Flange back side counter bore machining method

Abstract

A flange back face counter bore machining method comprises the steps that firstly, according to the diameter of a bottom hole in a flange and the diameter of a counter bore needing to be machined, a boring rod and a turning tool which are used for machining the counter bore are determined, and the flange is located on a part to be machined; secondly, the part to be machined is fixedly connected with a machine tool, then a main shaft of the machine tool is stopped at the center position of the bottom hole, meanwhile, the turning tool is fixedly connected with the lower portion of the boring rod, the mode that the boring rod and the turning tool penetrate through the bottom hole to reach the back face of the flange is judged according to the relation between the diameter of the boring rod and the diameter of the turning tool and the diameter of the bottom hole, and machining is completed. The machine tool spindle is connected with the boring rod through the clamp, and the turning tool and the boring rod penetrate through the bottom hole; thirdly, the machine tool is started, and a machine tool spindle operates according to the track to machine the counter bore; and fourthly, the turning tool and the boring rod retreat from the bottom hole. Therefore, according to the design, counter bores with large radial cutting depth and high precision can be machined in materials difficult to machine on the back face of the flange.

Description

Technical Field

[0001] The invention relates to a countersink processing method, belonging to the field of mechanical technology, and in particular to a countersink processing method for the back side of a flange. Background Art

[0002] At present, there are two main methods for processing flange back countersinks: three-sided milling and reverse scraper boring. The three-sided milling cutter milling process is suitable for the situation where the difference between the countersink and the bottom hole diameter is small because its cutter diameter needs to be smaller than the bottom hole diameter. When the difference between the bottom hole and the countersink diameter is large, the radial cutting depth is large. In order to avoid interference between the tool bar and the bottom hole, the tool bar specification is small, resulting in poor rigidity, which is not conducive to processing; reverse scraper boring is suitable for situations where the precision requirements are not high and the material strength is not high. The reverse scraper blade is long (i.e., radial cutting depth), the contact area is large, the cutting force is large, and the strength requirements of the tool body are high. It is not suitable for difficult-to-process materials. In addition, the blade of the reverse scraper is manually sharpened, and the surface finish and end face flatness of the processed countersink are poor, which is not suitable for countersink processing with high precision requirements. Therefore, the current processing method is not suitable for reverse countersink processing of difficult-to-process materials, large radial cutting depth, and high precision.

[0003] The Chinese patent application with application number 201910645262.6 and application date July 17, 2019 discloses a processing tool and processing method for countersinking on the back of a workpiece, the processing tool comprising a mounting seat, a scraper assembly and a transmission connection mechanism arranged between the mounting seat and the scraper assembly, the mounting seat comprising a main body, a connecting portion and a pushing portion; the scraper assembly comprises a scraper sleeve and a scraper, the scraper comprises a blade seat and a blade, the scraper sleeve has a main body and a through-connection portion, the blade seat and the through-connection portion are rotatably connected, so that the scraper has a retracted and unfolded state; the pushing portion of the mounting seat is inserted into the cavity of the scraper sleeve, and the pushing portion has a pushing state; the mounting seat and the scraper assembly are connected by a transmission connection mechanism, so that the driving mounting seat to move can drive the processing tool to move and rotate the scraper. The processing tool provided by the present invention can process the countersink on the reverse side of the workpiece to realize automatic processing; it can process holes of different diameters and has universality; the processing method is simple to operate, the processing time is short, and the production efficiency is improved, but it still has the following defects: This design cannot produce a countersink with large radial cutting depth and high precision on the back side of the flange for difficult-to-machine materials.

[0004] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of this patent application, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to ordinary technicians in this field. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects and problems in the prior art that a countersink with a large radial cutting depth and high precision cannot be machined on the back side of a flange for materials that are difficult to machine, and to provide a flange back side countersink processing method that can machine a countersink with a large radial cutting depth and high precision on the back side of a flange for materials that are difficult to machine.

