A machining die and machining method for a hollow part

Abstract

The present application relates to the technical field of mechanical manufacturing, and more particularly to a machining die and machining method for hollow parts. The machining die comprises an external pressing plate, a pull rod and a bottom fixing member. The external pressing plate is located at one end of the pull rod, and the bottom fixing member is located at the other end of the pull rod. The external pressing plate and the bottom fixing member are fixedly connected through the pull rod. A fixing area for clamping and fixing a preformed hollow part blank is arranged between the external pressing plate and the bottom fixing member. A positioning block parallel to the built-in axial parallel plane of the preformed hollow part blank is arranged at the end of the external pressing plate away from the bottom fixing member. The present application realizes visual positioning and correction of the plane to be machined by arranging the positioning block parallel to the radial projection of the built-in plane. Meanwhile, the positioning precision of the positioning block is optimized with the aid of an optoelectronic autocollimator, thereby further improving the positioning precision of the built-in plane and greatly improving the machining precision compared with the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material manufacturing, and in particular to a processing die and a processing method for a hollow part. Background Art

[0002] High-precision hollow parts with special internal shapes are in widespread demand in the aviation field, especially for the new generation of aviation materials represented by lightweight alloys (such as magnesium-aluminum alloys). Lightweight alloys and other materials cannot be welded or the welding accuracy is difficult to control, and the casting process cannot meet the precision requirements for internal special-shaped structures. Currently, the production of lightweight alloy hollow parts is mainly based on machine tool processing (turning, milling, etc.).

[0003] A common processing method for built-in planes parallel to the axial direction in high-precision hollow parts is to fix the preformed hollow part blank and adjust the coordinate position of the tool for processing. This method has the disadvantages of long tool travel, complex calibration and program control, poor accuracy, and difficulty in calibration. Another common processing method is to fix the preformed hollow part blank on a rotary table, confine the tool to a limited area, and then rotate the rotary table to place different areas of the preformed hollow part blank in the limited processing area of ​​the tool. This method generally requires the use of the angle scale of the rotary table to determine the rotation angle of the rotary table and complete the alignment of the plane to be processed. The current existing technology has a graduation accuracy of 0.01° for vertical rotary tables. However, due to factors such as superimposed part deformation and accumulated errors in other directions during the processing process, the angular tolerance between the combined planes is difficult to guarantee, the risk of out-of-tolerance is high, and the yield rate is low, which still cannot meet the requirements of high-precision processing. The market is currently in urgent need of a processing device and processing method for built-in planes parallel to the axial direction in high-precision hollow parts. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a processing mold and processing method for hollow parts to solve at least one of the problems in the prior art, such as low yield rate, low processing accuracy, and being greatly affected by the precision of the machine tool itself.

[0005] The purpose of the present invention is mainly achieved through the following technical solutions:

[0006] The present invention provides a processing mold for hollow parts, comprising: an external pressure plate, a pull rod and a bottom fixing piece, the external pressure plate is located at one end of the pull rod, the bottom fixing piece is located at the other end of the pull rod, the external pressure plate and the bottom fixing piece are fixedly connected by the pull rod, and a fixing area for clamping and fixing a preformed hollow part blank is provided between the external pressure plate and the bottom fixing piece; the hollow part has a built-in axial parallel plane, and the external pressure plate is provided with a positioning block parallel to the built-in axial parallel plane of the preformed hollow part blank at one end away from the bottom fixing piece, and a central hole for the entry and exit of the processing tool is provided in the center of the external pressure plate, and the positioning block is arranged in the solid area of ​​the outer peripheral edge of the central hole.

[0007] Preferably, there are one or more positioning blocks corresponding one to one with the built-in axially parallel planes.

[0008] Preferably, the angular relationship between the projections of the plurality of positioning blocks in the radial plane is calibrated by a photoelectric autocollimation instrument.

[0009] Preferably, the arrangement of the plurality of positioning blocks on the outer pressure plate is calibrated and positioned by a rotary table.

[0010] Preferably, the positioning block is fixed to the solid area of ​​the outer peripheral edge of the external pressure plate (1) along its length direction; and the ratio of the length to the width or height of the positioning block is greater than 2.

[0011] Preferably, a pull rod mounting hole is provided on the edge of the body of the external pressure plate; one end of the pull rod is provided with a thread, and the other end is fixedly connected to the bottom fixing piece, and the thread matches the nut.

[0012] Preferably, the pull rod mounting hole, the pull rod and the nut form a movable connection structure for adjusting the degree of compression of the hollow part by the external pressure plate and the bottom fixing member.

[0013] Preferably, the pull rod mounting holes are arranged centrally symmetrically with respect to the center of the external pressure plate.

[0014] Preferably, a plurality of first positioning through holes are provided in the solid edge area; and a positioning pin having one end axially movably connected to the preformed hollow part blank is passed through the first positioning through hole.

[0015] A method for processing a hollow part having a built-in axially parallel plane uses the above-mentioned processing mold.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] (1) The present invention completes the transmission of the angular relationship of the radial projection of the axially parallel built-in plane to the angular relationship of the corresponding positioning block by setting a positioning block parallel to the radial projection of the axially parallel built-in plane of the target hollow part, thereby decomposing the processing of the axially parallel built-in plane into two parts: axially parallel built-in plane alignment and positioning and axially parallel built-in plane cutting; therefore, the present invention does not need to add a positioning function module when designing the processing program. Compared with the prior art, the workpiece to be processed is fixed and only the processing tool cutting method is used, which reduces the complexity of program design and the elongation of the processing tool, and improves the processing accuracy and reliability.

[0018] (2) The present invention converts the alignment of the axially parallel built-in plane into the horizontal adjustment of the corresponding positioning block, and converts the positional relationship of the built-in plane of the target hollow part that is abstract and invisible before processing into the angular relationship between the positioning blocks and between the positioning blocks and the horizontal plane. Before processing the built-in plane, the positioning blocks can be measured and corrected to achieve the correction of the built-in plane of the target hollow part, thereby improving the processing accuracy.

[0019] (3) The present invention uses a rotating method for the preformed hollow part blank to realize the processing of different areas of the preformed hollow part blank. The tool only needs to move within a local range on one side of the area to be processed, which reduces the tool processing stroke. Compared with the processing method in the prior art in which the processed part is fixed and the tool is moved to each processing area, the cumulative error caused by the increase in the tool stroke is reduced, and the accuracy is improved.

[0020] (4) The present invention sets a positioning block parallel to the radial projection of the built-in axially parallel plane, and uses the parallel transmission law to convert the angular relationship of the built-in plane of the target hollow part on the radial plane projection into the angular relationship between the positioning blocks; further, the present invention uses a photoelectric autocollimator to correct the angular relationship between the positioning blocks, which improves the accuracy compared with the angle scale provided by the vertical rotary table; and realizes the precise positioning of the built-in plane of the target hollow part.

[0021] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages will become apparent from the description or be understood through practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the embodiments of the description and the contents particularly pointed out in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0023] Figure 1This is a schematic diagram of an assembly of a hollow part with a built-in axially parallel plane and a processing mold in one embodiment of the present invention, viewed from a 45° top angle;

[0024] Figure 2 This is a schematic diagram of a hollow part with a built-in axially parallel plane, viewed from a 45° top angle, in one embodiment of the present invention;

[0025] Figure 3 This is a cross-sectional view of the AA surface of a hollow part with a built-in axially parallel plane in one embodiment of the present invention;

[0026] Figure 4 This is a cross-sectional view of the AA plane of a hollow part blank with a built-in axially parallel plane in one embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the assembly of an unformed hollow part with an internal axially parallel plane, an external pressure plate, and a positioning block from a 45° top view in one embodiment of the present invention;

[0028] Figure 6 A schematic diagram of a processing device and installation method for a hollow part with a built-in axially parallel plane in one embodiment of the present invention;

[0029] Figure 7 This is a flow chart of a method for processing a hollow part with a built-in axially parallel plane in one embodiment of the present invention;

[0030] Figure 8 This is a flow chart of a method for positioning a built-in axially parallel plane of a hollow part in one embodiment of the present invention.

