A method of drilling a support plate

Abstract

This invention provides a drilling method for a support plate, comprising: clamping the support plate using a drilling fixture, and drilling holes in the clamped support plate; wherein the drilling fixture includes a worktable, support pins, and clamping bolts; clamping the support plate using the drilling fixture includes: fixing one end of the support pin to the worktable, the position distribution of the support pin on the worktable being determined by simulation based on the target hole position on the support plate; milling the other end face of the support pin flat and drilling threaded holes on the milled surface of the support pin; hoisting the support plate onto the support pin; aligning the support plate so that the support plate is concentric with the worktable; using multiple pressure plates to press down the edges of the support plate; drilling a predetermined number and position of clamping holes on the support plate; and connecting the clamping holes and threaded holes using clamping bolts to clamp the support plate onto the support pin. This invention can improve drilling accuracy and drilling quality, and improve processing efficiency and quality stability.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and more specifically, to a drilling method for a support plate. Background Technology

[0002] Large support plates typically have a diameter of Ф3000mm or more and a thickness of 20mm or more. They are made of materials such as martensitic stainless steel, austenitic stainless steel, and carbon steel, and are large, thin-plate workpieces. Over 10,000 holes need to be drilled on the support plate, with a diameter tolerance within 0.1mm, a center distance tolerance within ±0.2mm, and a surface roughness Ra1.6-3.2. After batch drilling, the overall stability of the support plate will change significantly, and its flatness is easily deformed, making it difficult to control the positional accuracy of each hole. Furthermore, the sheer number of holes, the strict requirements for hole diameter and positional accuracy, and the need to ensure that all holes are machined to quality in a single pass make the machining extremely difficult. This also places very stringent demands on key factors such as machine tool stability, tool stability, clamping system stability, and the rationality of the process flow.

[0003] To ensure the consistency of holes on each support plate, existing drilling solutions generally use a method of fixing multiple plates together. That is, multiple support plates are stacked together, and the hole positions are located using a template. Drilling, reaming, and boring are then used for processing. However, this method results in the hole diameter, hole position, and hole perpendicularity failing to meet the processing accuracy requirements of the support plate. Summary of the Invention

[0004] The problem that this invention aims to solve is that in the prior art, drilling holes in support plates often involves stacking and fixing multiple plates together, which results in problems such as low drilling quality and precision, and cannot meet the final assembly requirements.

[0005] To address at least one of the aforementioned problems, the present invention provides a drilling method for a support plate, comprising:

[0006] The support plate is clamped using a drilling jig, and holes are drilled in the clamped support plate.

[0007] The drilling fixture includes a worktable, support pins, and clamping bolts. The clamping of the support plate using the drilling fixture includes:

[0008] One end of the support pin is fixed to the worktable, and the position distribution of the support pin on the worktable is determined by simulation based on the position of the target hole on the support plate.

[0009] The other end face of the support pin is milled flat, and a threaded hole is drilled on the milled surface of the support pin.

[0010] The support plate is hoisted onto the support pin, and the support plate is aligned so that it is concentric with the worktable. Multiple pressure plates are then used to hold the edges of the support plate in place.

[0011] Drill a set number of engagement holes at a predetermined position on the support plate, and use the clamping bolts to connect the engagement holes and the threaded holes to engage the support plate onto the support pin.

[0012] Preferably, the drilling fixture further includes a height adjustment shim, which is disposed at the bottom of the worktable.

[0013] Preferably, after fixing one end of the support pin to the worktable, the method further includes: aligning the drilling fixture according to the side reference surface of the worktable, determining the center of the worktable according to the side reference surface of the worktable, and determining the machining zero point according to the center of the worktable.

[0014] Preferably, after milling the other end face of the support pin, the method further includes: leveling the milled surface of the support pin using a dial indicator.

[0015] Preferably, drilling a threaded hole on the milled surface of the support pin includes: drilling a pilot hole on the milled surface of the support pin, setting a chamfer at the end of the pilot hole, tapping the pilot hole, removing burrs, cleaning impurities inside the hole, and obtaining the threaded hole.

[0016] Preferably, the step of connecting the engagement hole and the threaded hole using the clamping bolt includes: sequentially increasing the preload torque on the engagement hole and the threaded hole to engage the clamping bolt.

[0017] Preferably, drilling the clamped support plate includes: using a drilling machine dotting tool to mark the target holes on the support plate.

