Processing technology of deep blind arc stepped hole

Abstract

The invention relates to a processing technology of a deep blind arc stepped hole structure which is generally not more than 2000mm in deepest depth, is in a shape that a hole bottom plane is connected with an arc, is connected with a linear section of an inner hole in taper, and is in transition connection with a stepped hole through a large arc. According to the machining process, arc stepped holes are machined and formed in a segmented mode through a deep hole drilling and boring machine and a forming tool, and a numerical control lathe and a damping tool bar are not needed; 3-4 mm allowance is reserved on a single side of each section of arc hole according to the hole diameter, the arc holes are drilled and bored into a plurality of stepped holes, after drilling and boring are completed, a forming cutter body and a forming cutter are replaced to machine and form the arc holes, the steps are repeated to complete machining of other arc holes, and the depth requirement is met. According to the machining method, the characteristic that the deep hole drilling and boring machine is large in cutting output is utilized, the machining period is greatly shortened, tools are easy and convenient to use in the machining process, the machining process is convenient to control, the product machining quality is guaranteed, the machining efficiency is improved, and the requirement for batch production of the products is met.

Description

Technical Field

[0001] The present invention belongs to the field of mechanical manufacturing technology and relates to a deep blind circular step hole processing technology which utilizes a deep hole drilling and boring machine to process the deep blind circular step hole. The deep blind circular step hole structure has a maximum depth of no more than 2000 mm and a shape in which the bottom plane of the hole is connected to the circular arc, the taper is connected to the straight line section of the inner hole, and the step hole is connected through a large circular arc transition. Background Art

[0002] This deep blind hole shell product is a key structural part in the defense field, requiring ultra-high strength and toughness mechanical properties and processing accuracy; its typical structure is a deep blind arc step hole, the segmented depth of the blind hole is generally no more than 2000mm, its shape is the bottom plane of the hole connected to the arc, the taper is connected to the inner hole straight line segment, the step hole is connected through a large arc transition, the dimensional accuracy is generally 0.2mm, and the surface roughness Ra≤6.3μm. The current processing method is to pre-drill and bore multiple step holes according to the diameter margin of the arc step hole on a deep hole drilling and boring machine, and then use an extended shock-absorbing tool bar on a CNC lathe to turn the bottom flat and turn it into the size of the arc step at each location. This method of processing using an extended shock-absorbing tool bar has the problem of small turning volume and slow processing, and also increases the occupation and investment of CNC lathes and shock-absorbing tool bars; this method is suitable for production and processing in the research and development stage, but not suitable for mass production of models. Therefore, it is necessary to design a reasonable processing technology to adapt to the mass production of products and play a role in reducing costs and increasing efficiency. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a processing technology for deep blind circular step holes which no longer uses a CNC lathe and a shock-absorbing tool bar for precision machining of deep blind circular step holes, but instead uses a deep hole drilling and boring machine and a forming tool to segmentally machine the circular step holes, thereby meeting the design requirements of the warhead shell and achieving the effect of reducing costs and increasing efficiency.

