Processing technology of deep holes and grooves for temperature measuring elements in the sealing chamber of nuclear main pumps

Abstract

The present invention relates to a process for processing deep holes and grooves of temperature measuring elements in the sealing chamber of a nuclear main pump. The process completes the processing of deep holes and grooves on multiple levels of the sealing chamber by equipping a machining center with an angle head, a three-face milling cutter, and a variety of tools. The sealing chamber (1) is fixed on a workbench (21) of the machining center; an angle head (16) is installed on the machining center (20), and a three-face milling cutter (19) with a diameter of 100 mm is installed on the angle head (16). The three-face milling cutter (19) is used to process the position of the temperature measuring hole (5) on the inner arc surface (2) into a flat surface. The present invention achieves high-precision deep hole processing on multiple levels, has a stable drilling method, saves the purchase of professional deep hole processing machines, saves costs for enterprises, improves machine tool utilization and production capacity, and multiplies processing efficiency. It has been successfully applied to nuclear main pumps and many other nuclear main pump projects.

Description

Technical field:

[0001] The invention relates to a process for processing deep holes and grooves of temperature measuring elements in a sealing chamber of a nuclear main pump. Background technology:

[0002] The sealing chamber is a key component of the main pump of a nuclear power plant. It is equipped with three-level sealing components, and has extremely high requirements for temperature control and temperature measuring elements. In addition, the interior of the sealing chamber is subjected to high temperature and high pressure, so the processing quality of the deep holes of the temperature measuring elements in the sealing chamber is crucial.

[0003] The deep hole length of the temperature measuring element in the sealed chamber is close to 400mm, with a minimum diameter of 7mm. The roughness requirement for some positions is Ra1.6μm, and it is necessary to pass through two levels, which is very easy to damage the processing tool. For this kind of high-precision deep hole processing, professional deep hole processing machines are generally used at home and abroad. Even when professional deep hole processing machines are used, it is difficult to meet the drawing requirements due to the multi-level processing. It is often the case that the tool on the second level is damaged or is not coaxial with the hole on the first level. At the same time, professional deep hole processing machines occupy a large area, have a single machine processing method, low utilization rate, and low efficiency. In addition, professional deep hole processing machines are relatively expensive. Ordinary machine tools cannot meet the requirements of nuclear power products in terms of roughness or position when processing deep holes.

[0004] The groove of the temperature measuring element in the sealed chamber is inclined inward, and is generally processed by a boring machine using an extended tool bar. However, due to the excessive length of the tool bar, chatter marks are generated, affecting the processing quality. Because the groove is inclined inward, if an extended tool bar is used to process the inward-inclined angle, the tool bar will interfere with the upper part of the sealed chamber. Therefore, manual grinding can only be used to complete the grinding of the groove's inclination angle, which affects the product processing quality and makes it difficult to meet the design requirements. Summary of the invention:

[0005] The purpose of the present invention is to provide a processing technology for deep holes and grooves of temperature measuring elements in the sealing chamber of a nuclear main pump, which has high processing accuracy, stable drilling method, cost savings, improved machine tool utilization and production capacity, and multiplied processing efficiency.

[0006] The technical solution of the present invention is a process for processing deep holes and grooves of temperature measuring elements in the sealing chamber of a nuclear main pump;

[0007] 1) Fixing the sealing chamber (1) on a workbench (21) of a machining center;

[0008] 2) Installing the angle head (16) on the machining center (20), installing a three-edge milling cutter (19) with a diameter of 100 mm on the angle head (16), and using the three-edge milling cutter (19) to machine the position of the temperature measuring hole (5) on the inner arc surface (2) into a flat surface;

[0009] 3) Using a 30mm diameter plate drill (8) on a machining center, pre-machine a temperature measuring hole (5) and two process holes (4) on the outer arc surface (3);

