to the bottom wall of the mounting groove 210 and the two side walls connected at right angles. A gap space 220 is formed between the blade 300 and the other side wall of the mounting groove 210. A circular guide groove 230 connected to the gap space 220 is opened on the tool holder 200. The circular guide groove 230 runs through the opposite sides of the tool holder 200. Iron chips cut by the blade 300 can enter the gap space 220 and be thrown out from the circular guide groove 230 when the tool holder 200 rotates.

[0066] Reference Figures 4 to 7 In this embodiment, the blade 300 is a square-shaped component, and the blade edge of the blade 300 protrudes outside the tool holder 200 to cut the workpiece 2000. The blade 300 is inclined in the radially outward direction toward the direction close to the tool handle 100, so that an angle is formed between the blade 300 and the surface to be processed of the workpiece 2000, which facilitates the blade 300 to cut into the surface to be processed. Among them, the angle between the blade 300 and the surface of the tool holder 200 facing the tool handle 100 is 5°-10°, and preferably 7° in this embodiment.

[0067] A chamfered surface 320 is provided on the outer side of the blade 300, and the chamfered surface 320 extends along the thickness direction of the blade 300 (i.e., the axial direction of the tool handle 100), and along the direction close to the tool holder 200, the chamfered surface 320 is inclined toward the direction close to the central axis of the tool handle 100, thereby reducing the probability of the part of the blade 300 other than the cutting edge contacting and interfering with the workpiece 2000 during cutting.

[0068] The blade 300 is provided with a slag groove 330, which extends axially along the tool holder 200. The slag groove 330 is connected to the gap space 220, and the edge of the slag groove 330 extends to the blade of the blade 300, so that the iron chips cut by the blade can be accommodated in the slag groove 330 and thrown out when the blade 300 rotates, thereby preventing the iron chips from being stuck between the blade 300 and the surface to be processed and affecting the normal cutting work of the blade 300.

[0069] Reference Figure 8 In this embodiment, the counter boring hole 2200 (i.e., the countersunk hole on the turbine cylinder) to be processed is circular. The distance from the blade 300 to the center axis of the tool handle 100 (i.e., the radius of the rotation circle of the blade 300) is smaller than the diameter of the avoidance hole 2100, so that the counter boring tool 1000 can pass through the avoidance hole 2100. By using the counter boring tool 1000 to rotate and revolve for cutting, the diameter of the counter boring hole 2200 after final processing can be larger than the diameter of the rotation circle of the blade 300.

[0070] In this embodiment, when the tool handle 100 rotates one circle, the cutting tracks of multiple blades 300 on the surface to be processed are continuously connected to form an arc with the center of the avoidance hole 2100 as the center, so that the surface to be processed is smooth and continuous after back boring, which is convenient for further processing.

[0071] Define that the cutting depth of the blade 300 each time is r, the cutting length of each time is L, the radius of the surface to be processed of the back boring hole 2200 is R, the angular velocity of the rotation of the tool handle 100 is ω1, the angular velocity of the revolution of the tool handle 100 is ω2, and the angle between two adjacent blades 300 is θ, where ω1 / ω2=θ(R+r) / L.

[0072] Therefore, the distance from the surface to be processed to the central axis of the avoidance hole 2100 after being cut by the blade 300 is (R+r). The blade 300 cuts an arc groove with an arc length of L on the surface to be processed each time, and the central angle of the arc groove cut by the blade 300 each time is (L / (R+r)). When the tool handle 100 rotates by an angle of θ, the previous blade 300 completes cutting, and the next blade 300 rotates to contact the surface to be processed. The tool handle 100 revolves by an angle of (ω2θ / ω1). Since ω1 / ω2=θ(R+r) / L, that is, the tool handle 100 revolves by an angle of (L / (R+r)), the blade 300 in contact with the surface to be processed just rotates by the arc length L, so that the arc groove cut by the blade 300 is continuous with the arc groove cut by the previous blade 300, thereby realizing continuous cutting of the surface to be processed by multiple blades 300.