[0004] The object of the present invention is achieved as follows: a processing technology for a deep blind arc step hole, because the arc step hole includes two arc holes, and the two arc holes are connected by a straight hole, the two arc holes are processed in sections during processing, and each arc hole is drilled and bored into multiple step holes with a single side reserved for 3-4mm margin according to the aperture size and the processing range of the boring tool body. After drilling and boring, the forming tool body and the forming tool are replaced to process the arc hole and ensure the depth requirement. The specific processing technology is as follows: Step 1), Processing of the first section of deep blind arc flat bottom hole: Step 1.1), put one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, and place it on the frame position that has been pre-machined for the product. Align the chuck and the frame position so that the jump is within 0.1mm; drill the bottom hole Φd, spindle speed 70r / min, drill rod speed 220r / min, feed speed 40±10mm / min, and ensure the hole depth L1 including the drill tip; replace the reaming cutter body, and expand the step holes Φd1 and Φd2 in turn, spindle speed 70r / min, drill rod speed 20r / min ; Feed speed 40-50mm / min, ensure the depth of the two steps of the hole expansion L2, L3; replace the boring tool body, bore Φd3, Φd4, Φd5 in turn, lock the drill rod, spindle speed 60r / min, feed speed 20-30mm / min, ensure the corresponding hole depth L4, L5, L6 size; replace the floating boring tool body, repair the Φd5 inner hole finish, lock the drill rod, spindle speed 143r / min, feed speed 20-30mm / min, ensure the hole depth L6; Step 1.2), put the product on the lathe, align it with the inner hole Φd5 as the reference, turn the solid end spindle aligning frame and the open end center frame frame, and ensure the coaxiality of the frame is ≤0.05mm; Step 1.3), install one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, and place it on the frame position that has been pre-machined on the product. Align the chuck and the center frame position to within 0.05mm; install the forming cutter body and forming blade on the boring bar, align the gap between the forming blade and the hole wall, ensure centering, lock the drill rod, spindle speed 50~60r / min, feed speed 5mm / min, after the wooden guide key on the forming cutter body is completely consumed into the hole, feed to a depth of (L1-60)mm, feed speed adjusted to 3mm / min, feed speed adjusted to 2mm / min after the forming cutter eats the cut, and pay attention to the shape of the iron chips and the vibration of the cutter bar to adjust the feed speed in time. After the forming cutter completely turns off the steps of the inner hole, retract the cutter to check the wear of the forming cutter, grind or replace the new cutter, re-feed to the cutting position, feed speed adjusted to 1mm / min, and retract the cutter after processing to the required depth L; Step 2), the second section of deep blind arc hole processing: Step 2.1), after the first section of deep blind arc flat bottom hole processing is completed, do not get off the bed, replace the boring bar and boring tool body, and bore holes Φd6, Φd7, Φd8 in turn, spindle speed 60r / min, feed speed 20-30mm / min, to ensure the corresponding hole depths L7, L8, L9; replace the floating boring tool body, repair the Φd8 inner hole finish, lock the drill rod, spindle speed 143r / min, feed speed 20-30mm / min, to ensure the hole depth L9; Step 2.2), put the product on the lathe, align it with the inner hole Φd8 as the reference, repair the solid end spindle alignment frame and the open end center frame frame, and ensure the coaxiality of the frame is ≤0.05mm; Step 2.3), put one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, which is placed on the frame position pre-machined by the product. Align the chuck and the center frame position so that the jump is within 0.05mm. According to the processing parameters and processing steps of the first arc flat bottom hole, use the forming tool body and forming tool to form the inner cavity of the second deep blind arc hole; use the special device for measuring the depth of the transition section of the inner hole arc taper to measure the depth of the second arc hole to ensure that the depth L of the second arc hole is 10 .

[0005] The present invention adopts a deep hole drilling and boring machine and, through reasonable process design, can process deep blind flat-bottomed arc step holes without using a CNC lathe and a shock-absorbing tool bar, thereby reducing the occupancy of CNC equipment and saving 6 hours of processing time in this case. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a schematic diagram of an example of a deep blind flat bottom circular arc step hole of the present invention. Description: Typical features of the example: The first section of the deep blind flat bottom circular arc hole has a depth of L=1282mm, and the second section of the circular arc hole has a depth of L 10 =1113mm and the maximum aperture Φd8=206mm, the straight hole in the transition section controlled by two arcs Φd9=143mm.

[0007] Figure 2 This is a schematic diagram of the process of drilling a step hole for the first deep blind flat bottom circular arc hole of the present invention. Description: In order to reduce the cutting amount of the tool for forming the first deep blind flat bottom circular arc hole, prefabricate Φd1 to Φd5 step holes, and reserve 3~4mm machining allowance on one side; and bore and float bore a straight hole Φd6=146mm as the machining benchmark for the tool for forming the first circular arc hole.

[0008] Figure 3 This is a schematic diagram of the inner cavity forming of the first section of the deep blind flat bottom circular arc hole of the present invention. Description: The first section of the deep blind flat bottom circular arc hole is processed using a forming tool to ensure that the depth L=1282mm, and two circular arc transition section straight holes Φd9=143mm are bored.

[0009] Figure 4 This is a schematic diagram of the second-stage deep blind arc hole drilling step hole process of the present invention. Explanation: In order to reduce the cutting amount of the second-stage arc hole forming tool, Φd6 to Φd8 step holes are prefabricated, and 3~4mm machining allowance is reserved on one side; boring and floating boring straight holes Φd8=206mm are used as the second-stage arc hole forming tool processing benchmark, which is also the final inner diameter size.