[0031] Reference numerals:

[0032] External pressure plate 1; pull rod 2; bottom fixing part 3; hollow part 4; rotary worktable 5; machine tool platform 6; machine tool spindle 7, processing tool 8; positioning block 101; first positioning block 1011; second positioning block 1012; center hole 102; edge solid area 103; pull rod mounting hole 104; first positioning through hole 105; positioning pin 106; second positioning hole 401; axially parallel built-in plane 402; built-in plane 402' of target hollow part; first built-in plane 4021; second built-in plane 4022; first plane to be processed 4021'; second plane to be processed 4022'; part body 403; processing range 405 of processing tool. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0034] In order to clearly explain the technical solution of the present invention, the following technical terms are further defined:

[0035] Alignment:

[0036] The present invention defines alignment as a state in which the plane to be processed is parallel to the horizontal plane.

[0037] The angle between the straight line l1 and the straight line l2 is:

[0038] The angle required to rotate line l1 counterclockwise until it becomes parallel to line l2.

[0039] The current existing technology has a vertical rotary table indexing accuracy higher than 0.01°. Limited by the accuracy of the vertical rotary table, it is difficult to further improve the horizontal alignment accuracy of the plane to be processed. To solve the above problem, the present invention provides a high-precision processing device and method for a built-in plane parallel to the axial direction in a hollow part that does not rely on the indexing accuracy of the rotary table.

[0040] On the one hand, the present invention discloses a processing mold for a hollow part, such as Figure 1 As shown: it includes an external pressure plate 1, a pull rod 2 and a bottom fixing part 3, the external pressure plate 1 is located at one end of the pull rod, and the bottom fixing part 3 is located at the other end of the pull rod 2, the external pressure plate 1 and the bottom fixing part 3 are fixedly connected by the pull rod 2, and a fixing area for clamping and fixing the preformed hollow part blank is provided between the external pressure plate 1 and the bottom fixing part 3; the external pressure plate 1 is provided with a positioning block 101 parallel to the built-in axial parallel plane at one end away from the bottom fixing part 3 (i.e., the outer end face), and a central hole 102 for the entry and exit of the machining tool 8 is provided in the center of the external pressure plate 1, and the positioning block 101 is provided in the solid area 103 on the outer peripheral edge of the central hole 102.

[0041] Specifically, such as Figure 2 As shown, the formed hollow part 4 is a hollow part with an inner side wall provided with a built-in plane 402 parallel to the axial direction. Figure 3 It is a cross-sectional view of the formed hollow part 4 at the radial section (AA plane) where the center of the built-in plane 402 parallel to the axial direction is located: multiple built-in planes 402 parallel to the axial direction are not parallel to each other. Figure 4 This is a cross-sectional view of the raw material blank of the hollow part 4 in the radial section (AA surface): the raw material blank of the hollow part 4 is a centrally symmetrical cylindrical part.

[0042] like Figure 1 As shown, the inner side wall of the hollow part 4 is provided with a first built-in plane 4021 and a second built-in plane 4022 ; the first built-in plane 4021 and the second built-in plane 4022 are not parallel to each other.

[0043] The outer end surface of the external pressure plate 1 of the above-mentioned hollow part processing mold is provided with a first positioning block 1011 and a second positioning block 1012; the first positioning block 1011 is parallel to the first built-in plane 4021, and the second positioning block 1012 is parallel to the second built-in plane 4022.

[0044] The positioning block 101 is provided with one or more built-in flat surfaces 402 ′ which correspond one-to-one to the axial direction of the target hollow part.

[0045] Figure 5 The figure shows the unfinished processing state of the first built-in plane 4021 and the second built-in plane 4022: the side wall of the preformed hollow part blank is provided with a first plane to be processed 4021' and a second plane to be processed 4022'; the first plane to be processed 4021' is obtained by processing at the dotted line. Figure 1 The first built-in plane 4021 and the second to-be-processed plane 4022' at the dotted line are obtained by processing Figure 1 the second built-in plane 4022; the first positioning block 1011 is parallel to the first plane to be processed 4021 ', and the second positioning block 1012 is parallel to the second plane to be processed 4022 '; after parallel transfer, the first built-in plane 4021 and the second built-in plane 4022 are at the same angle as the first plane to be processed 4021 ' and the second plane to be processed 4022 '.

[0046] Specifically, such as Figure 5 As shown, since the built-in plane 402' of the target hollow part is axially parallel, its projection along the axis to the end face is a straight line segment; the positioning block 101 is set to be parallel to the projection of the built-in plane 402' of the target hollow part along the axis to the end face.

[0047] During implementation, the positioning block 101 is set to be a long strip and fixed to the outer end face of the external pressure plate 1; the radial cross-section of the positioning block is set to be circular or quadrilateral; according to the principle of parallel transmission, by measuring the horizontal state of the positioning block 101, the horizontal state of the built-in plane of the target hollow part corresponding to the positioning block 101 can be judged more conveniently and accurately; and, since the tool is perpendicular to the horizontal plane, by adjusting the positioning block 101 to the horizontal, the alignment of the built-in plane of the corresponding target hollow part can be achieved.

[0048] Compared with the prior art, the present invention converts the inclination angle of the built-in plane of the target hollow part relative to the horizontal plane into the angle between the positioning block and the horizontal plane by setting a positioning block parallel to the radial projection of the built-in plane of the target hollow part. The built-in plane of the target hollow part is abstract and invisible before the processing is completed, and the positioning block is concrete and visible. The advantage of this is that the positioning block can be measured and corrected before processing the built-in plane, thereby realizing the correction of the built-in plane of the target hollow part and improving the processing accuracy.

[0049] Furthermore, the positioning block 101 is fixed to the body of the external pressure plate 1; the ratio of the length to the width or height of the positioning block is greater than 2; when detecting the horizontal state of the positioning block 101, the larger length to width or height ratio of the positioning block is used, which is conducive to obtaining more sensitive signals at both ends of the top of the positioning block, and is conducive to further improving the alignment accuracy of the positioning block 101 corresponding to the built-in plane.

[0050] Specifically, the angular relationship between the radial projections of multiple positioning blocks is calibrated by a photoelectric autocollimator, and the multiple positioning blocks 101 are calibrated and positioned on the rotary worktable; specifically, the external pressure plate 1 is fixed to the rotary worktable, and based on the angle of the radial projection of the built-in plane of the target hollow part, the rotary worktable is rotated to determine the installation position of the positioning block.

[0051] In the case of processing multiple axially parallel built-in planes, it is necessary to set multiple positioning blocks 101 on the external pressure plate 1, which are parallel to the projections of the built-in planes on the radial plane. According to the principle of parallel transmission, the angle between the projections of any two axially parallel built-in planes on the radial plane is the same as the angle between the corresponding positioning blocks 101 on the radial plane.