[0006] To achieve the above purpose, the technical solution of the present invention is: a flange back countersink processing method, the flange back countersink processing method comprises the following steps: Step 1: Determine the boring bar and turning tool for machining the countersink according to the diameter of the bottom hole on the flange and the diameter of the countersink to be machined, wherein the flange is located on the part to be machined; The second step: first, the above-mentioned part to be processed is fixedly connected to the machine tool, and then the machine tool spindle is stopped at the center position of the above-mentioned bottom hole. At the same time, the above-mentioned turning tool is fixedly connected to the lower part of the boring bar, and then, according to the relationship between the boring bar, the turning tool and the bottom hole, the method of passing the boring bar and the turning tool through the bottom hole to reach the back of the flange is determined; when the sum of the boring bar diameter and the turning tool overhang length is less than the diameter of the bottom hole, the head end of the boring bar is first fixedly connected to one end of the fixture, and the other end of the fixture is fixedly connected to the machine tool spindle, and then the machine tool spindle is moved until the boring bar, the turning tool and the bottom hole do not interfere, and then the machine tool spindle is axially moved to make the boring bar and the turning tool directly pass through the bottom hole to reach the back of the flange; when the sum of the boring bar diameter and the turning tool overhang length is greater than or equal to the diameter of the bottom hole, the head end of the boring bar is first passed through the bottom hole from the back of the flange, and then fixedly connected to one end of the fixture, and the other end of the fixture is fixedly connected to the machine tool spindle; Step 3: First start the above-mentioned machine tool, the machine tool spindle starts to rotate, the machine tool spindle drives the boring bar and the turning tool to rotate, and then the machine tool spindle is moved linearly from the center position of the bottom hole to the center position of the boring track, the turning tool rotates along the boring track, and the bottom hole on the back of the flange is cut. At the same time, the machine tool spindle that keeps rotating runs along the milling track until the machine tool spindle runs along the milling track for one circle, and the radial cutting of the countersink is completed, so that the countersink diameter meets the design requirements; while the machine tool spindle repeatedly rotates along the boring track and moves along the milling track, the machine tool spindle is controlled to move upward along the axial direction until the countersink reaches the required processing depth, and the movement of the machine tool spindle is stopped, and the countersink processing is completed; Step 4: First, determine the way the boring bar and the turning tool exit the bottom hole based on the relationship between the boring bar, the turning tool and the bottom hole; when the sum of the boring bar diameter and the turning tool overhang is less than the diameter of the bottom hole, first move the machine tool spindle until the boring bar, the turning tool and the bottom hole do not interfere, and then move the machine tool spindle axially to move the boring bar and the turning tool directly out of the bottom hole; when the sum of the boring bar diameter and the turning tool overhang is greater than or equal to the diameter of the bottom hole, first remove the head end of the boring bar from the fixture, and then pass the boring bar and the turning tool through the bottom hole and move them out from the back of the flange.

[0007] In the second step, the turning tool is fixedly connected to the lower part of the boring bar, which means that: a mounting hole is provided on the lower side of the boring bar, and a fixing hole is provided on the bottom end face of the boring bar, and the mounting hole and the fixing hole are interconnected. After one side of the turning tool is inserted into the mounting hole, a screw is fixedly connected to the turning tool and the boring bar through the fixing hole.

[0008] The boring bar is a cylinder, the gap between the boring bar and the bottom hole is greater than or equal to 1 mm, and the diameter of the boring bar is greater than one third of the diameter of the bottom hole.

[0009] The turning tool is a standard turning tool with a main deflection angle greater than 90°.

[0010] In the first step, determining the boring bar and turning tool for processing the countersink means: the diameter of the boring bar is smaller than the diameter of the bottom hole minus the radius difference between the countersink and the bottom hole, and the diameter of the boring bar is first determined in combination with the diameters of the bottom hole and the countersink; the sum of the boring bar diameter and the turning tool overhang is larger than the diameter of the countersink minus the diameter difference between the bottom hole and the boring bar, and smaller than the diameter of the countersink minus the radius difference between the countersink and the bottom hole, thereby determining the sum of the boring bar diameter and the turning tool overhang, and further determining the turning tool overhang for processing the countersink.

[0011] The sum of the boring bar radius and the overhang length of the turning tool is less than half of the sum of the bottom hole radius and the countersink radius.

[0012] In the second step, the machine tool is a CNC machine tool.

[0013] The CNC machine tool is a milling machine or a boring machine.

[0014] In the third step, the boring trajectory refers to: determining the position of the boring trajectory according to the diameter of the countersink to be processed, and controlling it through a numerical control program; In the third step, the milling track means: determining the position of the milling track according to the diameter of the boring bar and the overhang length of the turning tool, and controlling it through a numerical control program, and the center position of the boring track is located at the milling track; In the third step, controlling the machine tool spindle to move axially upward until the countersink reaches the required processing depth means: controlling the feed amount of the machine tool spindle to move axially upward through a CNC program until the countersink reaches the required processing depth.