[0010] 4) On the machining center, a thermal expansion rod (10) is used in conjunction with a 16mm diameter centering drill (9) to penetrate a temperature measuring hole (5) and two process holes (4) on the outer arc surface (3), and respectively process a temperature measuring hole (5) and a centering hole of M20 thread (6) on the inner arc surface (2);

[0011] 5) On the machining center, a thermal expansion rod (10) is used in conjunction with a stepped drill (11) with a diameter of 7 mm and 14.1 mm to penetrate the temperature measuring hole (5) on the outer arc surface (3) and machine the depth of the temperature measuring hole (5) on the inner arc surface;

[0012] 6) On the machining center, a thermal expansion rod (10) is used in conjunction with a 30.4 mm diameter drill (12) to expand the temperature measuring hole (5);

[0013] 7) Using a 7mm diameter drill bit (13) on a machining center, a through hole for the temperature measuring hole (5) is machined;

[0014] 8) Using a 30.6mm diameter inverted strip reamer (14) on a machining center, the temperature measuring holes (5) on the outer arc surface (3) and the inner arc surface (2) are simultaneously reamed;

[0015] 9) Using a high-speed steel deep hole drill (15) with a diameter of 17.5 mm, the bottom hole of the M20 threaded hole (6) is machined on a machining center;

[0016] 10) Manually tap the threads of the M20 threaded hole (6);

[0017] 11) An angle head (16) is mounted on a machining center (20), and a high-speed milling cutter (17) with a diameter of 20 mm is mounted on the angle head (16) to machine a 45 mm wide bevel groove (7);

[0018] 12) Install the angle head (16) on the machining center (20), and install a ball-end cutter (18) with a diameter of 20 mm on the angle head (16) to fine-mill the R10 chamfer position of the inclined groove (7);

[0019] The inverted strip reamer (14) used in step 8) is an integral segmented type. The inverted strip of the inverted strip reamer (14) used in step 8) can play a guiding and supporting role, and simultaneously hinge the holes of the inner layer arc surface and the outer layer arc surface to ensure the coaxiality of the holes.

[0020] Step 2) The speed of the three-edge milling cutter is n = 160r / min ± 5r / min, the feed speed vf = 80mm / min ± 5mm / min, and the cutting depth ap = 6mm ± 1mm; Step 3) The speed of the plate drill is n = 800r / min ± 20r / min, the feed speed vf = 150mm / min ± 10mm / min; Step 4) The speed of the spot drill is n = 1000r / min ± 20r / min, the feed speed vf = 200mm / min ± 10mm / min; Step 5) The speed of the step drill is n = 900 r / min±20r / min, feed speed vf=90mm / min±5mm / min; step 6) drill speed n=80r / min±5r / min, feed speed vf=16mm / min±2mm / min; step 7) drill speed n=1550r / min±30r / min, feed speed vf=60mm / min±5mm / min; step 8) inverted reamer speed n=80r / min±5r / min, feed speed vf=20mm / min±2mm / min.

[0021] Technical effects of the present invention:

[0022] This process first uses a machining center equipped with an angle head to machine the inner arc plane. By varying the angles and using simulation software to simulate the machining process, interference between the angle head and the workpiece is prevented, thus avoiding collisions during machining. Then, a centering hole is drilled on the inner arc plane to avoid centering problems. By combining various tools and selecting appropriate parameters, high-precision multi-layered stepped deep holes are achieved, with a stable drilling method that meets design requirements. Second, this process eliminates the need for specialized deep-hole machining machines, saving costs and increasing machine tool utilization and production capacity. Third, it exponentially improves machining efficiency. Dedicated machines can only machine deep holes, not flat surfaces or beveled grooves. Both can be machined in a single clamping operation on a machining center, more than doubling machining time compared to dedicated machines. Fourth, in steps 11) and 12, the beveled grooves are machined using a machining center and an angle head, replacing manual grinding to achieve the desired angles. This significantly improves manufacturing efficiency and machining accuracy. This process method is of great significance to the localization of key processes for nuclear main pumps, and has been successfully applied to the "Hualong One" nuclear main pump and many other nuclear main pump projects.

