One-stop machining method for high-precision step deep and long hole of high-voltage switch butt joint

Abstract

The invention discloses a one-stop machining method for a high-precision step deep and long hole in a high-voltage switch butt joint. The one-stop machining method comprises the steps that a special tool is adopted for clamping and aligning a workpiece. And oppositely drilling through holes in the two sides of the workpiece by using the combined tool to obtain the through holes. And the combined tool enters the through hole from the two ends of the main hole to bore the right-end stepped hole and the left-end stepped hole step by step. And the coaxiality of the left end stepped hole and the right end stepped hole is detected on the machine. The special tool is matched with the combined tool to complete machining of deep and long holes of parts, on-machine detection can be achieved, defective products are effectively prevented from flowing out, a traditional machining method for the high-precision stepped deep and long holes is broken through, the problem that a drill bit deflects, and consequently a follow-up tool is broken is solved, and the machining efficiency is improved. The high-precision step deep and long hole machining device reduces low production efficiency and product percent of pass caused by out-of-tolerance straightness of a grinding process, and realizes one-stop machining of a high-precision step deep and long hole of a high-voltage switch with higher efficiency and higher quality under the condition of ensuring dimensional precision, form and location tolerance and surface quality.

Description

Technical Field

[0001] This invention relates to the field of high-precision stepped deep and long hole machining technology for connectors, and particularly to a one-stop machining method for high-precision stepped deep and long holes in high-voltage switch connectors. Background Technology

[0002] High-precision stepped parts are important components of high-voltage switches. The machining of deep and long holes in high-precision stepped parts is an important step in the machining of mechanical parts. Whether the dimensional tolerances and geometric tolerances are qualified plays a key role in subsequent assembly.

[0003] Currently, the common process for machining high-precision stepped deep holes is drilling-reaming-boring-grinding. While this process can achieve the required precision—drilling: using an extended twist drill bit to create the initial channel for subsequent machining; reaming: enlarging the hole diameter and correcting the rough surface after drilling, reducing machining allowance in subsequent processes; boring: further improving hole diameter accuracy and surface finish, bringing the dimensions close to the final requirements; grinding: eliminating errors from previous processes through fine grinding, ultimately achieving the designed high-precision standard—it also has many drawbacks, especially for 701 stainless steel, where the cutting edge is vulnerable when using an extended twist drill bit in the initial drilling process. The closer to the center of the part, the more uneven the force, making it prone to wobble. This increases the probability of the drill bit deviating from the initial hole axis. This deviation is directly transmitted to subsequent processes, requiring reaming and boring tools to forcibly correct the deviation, significantly increasing the probability of tool breakage and the risk of subsequent tool breakage. Furthermore, the straightness error of the machined hole is large and difficult to completely eliminate during the reaming and boring stages, and cannot be detected in time. The straightness deviation problem can only be discovered after the grinding process. By this time, the part has already undergone multiple processing costs and can only be scrapped or reworked. This not only results in low production efficiency and product qualification rate but also increases production costs.

[0004] Therefore, drill bit misalignment can easily lead to subsequent tool breakage and straightness deviations in the grinding process, ultimately affecting production efficiency and product qualification rate. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a one-stop machining method for high-precision stepped deep and long holes of high-voltage switch heads. The high-precision stepped deep and long holes of the heads are machined to meet the requirements of the drawings by pre-drilling through holes, boring in stages, and checking coaxiality on the machine.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A one-stop machining method for high-precision stepped deep and elongated holes in high-voltage switch heads includes:

[0008] Specialized tooling is used to clamp and align the workpiece.

[0009] Using a combination of cutting tools, through holes are drilled on both sides of the workpiece to obtain the main hole.

[0010] The combined cutting tool enters from both ends of the main hole and borings the stepped hole at the right end and the stepped hole at the left end in stages.

[0011] The coaxiality of the stepped hole at the left end and the stepped hole at the right end is checked in the machine.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] Specialized tooling simultaneously positions both ends of the workpiece, ensuring its geometric tolerances. A combination of cutting tools machines deep, elongated holes step-by-step on both sides of the workpiece, preventing drill bit wobble from causing deviation between the main hole and the design axis, thus avoiding the risk of subsequent tool breakage. This also reduces straightness deviations in subsequent machining processes of the stepped hole and ensures the dimensional accuracy of the deep, elongated hole. Combined with in-machine inspection of the coaxiality of the stepped holes at both ends, defective products are effectively prevented from being exported, improving product quality and production efficiency. This achieves one-stop machining of high-precision stepped, deep, elongated holes for high-voltage switch heads with higher efficiency and quality while ensuring dimensional accuracy, geometric tolerances, and surface quality.