[0073] The surface to be processed of the workpiece 2000 is not necessarily an arc surface at the beginning. Here, the radius of the surface to be processed refers to the radius of a circle tangent to the surface to be processed with the central axis of the avoidance hole 2100 as the center. When the back boring tool 1000 completes a layer of cutting of the surface to be processed (that is, the blade 300 can no longer cut the workpiece 2000 by revolving at the current revolution radius), the surface to be processed is processed into an arc surface coaxial with the central axis of the avoidance hole 2100, and when the blade 300 revolves, the rotation circle of the blade 300 is tangent to the surface to be processed after cutting, that is, the radius of the surface to be processed after cutting is the sum of the radius of the rotation circle of the blade 300 and the radius of the revolution circle of the blade 300.

[0074] In this embodiment, the rotation direction of the tool handle 100 is opposite to the revolution direction. Therefore, when the cutting depth of the blade 300 is too large and the force between the blade 300 and the workpiece 2000 is too large to cause the blade to get stuck, the tool handle 100 can rotate in the opposite direction to make the blade 300 disengage from the stuck part, reducing the risk of the blade 300 breaking.

[0075] Specifically, from the side of the workpiece 2000 where the back boring hole 2200 is machined, the back boring tool 1000 rotates clockwise around the tool handle 100, and at the same time, the back boring tool 1000 revolves counterclockwise around the central axis of the avoidance hole 2100. In addition, in other embodiments, the rotation direction and the revolution direction of the back boring tool 1000 may be the same.

[0076] Reference Figures 1 to 12The present embodiment further provides a back boring method 2200, which is implemented based on a back boring tool 1000 of the present embodiment. The back boring method 2200 includes the following steps:

[0077] S1. The back boring tool 1000 passes through the avoidance hole 2100 on the workpiece 2000, wherein the back boring tool 1000 is connected to a machine tool to be driven to rotate by the machine tool.

[0078] S2. Adjust the position of the back boring tool 1000 so that the blade 300 of the back boring tool 1000 contacts the surface to be processed.

[0079] The distance from the blade of the blade 300 to the center axis of the tool handle 100 (i.e., the radius of the rotation circle of the blade 300) is smaller than the radius of the avoidance hole 2100, so that the blade 300 can pass through the avoidance hole 2100 for back boring. After the back boring tool 1000 passes through the avoidance hole 2100, the position of the back boring tool 1000 is adjusted by the machine tool so that the blade 300 can contact the surface to be processed for cutting when rotating.

[0080] The method to adjust the position of the back boring tool 1000 is:

[0081] Define that the cutting depth of the blade 300 each time is r, and the length of the arc groove cut by each blade 300 on the surface to be processed each time is L; the radius of the surface to be processed is R, the radius of the rotation circle of the blade 300 is R1, the radius of the revolution circle of the blade 300 is R2, and the cutting depth of the blade 300 each time is r, then the machine tool drives the tool holder 100 to translate, so that (R1+R2-r=R), that is, the sum of the radius of the rotation circle of the blade 300 and the radius of the revolution circle is r greater than the radius of the surface to be processed, so that the blade 300 can cut off a layer of material with a thickness of r on the surface to be processed under the revolution radius.

[0082] S3. The machine tool drives the tool handle 100 of the back boring tool 1000 to rotate, and at the same time drives the back boring tool 1000 to revolve around the central axis of the avoidance hole 2100, so that the multiple blades 300 of the back boring tool 1000 contact the surface to be processed in turn for cutting.

[0083] like Figures 9 to 12 As shown, in this embodiment, four blades 300 are specifically provided on the tool holder 200, and the angle between two adjacent blades 300 (that is, the angle between the cutting edges of the two blades 300 and the line connecting the central axis of the tool handle 100) is θ, and the four blades 300 are defined as a first blade 301, a second blade 302, a third blade 303 and a fourth blade 304 in sequence. When the back boring tool 1000 rotates, the first blade 301, the second blade 302, the third blade 303 and the fourth blade 304 contact the surface to be processed in sequence for cutting.

[0084] S3 includes the following steps:

[0085] S31, the tool holder 100 rotates by an angle of θ and revolves by an angle of L / (R+r). After the blade 300 on the tool holder 200 that is currently in contact with the surface to be processed cuts a length of L on the surface to be processed, the next blade 300 contacts the surface to be processed.

[0086] Taking the four blades 300 in this embodiment as an example, in S2, the first blade 301 contacts the surface to be processed, and in S31, the tool holder 100 rotates clockwise by an angle θ and revolves counterclockwise by an angle L / (R+r), so that the first blade 301 cuts an arc groove with a length of L on the surface to be processed and then leaves the surface to be processed, and the second blade 302 moves to a position on the surface to be processed at a distance of L from the arc groove cut by the first blade 301, so that when the second blade 302 cuts the surface to be processed, the arc groove cut by the first blade 301 is continuous.