[0018] Preferably, after marking the target holes on the support plate using a drilling machine dotting tool, the method further includes: drilling a reference hole on the support plate, boring the reference hole, and after trial installation and removal of the reference pin based on the reference hole, determining the process zero point based on the reference hole.

[0019] Preferably, after determining the process zero point, the method further includes: performing zoned drilling on the support plate, with the drilling sequence proceeding from the central region to the peripheral region.

[0020] Preferably, the step of drilling holes in the support plate in sections includes: drilling a first row of holes or a first column of holes, and after drilling the first row of holes or the first column of holes, obtaining the length between the first and last holes in the first row of holes or the first column of holes, and after each drilling, detecting the length between the first and last holes in the first row of holes or the first column of holes, and continuing drilling only when the length between the first and last holes in the first row of holes or the first column of holes detected each time is the same as the length between the first and last holes in the first row of holes or the first column of holes detected in the first time.

[0021] The advantages of this invention compared to existing technologies are:

[0022] This invention uses a drilling fixture to clamp a support plate, drilling holes individually in each thin plate to ensure drilling quality and accuracy. Simultaneously, the distribution of support pins on the worktable is calculated by simulating the target hole positions on the support plate. Threaded holes are drilled in the milled plane of the support pins. The support plate is then placed on the support pins and fixed in place by a pressure plate. Partial mating holes are drilled first, and clamping bolts are used to fix the support plate and support pins. This achieves a secure and reliable clamping of the support plate, controlling its deformation, improving drilling accuracy and quality, and maintaining good consistency in the drilling positions among multiple thin plates. This improves processing efficiency and quality stability, ensuring the support plate meets the final assembly accuracy requirements. Attached Figure Description

[0023] Figure 1 This is a distribution diagram of the support pins on the workbench in an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of drilling a threaded hole in the support pin in an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the support plate being clamped onto the drilling fixture in an embodiment of the present invention;

[0026] Figure 4 This is a point diagram of the support plate in an embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1-Workbench; 2-Support pin; 3-Support plate; 4-Clamping bolt; 5-Screw. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] A drilling method for a support plate according to an embodiment of the present invention includes:

[0031] The support plate 3 is clamped using a drilling jig, and holes are drilled in the clamped support plate 3.

[0032] The drilling fixture includes a worktable 1, a support pin 2, and a clamping bolt 4. The clamping of the support plate 3 using the drilling fixture includes:

[0033] One end of the support pin 2 is fixed to the worktable 1. The position distribution of the support pin 2 on the worktable 1 is determined by simulation based on the position of the target hole on the support plate 3.

[0034] The other end face of the support pin 2 is milled flat, and a threaded hole is drilled on the milled surface of the support pin 2.

[0035] The support plate 3 is hoisted onto the support pin 2, and the support plate 3 is aligned so that it is concentric with the worktable plate 1. Multiple pressure plates are then used to hold the edges of the support plate 3 in place.

[0036] A set number of engagement holes are drilled on the support plate 3, and the engagement holes and the threaded holes are connected by the clamping bolts 4 to engage the support plate 3 with the support pin 2.

[0037] For support plate 3, which is a large thin plate, drilling a series of holes in it is generally quite difficult. To ensure consistency in the drilling of each thin plate, existing technologies typically place multiple thin plates together before drilling, but this results in lower drilling quality. In this embodiment, a drilling jig is used to clamp support plate 3, and holes are drilled individually for each thin plate, ensuring drilling quality and accuracy. Simultaneously, the position of support pin 2 on the worktable 1 is calculated by simulating the target hole position on support plate 3, and threaded holes are drilled in the milled plane of support pin 2. Then, support plate 3 is placed on support pin 2 and fixed with a pressure plate. Partial mating holes are drilled first, and clamping bolts 4 are used to fix support plate 3 and support pin 2, thereby achieving clamping and fixing of support plate 3.

[0038] In this embodiment, the support plate 3 is mounted onto the drilling fixture using clamping bolts 4 and surrounding pressure plates, and then tightened securely. The use of the drilling fixture ensures that the support plate 3 is firmly and reliably clamped, making the machining hole system more stable, and also facilitates the operator's installation and removal of the support plate 3.

[0039] Therefore, this embodiment utilizes the clamping stability of the drilling fixture on the support plate 3 to control the clamping deformation of the support plate 3, improve drilling accuracy and drilling quality, and ensure that the drilling positions of multiple thin plates maintain good consistency, thereby improving processing efficiency and quality stability, so that the support plate 3 can meet the final assembly accuracy requirements.