[0014] More preferably, the combined cutting tool enters the right-end stepped hole and the left-end stepped hole of the step boring process from both ends of the main hole, including:

[0015] The combined cutting tool starts to enlarge the stepped hole from the right end of the through hole, and then proceeds through semi-finish boring, finish boring, and finish boring to obtain the stepped hole at the right end.

[0016] Enter from the left end of the main hole to enlarge and fine bore, resulting in a stepped hole at the left end.

[0017] A further preferred embodiment involves using a combination tool to enlarge a stepped hole from the right end of the main hole, through semi-finish boring, finish boring, and finish boring, to obtain the stepped hole at the right end, including:

[0018] The rough boring tool enters the through hole from the right end of the workpiece, begins to enlarge the stepped hole at the right end, and guides the semi-finish boring tool to obtain the main hole.

[0019] The semi-finish boring tool enters the main hole to perform semi-finish boring, resulting in a semi-finish stepped hole on the right end.

[0020] The first composite precision boring tool enters the right-end semi-precision stepped hole for precision boring and guides the guide bar boring tool.

[0021] The guide bar boring tool enters the right end semi-finish stepped hole for fine boring to obtain the right end stepped hole.

[0022] By adopting the above technical solution, a rough hole for the main hole is machined from the right end of the workpiece using a rough boring tool. Then, a semi-finish boring tool, a first compound finish boring tool, and a guide bar boring tool are used for semi-finish boring to obtain the stepped hole at the right end. The tool paths of the guide bar boring tool and the semi-finish boring tool are matched to each other, which can better ensure the dimensional accuracy, form and position tolerance, and surface quality of the stepped hole at the right end, reduce the error of a single machining, and achieve the purpose of meeting the requirements of the drawing.

[0023] A further preferred embodiment involves entering from the left end of the main hole to perform reaming and fine boring, resulting in a stepped hole at the left end, including:

[0024] The rough boring tool enters the main hole from the left end of the workpiece to create a step, resulting in a rough hole with a step on the left end.

[0025] Under the influence of the machine tool's rotational accuracy and the main hole's alignment and guidance, the second composite precision boring tool enters the left-end stepped rough hole for precision boring, thus obtaining the left-end stepped hole.

[0026] By adopting the above technical solution, the left-end stepped hole is directly obtained after rough boring with a rough boring tool and fine boring with a second compound fine boring tool. This not only saves process steps but also ensures that the machining accuracy meets the drawing requirements.

[0027] Further optimization involves on-machine testing of the coaxiality of the left and right stepped holes, including:

[0028] The machine tool probe collects the coordinate data of the main hole and establishes the reference axis.

[0029] Measure the positional data of each diameter segment of the right-end stepped hole and the corresponding points, and fit the actual axis.

[0030] The target coaxiality is obtained by combining the coaxiality of the actual axis with respect to the reference axis.

[0031] Compare whether the target coaxiality meets the coaxiality requirements on the drawing.

[0032] By adopting the above technical solution, in-machine inspection can complete accuracy verification without disassembling parts, promptly detect unqualified products, effectively prevent defective products from flowing out, and avoid waste in subsequent processes.

[0033] Further optimization involves the machine tool probe acquiring the main hole coordinate data and establishing a reference axis, including:

[0034] The machine tool spindle is driven to move the machine tool probe to the right end of the main hole, and the probe trigger end is adjusted to be perpendicular to the hole wall.

[0035] According to the preset detection program path in the machine tool's measurement system, the probe is driven to collect coordinate data in the circumferential direction of the main hole.

[0036] The machine tool's measurement system fits the axis based on the coordinate data to obtain the reference axis.

[0037] Using the above technical solution, a baseline is established with the main hole to create a reference object for judging the coaxiality of the subsequent right-end stepped hole and left-end stepped hole.

[0038] Further optimization involves measuring the positional data of the right-end stepped hole and each diameter segment of the right-end stepped hole, and fitting the actual axis, including:

[0039] The machine tool is driven to move the probe to the right-end stepped hole position, and the circumferential point data corresponding to each hole diameter segment of the right-end stepped hole are collected to obtain the right-end point position data.