[0010] Figure 5 This is a schematic diagram of the first section of the deep blind flat bottom arc hole forming tool body and tool of the present invention.

[0011] Figure 6 It is a schematic diagram of the second section of the deep blind arc hole forming tool body and tool of the present invention. DETAILED DESCRIPTION

[0012] Example 1: The present invention discloses a method for processing a deep blind flat bottom circular arc step hole product: the typical feature is that the inner hole is a deep blind flat bottom circular arc step hole, the shape of which is that the hole bottom plane is connected to the circular arc, the taper is connected to the inner hole straight line segment, and the step hole is connected through a large circular arc transition, the first section of the deep blind flat bottom circular arc hole depth L = 1282mm, the second section of the circular arc hole depth L 10 =1113mm, the straight hole in the transition section of the two arc inner holes is Φd9=143mm, and the maximum aperture of the example is Φd8=206mm. Because the arc step hole contains two arc holes, and the two arc holes are connected by a straight hole, the two arc holes are processed in sections during processing. Each arc hole is drilled and bored into multiple step holes with a 3~4mm margin on one side according to the aperture size and the processing range of the boring tool body. After drilling and boring, replace the forming tool body and forming tool to process the arc hole and ensure the depth requirements. The specific processing technology is as follows: Step 1), such as Figure 2 , Figure 3 , Figure 5 , Processing of the first section of deep blind arc flat bottom hole: Step 1.1), put one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, and place it on the frame position that has been pre-machined for the product. Align the chuck and the frame position so that the jump is within 0.1mm; drill the bottom hole Φd, spindle speed 70r / min, drill rod speed 220r / min, feed speed 40±10mm / min, and ensure the hole depth L1 including the drill tip; replace the reaming cutter body, and expand the step holes Φd1 and Φd2 in turn, spindle speed 70r / min, drill rod speed 20r / min ; Feed speed 40-50mm / min, ensure the depth of the two steps of the hole expansion L2, L3; replace the boring tool body, bore Φd3, Φd4, Φd5 in turn, lock the drill rod, spindle speed 60r / min, feed speed 20-30mm / min, ensure the corresponding hole depth L4, L5, L6 size; replace the floating boring tool body, repair the Φd5 inner hole finish, lock the drill rod, spindle speed 143r / min, feed speed 20-30mm / min, ensure the hole depth L6; Step 1.2), put the product on the lathe, align it with the inner hole Φd5 as the reference, turn the solid end spindle aligning frame and the open end center frame frame, and ensure the coaxiality of the frame is ≤0.05mm; Step 1.3), install one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, and place it on the frame position that has been pre-machined on the product. Align the chuck and the center frame position to within 0.05mm; install the forming cutter body and forming blade on the boring bar, align the gap between the forming blade and the hole wall, ensure centering, lock the drill rod, spindle speed 50~60r / min, feed speed 5mm / min, after the wooden guide key on the forming cutter body is completely consumed into the hole, feed to a depth of (L1-60)mm, feed speed adjusted to 3mm / min, feed speed adjusted to 2mm / min after the forming cutter eats the cut, and pay attention to the shape of the iron chips and the vibration of the cutter bar to adjust the feed speed in time. After the forming cutter completely turns off the steps of the inner hole, retract the cutter to check the wear of the forming cutter, grind or replace the new cutter, re-feed to the cutting position, feed speed adjusted to 1mm / min, and retract the cutter after processing to the required depth L; Step 2), such as Figure 4 , Figure 1 , Figure 6 , the second section of deep blind arc hole processing: Step 2.1), after the first section of deep blind arc flat bottom hole processing is completed, do not get off the bed, replace the boring bar and boring tool body, and bore holes Φd6, Φd7, Φd8 in turn, spindle speed 60r / min, feed speed 20-30mm / min, to ensure the corresponding hole depths L7, L8, L9; replace the floating boring tool body, repair the Φd8 inner hole finish, lock the drill rod, spindle speed 143r / min, feed speed 20-30mm / min, to ensure the hole depth L9; Step 2.2), put the product on the lathe, align it with the inner hole Φd8 as the reference, repair the solid end spindle alignment frame and the open end center frame frame, and ensure the coaxiality of the frame is ≤0.05mm; Step 2.3), put one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, which is placed on the frame position pre-machined by the product. Align the chuck and the center frame position so that the jump is within 0.05mm. According to the processing parameters and processing steps of the first arc flat bottom hole, use the forming tool body and forming tool to form the inner cavity of the second deep blind arc hole; use the special device for measuring the depth of the transition section of the inner hole arc taper to measure the depth of the second arc hole to ensure that the depth L of the second arc hole is 10 .