[0052] During implementation, the first positioning block 101 is set as the reference positioning block, and the remaining positioning blocks are set according to the angle with the reference positioning block. It should be noted that the positioning block can be set on multiple parallel lines that meet the angle relationship with the reference positioning block, and there are multiple feasible installation positions for the positioning block to be translated on the same parallel line. Therefore, it is necessary to select an installation position on the outer side of the external pressure plate 1 where the positioning block can be set without obstruction. The positioning block set at this installation position should not hinder the other structures and functions on the same side of the external pressure plate 1. Based on this, the angle between any two positioning blocks set on the external pressure plate 1 of the present invention is the same as the angle between the projections of the corresponding axially parallel built-in planes on the radial plane; the angular relationship of the positioning blocks set by the above method corresponds to the angle between the projections of the axially parallel built-in plane of the target hollow part on the radial plane, and the angular relationship of the projections of the axially parallel built-in plane of the target hollow part on the radial plane is consistent with the design expectation based on the axially parallel built-in plane obtained after the positioning block alignment.

[0053] Specifically, such as Figure 1 As shown: the processing tool can move in and out of the central hole 102 freely, so it can meet the processing needs of the interior of the preformed hollow part blank; the outer side of the edge solid area 103 is used to fix the positioning block 1, and the inner side is press-fitted with the hollow part 4.

[0054] Furthermore, in order to achieve the fastening connection between the bottom fixing member 3 and the external pressure plate 1, the processing mold is provided with a movable connection structure for adjusting the degree of compression of the external pressure plate 1 and the bottom fixing member 3 on the hollow part 4, such as Figure 1As shown, the movable connection structure includes: a tie rod mounting hole 104 provided on the edge of the outer platen 1; a tie rod 2 with threads on one end and fixedly connected to the bottom fixing member 3 at the other end; and a nut that matches the threads; and a press-fit connection to the solid edge area 103 via the nut. The threaded arrangement allows the tie rod 2 to adjust the tightening degree of the bottom fixing member 3 and the outer platen 1, thereby adjusting the end face pressing strength of the preformed hollow part blank.

[0055] Preferably, the pull rod mounting holes 104 are centrally symmetrically arranged relative to the center of the external pressure plate 1, and the pull rods 2 corresponding to the number of pull rod mounting holes 104 pass through the pull rod mounting holes 104 and are fixedly connected to the edge solid area 103, and force is uniformly applied in all directions relative to the edge solid area 103 and the center of the bottom fixing member 3.

[0056] At the same time, in order to further improve the fastening degree of the preformed hollow part blank and the mold to prevent relative sliding, such as Figure 3 As shown, the edge solid area 103 is provided with a plurality of first positioning through holes 105; Figure 4 As shown, a second positioning hole 401 is provided on one side where the preformed hollow part blank is connected to the external pressure plate 1; one end of the first positioning through hole 105 is axially movably connected to the preformed hollow part blank; the radial rotation of the preformed hollow part blank can be locked by matching the positioning pin 106 with the first positioning through hole 105 and the second positioning hole 401 to prevent radial relative sliding and ensure stability and precision during processing.

[0057] Specifically, the second positioning hole 401 is a concave hole with one end open, and the positioning pin 106 passes through the first positioning through hole 105 and is fixed to the second positioning hole 401 .

[0058] On the other hand, the present invention discloses a processing device for hollow parts with built-in axially parallel planes, which, in addition to the above-mentioned processing mold, also includes: a vertical rotary worktable 5, which is fixedly connected to the other end of the bottom fixing member 3 facing away from the external pressure plate 1, and the vertical rotary worktable 5 is movably connected to one side of the machine tool platform 6; the other side of the machine tool platform 6 is movably connected to a machine tool spindle 7, and the end of the machine tool spindle 7 close to the external pressure plate 1 is connected to a processing tool 8.

[0059] During implementation, the processing range of the processing tool 8 is limited to a fixed area on one side relative to the center of the preformed hollow part blank through program control; correspondingly, the rotation angle of the vertical rotary worktable 5 is adjusted so that different areas of the preformed hollow part blank enter the fixed area where the processing tool 8 is located during processing, thereby realizing processing of different areas of the preformed hollow part blank.

[0060] It should be noted that the control program of the machine tool does not include an identification module for identifying the position of the preformed hollow part blank. Therefore, before processing the preformed hollow part blank to obtain the corresponding built-in plane of the target hollow part, it is necessary to complete the alignment of the built-in plane to be processed of the preformed hollow part blank.

[0061] Compared with the prior art, the present invention completes the transfer of the angular relationship of the radial projection of the built-in plane of the target hollow part to the angular relationship of the corresponding positioning block by setting a positioning block parallel to the radial projection of the built-in plane of the target hollow part, thereby decomposing the built-in plane processing of the target hollow part into two parts: the built-in plane alignment and positioning of the target hollow part and the built-in plane processing of the target hollow part; therefore, the present invention does not need to add a positioning function module when designing the processing program. Compared with the prior art, the workpiece to be processed is fixed, and only the cutting tool is processed, which reduces the complexity of the program design and the stroke of the processing tool, and improves the processing accuracy and reliability.

[0062] On the other hand, the present invention provides a method for processing a hollow part with a built-in axial parallel plane, using the above processing device, such as Figure 7 As shown, the following steps are included:

[0063] Step 1: Set a positioning block with a built-in plane parallel to the axial direction of the target hollow part on the outside of the feed end of the processing mold;

[0064] Specifically, one end of the processing mold is fixedly connected to the vertical rotary worktable, and the other end serves as the feed end. The angle of the positioning block corresponding to the built-in plane of the two target hollow parts is determined according to the angle of the radial projection of the built-in plane of the two target hollow parts, and each positioning block is set in sequence according to the angle of the positioning block.

[0065] During implementation, the first positioning block 1011 is set as the reference positioning block, and the remaining positioning blocks are set according to the angles between the positioning blocks and the reference positioning block.

[0066] It should be noted that: there are multiple installation positions for the positioning block that meets the angular relationship with the reference positioning block, and the straight lines at all the installation positions are parallel to each other and have the same angle with the reference positioning block; an installation position is selected on the outer side of the external pressure plate 1 to set the positioning block without obstacles, and the positioning block set at this installation position should not hinder the other structures and functions on the same side of the external pressure plate 1. Based on this, the angle between any two positioning blocks set on the external pressure plate 1 of the present invention is the same as the angle between the projections of their corresponding built-in planes on the radial plane; the angular relationship of the positioning blocks set by the above method corresponds to the angle between the projections of the axially parallel built-in plane of the target hollow part on the radial plane, and the inclination angle of the built-in plane of the target hollow part relative to the horizontal plane is converted into the angle between the positioning block and the horizontal plane.

[0067] Step 2: Based on the positioning block, the preformed hollow part blank is aligned on the built-in plane of the positioning block corresponding to the target hollow part;

[0068] Specifically, the rotation angle of the vertical rotary table is adjusted to the level of the positioning block. Based on the principle of parallel transmission, the built-in plane of the target hollow part corresponding to the positioning block can be placed horizontally and within the processing range of the machining tool, thereby completing the alignment of the built-in plane of the target hollow part; the processing range of the machining tool is limited to a fixed area on one side relative to the center of the hollow part through program control.

[0069] Step 3: Processing the aligned preformed hollow part blank to obtain the built-in plane; specifically, based on the processing program, the processing tool processes from the inner wall to the outer wall of the preformed hollow part blank to remove excess material and obtain the built-in plane of the target hollow part.

[0070] On the one hand, the built-in plane parallel to the axis to be machined is abstract and invisible before the machining is completed, while the positioning block is concrete and visible. The advantages of using the positioning block for zeroing in the present invention are: compared with the prior art, the present invention converts the zeroing of the built-in plane parallel to the axis to be machined into the horizontal adjustment of the corresponding positioning block, and the positioning block can be measured and corrected before machining the built-in plane, thereby realizing the correction of the built-in plane parallel to the axis to be machined and improving the machining accuracy;

[0071] On the other hand, the processing error of the tool is proportional to its stroke. Compared with the existing technology, the present invention adopts the rotation method of the preformed hollow part blank to realize the processing of different areas of the preformed hollow part blank. The tool only needs to move within a local range on one side of the area to be processed, which reduces the tool processing stroke. Compared with the existing technology, the tool accumulates and moves between each processing area, which reduces the cumulative error of the tool caused by the increase in stroke and improves the accuracy.