[0015] Increase the speed of the machine tool spindle and at the same time reduce the speed at which the machine tool spindle moves along the milling path.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. In a method for processing a countersink on the back of a flange, first, according to the bottom hole on the flange and the diameter of the countersink to be processed, a suitable boring bar and a turning tool are selected, the gap between the boring bar and the bottom hole is greater than or equal to 1 mm, and the diameter of the boring bar is greater than one-third of the diameter of the bottom hole. The turning tool used for processing the countersink is a standard turning tool with a main deflection angle greater than 90°. The turning tool is first fixedly connected to the lower part of the boring bar, and then the boring bar and the turning tool are selected to pass through the bottom hole to reach the back of the flange, so that the machine tool spindle is connected to the boring bar through a fixture, and the turning tool and the boring bar are connected to the back of the flange. The boring bar passes through the bottom hole, and the machine tool is started to process the countersink. After the processing is completed, the boring bar and the turning tool are taken out of the bottom hole. When applying, first select the appropriate boring bar and turning tool according to the diameter of the bottom hole on the flange and the countersink to be processed, and then fix one side of the turning tool with the lower part of the boring bar by screws. At the same time, stop the machine tool spindle at the center of the bottom hole, and then select the way for the boring bar and the turning tool to pass through the bottom hole to reach the back of the flange according to the relationship between the boring bar, the turning tool and the bottom hole, so that the turning tool and the boring bar pass through the bottom hole and are fixed to the machine tool spindle. Fixed connection, then start the machine tool, move the machine tool spindle straightly from the center of the bottom hole to the center of the boring track, the machine tool spindle drives the turning tool and the boring bar to rotate together, the turning tool rotates along the boring track for cutting, at the same time, the machine tool spindle runs along the milling track for one circle, completes the radial cutting of the countersink, controls the machine tool spindle to move upward along the axial direction until the countersink reaches the required processing depth, stops the movement of the machine tool spindle, the countersink processing is completed, finally withdraws the turning tool and the boring bar from the bottom hole, selects the method of countersinking with the boring bar and the turning tool, It can process large radial depth countersinks. Since the boring bar has better rigidity and the standard turning tool with a main deflection angle greater than 90°, it can process high-strength and difficult-to-cut materials such as nickel-copper alloy and high-temperature alloy (GH99), and the processed countersinks have higher precision. The diameter tolerance of the countersink reaches level 7, the depth tolerance reaches level 7, and the surface roughness reaches Ra3.2. At the same time, the boring bar and the turning tool are fixedly connected by screws. This connection method has higher positioning accuracy and more secure connection, ensuring the stability of the processing process. Therefore, the present invention can not only process countersinks on difficult-to-process materials on the back of the flange, but also the processed countersinks have both large radial depth and high precision.

[0017] 2. In a method for processing a countersink on the back of a flange, the diameter of the boring bar is smaller than the diameter of the bottom hole minus the radius difference between the countersink and the bottom hole. The diameter of the boring bar is first determined in combination with the diameter of the bottom hole and the countersink. The sum of the boring bar diameter and the tool overhang is greater than the countersink diameter minus the diameter difference between the bottom hole and the boring bar, and is smaller than the countersink diameter minus the radius difference between the countersink and the bottom hole. Thus, the sum of the boring bar diameter and the tool overhang is determined, and then the tool overhang for processing the countersink is determined. When applied, the diameter of the boring bar is first determined based on the diameter of the boring bar being smaller than the diameter of the bottom hole. The diameter of the bottom hole minus the radius difference between the countersink and the bottom hole is required, and then the diameter of the boring bar is determined in combination with the known diameters of the bottom hole and the countersink. Then, the sum of the boring bar diameter and the tool overhang is determined based on the requirement that the sum of the boring bar diameter and the tool overhang is greater than the countersink diameter minus the diameter difference between the bottom hole and the boring bar, and less than the countersink diameter minus the radius difference between the countersink and the bottom hole. Then, the tool overhang for machining the countersink is determined, and a countersink with a large radial cutting depth is machined through the cooperation between the boring bar, the tool and the bottom hole. Therefore, the present invention can not only machine a countersink with higher precision, but also machine a reverse countersink with a large radial cutting depth and a cutting width greater than 10 mm.

[0018] 3. In a flange back countersink processing method, the sum of the boring bar radius and the tool overhang is less than half of the sum of the bottom hole radius and the countersink radius; when applied, when the sum of the boring bar radius and the tool overhang is less than half of the sum of the bottom hole radius and the countersink radius, the cutting in the countersink processing process is smoother, and the cutting amount is balanced and stable. Therefore, the present invention can not only process a reverse countersink with a large radial cutting depth and high precision, improve the surface quality of the countersink, but also reduce the wear of the processing tool.

[0019] 4. In a method for processing countersinks on the back of flanges, the machine tool used for processing the countersinks is a CNC machine tool, which is a milling machine or a boring machine. The feed amount, boring trajectory and milling trajectory of the machine tool spindle moving upward along the axial direction are controlled by a CNC program. The rotation speed of the machine tool spindle is increased and the speed of the machine tool spindle moving along the milling trajectory is reduced by the CNC program. When applied, the CNC machine tool is used to make the processing more precise and is suitable for different CNC machine tools. Then, during the processing, the feed amount of the upward movement is controlled by the CNC program to make the depth of the countersink more precise, and the boring trajectory and milling trajectory are controlled by the CNC program to make the diameter of the countersink more in line with the processing requirements. At the same time, the surface quality of the countersink can be improved by increasing the rotation speed of the machine tool spindle and reducing the speed of the machine tool spindle moving along the milling trajectory, so that the surface roughness of the countersink is improved. Therefore, the present invention can not only process a higher precision countersink, but also the surface quality of the processed countersink is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the relationship between the processing tool and the flange in the present invention.