[0040] In some embodiments, the drilling fixture further includes height adjustment shims disposed at the bottom of the workbench 1 to clamp the support plate 3 at a suitable height for subsequent drilling. The height adjustment shims can be dedicated pipe pier shims.

[0041] In some embodiments, after one end of the support pin 2 is fixed to the worktable 1, the drilling method further includes: aligning the drilling fixture according to the side reference surface of the worktable 1, determining the center of the worktable 1 according to the side reference surface of the worktable 1, and determining the machining zero point according to the center of the worktable 1.

[0042] In some embodiments, after milling the other end face of the support pin 2, the method further includes: leveling the milled surface of the support pin 2 using a dial indicator.

[0043] In this embodiment, the jig is aligned according to the side reference surface to ensure that the X and Y directions meet the process requirements. The flatness of the end face of the jig support pin 2 is checked using a dial indicator to ensure it meets the process requirements. After mounting the jig, the accuracy change is re-inspected to ensure it meets the process requirements. The center of the worktable 1 is determined according to the dimensions returned from the A and B reference surfaces on both sides of the worktable 1, and the machining zero point is determined according to the center of the worktable 1. The drilling jig is positioned as follows... Figure 1 As shown. The position and size distribution of the target holes on the support plate 3 are determined according to actual needs. When arranging the support pins 2, the distribution and size of the support pins 2 on the worktable 1 correspond to the target holes. Therefore, Figure 1 In one example shown, support pins 2 of various sizes are installed on the workbench 1.

[0044] In some embodiments, drilling a threaded hole on the milled surface of the support pin 2 includes: drilling a pilot hole on the milled surface of the support pin 2, setting a chamfer at the end of the pilot hole, tapping the pilot hole, removing burrs, cleaning impurities inside the hole, and obtaining the threaded hole.

[0045] Since the support pin 2 comes in various specifications, this embodiment drills threaded pilot holes for each specification of support pin 2 and chamfers the hole ends. Then, the pilot holes are tapped, burrs are removed, and impurities such as iron filings and cutting fluid are cleaned from the inside of the threaded holes. See [the diagram for machining the threaded holes on the support pin 2]. Figure 2 As shown.

[0046] In some embodiments, connecting the engagement hole and the threaded hole using the clamping bolt 4 includes: sequentially increasing the preload torque on the engagement hole and the threaded hole to engage the clamping bolt 4.

[0047] In this embodiment, a predetermined number of engagement holes are drilled on the support plate 3. For example, if a total of 10,000 holes need to be drilled on the support plate 3, 10 engagement holes are drilled first. After drilling, clamping bolts 4 are passed through the engagement holes and threaded holes to connect the support plate 3 and the support pin 2, thereby clamping the support plate 3 and facilitating subsequent processing of the remaining holes. When engaging the clamping bolts 4, the preload torque increases sequentially. For example, when using a four-level preload torque to engage the clamping bolts 4, all clamping bolts 4 are first engaged with a level one preload torque, then with a level two preload torque, and so on, until a level four preload torque is used. The preload torque increases sequentially from level one to level four. Of course, for clamping bolts 4 of different specifications, it is not necessary to start with a level one preload torque. For example, for some small-diameter bolts, a level three preload torque can be used directly.

[0048] The clamping process of support plate 3 will be explained in detail below with specific examples.

[0049] The drilling fixture for the support plate 3 (also referred to as the fixture) is an important auxiliary tool for clamping and precisely drilling the support plate 3. It consists of a worktable 1, support pins 2, clamping bolts 4, and height adjustment shims. The fixture is designed with multiple support pins 2 according to the distribution of the holes on the support plate 3. The positions of the support pins 2 are calculated through computer simulation. After the support pins 2 are installed on the worktable 1, the end faces of the support pins 2 are milled flat to ensure the flatness of each support pin 2 end face. The clamping bolts 4 and surrounding pressure plates are used to install the support plate 3 onto the fixture and tighten it securely. The use of the fixture ensures that the support plate 3 is clamped firmly and reliably, making the machining system more stable, and also facilitates the operator's installation and removal of the workpiece.