[0072] Specifically, the step 1 of setting a positioning block parallel to the built-in plane of the target hollow part on the outer side of the feed end of the processing mold includes the following steps:

[0073] S101: The external pressure plate 1 is coaxially fixed to the horizontal rotary table through a group of first positioning through holes 105 which are centrally symmetrical with respect to the geometric center of the feed end of the processing mold; the geometric center of the feed end of the processing mold is taken as the origin, the center line of the first positioning through holes 105 at the initial position is taken as the coordinate axis x' axis, and the coordinate axis z' axis is established perpendicular to the x' axis in the plane of the horizontal rotary table at the initial position, and the perpendicular line passing through the origin and perpendicular to the coordinate axis x' axis and z' axis is taken as the y' axis; a first positioning block 1011 is set perpendicular to the z' axis in the solid area outside the external pressure plate 1; it should be noted that the initial position is an optional position after the external pressure plate 1 is fixed on the horizontal rotary table as the initial position. After the coordinate system is constructed, the rotation of the horizontal rotary table has no effect on the coordinate system.

[0074] S102: Obtain the angle α between the first positioning block 1011 and the second positioning block 1012. A polyhedron is fixedly provided in the center area of ​​the horizontal rotary table. The polyhedron is rotated α degrees and the second positioning block 1012 is provided perpendicular to the z'-axis in the solid area outside the external pressure plate 1.

[0075] S103: Based on the angle between the first positioning block and the Mth positioning block, the steps are the same as S102, where M is an integer greater than or equal to 3.

[0076] It should be noted that S101-S103 are implemented on a horizontal rotary worktable, which is different from the vertical rotary worktable described in steps 1-3: the rotation plane of the horizontal rotary worktable is set horizontally, which is the worktable of the horizontal machining center; the rotation plane of the vertical rotary worktable is set vertically to the horizontal plane.

[0077] It should be noted that, in order to ensure the consistent angular relationship relative to the first positioning block, the second positioning block, the third positioning block, ..., the Mth positioning block are provided in S102 and S103, and the polyhedrons rotate in the same direction.

[0078] Specifically, in order to calibrate the positioning accuracy of the positioning block in the direction perpendicular to the z'-axis, a first positioning block 1011 is set in the direction perpendicular to the z'-axis in S101, a second positioning block 1012 is set in the direction perpendicular to the z'-axis in S102, and a third positioning block, ..., an M-th positioning block is set in S103, including the following steps:

[0079] S1011: Set the positioning block vertically in the z' axis direction;

[0080] S1012: Install a dial indicator on the machine tool spindle and allow the spindle to translate along the x' axis. Gently tap the positioning block according to the reading to fine-tune its angle until the dial indicator pointer reading changes below the threshold when sliding from one end to the other on the positioning block. This determines that the positioning block is strictly perpendicular to the z' axis.

[0081] It should be noted that in S1011, the positioning block can be set perpendicular to the z'-axis direction by visual judgment or angle measurement with an angle ruler; however, the positioning accuracy of the positioning block set by these two methods cannot meet the requirements of precision machining; therefore, it is necessary to further correct the vertical relationship of the positioning block relative to the z'-axis.

[0082] During implementation, in S1012, by installing a dial indicator on the machine tool spindle, parallel movement along the dial indicator coordinate axis x' axis can be achieved, and the dial indicator displacement probe contacts the side to be measured of the positioning block; if the side to be measured is not parallel to the coordinate axis x' axis, the dial indicator displacement probe has a displacement change on the side to be measured, resulting in a change in the percentage indication number; if the side to be measured is parallel to the coordinate axis x' axis, the percentage indication number change cannot be detected or is 0.

[0083] Specifically, the side surface to be measured is: the side surface of the positioning block parallel to the coordinate axis y' axis.

[0084] Specifically, the change in the dial indicator pointer reading is introduced to evaluate the parallelism between the side to be measured and the coordinate axis x': η is selected according to the accuracy requirement; the reading change η satisfies: η=S max -S min , where S max The maximum value of the dial indicator pointer, S min It is the minimum value indicated by the dial indicator pointer.

[0085] Specifically, in S102, the angle between the first positioning block 1011 and the second positioning block 1012 is the same as the angle between the projections of the first plane to be processed 4021' and the second plane to be processed 4022' on the radial plane; wherein, the first plane to be processed 4021' is parallel to the first positioning block 1011; the second plane to be processed 4022' is parallel to the second positioning block 1012.

[0086] Specifically, the rotating of the polyhedron by α degrees in S102 includes accurately calibrating the rotation angle of the polyhedron by a photoelectric autocollimator.

[0087] Specifically, the photoelectric autocollimator can measure the deflection angle between its own outgoing light and the received reflected light signal, with a measurement accuracy higher than 0.8". By adjusting the angle between the photoelectric autocollimator and the polyhedral prism's reflective surface, when the photoelectric autocollimator reading is 0, the polyhedral prism's reflective surface is perpendicular to the photoelectric autocollimator's outgoing light direction.

[0088] Specifically, in S102 , the side surfaces of the polyhedron are rectangular reflective surfaces with the same size as the vertical and horizontal surfaces.

[0089] Specifically, the number of faces N of the polyhedron in S102 needs to be selected based on k = α / (360 / N), where k is a positive integer; wherein 360 / N is the central angle corresponding to a single reflecting surface of the polyhedron. In order to match the correction of the polyhedron reflecting surface by the photoelectric autocollimator, the rotation of the polyhedron is based on the central angle corresponding to the single reflecting surface as the basic unit. In the case of less than one basic unit (k is not an integer), the value of N should be adjusted to satisfy k taking a positive integer, and the number of reflecting surfaces of the polyhedron is determined to obtain a suitable polyhedron.

[0090] Specifically, in S102, the polyhedron rotates α degrees along with the workbench, which includes the following steps:

[0091] S1021: Setting the photoelectric autocollimator parallel to the plane where the coordinate axes x' and z' are located; selecting the initial position when the first positioning block 1011 is set perpendicular to the z' axis in S101, adjusting the angle of the photoelectric autocollimator relative to the x' axis so that the reading of the photoelectric autocollimator on any optional reflective surface of the polyhedron is 0, and fixing the photoelectric autocollimator;

[0092] S1022: Rotate the polyhedron by k reflective surfaces, fine-tune the bedroom rotating workbench, adjust the rotation angle of the polyhedron so that the photoelectric autocollimator reading is 0, and fix the polyhedron to complete the calibration; where k satisfies: k = α × N / 360, k is a positive integer, and N is the number of reflective surfaces of the polyhedron.

[0093] It should be noted that when the photoelectric autocollimator in S1022 shows 0, the direction of the photoelectric autocollimator's emitted light is strictly perpendicular to the reflection surface of the polyhedron after rotating k reflection surfaces from the initial position, with an accuracy greater than 0.08", which has higher positioning accuracy than the angle scale built into the horizontal rotary table.

[0094] In the prior art, the positioning of the built-in plane of the target hollow part is based on the rotation angle scale of the vertical rotary table on the processing machine tool, and thus the positioning accuracy of the built-in plane of the target hollow part is affected by the rotation angle accuracy of the vertical rotary table; compared with the prior art: on the one hand, the present invention sets a positioning block parallel to the radial projection of the built-in axially parallel plane to be processed, and utilizes the parallel transfer law to convert the angular relationship of the projection of the built-in plane of the target hollow part on the radial plane into the angular relationship between the positioning blocks; further, the present invention utilizes a photoelectric autocollimator to correct the angular relationship between the positioning blocks, which improves the accuracy compared to the angle scale provided by the vertical rotary table, and realizes the precise positioning of the built-in plane of the target hollow part.