[0021] Figure 2It is a schematic diagram of the part to be processed and its flange in the present invention.

[0022] Figure 3 It is a top view of the positional relationship between the flange, countersunk hole and bottom hole in the present invention.

[0023] Figure 4 It is a top view of the positional relationship between point C and the processing tool in the present invention.

[0024] Figure 5 It is a schematic diagram of the trajectory of processing the countersink in the present invention.

[0025] In the figure: boring bar 1, mounting hole 11, fixing hole 12, turning tool 2, bottom hole 3, screw 32, countersunk hole 4, fixture 5, flange 6, boring track A, milling track B. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0027] See also Figure 1 — Figure 5 , a flange back countersink processing method; the flange back countersink processing method comprises the following steps: Step 1: Determine the boring bar 1 and the turning tool 2 for machining the countersink 4 according to the diameter of the bottom hole 3 on the flange 6 and the diameter of the countersink 4 to be machined, wherein the flange 6 is located on the part to be machined; Step 2: first, fix the part to be processed to the machine tool, then stop the spindle of the machine tool at the center of the bottom hole 3, and at the same time, fix the turning tool 2 to the lower part of the boring bar 1, and then determine the way in which the boring bar 1 and the turning tool 2 pass through the bottom hole 3 to reach the back of the flange 6 according to the relationship between the boring bar 1, the turning tool 2 and the bottom hole 3; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is smaller than the diameter of the bottom hole 3, first, fix the head end of the boring bar 1 to one end of the fixture 5, and the fixture 5 is fixed to the center of the bottom hole 3. The other end is fixedly connected to the machine tool spindle, and then the machine tool spindle is moved until the boring bar 1, the turning tool 2 and the bottom hole 3 do not interfere with each other, and then the machine tool spindle is axially moved to make the boring bar 1 and the turning tool 2 directly pass through the bottom hole 3 and reach the back of the flange 6; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is greater than or equal to the diameter of the bottom hole 3, the head end of the boring bar 1 is first passed through the bottom hole 3 from the back of the flange 6, and then fixedly connected to one end of the fixture 5, and the other end of the fixture 5 is fixedly connected to the machine tool spindle; Step 3: First start the above-mentioned machine tool, the machine tool spindle starts to rotate, the machine tool spindle drives the boring bar 1 and the turning tool 2 to rotate, and then the machine tool spindle is moved linearly from the center position of the bottom hole 3 to the center position of the boring track A, the turning tool 2 rotates along the boring track A, and cuts the bottom hole 3 on the back of the flange 6. At the same time, the machine tool spindle that keeps rotating runs along the milling track B until the machine tool spindle runs along the milling track B for one circle, and the radial cutting of the countersink 4 is completed, so that the diameter of the countersink 4 meets the design requirements; while the machine tool spindle repeatedly rotates along the boring track A and moves along the milling track B, the machine tool spindle is controlled to move upward along the axial direction until the countersink 4 reaches the required processing depth, the movement of the machine tool spindle is stopped, and the processing of the countersink 4 is completed; Step 4: First, determine the way for the boring bar 1 and the turning tool 2 to withdraw from the bottom hole 3 according to the relationship between the boring bar 1, the turning tool 2 and the bottom hole 3; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is less than the diameter of the bottom hole 3, first move the machine tool spindle until the boring bar 1, the turning tool 2 and the bottom hole 3 do not interfere, and then move the machine tool spindle axially to directly move the boring bar 1 and the turning tool 2 out of the bottom hole 3; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is greater than or equal to the diameter of the bottom hole 3, first remove the head end of the boring bar 1 from the fixture 5, and then pass the boring bar 1 and the turning tool 2 through the bottom hole 3 and move them out from the back of the flange 6.

[0028] In the second step, the turning tool 2 is fixedly connected to the lower part of the boring bar 1, which means that: a mounting hole 11 is provided on the lower side of the boring bar 1, and a fixing hole 12 is provided on the bottom end face of the boring bar 1, and the mounting hole 11 and the fixing hole 12 are connected to each other. After one side of the turning tool 2 is inserted into the mounting hole 11, the screw 32 is fixedly connected to the turning tool 2 and the boring bar 1 through the fixing hole 12.

[0029] The boring bar 1 is a cylinder, a gap between the boring bar 1 and the bottom hole 3 is greater than or equal to 1 mm, and a diameter of the boring bar 1 is greater than one third of a diameter of the bottom hole 3 .

[0030] The turning tool 2 is a standard turning tool with a main deflection angle greater than 90°.