[0040] The machine tool's measurement system calculates the position data of the right end point, fits the actual axis of the right end stepped hole, and obtains the actual axis of the right end.

[0041] The machine tool moves the probe to the left-end stepped hole position and collects the circumferential point data corresponding to each diameter segment of the left-end stepped hole to obtain the left-end point position data.

[0042] The machine tool's measurement system calculates the position data of the left endpoint, fits the actual axis of the left-end stepped hole, and obtains the actual axis of the left end. The position data of the right endpoint is located on the critical diameter segment of the right-end stepped hole that is associated with the reference axis. The position data of the left endpoint is located on the critical diameter segment of the left-end stepped hole that is associated with the reference axis.

[0043] By adopting the above technical solution, the actual axis can be obtained, providing a specific object to be measured for judging the coaxiality of the right-end stepped hole and the left-end stepped hole, thus ensuring accurate judgment of the coaxiality of the holes at both ends of the workpiece.

[0044] Further optimization involves combining the coaxiality of the actual axis with respect to the reference axis to obtain the target coaxiality, including:

[0045] Obtain the actual axis on the right, the actual axis on the left, and the reference axis.

[0046] The machine tool's measurement system calculates the deviation between the actual axis on the right end and the reference axis to obtain the coaxiality of the right end.

[0047] The machine tool's measurement system calculates the deviation between the actual axis at the left end and the reference axis to obtain the coaxiality of the left end.

[0048] The target coaxiality includes the coaxiality of the right end and the coaxiality of the left end.

[0049] Further optimization involves comparing whether the target coaxiality meets the coaxiality requirements on the drawing, including:

[0050] Determine whether the coaxiality of the right end is within the coaxiality range of the right-end stepped hole preset on the drawing.

[0051] Determine whether the coaxiality of the left end is within the coaxiality range of the left end stepped hole preset on the drawing.

[0052] The test results were obtained.

[0053] By adopting the above technical solution, it is possible to determine whether the coaxiality of the left and right stepped holes of the deep and long hole of the workpiece meets the requirements by comparison and judgment, verify whether the machining accuracy of the workpiece meets the drawing tolerance requirements, screen out unqualified products in a timely manner, and prevent defective products from flowing into subsequent processes.

[0054] A further optimization involves using a combination tool to drill through holes on both sides of the workpiece, or using a gun drill in the combination tool to pre-drill through holes at corresponding positions on both sides of the workpiece.

[0055] By adopting the above technical solution, the use of a gun drill shortens the tool length and reduces the phenomenon of the drill bit cutting edge deflecting due to uneven force near the center of the part. Attached Figure Description

[0056] Figure 1 This is a block diagram of the method in this embodiment.

[0057] Figure 2 This is a flowchart illustrating the method for obtaining the right-end stepped hole using a combination of semi-finish boring, finish boring, and finish boring tools in this embodiment.

[0058] Figure 3 This is a flowchart illustrating the method for fitting the actual axis by measuring the point data of the right-end stepped hole and each diameter segment of the right-end stepped hole in this embodiment.

[0059] Figure 4 This is a schematic diagram of the part clamping and alignment in this embodiment.

[0060] Figure 5 This is a schematic diagram of the gun drilling process in this embodiment.

[0061] Figure 6 This is a schematic diagram of the rough boring tool machining in this embodiment.

[0062] Figure 7 This is a schematic diagram of the semi-finish boring tool machining in this embodiment.

[0063] Figure 8 This is a schematic diagram of the first composite precision boring tool machining in this embodiment.

[0064] Figure 9 This is a schematic diagram of the guide bar boring tool machining in this embodiment.

[0065] Figure 10 This is a schematic diagram of the rough boring tool machining in this embodiment.

[0066] Figure 11 This is a schematic diagram of the second composite precision boring tool in this embodiment.

[0067] Figure 12 This is a schematic diagram of the machine tool probe's in-machine testing in this embodiment.

[0068] Figure 13 This is a schematic diagram of the structure of the deep, elongated hole fabricated in this embodiment.

[0069] Figure 14 This is a flowchart of the process flow for processing the workpiece in this embodiment.