[0095] During implementation, the bottom fixing member 3 in step 2 is fixedly connected to the vertical rotary workbench on the side away from the pull rod 2, thereby realizing the rotation of the preformed hollow part blank along the axis, adjusting the positioning block to be horizontal, and realizing the built-in plane alignment of the target hollow part corresponding to the positioning block.

[0096] Furthermore, in order to improve the accuracy of the positioning block timing, step 2 includes using a dial indicator to calibrate the positioning block position, specifically including the following steps:

[0097] S201: Adjust the rotation angle of the horizontal rotary table and set the positioning block approximately horizontally;

[0098] S202: Install a dial indicator on the machine tool spindle and move the spindle left and right along the projection line of the x' axis on the horizontal plane, and fine-tune the workbench angle according to the percentage indication and drive the angle of the positioning block to change until the dial indicator pointer reading changes below the threshold when the dial indicator needle slides from one end to the other end on the positioning block, and determines that the positioning block is strictly horizontal.

[0099] It should be noted that in S201, the positioning block can be set in an approximately horizontal direction by visual judgment or measuring the angle with an angle ruler; however, the positioning accuracy of the positioning block set by these two methods cannot meet the requirements of precision machining; therefore, it is necessary to further correct the vertical relationship of the positioning block relative to the z' axis.

[0100] During implementation, in S202, parallel movement along the x' axis can be achieved by installing a dial indicator on the machine tool spindle, and the dial indicator displacement probe contacts the side to be measured (top or bottom side) of the positioning block; if the side to be measured is not parallel to the projection line, the dial indicator displacement probe has a displacement change on the side to be measured, resulting in a change in the percentage indication number; if the side to be measured is parallel to the projection line, the percentage indication number change cannot be detected or is 0.

[0101] Specifically, the change of the dial indicator pointer is introduced to evaluate the horizontal degree of the positioning block: η is selected according to the accuracy requirement; the change of the indication η satisfies: η=S max -S min , where S max The maximum value of the dial indicator pointer, S min It is the minimum value indicated by the dial indicator pointer.

[0102] Preferably, the ratio of the length to the width or height of the positioning block is greater than 2; increasing the ratio of the length to the width or height of the positioning block is conducive to obtaining a larger height difference at both ends of the top of the positioning block, so that the dial indicator has a larger reading change and obtains a more sensitive signal.

[0103] Compared to existing technologies, this invention achieves alignment of the target hollow part's internal plane by placing a locating block parallel to the target hollow part's internal plane. This horizontal positioning of the locating block avoids the limitation of the vertical rotary table's angular scale accuracy on the positioning accuracy of the target hollow part's internal plane. Furthermore, the present invention uses a dial indicator to correct the position of the locating block during alignment, significantly improving positioning accuracy from 0.01° to 0.08″ compared to existing technologies.

[0104] Optionally, the machining program in step 3 may be generated by machining programming software based on the three-dimensional models of the preformed hollow part blank and the finished machined part.

[0105] Specifically, the machine tool processing is based on the three-axis x, y, and z spatial coordinate system set by itself, where the x-axis is set parallel to the horizontal plane, the z-axis is set parallel to the axial direction of the processing part, and the y-axis is set perpendicular to the horizontal plane; the machine tool processing is performed through program settings on each point in the F (x, y, z) processing area of ​​the preformed hollow part blank that has completed the built-in plane alignment operation to be processed.

[0106] During implementation, the processing range of the processing tool 8 is limited to a fixed area on one side relative to the center of the preformed hollow part blank through program control; correspondingly, the rotation angle of the vertical rotary table 5 is adjusted to achieve processing of different areas of the hollow part 4.

[0107] It should be noted that the control program of the machine tool does not include a module for identifying the position of the preformed hollow part blank. Therefore, before processing the hollow part 4 to obtain the corresponding built-in plane to be processed, the preformed hollow part blank needs to be aligned with the built-in plane to be processed.

[0108] Specifically, step 3 of machining parts using a machine tool includes the following steps:

[0109] S301: Constructing a three-dimensional model of a preformed hollow part blank and a three-dimensional model of a finished processed part in programming software;

[0110] S302: The programming software generates a machining program based on the three-dimensional model of the preformed hollow part blank and the three-dimensional model of the finished machined part;

[0111] S303: The machine tool processes the aligned part based on the machining program to obtain a finished part with a corresponding built-in plane.

[0112] Specifically, in S301, the three-axis spatial coordinate system of x, y, and z set by the machine tool itself is used, wherein the x-axis is set parallel to the horizontal plane, the y-axis is set parallel to the axial direction of the processed part, and the z-axis is set perpendicular to the horizontal plane, to construct a three-dimensional model of the preformed hollow part blank and a three-dimensional model of the processed part product; in S302, the programming software compares the three-dimensional model of the preformed hollow part blank and the three-dimensional model of the processed part product to confirm the area to be processed F (x, y, z) and generate a processing program.

[0113] In this field, parts processing is often divided into two or more processing steps: on the one hand, it prevents local overheating during long-term processing, expansion and deformation of the tool and material, and drift of the reference position, which affect the processing accuracy; on the other hand, different processing accuracies have different requirements for tools, and rough processing causes greater wear on the tool, reducing the service life of the tool.

[0114] Preferably, a pre-processing process of the preformed hollow part blank is further included between step 1 and step 2 to further improve the above technical problems, including the following steps:

[0115] S104: Select a group of centrosymmetrical first positioning through holes 105 , use the center line connecting the two as the reference line of the first positioning block, and obtain the angle α0 between the reference line and the first positioning block;

[0116] S105: Fix the preformed hollow part blank on the rotary table through the processing mold, and obtain the inclination angle α between the reference line and the horizontal plane -, based on the angle α0 and angle α - Get the rotary table rotation angle α required for the first positioning block to align t1 ; Based on α t1 Complete the initial alignment of the first built-in plane; specifically, α t1 Satisfaction: α t1 =α - +90°-α0;

[0117] S106: Processing the mold to be processed after the preliminary alignment of the first built-in plane is completed, leaving a margin of 0.2mm to 0.6mm;

[0118] S107: Based on α t1 The angle α1 between the first to-be-machined plane and the second to-be-machined plane is used to obtain the rotary table rotation angle α required for the second positioning block to align. t2 , based on α t1 The angle α2 between the first built-in plane and the third built-in plane is used to obtain the rotary table rotation angle α required for the third positioning block to align. t3 ,…, based on α t and the angle α between the Nth built-in plane and the first built-in plane N Get the rotary table rotation angle α required for the Nth positioning block to align tN Specifically, the Nth positioning block aligns the required rotary table rotation angle α tN , satisfying: α tN =α t1 +α N ; Based on α t2 ,…,α tN The second built-in plane, ..., the Nth built-in plane are preliminarily aligned; the preformed hollow part blank having the preliminarily aligned second built-in plane, ..., the Nth built-in plane is processed with a margin of 0.2 mm to 0.6 mm.

[0119] Preferably, in order to ensure positioning accuracy, the angle α0 between the reference line and the first positioning block is obtained by a photoelectric autocollimator.

[0120] The present invention provides a pre-machining process for the built-in plane of the target hollow part before fine machining, which can remove the raw material excess designed in the pre-formed hollow part blank, reduce the burden on the tool during precise machining, avoid tool overheating and raw material aging problems caused by long fine machining time, and help improve machining accuracy and extend tool life.