[0031] In the first step, determining the boring bar 1 and the turning tool 2 for processing the countersink 4 means: the diameter of the boring bar 1 is smaller than the diameter of the bottom hole 3 minus the radius difference between the countersink 4 and the bottom hole 3, and the diameter of the boring bar 1 is first determined in combination with the diameters of the bottom hole 3 and the countersink 4; the sum of the diameter of the boring bar 1 and the overhang of the turning tool 2 is larger than the diameter of the countersink 4 minus the diameter difference between the bottom hole 3 and the boring bar 1, and smaller than the diameter of the countersink 4 minus the radius difference between the countersink 4 and the bottom hole 3, thereby determining the sum of the diameter of the boring bar 1 and the overhang of the turning tool 2, and then determining the overhang of the turning tool 2 for processing the countersink 4.

[0032] The sum of the radius of the boring bar 1 and the overhang length of the turning tool 2 is less than half of the sum of the radius of the bottom hole 3 and the radius of the countersink 4.

[0033] In the second step, the machine tool is a CNC machine tool.

[0034] The CNC machine tool is a milling machine or a boring machine.

[0035] In the third step, the boring trajectory A refers to: determining the position of the boring trajectory A according to the diameter of the countersink 4 to be processed, and controlling it through a numerical control program; In the third step, the milling track B means: the position of the milling track B is determined according to the diameter of the boring bar 1 and the overhang length of the turning tool 2, and is controlled by a numerical control program, and the center position of the boring track A is located at the milling track B; In the third step, controlling the machine tool spindle to move axially upward until the countersink 4 reaches the required processing depth means: controlling the feed amount of the machine tool spindle to move axially upward through a CNC program until the countersink 4 reaches the required processing depth.

[0036] Increase the speed of the machine tool spindle and at the same time reduce the speed of the machine tool spindle moving along milling path B.

[0037] The supplementary description of the present invention is as follows: The difficult-to-process materials described in the present invention preferably refer to: materials to be processed have high strength and are difficult to cut, such as nickel-copper alloys, high-temperature alloys (GH99), etc.

[0038] The large radial cutting depth mentioned in the present invention preferably means that half of the difference between the diameter of the countersunk hole 4 to be processed and the bottom hole 3 is greater than 10 mm, that is, the cutting width is greater than 10 mm.

[0039] The high precision mentioned in the present invention preferably means that the diameter tolerance of the countersunk hole 4 reaches level 7, the depth tolerance reaches level 7, the surface roughness reaches Ra3.2, and at the same time, the shape of the countersunk hole 4 is regular.

[0040] Preferably, in the second step of the present invention, the step of then moving the machine tool spindle until the boring bar 1, the turning tool 2 and the bottom hole 3 do not interfere with each other means: moving the machine tool spindle until the clearance between the boring bar 1, the turning tool 2 and the bottom hole 3 is greater than or equal to 1 mm.

[0041] In the fourth step of the preferred embodiment of the present invention, first moving the machine tool spindle until the boring bar, the turning tool and the bottom hole do not interfere means: moving the machine tool spindle until the clearance between the boring bar 1, the turning tool 2 and the bottom hole 3 is greater than or equal to 1 mm.

[0042] In the present invention, the turning tool 2 is preferably perpendicular to the axis of the boring bar 1 .

[0043] In the present invention, the size of the mounting hole 11 is preferably larger than the cross section of the side where the turning tool 2 is inserted into the mounting hole 11 .

[0044] Embodiment 1: See also Figure 1 — Figure 5, a flange back countersink processing method; the flange back countersink processing method comprises the following steps: Step 1: Determine the boring bar 1 and the turning tool 2 for machining the countersink 4 according to the diameter of the bottom hole 3 on the flange 6 and the diameter of the countersink 4 to be machined, wherein the flange 6 is located on the part to be machined; Step 2: first, fix the part to be processed to the machine tool, then stop the spindle of the machine tool at the center of the bottom hole 3, and at the same time, fix the turning tool 2 to the lower part of the boring bar 1, and then determine the way in which the boring bar 1 and the turning tool 2 pass through the bottom hole 3 to reach the back of the flange 6 according to the relationship between the boring bar 1, the turning tool 2 and the bottom hole 3; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is smaller than the diameter of the bottom hole 3, first, fix the head end of the boring bar 1 to one end of the fixture 5, and the fixture 5 is fixed to the center of the bottom hole 3. The other end is fixedly connected to the machine tool spindle, and then the machine tool spindle is moved until the boring bar 1, the turning tool 2 and the bottom hole 3 do not interfere with each other, and then the machine tool spindle is axially moved to make the boring bar 1 and the turning tool 2 directly pass through the bottom hole 3 and reach the back of the flange 6; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is greater than or equal to the diameter of the bottom hole 3, the head end of the boring bar 1 is first passed through the bottom hole 3 from the back of the flange 6, and then fixedly connected to one end of the fixture 5, and the other end of the fixture 5 is fixedly connected to the machine tool spindle; Step 3: First start the above-mentioned machine tool, the machine tool spindle starts to rotate, the machine tool spindle drives the boring bar 1 and the turning tool 2 to rotate, and then the machine tool spindle is moved linearly from the center position of the bottom hole 3 to the center position of the boring track A, the turning tool 2 rotates along the boring track A, and cuts the bottom hole 3 on the back of the flange 6. At the same time, the machine tool spindle that keeps rotating runs along the milling track B until the machine tool spindle runs along the milling track B for one circle, and the radial cutting of the countersink 4 is completed, so that the diameter of the countersink 4 meets the design requirements; while the machine tool spindle repeatedly rotates along the boring track A and moves along the milling track B, the machine tool spindle is controlled to move upward along the axial direction until the countersink 4 reaches the required processing depth, the movement of the machine tool spindle is stopped, and the processing of the countersink 4 is completed; Step 4: First, determine the way for the boring bar 1 and the turning tool 2 to withdraw from the bottom hole 3 according to the relationship between the boring bar 1, the turning tool 2 and the bottom hole 3; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is less than the diameter of the bottom hole 3, first move the machine tool spindle until the boring bar 1, the turning tool 2 and the bottom hole 3 do not interfere, and then move the machine tool spindle axially to directly move the boring bar 1 and the turning tool 2 out of the bottom hole 3; when the sum of the diameter of the boring bar 1 and the overhang length of the turning tool 2 is greater than or equal to the diameter of the bottom hole 3, first remove the head end of the boring bar 1 from the fixture 5, and then pass the boring bar 1 and the turning tool 2 through the bottom hole 3 and move them out from the back of the flange 6.