[0070] Reference numerals: 1-Workpiece; 2-Special tooling; 3-Gun drill; 4-Rough boring tool; 5-Semi-finish boring tool; 6-First compound finish boring tool; 7-Guide bar boring tool; 8-Second compound finish boring tool; 9-Machine tool probe. Detailed Implementation

[0071] The following is in conjunction with the appendix Figures 1-14 The present invention will be described in further detail below.

[0072] A one-stop machining method for high-precision stepped deep holes in high-voltage switch heads, such as... Figure 1 As shown, it includes:

[0073] S101 uses a special fixture 2 to clamp and align the workpiece 11. The workpiece 11 is clamped in the special fixture 2, and the two side walls to be processed are placed near the combined tool.

[0074] S102 uses the gun drill 3 in the combination tool to pre-drill through holes at corresponding positions on both sides of the workpiece 11 to obtain the main hole. The use of the gun drill shortens the tool length and reduces the phenomenon of the drill bit cutting edge deflecting due to uneven force when it is close to the center of the part.

[0075] The S103 combination tool enters the step boring holes at the right and left ends from both ends of the main hole.

[0076] S104 performs on-machine testing to check the coaxiality of the left and right stepped holes.

[0077] Specialized tooling 2 simultaneously positions both ends of the workpiece, ensuring its geometric tolerances. A combination of cutting tools then machines deep, elongated holes in stages on both sides of the workpiece. This prevents drill bit misalignment from causing deviation between the main hole and the design axis, thus avoiding the risk of subsequent tool breakage. It also reduces straightness deviations in subsequent machining processes of the stepped hole and ensures the dimensional accuracy of the deep, elongated hole. Combined with in-machine inspection of the coaxiality of the stepped holes at both ends, it effectively prevents defective products from being manufactured, improving product quality and production efficiency. Therefore, while ensuring dimensional accuracy, geometric tolerances, and surface quality, it achieves one-stop machining of high-precision stepped, deep, elongated holes for high-voltage switch heads with higher efficiency and higher quality.

[0078] Specifically, in this embodiment, the combined tool performs step boring of the right-end stepped hole and the left-end stepped hole, including:

[0079] The combined cutting tool starts to enlarge the stepped hole from the right end of the through hole, and then proceeds through semi-finish boring, finish boring, and finish boring to obtain the stepped hole at the right end.

[0080] Enter from the left end of the main hole to enlarge and fine bore, resulting in a stepped hole at the left end.

[0081] Specifically, the combination tool includes a gun drill 3, a rough boring tool 4, a semi-finish boring tool 5, a first compound finish boring tool 6, a guide bar boring tool 7, and a second compound finish boring tool 8. It can be clamped on the machine tool at once, saving the trouble of clamping the tool multiple times during the machining process and saving the time of changing the tool.

[0082] Specifically, such as Figure 2 As shown, in this embodiment, the combined cutting tool expands a stepped hole from the right end of the through hole, and through semi-finish boring, finish boring, and finish boring, a stepped hole is obtained at the right end, including:

[0083] The rough boring tool 4 enters the through hole from the right end of the workpiece 1, begins to enlarge the stepped hole at the right end, and guides the semi-finish boring tool 5 to obtain the main hole.

[0084] The semi-finish boring tool 5 enters the main hole to perform semi-finish boring, resulting in a semi-finish stepped hole on the right end.

[0085] The first composite precision boring tool 6 enters the right-end semi-precision stepped hole for precision boring and guides the guide bar boring tool 7.

[0086] The guide bar boring tool 7 enters the right end semi-finish stepped hole for fine boring to obtain the right end stepped hole.

[0087] The rough hole of the main hole is machined from the right end of the workpiece 1 by the rough boring tool 4, and then the right end stepped hole is obtained by the semi-finish boring tool 5, the first compound fine boring tool 6, and the guide bar boring tool 7. The tool paths of the guide bar boring tool 7 and the semi-finish boring tool 5 are matched with each other, which can better ensure the dimensional accuracy, form and position tolerance and surface quality of the right end stepped hole, reduce the error of a single machining, and achieve the purpose of meeting the drawing requirements.

[0088] Specifically, in this embodiment, the hole is enlarged and precision bored from the left end of the main hole to obtain a stepped hole at the left end, including:

[0089] The rough boring tool 4 enters the main hole from the left end of the workpiece 1 to expand the step, thus obtaining a rough hole with a step on the left end.