[0013] According to the above implementation method, the processing of deep blind flat-bottomed circular arc step holes is successfully completed on a deep hole drilling and boring machine without using a CNC lathe and a shock-absorbing tool bar, and the dimensional accuracy requirements are met.

Claims

1. A processing technology for deep blind arc step hole, characterized by: Because the arc step hole contains two arc holes, and the two arc holes are connected by a straight hole, the two arc holes are processed in sections. Each arc hole is drilled and bored into multiple step holes with a 3~4mm margin on one side according to the hole size and the processing range of the boring tool body. After drilling and boring, the forming tool body and forming tool are replaced to shape the arc hole and ensure the depth requirements. The specific processing technology is as follows: Step 1), Processing of the first section of deep blind arc flat bottom hole: Step 1.1), put one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, and place it on the frame position that has been pre-machined for the product. Align the chuck and the frame position so that the jump is within 0.1mm; drill the bottom hole Φd, spindle speed 70r / min, drill rod speed 220r / min, feed speed 40±10mm / min, and ensure the hole depth L1 including the drill tip; replace the reaming cutter body, and expand the step holes Φd1 and Φd2 in turn, spindle speed 70r / min, drill rod speed 20r / min ; Feed speed 40-50mm / min, ensure the depth of the two steps of the hole expansion L2, L3; replace the boring tool body, bore Φd3, Φd4, Φd5 in turn, lock the drill rod, spindle speed 60r / min, feed speed 20-30mm / min, ensure the corresponding hole depth L4, L5, L6 size; replace the floating boring tool body, repair the Φd5 inner hole finish, lock the drill rod, spindle speed 143r / min, feed speed 20-30mm / min, ensure the hole depth L6; Step 1.2), put the product on the lathe, align it with the inner hole Φd5 as the reference, turn the solid end spindle aligning frame and the open end center frame frame, and ensure the coaxiality of the frame is ≤0.05mm; Step 1.3), install one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, and place it on the frame position that has been pre-machined on the product. Align the chuck and the center frame position to within 0.05mm; install the forming cutter body and forming blade on the boring bar, align the gap between the forming blade and the hole wall, ensure centering, lock the drill rod, spindle speed 50~60r / min, feed speed 5mm / min, after the wooden guide key on the forming cutter body is completely consumed into the hole, feed to a depth of (L1-60)mm, feed speed adjusted to 3mm / min, feed speed adjusted to 2mm / min after the forming cutter eats the cut, and pay attention to the shape of the iron chips and the vibration of the cutter bar to adjust the feed speed in time. After the forming cutter completely turns off the steps of the inner hole, retract the cutter to check the wear of the forming cutter, grind or replace the new cutter, re-feed to the cutting position, feed speed adjusted to 1mm / min, and retract the cutter after processing to the required depth L; Step 2), the second section of deep blind arc hole processing: Step 2.1), after the first section of deep blind arc flat bottom hole processing is completed, do not get off the bed, replace the boring bar and boring tool body, and bore holes Φd6, Φd7, Φd8 in turn, spindle speed 60r / min, feed speed 20-30mm / min, to ensure the corresponding hole depths L7, L8, L9; replace the floating boring tool body, repair the Φd8 inner hole finish, lock the drill rod, spindle speed 143r / min, feed speed 20-30mm / min, to ensure the hole depth L9; Step 2.2), put the product on the lathe, align it with the inner hole Φd8 as the reference, repair the solid end spindle alignment frame and the open end center frame frame, and ensure the coaxiality of the frame is ≤0.05mm; Step 2.3), put one end of the product into the chuck of the deep hole drilling and boring machine, and put the other end on the center frame, which is placed on the frame position pre-machined by the product. Align the chuck and the center frame position so that the jump is within 0.05mm. According to the processing parameters and processing steps of the first arc flat bottom hole, use the forming tool body and forming tool to form the inner cavity of the second deep blind arc hole; use the special device for measuring the depth of the transition section of the inner hole arc taper to measure the depth of the second arc hole to ensure that the depth L of the second arc hole is 10 .

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