[0050] Place special pipe supports and shims under the jig. Align the jig with the reference surface on the side of the jig, ensuring that both the X and Y directions meet the process requirements. Use a dial indicator to level the end face of the jig support pin 2, ensuring that the flatness meets the process requirements. After assembling the jig, re-inspect the accuracy changes to ensure they meet the process requirements. Determine the center of the worktable based on the dimensions returned from the reference surfaces A and B on both sides of the worktable 1, and determine the machining zero point based on the jig center.

[0051] Next, the threaded hole of the fixture is processed. The threaded bottom hole on the fixture support pin 2 is drilled and the hole end is chamfered. The threaded hole on the fixture is tapped, the burrs are removed, and the iron filings, cutting fluid and other impurities inside the threaded hole are cleaned.

[0052] Next, the support plate 3 will be clamped. First, the support plate 3 will be hoisted, and the position of all the support pins 2 will be checked to ensure they meet the process requirements. After passing the checks, the support plate 3 will be hoisted onto the jig using a special hoisting tool. The support plate 3 will be aligned with the jig according to the marking lines to ensure it is concentric and meets the process requirements. Then, the engagement holes will be machined. A special process pad will be placed between the pressure plate around the support plate 3 and the support plate 3 to ensure that the clamping force is vertically downward and evenly pressed and tightened. After tightening, the process holes will be machined to the required dimensions. The alignment accuracy of the jig's A and B reference surfaces will be checked to ensure it meets the process requirements.

[0053] The principles for bolt engagement torque and sequence are as follows: When engaging the peripheral pressure plates, use preload torque levels one to four to engage the bolts, following the process requirements. For small-diameter bolts, directly use the third-level preload torque, and the engagement sequence is to immediately engage the bolts after drilling a hole. The peripheral pressure plates must not be loosened during bolt engagement. After all bolts are engaged, loosen the peripheral pressure plates and the four alignment ejectors, then apply the fourth-level preload torque to tighten all engaged bolts to their corresponding maximum preload force. Loosen the support plate, peripheral pressure plates, and four alignment ejectors, re-inspect the tightened bolts according to the process data requirements, then re-tighten the peripheral pressure plates, placing a process-specific pad under the pressure plates, and having the four alignment ejectors hold the workpiece in place.

[0054] like Figure 3 The diagram shown is a simplified diagram after the support plate 3 is clamped. The support pin 2 is held in place on the workbench plate 1 by two screws 5. Threaded holes are drilled in the support pin 2. The support plate 3 is placed on the support pin 2. A clamping hole is drilled in the support plate 3, and the support plate 3 and the support pin 2 are fixed with clamping bolts 4.

[0055] In some embodiments, drilling the clamped support plate 3 includes: using a drilling machine's marking tool to mark the target holes on the support plate 3. Before machining the first support plate 3, all hole positions need to be marked, and all hole positions are compared with the drawing, and the work is submitted for inspection. When the program changes, the marking test is repeated and the work is submitted for inspection again. This process can enhance the process control of drilling the support plate 3, ensuring that the drilling program is complete and correct, with no missed holes or extra holes. Before the actual drilling, the machine tool operation process is monitored for any abnormalities, achieving the purpose of early detection and early handling of problems.

[0056] In some embodiments, after marking the target holes on the support plate 3 using a drilling machine dotting tool, the method further includes: drilling reference holes on the support plate 3, boring the reference holes, and after trial assembly and disassembly of the reference pins based on the reference holes, determining the process zero point based on the reference holes.

[0057] In this embodiment, the reference hole is first drilled and bored. This hole serves as the process zero point. The reference pin is then trial-installed to ensure that it can be installed and removed smoothly. The clearance size is checked, and after confirming that there are no problems, the reference pin is removed, and the machine tool is set to the process zero point.

[0058] In some embodiments, after determining the process zero point, the method further includes: performing zone drilling on the support plate 3, with the drilling sequence proceeding from the central region to the peripheral region.

[0059] In this embodiment, the support plate 3 is processed in sections to release residual stress evenly and avoid deformation of the drilled area, which could cause the hole diameter and position to exceed the tolerance.

[0060] In some embodiments, the step of drilling holes in the support plate 3 in sections includes: drilling a first row of holes or a first column of holes, and after drilling the first row of holes or the first column of holes, obtaining the length between the first and last holes in the first row of holes or the first column of holes, and after each drilling, detecting the length between the first and last holes in the first row of holes or the first column of holes, and continuing drilling only when the length between the first and last holes in the first row of holes or the first column of holes detected each time is the same as the length between the first and last holes in the first row of holes or the first column of holes detected in the first time.