[0090] Under the influence of the machine tool's rotational accuracy and the main hole's alignment and guidance, the second composite precision boring tool 8 enters the right-end stepped rough hole for precision boring, resulting in the left-end stepped hole.

[0091] After rough boring with rough boring tool 4 and finish boring with the second compound finish boring tool 8, the left-end stepped hole is directly obtained, which not only saves the process but also ensures that the machining accuracy meets the drawing requirements.

[0092] Specifically, in this embodiment, the on-machine detection of the coaxiality of the left-end stepped hole and the right-end stepped hole includes:

[0093] The machine tool probe 9 collects the coordinate data of the main hole and establishes the reference axis.

[0094] Measure the positional data of each diameter segment of the right-end stepped hole and the corresponding points, and fit the actual axis.

[0095] The target coaxiality is obtained by combining the coaxiality of the actual axis with respect to the reference axis.

[0096] Compare whether the target coaxiality meets the coaxiality requirements on the drawing.

[0097] In-machine inspection can complete accuracy verification without disassembling parts, promptly identify unqualified products, effectively prevent defective products from flowing out, and avoid waste in subsequent processes.

[0098] Specifically, in this embodiment, the machine tool probe 9 collects the main hole coordinate data and establishes the reference axis, including:

[0099] The machine tool spindle is driven to move the machine tool probe 9 to the right end of the main hole, and the probe trigger end is adjusted to be perpendicular to the hole wall.

[0100] According to the preset detection program path in the machine tool's measurement system, the probe is driven to collect coordinate data in the circumferential direction of the main hole.

[0101] The machine tool's measurement system fits the axis based on the coordinate data to obtain the reference axis.

[0102] Establish a baseline using the main hole to create a reference object for determining the coaxiality of the subsequent right-end stepped hole and left-end stepped hole.

[0103] Specifically, such as Figure 3 As shown, in this embodiment, the point data of each diameter segment of the right-end stepped hole are measured respectively, and the actual axis is fitted, including:

[0104] The machine tool is driven to move the probe to the right-end stepped hole position, and the circumferential point data corresponding to each hole diameter segment of the right-end stepped hole are collected to obtain the right-end point position data.

[0105] The machine tool's measurement system calculates the position data of the right end point, fits the actual axis of the right end stepped hole, and obtains the actual axis of the right end.

[0106] The machine tool moves the probe to the left-end stepped hole position and collects the circumferential point data corresponding to each diameter segment of the left-end stepped hole to obtain the left-end point position data.

[0107] The machine tool's measurement system calculates the position data of the left endpoint, fits the actual axis of the left-end stepped hole, and obtains the actual axis of the left end. The position data of the right endpoint is located on the critical diameter segment of the right-end stepped hole that is associated with the reference axis. The position data of the left endpoint is located on the critical diameter segment of the left-end stepped hole that is associated with the reference axis.

[0108] The actual axis can be obtained, providing a specific object to be measured for judging the coaxiality of the right-end stepped hole and the left-end stepped hole, ensuring accurate judgment of the coaxiality of the holes at both ends of workpiece 1.

[0109] Specifically, in this embodiment, the target coaxiality is obtained by combining the coaxiality of the actual axis with respect to the reference axis, including:

[0110] Obtain the actual axis on the right, the actual axis on the left, and the reference axis.

[0111] The machine tool's measurement system calculates the deviation between the actual axis on the right end and the reference axis to obtain the coaxiality of the right end.

[0112] The machine tool's measurement system calculates the deviation between the actual axis at the left end and the reference axis to obtain the coaxiality of the left end.

[0113] The target coaxiality includes the coaxiality of the right end and the coaxiality of the left end.

[0114] Specifically, in this embodiment, comparing whether the target coaxiality meets the coaxiality requirements on the drawing includes:

[0115] Determine whether the coaxiality of the right end is within the coaxiality range of the right-end stepped hole preset on the drawing.

[0116] Determine whether the coaxiality of the left end is within the coaxiality range of the left end stepped hole preset on the drawing.

[0117] The test results were obtained.

[0118] By comparison, it can be determined whether the coaxiality of the left and right stepped holes of the deep and long hole of workpiece 1 meets the requirements, verify whether the machining accuracy of workpiece 1 meets the drawing tolerance requirements, and promptly screen out unqualified products to prevent defective products from flowing into subsequent processes.