[0087] In this embodiment, the machine tool preset program is controlled so that the angular velocity of the rotation of the tool handle 100 is ω1 and the angular velocity of the revolution of the tool handle 100 is ω2, which satisfies (ω1 / ω2=θ(R+r) / L), so that when the back boring tool 1000 rotates by an angle of θ, it just revolves by an angle of L / (R+r).

[0088] S32, repeat S31 until the last blade 300 on the tool holder 200 completes cutting the surface to be processed.

[0089] In this embodiment, the back boring tool 1000 repeats step S31 three times, namely:

[0090] The back boring tool 1000 rotates clockwise by an angle of θ and revolves counterclockwise by an angle of L / (R+r), so that the second blade 302 leaves the surface to be processed after cutting an arc groove, and the third blade 303 just moves to a position on the surface to be processed that is L away from the arc groove cut by the second blade 302; the back boring tool 1000 rotates clockwise by an angle of θ again and revolves counterclockwise by an angle of L / (R+r), so that the third blade 303 leaves the surface to be processed after cutting an arc groove, and the fourth blade 304 just moves to a position on the surface to be processed that is L away from the arc groove cut by the third blade 303; the back boring tool 1000 rotates clockwise by an angle of θ again and revolves counterclockwise by an angle of L / (R+r), so that the fourth blade 304 (i.e., the last blade 300) leaves the surface to be processed after cutting an arc groove. During this process, the counter boring tool 1000 rotates continuously, and the four blades 300 sequentially machine continuous arc grooves on the surface to be machined.

[0091] S33, the tool holder 100 stops revolving until the tool holder 100 rotates until the first blade 300 contacts the surface to be processed, and then returns to step S31.

[0092] After the last blade 300 (the fourth blade 304) has completed cutting, the program controls the machine tool to pause and drive the tool holder 100 to revolve for a set time t, t=(2π-nθ) / ω1, where n is the number of blades 300, and n is 4 in this embodiment; the tool holder 100 continues to rotate by an angle (2π-nθ), that is, the tool holder 100 completes one rotation starting from the cutting of the first blade 300, so that the first blade 300 (the first blade 301) is just moved to a position on the surface to be processed that is at a distance L from the arc groove cut by the previous blade 300, and then the cutting process of S31 is repeated, thereby allowing the blade 300 to continuously cut the same layer of the surface to be processed.

[0093] S34: After the tool handle 100 has completed one revolution, step S4 is executed.

[0094] The above operation is repeated until the tool holder 100 rotates several times and revolves once, and the cutting of a whole layer of the surface to be processed is completed. The radius of the surface to be processed increases from R to (R+r). At this time, the program controls the revolution radius of the back boring tool 1000 to increase by r to cut the next layer of the surface to be processed.

[0095] In some embodiments, the tool holder 100 may not stop the revolution in S33, that is, the cutting trajectory of the back boring tool 1000 is discontinuous each time it rotates, and the tool holder 100 revolves multiple times in S34 to complete the cutting of a whole layer of the processing surface through multiple revolutions.

[0096] S4. After a layer of the surface to be processed is cut, the revolution radius of the tool handle 100 is increased so that when the tool handle 100 rotates, the blade 300 can contact and cut the surface to be processed.

[0097] After a layer of the surface to be processed is cut, the diameter of the new surface to be processed increases to (R+r). The radius of revolution of the blade 300 can be increased by r by adjusting the machine tool, so that the blade 300 can cut the next layer of the surface to be processed after cutting.

[0098] S5. Repeat the above steps S3-S4 until the diameter of the surface to be processed reaches the required diameter of the back boring hole 2200.

[0099] Repeat the above operation to cut the surface to be processed layer by layer until the counter-boring hole 2200 reaches the required size.

[0100] When the back boring hole 2200 is processed in the depth direction, the axial adjustment position of the back boring tool 1000 can be controlled by the machine tool to adjust the processing depth of the back boring hole 2200 .

[0101] S6. The tool handle 100 stops rotating, and the counter boring tool 1000 is pulled out from the avoidance hole 2100 to complete the counter boring operation on the counter hole 2200.