[0045] Embodiment 2: The basic content is the same as that of Example 1, except that: in the second step, the fixing connection between the turning tool 2 and the lower part of the boring bar 1 means that: a mounting hole 11 is provided on the lower side of the boring bar 1, and a fixing hole 12 is provided on the bottom end face of the boring bar 1, and the mounting hole 11 and the fixing hole 12 are interconnected. After one side of the turning tool 2 is inserted into the mounting hole 11, the screw 32 is fixedly connected to the turning tool 2 and the boring bar 1 through the fixing hole 12.

[0046] When in use, after one side of the turning tool 2 is inserted into the mounting hole 11 on the lower side of the boring bar 1, the screw 32 passes through the fixing hole 12 on the bottom end face of the boring bar 1 to press one side of the turning tool 2, so that the turning tool 2 and the boring bar 1 are fixedly connected. This connection method makes the installation of the boring bar 1 and the turning tool 2 more convenient, and this fixed connection method is more firm and has higher positioning accuracy, which improves the stability during the processing and makes the precision of the processed countersunk hole higher.

[0047] Embodiment 3: The basic content is the same as that of Example 1, except that: the turning tool 2 is a standard turning tool with a main deflection angle greater than 90°; the boring bar 1 is a cylinder, the gap between the boring bar 1 and the bottom hole 3 is greater than or equal to 1 mm, and the diameter of the boring bar 1 is greater than one third of the diameter of the bottom hole 3; in addition, the boring bar 1 can also be a cone, the lower end of the boring bar 1 is a cylinder, which is fixedly connected to the turning tool 2, and the cone part of the boring bar 1 is fixedly connected to the fixture 5.

[0048] When in use, the gap between the boring bar 1 and the bottom hole 3 is greater than or equal to 1 mm, so that the boring bar and the bottom hole will not interfere with each other during the processing. The diameter of the boring bar 1 is greater than one-third of the diameter of the bottom hole 3, which can ensure the rigidity of the boring bar, making it easier to process the reverse countersink of difficult-to-process materials. The turning tool 2 is a standard turning tool with a main deflection angle greater than 90°, so that the cutting resistance is small during the processing and the processing is easier; when the boring bar 1 is a cone, the rigidity is greater, and difficult-to-process materials can be better processed.

[0049] Embodiment 4: The basic content is the same as that of Example 1, except that: in the first step, determining the boring bar 1 and the turning tool 2 for processing the countersink 4 means that: the diameter of the boring bar 1 is smaller than the diameter of the bottom hole 3 minus the radius difference between the countersink 4 and the bottom hole 3, and the diameter of the boring bar 1 is first determined in combination with the diameters of the bottom hole 3 and the countersink 4; the sum of the diameter of the boring bar 1 and the overhang of the turning tool 2 is larger than the diameter of the countersink 4 minus the diameter difference between the bottom hole 3 and the boring bar 1, and is smaller than the diameter of the countersink 4 minus the radius difference between the countersink 4 and the bottom hole 3, thereby determining the sum of the diameter of the boring bar 1 and the overhang of the turning tool 2, and then determining the overhang of the turning tool 2 for processing the countersink 4.