[0119] Example 1

[0120] Please combine Figures 1-14Taking the machining of a φ35 stepped deep hole as an example, a special tooling 2, a combination of cutting tools, and a machine tool probe 9 for coaxiality detection are selected. Among them, the gun drill 3 is a D33*8D gun drill, the rough boring tool 4 is a compound rough boring tool, the semi-finish boring tool 5 is a semi-finish guide bar boring tool, the first compound finish boring tool 6 is a first compound guide bar finish boring tool, used for finish boring the stepped part of the deep hole from the right end of part 1, the guide bar boring tool 7 is a guide bar finish boring tool, the second compound finish boring tool 8 is a second compound guide bar finish boring tool, used for finish boring the stepped part of the deep hole from the left end of part 1, and the machine tool probe 9 is a trigger-type optical machine tool probe.

[0121] The combined tool is installed on the machine tool at one time, avoiding the risk of deviation when drilling with an extended twist drill bit, reducing the probability of tool breakage, and better ensuring the dimensional accuracy, form and position tolerance and surface quality of part 1, reducing straightness error, eliminating the need to wait for the grinding process to discover defects, and improving production efficiency; the special tooling 2 is designed according to the stepped drop of the workpiece 1's shape, which is specifically designed for use, making it easy to process deep and long holes on the machine tool and providing good stability.

[0122] The main hole machining is divided into three steps: φ33 pre-drilling, φ34 semi-finish boring, and φ35 finish boring, progressively refining the dimensions and reducing errors in a single machining operation. The guide bar boring tool 7 and the semi-finish boring tool 5 are matched to ensure the accurate dimensions of the φ35 main hole, meeting the drawing requirements. The specific machining process is described below:

[0123] Workpiece 1 is clamped on special fixture 2 and aligned. The process involves three steps: boring the right-end stepped hole and the left-end stepped hole using a combination of tools, and then checking the coaxiality on the machine. The boring process for the right-end stepped hole is as follows:

[0124] Use a gun drill 3 to drill through holes of φ33 on both sides of workpiece 1, such as Figure 5 As shown, the tool length can be shortened while meeting the usage requirements, effectively controlling tool costs, reducing the risk of tool deviation during drilling, and providing a precise guiding channel for subsequent boring processes.

[0125] Use a compound rough boring tool to enter the through hole from the right end of workpiece 1, such as... Figure 6 As shown, the right-end stepped hole is enlarged to the target size, resulting in a main hole with a step. During the enlargement process, it also guides the φ34 semi-finish guide boring tool. This tool has both enlargement and guiding functions, providing stable guidance for the subsequent φ34 semi-finish guide boring tool while machining the right-end stepped hole, thus preventing path deviation during the semi-finish boring process.

[0126] Using a semi-finish guide bar boring tool, the φ34 main hole is semi-finished to obtain a semi-finished stepped hole on the right end, as shown below. Figure 7 As shown, the guide bar structure ensures the stability of the tool during the machining process, effectively controls the straightness of the φ34 main hole, and reserves a uniform machining allowance for the subsequent precision boring process.

[0127] Use the first composite guide bar precision boring tool to precision bore the right end semi-precision stepped hole, such as... Figure 8 As shown, it guides the φ35 guide bar precision boring tool into the right end semi-precision stepped hole.

[0128] Use a guide bar precision boring tool to precision bore the right end of the semi-finished stepped hole, such as... Figure 9 As shown, a stepped hole with a diameter of φ35 is obtained at the right end.

[0129] Boring the stepped hole at the left end:

[0130] The compound rough boring tool enters the main hole from the left end of workpiece 1 to create a step, as shown below. Figure 10 As shown, the coarse hole of the left end step is obtained.

[0131] Under the influence of machine tool rotation accuracy and the alignment and guidance of the φ35 precision boring main hole, such as Figure 11 As shown, the left-end stepped rough hole is precision bored using a second composite guide bar precision boring tool to obtain the left-end stepped hole.

[0132] Then, the coaxiality of the left-end stepped hole and the right-end stepped hole is checked in the machine, including:

[0133] The drive machine tool spindle moves the trigger-type optical machine tool probe to the right end of the main hole, such as... Figure 12 As shown, adjust the probe trigger end to be perpendicular to the hole wall.

[0134] According to the preset detection program path in the machine tool's measurement system, the probe is driven to collect coordinate data in the circumferential direction of the main hole.