[0102] The method can realize back boring processing on the to-be-machined surface of the workpiece 2000 on the side of the avoidance hole 2100 away from the machine tool, and can adjust the diameter of the machined back boring hole 2200 , and the size of the back boring hole 2200 is not limited by the avoidance hole 2100 .

[0103] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A back boring method, the back boring method is implemented by a back boring tool, characterized in that: The reverse boring tool (1000) is suitable for passing through the avoidance hole (2100) of the workpiece (2000) and processing a reverse boring hole (2200) on the workpiece (2000) that is coaxial with the avoidance hole (2100). The reverse boring tool (1000) comprises a tool handle (100), a tool holder (200) and a blade (300). The tool holder (200) is connected to the tool handle (100), and the blade (300) is fixed to the tool holder (200). A plurality of blades (300) are provided, and the plurality of blades (300) are evenly spaced and arranged on the outer edge of the tool holder (200). The plurality of blades (300) are arranged in an arc shape with the central axis of the tool handle (100) as the center. The back boring method comprises the following steps: S1, a back boring tool (1000) passes through a avoidance hole (2100) on a workpiece (2000), wherein the back boring tool (1000) is connected to a machine tool; S2, adjusting the position of the back boring tool (1000) so that the blade (300) of the back boring tool (1000) contacts the surface to be processed; S3, the machine tool drives the tool handle (100) of the counter boring tool (1000) to rotate, and at the same time drives the counter boring tool (1000) to revolve around the central axis of the avoidance hole (2100), so that the multiple blades (300) of the counter boring tool (1000) sequentially contact the surface to be processed to perform cutting; The cutting depth of the blade (300) is defined as r, the cutting length is defined as L, the radius of the surface to be processed of the back boring hole (2200) is defined as R, the angular velocity of the rotation of the tool handle (100) is defined as ω1, the angular velocity of the revolution of the tool handle (100) is defined as ω2, and the angle between two adjacent blades (300) is defined as θ, wherein ω1 / ω2=θ(R+r) / L; S4, after a layer of the surface to be processed is cut, the revolution radius of the tool handle (100) is increased so that when the tool handle (100) rotates, the blade (300) can contact and cut the surface to be processed after cutting; S5, repeating the above steps S3-S4 until the diameter of the surface to be processed reaches the required diameter of the back boring hole (2200); S6. The tool handle (100) stops rotating, and the counter boring tool (1000) is pulled out from the avoidance hole (2100).

2. A back boring method according to claim 1, characterized in that: The counter-boring hole (2200) is circular, the diameter of the counter-boring hole (2200) is larger than the diameter of the avoidance hole (2100), and the distance from the blade (300) to the center axis of the shank (100) is smaller than the diameter of the avoidance hole (2100).

3. A back boring method according to claim 1, characterized in that: The rotation direction of the knife handle (100) is opposite to the revolution direction.

4. A back boring method according to claim 1, characterized in that: The knife clamp (200) is provided with a plurality of mounting grooves (210) on one side facing the knife handle (100), and the blades (300) are fixedly mounted in the mounting grooves (210) in a one-to-one correspondence, and the cutting edges of the blades (300) protrude from the mounting grooves (210) in a direction away from the knife clamp (200).

5. A back boring method according to claim 4, characterized in that: The blade (300) is inclined in a radially outward direction toward the tool handle (100), and the blade (300) is inclined at an angle of 5°-10° relative to the tool holder (200) on the side facing the tool handle (100).

6. A back boring method according to claim 4, characterized in that: The blade (300) is provided with a slag discharge groove (330), the slag discharge groove (330) extends axially along the tool holder (200), and the edge of the slag discharge groove (330) extends to the cutting edge of the blade (300).

7. A back boring method according to claim 1, characterized in that: S3 includes the following steps: S31, the tool holder (100) rotates by an angle of θ and simultaneously revolves by an angle of L / (R+r), and after the blade (300) on the tool holder (200) currently in contact with the surface to be processed cuts a length of L on the surface to be processed, the next blade (300) contacts the surface to be processed; S32, repeating S31 until the last blade (300) on the tool holder (200) completes cutting the surface to be processed; S33, the tool handle (100) stops revolving until the tool handle (100) rotates until the first blade (300) contacts the surface to be processed, and then returns to step S31; S34: After the tool handle (100) has completed one revolution, execute step S4.

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