[0050] When applying, first determine the diameter of the boring bar 1 based on the requirement that the diameter of the boring bar 1 is smaller than the diameter of the bottom hole 3 minus the radius difference between the countersink 4 and the bottom hole 3, and then combine the known diameters of the bottom hole 3 and the countersink 4 to determine the diameter of the boring bar 1. Then, determine the sum of the diameter of the boring bar 1 and the overhang of the turning tool 2 based on the requirement that the sum of the diameter of the boring bar 1 and the overhang of the turning tool 2 is larger than the diameter of the countersink 3 minus the diameter difference between the bottom hole 4 and the boring bar 1, and smaller than the diameter of the countersink 4 minus the radius difference between the countersink 4 and the bottom hole 3. Then determine the overhang of the turning tool 2 used for processing the countersink 4. Through the cooperation between the boring bar 1, the turning tool 2 and the bottom hole 3, a countersink with a large radial cutting depth can be processed.

[0051] Embodiment 5: The basic content is the same as that of Embodiment 1, except that the sum of the radius of the boring bar 1 and the overhang length of the turning tool 2 is less than half of the sum of the radius of the bottom hole 3 and the radius of the countersunk hole 4.

[0052] When applied, when the sum of the radius of the boring bar 1 and the overhang length of the turning tool 2 is less than half of the sum of the radius of the bottom hole 3 and the radius of the countersink 4, the cutting of the bottom hole 3 during the processing is smoother. At the same time, the cutting amount in the first half circle of the cutting and the subsequent half circle of the cutting is balanced and stable, and will not cause excessive difference in cutting amount. This can reduce the wear of the processing tools, increase the service life of the tools, and is beneficial to improving the surface quality of the countersink 4.

[0053] Embodiment 6: The basic content is the same as Example 1, except that: in the second step, the machine tool is a CNC machine tool; the CNC machine tool is a milling machine or a boring machine; in the third step, the boring trajectory A refers to: determining the position of the boring trajectory A according to the diameter of the countersink 4 to be processed, and controlling it through a CNC program; in the third step, the milling trajectory B refers to: determining the position of the milling trajectory B according to the diameter of the boring bar 1 and the overhang length of the turning tool 2, and controlling it through a CNC program, and the center position of the boring trajectory A is located at the milling trajectory B; in the third step, controlling the machine tool spindle to move upward along the axial direction until the countersink 4 reaches the required processing depth refers to: controlling the feed amount of the machine tool spindle to move upward along the axial direction through the CNC program until the countersink 4 reaches the required processing depth.

[0054] When applied, the countersink 4 is processed by a CNC machine tool, and a CNC milling machine or a CNC boring machine is selected for processing, so that the processed countersink 4 has higher precision, and can also be applied to different CNC machine tools, making the applicability of the present invention higher; then during the processing, the boring trajectory A, the milling trajectory B and the feed amount of the upward movement are controlled by the CNC program, so that the diameter and depth of the countersink are more in line with the requirements, and the use of CNC program control makes the processing process more convenient, stable, and more precise.

[0055] Embodiment 7: The basic content is the same as that of Example 1, except that the rotation speed of the machine tool spindle is increased, and at the same time, the speed at which the machine tool spindle moves along the milling trajectory B is reduced.

[0056] When applied, the CNC program of the CNC machine tool is used to increase the rotation speed of the machine tool spindle and reduce the speed at which the machine tool spindle moves along the milling trajectory B, so that the surface quality of the countersink is improved and the surface roughness of the countersink is improved.

[0057] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.

Claims

1. A method for processing a countersink on the back of a flange, characterized in that: The flange back countersink processing method comprises the following steps: The first step: determining a boring bar (1) and a turning tool (2) for machining the countersunk hole (4) according to the diameter of the bottom hole (3) on the flange (6) and the diameter of the countersunk hole (4) to be machined, wherein the flange (6) is located on the part to be machined; Step 2: first, the part to be processed is fixedly connected to the machine tool, and then the machine tool spindle is stopped at the center of the bottom hole (3). At the same time, the turning tool (2) is fixedly connected to the lower part of the boring bar (1). Then, according to the relationship between the boring bar (1), the turning tool (2) and the bottom hole (3), the method for the boring bar (1) and the turning tool (2) to pass through the bottom hole (3) and reach the back of the flange (6) is determined; when the sum of the diameter of the boring bar (1) and the overhang length of the turning tool (2) is smaller than the diameter of the bottom hole (3), the head end of the boring bar (1) is first fixedly connected to one end of the clamp (5), and the clamp (5) is fixedly connected to the bottom hole (3). The other end of the boring bar (1) is fixedly connected to the machine tool spindle, and then the machine tool spindle is moved until the boring bar (1), the turning tool (2) and the bottom hole (3) do not interfere with each other, and then the machine tool spindle is axially moved to allow the boring bar (1) and the turning tool (2) to directly pass through the bottom hole (3) and reach the back of the flange (6); when the sum of the diameter of the boring bar (1) and the overhang length of the turning tool (2) is greater than or equal to the diameter of the bottom hole (3), the head end of the boring bar (1) is first passed through the bottom hole (3) from the back of the flange (6), and then fixedly connected to one end of the fixture (5), and the other end of the fixture (5) is fixedly connected to the machine tool spindle; Step 3: First, start the above-mentioned machine tool, and the machine tool spindle starts to rotate, and the machine tool spindle drives the boring bar (1) and the turning tool (2) to rotate, and then the machine tool spindle is moved linearly from the center position of the bottom hole (3) to the center position of the boring track (A), and the turning tool (2) rotates along the boring track (A) to cut the bottom hole (3) on the back of the flange (6). At the same time, the machine tool spindle that keeps rotating runs along the milling track (B) until the machine tool spindle runs along the milling track (B) for one circle, and the radial cutting of the countersink (4) is completed, so that the diameter of the countersink (4) meets the design requirements; while the machine tool spindle repeatedly rotates along the boring track (A) and moves along the milling track (B), the machine tool spindle is controlled to move upward along the axial direction until the countersink (4) reaches the required processing depth, and the movement of the machine tool spindle is stopped, and the processing of the countersink (4) is completed; Step 4: First, determine the method for the boring bar (1) and the turning tool (2) to withdraw from the bottom hole (3) based on the relationship between the boring bar (1), the turning tool (2) and the bottom hole (3); when the sum of the diameter of the boring bar (1) and the overhang length of the turning tool (2) is smaller than the diameter of the bottom hole (3), first move the machine tool spindle until the boring bar (1), the turning tool (2) and the bottom hole (3) do not interfere with each other, and then axially move the machine tool spindle to directly remove the boring bar (1) and the turning tool (2) from the bottom hole (3); when the sum of the diameter of the boring bar (1) and the overhang length of the turning tool (2) is greater than or equal to the diameter of the bottom hole (3), first remove the head end of the boring bar (1) from the fixture (5), and then pass the boring bar (1) and the turning tool (2) through the bottom hole (3) and move them out from the back of the flange (6).