[0135] The machine tool's measurement system fits the axis based on the coordinate data to obtain the reference axis.

[0136] The machine tool is driven to move the probe to the right-end stepped hole position, and the circumferential point data corresponding to each hole diameter segment of the right-end stepped hole are collected to obtain the right-end point position data.

[0137] The machine tool's measurement system calculates the position data of the right end point, fits the actual axis of the right end stepped hole, and obtains the actual axis of the right end.

[0138] The machine tool moves the probe to the left-end stepped hole position and collects the circumferential point data corresponding to each diameter segment of the left-end stepped hole to obtain the left-end point position data.

[0139] The machine tool's measurement system calculates the position data of the left end point, fits the actual axis of the left end stepped hole, and obtains the actual axis of the left end.

[0140] Obtain the actual axis on the right, the actual axis on the left, and the reference axis.

[0141] The machine tool's measurement system calculates the deviation between the actual axis on the right end and the reference axis to obtain the coaxiality of the right end.

[0142] The machine tool's measurement system calculates the deviation between the actual axis at the left end and the reference axis to obtain the coaxiality of the left end.

[0143] Determine if the coaxiality of the right end is within the pre-defined coaxiality range of the right-end stepped hole on the drawing. Determine if the coaxiality of the left end is within the pre-defined coaxiality range of the left-end stepped hole on the drawing. Finally, obtain the test results.

[0144] In-machine inspection can complete accuracy verification without disassembling the workpiece, promptly identify unqualified products, effectively prevent defective products from flowing out, and avoid waste in subsequent processes.

[0145] Specifically, such as Figure 13 As shown, in this embodiment, the diameter accuracy of the precision-bored φ34 main hole is between IT10 and IT9, with a focus on ensuring the straightness of the hole to create favorable conditions for subsequent precision boring processes. The right-end stepped hole has a dimensional accuracy ≥ IT8 and a surface roughness < Ra1.6μm, ensuring not only the dimensional accuracy and surface roughness of the deep, long hole but also guiding the φ35 guide bar boring tool 7, ensuring accurate guidance of the precision boring tool. The precision-bored φ35 main hole has a dimensional accuracy of IT7 and a surface roughness < Ra0.8μm. Through matching with the path of the semi-precision boring tool 5, the cylindricity, straightness, and coaxiality with the stepped holes at both ends of the hole are ensured. The coaxiality between the left-end stepped hole and the right-end stepped hole is ≤0.02mm, meeting the tolerance requirements of the drawing, allowing for timely verification of machining accuracy, and ensuring product qualification.

[0146] In summary, the guide bar boring tool 7 performs semi-finish boring from the right end of workpiece 1 to the depth required by the drawing, and its tool path matches that of the semi-finish boring tool 5, thus better ensuring the dimensional accuracy, geometric tolerances, and surface quality of workpiece 1. Utilizing the combined effect of machine tool rotational accuracy and the alignment and guidance of the φ35 precision boring main hole, the second composite precision boring tool 8 precision borings the stepped hole at the left end. The front alignment and guidance portion does not participate in cutting, thus not affecting the surface quality of the part. The machine tool probe 9 is used for in-machine inspection to check whether the coaxiality meets the drawing requirements, achieving a one-stop machining process for high-precision stepped deep holes in high-voltage switch heads with higher efficiency and higher quality.

[0147] This specific embodiment is merely an explanation of the invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of protection of this invention, they are protected by patent law.

Claims

1. A one-stop machining method for high-precision stepped deep and long holes in high-voltage switch fittings, used to machine high-precision stepped deep and long holes in parts by combining one-stop machining with on-machine inspection, characterized in that, include: Special tooling (2) clamps and aligns the workpiece (1); Using a combination of cutting tools, drill through holes on both sides of the workpiece (1) to obtain the main hole; The combined cutting tool enters the step-boring hole at the right end and the step-boring hole at the left end from both ends of the main hole; The coaxiality of the stepped hole at the left end and the stepped hole at the right end is checked in the machine.

2. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 1, characterized in that, The combined cutting tool enters the right-end stepped hole and the left-end stepped hole of the step boring process from both ends of the main hole, including: The combined cutting tool starts from the right end of the main hole to enlarge the stepped hole, and then proceeds through semi-finish boring, finish boring, and finish boring to obtain the stepped hole at the right end; Enter from the left end of the main hole to enlarge and fine bore, and obtain a stepped hole at the left end.

3. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 2, characterized in that, The combined cutting tool extends a stepped hole from the right end of the main hole, and through semi-finish boring, finish boring, and finish boring, obtains the stepped hole at the right end, including: The rough boring tool (4) enters the through hole from the right end of the workpiece, begins to enlarge the stepped hole at the right end, and guides the semi-finish boring tool (5) to obtain the main hole; The semi-finish boring tool (5) enters the main hole to perform semi-finish boring, resulting in a semi-finish stepped hole at the right end; The first composite precision boring tool (6) enters the right end semi-precision stepped hole for precision boring and guides the guide bar boring tool (7); The guide bar boring tool (7) enters the right end semi-finished stepped hole for fine boring to obtain the right end stepped hole.

4. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 2, characterized in that, The process of entering from the left end of the main hole for reaming and fine boring to obtain a stepped hole at the left end includes: The rough boring tool (4) enters the main hole from the left end of the workpiece to expand the step, thus obtaining a rough hole with a step at the left end; Under the influence of the machine tool's rotational accuracy and the alignment and guidance of the main hole, the second composite precision boring tool (8) enters the left-end stepped rough hole for precision boring, thus obtaining the left-end stepped hole.

5. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 4, characterized in that, The in-machine testing of the coaxiality of the left-end stepped hole and the right-end stepped hole includes: The machine tool probe (9) collects the coordinate data of the main hole and establishes the reference axis; Measure the positional data of the right-end stepped hole and each diameter segment of the right-end stepped hole respectively, and fit the actual axis; The target coaxiality is obtained by combining the coaxiality of the actual axis with respect to the reference axis; Compare whether the target coaxiality meets the coaxiality requirements on the drawing.

6. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 5, characterized in that, The machine tool probe (9) collects the coordinate data of the main hole and establishes the reference axis, including: The machine tool spindle is driven to move the machine tool probe to the right end entrance of the main hole, and the probe trigger end is adjusted to be perpendicular to the hole wall; According to the preset detection program path in the machine tool's measurement system, the probe is driven to collect the coordinate data of the main hole in the circumferential direction; The machine tool's measurement system fits the axis based on the coordinate data to obtain the reference axis.

7. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 6, characterized in that, The step of measuring the positional data of the right-end stepped hole and each diameter segment of the right-end stepped hole, and fitting the actual axis, includes: The machine tool is driven to move the probe to the position of the right-end stepped hole, and the circumferential point data corresponding to each diameter segment of the right-end stepped hole are collected to obtain the right-end point position data. The machine tool's measurement system calculates the position data of the right end point, fits the actual axis of the right end stepped hole, and obtains the actual axis of the right end. The machine tool is driven to move the probe to the left end stepped hole position, and the circumferential point data corresponding to each hole diameter segment of the left end stepped hole are collected to obtain the left end position data; The machine tool's measurement system calculates the left endpoint position data, fits the actual axis of the left end stepped hole, and obtains the actual axis of the left end; the right endpoint position data is located on the key diameter segment of the right end stepped hole that is associated with the reference axis; the left endpoint position data is located on the key diameter segment of the left end stepped hole that is associated with the reference axis.

8. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 7, characterized in that, The process of obtaining the target coaxiality by combining the coaxiality of the actual axis with respect to the reference axis includes: Obtain the actual axis of the right end, the actual axis of the left end, and the reference axis; The machine tool's measurement system calculates the deviation between the actual axis at the right end and the reference axis to obtain the coaxiality of the right end; The machine tool's measurement system calculates the deviation between the actual axis at the left end and the reference axis to obtain the coaxiality of the left end; The target coaxiality includes right-end coaxiality and left-end coaxiality.

9. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 8, characterized in that, The comparison of whether the target coaxiality meets the coaxiality requirements on the drawing includes: Determine whether the coaxiality of the right end is within the coaxiality range of the right end stepped hole preset on the drawing; Determine whether the coaxiality of the left end is within the coaxiality range of the left end stepped hole preset on the drawing; The test results were obtained.

10. The one-stop machining method for high-precision stepped deep and long holes in high-voltage switch heads according to claim 2, characterized in that, The method of drilling through holes on both sides of the workpiece (1) using a combination tool is to pre-drill through holes at corresponding positions on both sides of the workpiece (1) using a gun drill in the combination tool.

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