[0061] In this embodiment, after each hole is drilled, the distance between the first and last holes in the first row or the first column is detected. If the distance between the first and last holes is not consistent, it indicates that deformation has occurred during subsequent drilling.

[0062] Specifically, the first row of holes is machined first. A verified CNC program is executed to machine the first row of holes in a fixed area. When machining the first row of holes, the reference hole is bypassed to avoid repeated machining; interference is prevented during machining. After the first row of holes is machined, the total length of the first and last holes in this row is checked and recorded by the spindle in a special form. Machining can only continue after the dimensions are confirmed to be acceptable.

[0063] Then, batch drilling of the products is performed using a dedicated drilling program and a special shallow hole drill to machine the remaining holes to achieve Ra3.2. Process requirements: The workpiece is machined in sections according to the process sequence to ensure that the residual stress of the workpiece is released evenly, so as to avoid deformation of the drilled areas of the workpiece, which would cause the hole diameter and position to exceed the tolerance.

[0064] The drilling process requirements include: before each shift, the machine tool's process zero point must be rechecked, and the actual value and direction recorded. If the difference exceeds the process requirements, a machine tool zeroing operation must be performed, and the X and Y axis values ​​must be input to re-determine the workpiece center, which must then be corrected using the process zero point. If the machine is stopped for more than the required process time, it must be warmed up according to the process time before resuming processing, and then the process zero point must be rechecked and the actual value and direction recorded. If the difference exceeds the process requirements, a machine tool zeroing operation must be performed, and the X and Y axis values ​​must be input to re-determine the workpiece center, which must then be corrected using the process zero point. After the machine tool is powered off and restarted, the machine tool return process must be executed. After operating at the reference point, use the spindle to return to the process zero point for re-inspection and record the actual value and direction. If the difference exceeds the process requirements, perform machine tool zeroing operation, input the X and Y values, re-determine the workpiece center, and use the process zero point to correct the workpiece center. After re-determining the workpiece center, each spindle goes to the process zero point and records the actual value and direction. During drilling, periodically check the total length of the first and last holes in a row and record it in the appendix table. If the difference does not exceed the process requirements, proceed with normal processing. During drilling, periodically check the clamping torque of all bolts and tighten all bolts with the corresponding fixed-level preload.

[0065] Next, the process holes are precision machined. After drilling, the process holes are machined to the finished holes. An edge finder is used for centering, and the diameters of the four adjacent holes around each hole are recorded to ensure that the hole position is up to standard. It should be noted that before machining the engagement hole, the interior of the surrounding adjacent holes must be cleaned thoroughly. There must be no cutting fluid, iron filings, or other factors that may interfere with the centering accuracy inside the holes. When machining the engagement hole, it is not allowed to remove all the bolts at the same time.

[0066] The requirements for changing blades include: when changing blades, the corresponding screw wrench must be used, and the blade edges must be turned clockwise.

[0067] The controlled management of cutting tools includes: after use, the cutting tools are placed sequentially into the corresponding cutting tool slots in the corresponding tool boxes according to the spindle number and cutting tool serial number. After machining one support plate 3, the tool boxes are uniformly placed into a pull-top plastic bag, sealed, and labeled with information about the support plate 3, including: drawing number, furnace number, card number, and sealing date. The cutting tools used for the support plate 3 and all cutting tool information are retained by the machine tool. After the hole-drawing process of the support plate 3 is completed and passes inspection, the cutting tools used for the support plate 3 are returned to the warehouse.