[0121] Compared with the prior art, the present invention uses the angle scale of the rotary table in the pre-machining process, which can achieve alignment more quickly while meeting the machining accuracy, thereby improving the machining efficiency.

[0122] Specifically, S106-S107 utilize the above-mentioned machine tool to process parts. In S106, S107 and step 3, a carbide tool is selected as the tool, which meets the following requirements: diameter 12mm-20mm, chamfer radius 1mm-3mm, and tool speed 800r / min-1500r / min.

[0123] Specifically, the hollow parts can be made of one or more of carbon steel, stainless steel, titanium alloy, aluminum alloy, and aluminum-magnesium alloy.

[0124] Preferably, a heat treatment process of the preformed hollow part blank is further included between the pre-processing process and step 2 to further reduce the residual stress of the pre-processing process, and the following steps are performed in sequence:

[0125] S108: Heat treatment at 120±10℃ for 2h~6h, then air cooling to room temperature;

[0126] S109: Treat at -50±5℃ for 1h~3h, then allow to warm up at room temperature;

[0127] S110: Heat treatment at 120±10℃ for 2h~6h, then air cool or cool to room temperature with the furnace.

[0128] The thermal stress continuously generated in the process of positive temperature-negative temperature-positive temperature is superimposed on the original residual stress, exceeding the yield strength of the material and causing plastic deformation, thereby reducing the original residual stress and further improving the plasticity and machinability of the cylindrical material.

[0129] In order to illustrate the technical advancement of the present invention, the following embodiments are further disclosed:

[0130] Example 1

[0131] This embodiment discloses a processing mold for hollow parts, such as Figure 1 As shown: an external pressing plate 1 is provided at one axial end of the processing mold, and a bottom fixing part 3 is provided at the other end; a fixing area for clamping and fixing the hollow part 4 is provided between the external pressing plate 1 and the bottom fixing part 3 and is fixedly connected by a pull rod 2; a positioning block 101 parallel to the built-in plane of the target hollow part is provided on the side of the external pressing plate 1 away from the bottom fixing part 3.

[0132] Figure 2 Shows a 45° top view of a molded hollow part; Figure 3 The cross-sectional view of the radial section (AA plane) where the center of the axially parallel built-in plane 402 is located is shown; Figure 2 and Figure 3 As shown, a plurality of axially parallel built-in planes 402 are not parallel to each other. Figure 4 The cross-sectional view of the raw material blank of the hollow part 4 in the radial section (AA surface) is shown. Figure 3 and Figure 4 As shown: the hollow part 4 is obtained by processing the part body 403 from the inside to the outside.

[0133] like Figure 5 As shown: the positioning block 101 is a rectangular parallelepiped, which is fixed to the external pressure plate 1 through the axial side surface; by measuring the horizontal state of the positioning block 101, the horizontal state of the built-in plane of the target hollow part corresponding to the positioning block 101 can be judged more conveniently and accurately; by adjusting the positioning block 101 to be horizontal, the built-in plane of the corresponding target hollow part can be aligned; at the same time, the positioning block can be measured and corrected before processing the built-in plane, so as to realize the correction of the built-in plane of the target hollow part and improve the processing accuracy.

[0134] like Figure 5 As shown: there are four positioning blocks 101 with the same size, and the ratio of the length to width or height of the positioning blocks is 5; the width and height are the same; a larger length to width or height ratio is conducive to obtaining more sensitive signals at both ends of the top of the positioning block, which is conducive to further improving the alignment accuracy of the positioning block corresponding to the built-in plane.

[0135] At the same time, the angular relationship between the radial projections of multiple positioning blocks is calibrated by a photoelectric autocollimator, and the multiple positioning blocks 101 are calibrated and positioned on the external pressure plate 1 through a rotary worktable; for multiple axially parallel built-in planes to be processed, it is necessary to set positioning blocks 101 on the external pressure plate 1 that are parallel to the projections of the built-in planes on the radial plane; according to the principle of parallel transmission, the angle between the projections of any two built-in planes on the radial plane is the same as the angle between the corresponding positioning blocks 101.

[0136] like Figure 1 As shown, the outer pressure plate 1 has a solid edge region 103 around the center hole 102. This solid edge region 103 has tie rod mounting holes 104 arranged symmetrically about the center of the outer pressure plate 1. Tie rods 2 are threaded and press-fitted to the solid edge region 103 via nuts, securing the bottom fixture 3 to the outer pressure plate 1. Multiple tie rods 2 are fixedly connected to the solid edge region 103 via tie rod mounting holes 104, applying uniform force in all directions relative to the center of the solid edge region 103 and the bottom fixture 3.

[0137] like Figure 3 As shown, the edge solid area 103 is provided with a plurality of first positioning through holes 105; Figure 4 As shown, a second positioning hole 401 is provided on one side of the hollow part 4 connected to the external pressure plate 1; the positioning pin 106 is matched with the first positioning through hole 105 and the second positioning hole 401 to prevent radial relative sliding, thereby ensuring stability and accuracy during processing.

[0138] The second positioning hole 401 is a concave hole with one end open. The positioning pin 106 passes through the first positioning through hole 105 and is fixed in the second positioning hole 401 .

[0139] Example 2

[0140] This embodiment discloses a processing device for a hollow part with a built-in axially parallel plane, comprising the processing mold described in embodiment 1, such as Figure 6 As shown, it also includes: a vertical rotary worktable 5, one end of the vertical rotary worktable 5 is fixedly connected to the other end of the bottom fixing part 3 facing away from the external pressure plate 1, and the other end of the vertical rotary worktable 5 is movably connected to one side of the machine tool platform 6; the other side of the machine tool platform 6 is movably connected to the machine tool spindle 7, and the end of the machine tool spindle 7 close to the external pressure plate 1 is connected to a machining tool 8.

[0141] During implementation, a central hole 102 is provided in the center of the external pressure plate 1 for the entry and exit of the processing tool 8; the processing range of the processing tool 8 is limited to a fixed area on one side relative to the center of the hollow part 4 through program control; correspondingly, the rotation angle of the vertical rotary worktable 5 is adjusted so that different areas of the hollow part 4 enter the fixed area where the processing tool 8 is located during processing, thereby meeting the processing of different areas of the hollow part 4.

[0142] It should be noted that the control program of the machine tool does not include a module for identifying the position of the hollow part 4 . Therefore, before processing the hollow part 4 to obtain the corresponding built-in plane to be processed, the built-in plane to be processed of the hollow part 4 needs to be aligned.

[0143] As an example, Figure 6 As shown, the processing range of the processing tool 8 is limited to the bottom area of ​​the hollow part 4 through program control; the rotation angle of the rotary table 5 relative to the machine tool platform 6 is adjusted to the level of the first positioning block 1011 to achieve the alignment of the first plane 4021' to be processed, and at the same time, the first plane 4021' to be processed is placed within the processing range 405 of the processing tool 8.

[0144] Example 3

[0145] This embodiment discloses a positioning method for a hollow part with an axially parallel plane built in it, using the processing mold described in Example 1, such as Figure 8 As shown, the following steps are included:

[0146] Step 1: Set a positioning block parallel to the built-in plane of the target hollow part on the outside of the feed end of the processing mold;

[0147] Specifically, one end of the processing mold is fixedly connected to the vertical rotary table, and the other end serves as the feed end. The angle of the positioning blocks corresponding to the parallel built-in planes of the two target hollow parts is determined according to the angle of the radial projection of the built-in planes of the two target hollow parts, and each positioning block is sequentially set according to the angle of the positioning blocks;

[0148] Step 2: Based on the positioning block, the preformed hollow part blank fixed on the vertical rotary table is aligned with the built-in plane of the positioning block corresponding to the target hollow part.