2. A flange back countersink processing method according to claim 1, characterized in that: In the second step, the turning tool (2) is fixedly connected to the lower part of the boring bar (1) by: a mounting hole (11) is provided on the lower side of the boring bar (1), a fixing hole (12) is provided on the bottom end surface of the boring bar (1), the mounting hole (11) and the fixing hole (12) are mutually connected, and after one side of the turning tool (2) is inserted into the mounting hole (11), a screw (32) is passed through the fixing hole (12) to fix the turning tool (2) and the boring bar (1) together.

3. A flange back countersink processing method according to claim 2, characterized in that: The boring bar (1) is a cylinder, the gap between the boring bar (1) and the bottom hole (3) is greater than or equal to 1 mm, and the diameter of the boring bar (1) is greater than one third of the diameter of the bottom hole (3).

4. A flange back countersink processing method according to claim 2, characterized in that: The turning tool (2) is a standard turning tool with a main deflection angle greater than 90°.

5. A flange back countersink processing method according to any one of claims 1 to 4, characterized in that: In the first step, the determination of the boring bar (1) and the turning tool (2) for machining the countersink (4) means that: the diameter of the boring bar (1) is smaller than the diameter of the bottom hole (3) minus the radius difference between the countersink (4) and the bottom hole (3), and the diameter of the boring bar (1) is first determined in combination with the diameters of the bottom hole (3) and the countersink (4); the sum of the diameter of the boring bar (1) and the overhang of the turning tool (2) is larger than the diameter of the countersink (4) minus the diameter difference between the bottom hole (3) and the boring bar (1), and smaller than the diameter of the countersink (4) minus the radius difference between the countersink (4) and the bottom hole (3), thereby determining the sum of the diameter of the boring bar (1) and the overhang of the turning tool (2), and further determining the overhang of the turning tool (2) for machining the countersink (4).

6. A flange back countersink processing method according to claim 5, characterized in that: The sum of the radius of the boring bar (1) and the overhang length of the turning tool (2) is less than half of the sum of the radius of the bottom hole (3) and the radius of the countersink (4).

7. A flange back countersink processing method according to any one of claims 1 to 4, characterized in that: In the second step, the machine tool is a CNC machine tool.

8. A flange back countersink processing method according to claim 7, characterized in that: The CNC machine tool is a milling machine or a boring machine.

9. A flange back countersink processing method according to claim 7, characterized in that: In the third step, the boring trajectory (A) refers to: determining the position of the boring trajectory (A) according to the diameter of the countersunk hole (4) to be processed, and controlling it through a numerical control program; In the third step, the milling track (B) is: the position of the milling track (B) is determined according to the diameter of the boring bar (1) and the overhang length of the turning tool (2), and is controlled by a numerical control program, and the center position of the boring track (A) is located on the milling track (B); In the third step, controlling the machine tool spindle to move upward along the axial direction until the countersink (4) reaches the desired processing depth means: controlling the feed rate of the machine tool spindle to move upward along the axial direction through a numerical control program until the countersink (4) reaches the desired processing depth.

10. A flange back countersink processing method according to claim 7, characterized in that: Increase the speed of the machine tool spindle and, at the same time, reduce the speed at which the machine tool spindle moves along the milling path (B).

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