[0068] Other requirements for the drilling process include: During the drilling program execution of support plate 3, the operator should remain on the machine at all times; carefully observe the chip situation; if excessively long chips or tool entanglement occur, stop the machine to clean and replace the tool, and check the accuracy of the drilled holes; carefully monitor power, torque, and cutting force; if abnormalities occur or the tool retracts automatically, stop the machine immediately to check the tool and the accuracy of the drilled holes; pay attention to any abnormal noises or vibrations from the machine tool, and regularly check the pressure plate and bolts for looseness; if abnormal noises or vibrations are found, stop the machine immediately for inspection; carefully clean the chips from the upper surface and bottom of support plate 3, ensuring no chip accumulation at the bottom of support plate 3; the pressure plate must not be loosened during workpiece processing, and the workpiece must not move or vibrate; before processing, the machine tool should return to the reference point; any modifications to the CNC program during the drilling cycle must be recorded; avoid power outages during program execution. And perform the return-to-reference-point operation. If it is necessary to return to the reference point due to force majeure, the workpiece center must be re-determined and re-inspected as required. During drilling, clean oil stains and dirt from the fixture, pads, and workpiece surface in a timely manner. When placing support plate 3 on the fixture, take care to prevent bumps and scratches. All personnel must not step on the workpiece surface unless necessary. All tools and auxiliary tools must be placed according to material classification. Carbon steel parts and stainless steel parts must not be mixed. Tools and auxiliary tools of the same type should be stored together to prevent loss. The cleanliness requirements of cutting fluid shall be implemented in accordance with the "Cutting Fluid Use Process Specification". Use of point color diagrams: Each support plate 3 is equipped with a set of color diagrams. During the processing, each time the cutting edge is changed, mark the number of tool changes at the first hole position of the row of holes. Write 1 for the first tool change, 2 for the second tool change, and so on. Mark "X" at the tool change hole of each axis (the first hole of the new cutting edge). The use of color diagrams is as follows. Figure 4 As shown, the support plate 3 is divided into 6 areas, separated by "X". The drilling sequence is from area 3 to area 2, then to area 1, and from area 4 to area 5, then to area 6.

[0069] The drilling process inspection includes: during the drilling process, new drill bits, inserts, and new cutting edges are first tested on a test piece to make a hole. Only after the diameter and surface roughness of the hole are measured and found to be within acceptable limits can the drill bit be used on the product part. After drilling a hole on the product part, the machine is immediately stopped to check the diameter and center distance of the hole, and the surface roughness of the hole is checked to be good. The results are recorded in the table before processing can continue. During drilling, after a new drill bit or insert drills a hole with a new cutting edge, immediately stop the machine to check the diameter and center distance of the hole, ensure the surface roughness is good, and record the result in the table before continuing machining. During program execution, pause the program each time the insert clearance is changed, measure the diameter and center distance of the last hole drilled by that insert, and randomly inspect holes drilled by each insert, including checking the hole diameter, surface roughness, and hole spacing. If the inspection is qualified, no record is needed. Before shift handover, each shift must create a complete inspection record of the holes drilled during that shift. For holes that automatically retract before drilling due to drill bit chipping, breakage, or other reasons, record the hole's position coordinates and accuracy inspection results in the table. When any non-conformity is found during inspection, the operator needs to record the spindle number, hole position (column, column number, such as R1-1), and non-conformity, and report it. Machining can only continue after the problem is resolved and improvement measures are clearly implemented. Hole position accuracy is measured using a dedicated hole spacing measuring instrument; hole diameter is measured using an inside dial indicator.

[0070] The final inspection of the drilling process includes: before the support plate 3 is loosened and clamped, checking to confirm that there are no missed holes; checking the diameter, roughness, and spacing of all holes, and recording the results by column; marking all unqualified holes with special pipe plugs and recording the inspection results; measuring the positional accuracy of all holes with a hole spacing measuring instrument; measuring the diameter of all holes with go and stop bars; and randomly checking the diameter and positional accuracy of any hole according to the arbitrary hole positional accuracy test location diagram.

[0071] The drilling method also includes flatness detection after drilling, including: using a dial indicator to detect the flatness of the support plate 3 before and after it is loosened from the clamping, and recording the flatness values ​​in detail. In addition to recording the values ​​at each point, the flatness of the surrounding area is also detected by dial indicator at process distances, with the highest and lowest points as the center. It is not necessary to record all the values ​​at all points; just find the highest point and record the extreme value.