[0149] Specifically, step 1 of setting a positioning block parallel to the built-in plane of the target hollow part includes the following steps:

[0150] S101: The external pressing plate 1 is coaxially fixed to the horizontal rotary table with a set of first positioning through holes 105 that are centrally symmetrical with respect to the geometric center of the external pressing plate 1; the geometric center of the outer side surface of the feed end of the processing mold is taken as the origin, the center line of the first positioning through holes 105 at the initial position is taken as the x'-axis, and the coordinate axis z'-axis is established perpendicular to the x'-axis in the plane of the horizontal rotary table at the initial position, and the perpendicular line passing through the origin and perpendicular to the coordinate axis x'-axis and the z'-axis is taken as the y'-axis; a first positioning block 1011 is set perpendicular to the z'-axis in the solid area outside the external pressing plate 1;

[0151] S102: The included angle between the first positioning block 1011 and the second positioning block 1012 is 60°; a polyhedron is fixedly provided in the center area of ​​the horizontal rotary worktable; the polyhedron is rotated 60°, and a second positioning block 1012 is provided in the solid area outside the external pressure plate 1 perpendicular to the z'-axis direction;

[0152] S103: Based on the angle (90°) between the first positioning block and the third positioning block and the angle (120°) between the first positioning block and the fourth positioning block, set the third positioning block and the fourth positioning block in sequence according to the S102 method.

[0153] Furthermore, in order to improve the positioning accuracy of the positioning block on the external pressure plate 1, it is necessary to calibrate the positional relationship of the first positioning block 1011, the second positioning block 1012, the third positioning block 1013 and the fourth positioning block 1014 relative to the z' axis, which includes the following steps:

[0154] S1011: Setting the positioning block approximately perpendicular to the z' axis by visual inspection;

[0155] S1012: By installing a dial indicator on the machine tool spindle, parallel movement along the dial indicator coordinate axis x' can be achieved, and the dial indicator displacement probe contacts the side of the positioning block to be measured; the change in the dial indicator pointer reading is calculated, and the angle of the positioning block is adjusted until η is less than the threshold, then it is determined that the alignment is completed.

[0156] Furthermore, in order to improve the positioning accuracy of the positioning block on the external pressure plate 1, it is necessary to calibrate the rotation accuracy of the polyhedron when it is rotated by α degrees in S102, which includes the following steps:

[0157] S1021: Setting the photoelectric autocollimator parallel to the plane where the coordinate axes x' and z' are located; selecting the initial position when the first positioning block 1011 is set perpendicular to the z' axis in S101, adjusting the angle of the photoelectric autocollimator relative to the x' axis so that the reading of the photoelectric autocollimator on any optional reflective surface of the polyhedron is 0, and fixing the photoelectric autocollimator;

[0158] S1022: For the second positioning block 1012, the number of reflecting surfaces N of the polyhedron satisfies N=k×360 / α=6k, where k is a positive integer. Therefore, considering the difficulty and cost of processing the polyhedron, a hexahedron, a dodecahedron and an octahedron can be selected; the polyhedron is rotated by k reflecting surfaces (the corresponding k values ​​for the hexahedron, the dodecahedron and the octahedron are 1, 2 and 3), the rotation angle of the polyhedron is fine-tuned so that the reading of the photoelectric autocollimator is 0, the rotation angle of the polyhedron is fixed, and the correction of the second positioning block is completed; the correction of the third positioning block and the fourth positioning block is completed in the same way.

[0159] Furthermore, in order to improve the accuracy of the positioning block timing, step 2 includes using a dial indicator to calibrate the positioning block position, specifically including the following steps:

[0160] S201: Adjust the rotation angle of the horizontal rotary table and visually determine that the positioning block is approximately horizontal.

[0161] S202: A dial indicator is mounted on the spindle of the machine tool and the spindle is moved left and right along the projection line of the radial plane of the preformed hollow part blank on the horizontal plane, and the angle of the positioning block is fine-tuned according to the percentage indication until the change η of the dial indicator pointer when the dial indicator needle slides from one end to the other end on the positioning block is less than the threshold value, and the positioning block is determined to be strictly horizontal.

[0162] The ratio of the length to the width or height of the positioning block is set to 5:1:1; increasing the ratio of the length to the width or height of the positioning block is conducive to obtaining a larger height difference at both ends of the top of the positioning block, so that the dial indicator has a larger reading change and obtains a more sensitive signal.

[0163] This embodiment sets a positioning block parallel to the built-in plane of the target hollow part, converts the angular relationship of the built-in plane of the target hollow part projected on the radial plane into the angular relationship between the positioning blocks, and realizes the relative position relationship positioning between the built-in planes of the target hollow part; at the same time, the inclination angle of the built-in plane of the target hollow part relative to the horizontal plane is converted into the angle between the positioning block and the horizontal plane, and the built-in plane of the target hollow part is aligned by confirming the position of the positioning block, thereby realizing the absolute position relationship positioning of the built-in plane of the target hollow part relative to the horizontal plane.

[0164] Example 4

[0165] This embodiment discloses a method for processing a hollow part with a built-in axially parallel plane, using the processing mold described in Example 1, such as Figure 7 As shown, in addition to step 1 and step 2 in embodiment 3, the following steps are also included:

[0166] Between step 1 and step 2, a pre-processing process of the preformed hollow part blank is also included;

[0167] A heat treatment process of the preformed hollow part blank is also included between the pre-processing process of the preformed hollow part blank and step 2;

[0168] After step 2, step 3 is provided: processing the preformed hollow part blank after alignment to obtain the built-in plane.

[0169] Specifically, the pre-processing process of the preformed hollow part blank includes the following steps:

[0170] S104: Select a group of centrosymmetrical first positioning through holes 105 , use the center line connecting the two as the reference line of the first positioning block, and obtain the angle α0 between the reference line and the first positioning block;

[0171] S105: Fix the preformed hollow part blank on the rotary table through the processing mold, and obtain the inclination angle α between the reference line and the horizontal plane - , based on the angle α0 and angle α - Get the rotary table rotation angle α required for the first positioning block to align t1 ; Based on α t1 Complete the initial alignment of the first built-in plane; specifically, α t1 Satisfaction: α t1 =α - +90°-α0;

[0172] S106: Processing the mold to be processed after the preliminary alignment of the first built-in plane is completed with a 0.2 mm margin;

[0173] S107: Based on α t1 The angle α1 between the first built-in plane and the second built-in plane is used to obtain the rotary table rotation angle α required for the second positioning block to align. t2 , based on α t1 The angle α2 between the first built-in plane and the third built-in plane is used to obtain the rotary table rotation angle α required for the third positioning block to align. t3 ,…, based on α t and the angle α between the Nth built-in plane and the first built-in plane N Get the rotary table rotation angle α required for the Nth positioning block to align tNSpecifically, the Nth positioning block aligns the required rotary table rotation angle α tN , satisfying: α tN =α t1 +α N ; Based on α t2 ,…,α tN The second built-in plane, ..., the Nth built-in plane are preliminarily aligned; a 0.2mm margin is left for processing the preformed hollow part blank after the preliminarily aligned second built-in plane, ..., the Nth built-in plane is preliminarily aligned.

[0174] Preferably, in order to ensure positioning accuracy, the angle α0 between the reference line and the first positioning block is obtained by a photoelectric autocollimator.

[0175] This embodiment sets up a pre-machining process and performs pre-machining under the premise of meeting the accuracy requirements, thereby improving the problems of reference drift, tool overheating and raw material aging and deformation caused by long finishing time, which helps to improve processing accuracy and extend tool life.