[0072] In summary, this embodiment provides a drilling method for a support plate, which is mainly applicable to the drilling of a large number of holes in parts with large diameters, thin plates that are easily deformed, and various materials. The drilling method of this embodiment has the following technical advantages: (1) The drilling tool is a shallow hole drill series drill rod and insert, and the drilling parameters are high speed and small feed mode. The drilling is completed in one go, the processing quality is stable, and the process tool is strictly monitored to ensure that there are no quality accidents in the entire drilling process. (2) The use of the dotting device enhances the process control of drilling the support plate 3, verifies the correctness of the CNC program, ensures that the drilling program is complete and correct, and there are no missing holes or multiple holes. Before the formal drilling, the machine tool operation process is monitored in advance to detect problems in advance and deal with them in advance. (3) The use of the drilling fixture solves the problem of clamping thin plate parts, controls the clamping deformation of the support plate 3, and uses the clamping bolts 4 and the surrounding pressure plates on the fixture to mount the workpiece onto the fixture and tighten it firmly. This can make the support plate 3 clamped firmly and reliably, the processing system more stable, and also facilitate the operator to install and disassemble the workpiece. (4) Computer simulation analysis was conducted to analyze the influence of the bolt torque on the flatness of the support plate 3, thereby clarifying the torque at each level of the support plate 3 and the order of engagement, thus strictly controlling the final flatness of the support plate 3 to meet the drawing requirements. (5) Through detailed process control measures for drilling, process zero-point correction and thermal mechanical measures were adopted during the drilling process to minimize the drilling position accuracy deviation caused by machine tool zero-point drift while ensuring efficiency. In addition, in order to ensure the uniform release of residual stress in the workpiece and to prevent deformation of the drilled area of ​​the workpiece from causing the hole diameter and position to exceed the tolerance, drilling was carried out in a certain shift and by area to ensure drilling accuracy and deformation control. (6) By reasonably arranging the frequency of process inspections and strictly controlling the process, the quality during the drilling process was fully controllable, while also taking into account processing efficiency, ultimately ensuring that the product drilling was completed efficiently and all drilling was qualified in one go.

[0073] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A drilling method for a support plate, characterized in that, include: The support plate (3) is clamped using a drilling jig, and holes are drilled in the clamped support plate (3); Drilling holes in the clamped support plate includes: drilling a first row of holes or a first column of holes, and after drilling the first row of holes or the first column of holes, obtaining the length between the first and last holes in the first row of holes or the first column of holes; after each drilling, the length between the first and last holes in the first row of holes or the first column of holes is measured, and drilling continues only if the length measured each time is the same as the length measured in the first time between the first and last holes in the first row of holes or the first column of holes. The drilling fixture includes a worktable (1), a support pin (2), and a clamping bolt (4). The clamping of the support plate (3) using the drilling fixture includes: One end of the support pin (2) is fixed to the worktable (1). The position distribution of the support pin (2) on the worktable (1) is determined by simulation based on the position of the target hole on the support plate (3). The other end face of the support pin (2) is milled flat, and a threaded hole is drilled on the milled surface of the support pin (2). The support plate (3) is hoisted onto the support pin (2), and the support plate (3) is aligned so that it is concentric with the worktable plate (1). Multiple pressure plates are used to press down the edges of the support plate (3). Drill a set number of engagement holes on the support plate (3), and sequentially add pre-tightening torque to the engagement holes and the threaded holes to engage the clamping bolts (4). The engagement sequence is to immediately engage the hole after drilling it, and use the clamping bolts (4) to connect the engagement holes and the threaded holes to engage the support plate (3) onto the support pin (2).

2. The drilling method for the support plate according to claim 1, characterized in that, The drilling fixture also includes a height adjustment shim, which is disposed at the bottom of the workbench (1).

3. The drilling method for the support plate according to claim 2, characterized in that, After fixing one end of the support pin (2) to the worktable (1), the method further includes: aligning the drilling fixture according to the side reference surface of the worktable (1), determining the center of the worktable (1) according to the side reference surface of the worktable (1), and determining the machining zero point according to the center of the worktable (1).

4. The drilling method for the support plate according to claim 1, characterized in that, After milling the other end face of the support pin (2), the method further includes: leveling the milled surface of the support pin (2) according to a dial indicator.

5. The drilling method for the support plate according to claim 1, characterized in that, The drilling of a threaded hole on the milling plane of the support pin (2) includes: drilling a bottom hole on the milling plane of the support pin (2), setting a chamfer at the end of the bottom hole, tapping the bottom hole, removing burrs, cleaning impurities in the hole, and obtaining the threaded hole.

6. The drilling method for the support plate according to claim 1, characterized in that, The drilling of the clamped support plate (3) includes: using a drilling machine dotting tool to mark the target holes on the support plate (3).

7. The drilling method for the support plate according to claim 6, characterized in that, After the target hole on the support plate (3) is marked using the drill bit, the process further includes: drilling a reference hole on the support plate (3), boring the reference hole, and after trial installation and disassembly of the reference pin according to the reference hole, determining the process zero point according to the reference hole.

8. The drilling method for the support plate according to claim 7, characterized in that, After determining the process zero point, the process further includes: drilling holes in the support plate (3) in sections, with the drilling sequence being from the middle area to the peripheral area.

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