[0176] The present invention provides a pre-machining process for the built-in plane of the target hollow part before fine machining, which can remove the raw material excess designed in the pre-formed hollow part blank, reduce the burden on the tool during precise machining, avoid tool overheating and raw material aging problems caused by long fine machining time, and help improve machining accuracy and extend tool life.

[0177] Compared with the prior art, the present invention uses the angle scale of the rotary table in the pre-machining process, which can achieve alignment more quickly while meeting the machining accuracy, thereby improving the machining efficiency.

[0178] Specifically, the tool used for processing in S106 and step 3 is a carbide tool that meets the following requirements: diameter 16 mm, chamfer radius 2 mm, and tool speed 1000 r / min.

[0179] Specifically, the hollow part is made of titanium alloy.

[0180] Preferably, a heat treatment process of the preformed hollow part blank is further included between the pre-processing process and step 2 to further reduce the residual stress of the pre-processing process, and the following steps are performed in sequence:

[0181] S108: Heat treatment at 120°C for 6 hours, followed by air cooling to room temperature;

[0182] S109: Treat at -50°C for 2 h, then allow to warm to room temperature;

[0183] S110: Heat treatment at 120℃ for 6h, then air cooling or furnace cooling to room temperature.

[0184] Specifically, step 3 and S106-S107 of machining parts using a machine tool include the following steps:

[0185] S301: Using the x, y, and z three-axis spatial coordinate system set by the machine tool itself, wherein the x-axis is parallel to the horizontal plane, the y-axis is parallel to the axis of the processed part, and the z-axis is perpendicular to the horizontal plane, a three-dimensional model of the preformed hollow part blank and a three-dimensional model of the processed part are constructed;

[0186] S302: The programming software compares the three-dimensional model of the preformed hollow part blank with the three-dimensional model of the finished part to obtain the area to be processed F (x, y, z) and generate a processing program;

[0187] S303: Processing the aligned part from the inside out based on the machining program to obtain a finished part with a corresponding built-in plane.

[0188] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for processing a hollow part, characterized in that: Using the following processing device, the processing device includes a processing mold; The processing mold comprises: an external pressing plate (1), a pull rod (2) and a bottom fixing member (3); The external pressing plate (1) is located at one end of the pull rod (2), and the bottom fixing piece (3) is located at the other end of the pull rod (2). The external pressing plate (1) and the bottom fixing piece (3) are fixedly connected via the pull rod (2). A fixing area for clamping and fixing the preformed hollow part blank is provided between the external pressing plate (1) and the bottom fixing piece (3); The hollow part has an internal axial parallel plane, and an end of the external pressure plate (1) away from the bottom fixing member (3) is provided with a positioning block (101) parallel to the internal axial parallel plane. A central hole (102) for the entry and exit of a machining tool (8) is provided at the center of the external pressure plate (1), and the positioning block (101) is arranged in a solid area (103) on the outer peripheral edge of the central hole (102); The processing device also includes a vertical rotary table (5), a machine tool platform (6) and a machine tool spindle (7); The vertical rotary table (5) is fixedly connected to the other end of the bottom fixing member (3) facing away from the external pressure plate (1), and the vertical rotary table (5) is movably connected to one side of the machine tool platform (6); the other side of the machine tool platform (6) is movably connected to a machine tool spindle (7), and the end of the machine tool spindle (7) close to the external pressure plate (1) is connected to a machining tool (8); The processing method comprises the following steps: Step 1: Set a positioning block with a built-in plane parallel to the axial direction of the target hollow part on the outside of the feed end of the processing mold; Step 2: Based on the positioning block, the preformed hollow part blank is aligned on the built-in plane of the positioning block corresponding to the target hollow part; Step 3: Processing the aligned preformed hollow part blank to obtain the built-in plane; Step 1 includes the following steps: S101: The external pressing plate (1) is coaxially fixed to the horizontal rotary table through a set of first positioning through holes (105) that are centrally symmetrical with respect to the geometric center of the feed end of the processing mold; the geometric center of the feed end of the processing mold is taken as the origin, the center line of the first positioning through holes (105) at the initial position is taken as the coordinate axis x' axis, and the coordinate axis z' axis is set perpendicular to the x' axis in the plane of the horizontal rotary table at the initial position, and the perpendicular line passing through the origin and perpendicular to the coordinate axis x' axis and the z' axis is taken as the y' axis; a first positioning block (1011) is set perpendicular to the z' axis in the solid area outside the external pressing plate (1); the initial position is the position of the external pressing plate, and an optional position after the horizontal rotary table is fixed is used as the initial position. After the coordinate system is established, the horizontal rotary table rotates without affecting the coordinate system; S102: Obtaining the included angle α between the first positioning block (1011) and the second positioning block (1012); fixing a polyhedron in the central area of ​​the horizontal rotary table; rotating the polyhedron by α degrees; and setting a second positioning block (1012) in the solid area outside the external pressure plate (1) perpendicular to the z'-axis direction; S103: Based on the angle between the first positioning block and the Mth positioning block, the steps are the same as S102, and the Mth positioning block is set, where M is an integer greater than or equal to 3; In S102, the polyhedron rotates with the workbench by α degrees, which includes the following steps: S1021: Setting the photoelectric autocollimator parallel to the plane where the coordinate axes x' and z' are located; selecting the initial position when the first positioning block is set perpendicular to the z' axis in S101, adjusting the angle of the photoelectric autocollimator relative to the x' axis so that the reading of the photoelectric autocollimator on any optional reflective surface of the polyhedron is 0, and fixing the photoelectric autocollimator; S1022: Rotate the polyhedron by k reflective surfaces, fine-tune the bedroom rotating workbench, adjust the rotation angle of the polyhedron so that the photoelectric autocollimator reading is 0, and fix the polyhedron to complete the calibration; where k satisfies: k = α × N / 360, k is a positive integer, and N is the number of reflective surfaces of the polyhedron.

2. The method for processing a hollow part according to claim 1, wherein: The positioning blocks (101) are provided with one or more, corresponding one to one with the built-in axially parallel planes.

3. The method for processing a hollow part according to claim 2, wherein: The angular relationship between the projections of a plurality of positioning blocks (101) in a radial plane is calibrated by a photoelectric autocollimation instrument.

4. The method for processing a hollow part according to claim 3, characterized in that: The arrangement of a plurality of positioning blocks (101) on the external pressure plate (1) is calibrated and positioned by a rotary table.

5. The method for processing a hollow part according to claim 1, wherein: The positioning block (101) is fixed to the solid area of ​​the outer peripheral edge of the external pressure plate (1) along its length direction; the ratio of the length to the width or height of the positioning block (101) is greater than 2.

6. The method for processing a hollow part according to claim 1, wherein: A pull rod mounting hole (104) is provided on the edge of the body of the external pressure plate (1); one end of the pull rod (2) is provided with a thread, and the other end is fixedly connected to the bottom fixing member (3), and the thread matches the nut.

7. The method for processing a hollow part according to claim 6, characterized in that: The pull rod mounting hole (104), the pull rod (2) and the nut form a movable connection structure for adjusting the degree of compression of the external pressure plate (1) and the bottom fixing member (3) on the hollow part (4).

8. The method for processing a hollow part according to claim 6, wherein: The pull rod mounting hole (104) is centrally symmetrically arranged relative to the center of the external pressure plate (1).

9. The method for processing a hollow part according to claim 1, wherein: The solid area (103) at the peripheral edge is provided with a plurality of first positioning through holes (105); each of the first positioning through holes (105) is provided with a positioning pin (106) having one end axially movably connected to the preformed hollow part blank.

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