[0023] In step 8) described in claim 2, the inverted strip reamer used is a customized integral segmented type. The advantages of this reamer are that it can first reduce the processing torque and avoid vibration during processing that affects the processing quality. Second, the segmented type facilitates the discharge of iron chips and improves the surface quality. Third, the inverted strip of the inverted strip reamer used can play a guiding and supporting role. At the same time, the holes of the inner arc surface and the outer arc surface can be reamed to ensure the coaxiality of the holes.

[0024] In claim 3, the rotation speed of the three-edge milling cutter in step 2) is n = 160r / min ± 5r / min, the feed speed vf = 80mm / min ± 5mm / min, and the cutting depth ap = 6mm ± 1mm; the rotation speed of the plate drill in step 3) is n = 800r / min ± 20r / min, and the feed speed vf = 150mm / min ± 10mm / min; the rotation speed of the spot drill in step 4) is n = 1000r / min ± 20r / min, and the feed speed vf = 200mm / min ± 10mm / min; the rotation speed of the step drill in step 5) is n = 900r / min ± 20r / min, and the feed speed vf = 90mm / min ± 5mm / min; step 6) the rotation speed of the forging drill n = 80r / min±5r / min, the feed speed vf = 16mm / min±2mm / min; step 7) the rotation speed of the drill bit n = 1550r / min±30r / min, the feed speed vf = 60mm / min±5mm / min; step 8) the rotation speed of the inverted reamer n = 80r / min±5r / min, the feed speed vf = 20mm / min±2mm / min. These parameters, which have been explored in practice, can make the technical requirements such as the processed deep hole size, surface roughness, and coaxiality meet the design requirements, and the tool breakage that is prone to occur in deep hole processing will not occur. Description of the drawings:

[0025] Figure 1 Location diagram of deep hole for temperature measuring element in sealing chamber of nuclear main pump

[0026] Figure 2 Position diagram of the temperature measuring element chute in the nuclear main pump sealing chamber

[0027] Figure 3 This is a schematic diagram of the overall processing of step 2 in the present invention;

[0028] Figure 4 It is a processing schematic diagram of step 2 in the present invention;

[0029] Figure 5 It is a processing schematic diagram of step 3 in the present invention;

[0030] Figure 6 It is a processing schematic diagram of step 4 in the present invention;

[0031] Figure 7 It is a processing schematic diagram of step 5 in the present invention;

[0032] Figure 8 It is a processing schematic diagram of step 6 in the present invention;

[0033] Figure 9 It is a processing schematic diagram of step 7 in the present invention;

[0034] Figure 10 It is a processing schematic diagram of step 8 in the present invention;

[0035] Figure 11 It is a processing schematic diagram of step 9 in the present invention;

[0036] Figure 12 It is a processing schematic diagram of step 11 in the present invention;

[0037] Figure 13 It is a processing schematic diagram of step 12 in the present invention; Specific implementation method:

[0038] The present invention relates to a process for processing deep holes and grooves of temperature measuring elements in a sealing chamber of a nuclear main pump. Figure 1 As shown, the following steps are included:

[0039] 1) If Figure 3 As shown, the sealed chamber 1 is fixed on the workbench 21 of the machining center 20;

[0040] 2) Install the angle head 16 on the machining center 20, install a three-edge milling cutter 19 with a diameter of 100mm on the angle head 16, and use the three-edge milling cutter 19 to process the position of the temperature measuring hole 5 on the inner arc surface 2 into a flat surface, such as Figure 3 and Figure 4 As shown;

[0041] 3) A plate drill 8 with a diameter of 30 mm is used on the machining center to pre-machine a temperature measuring hole 5 and two process holes 4 on the outer arc surface 3, such as Figure 5 As shown;

[0042] 4) On the machining center, a thermal expansion rod 10 is used in conjunction with a 16mm diameter pilot drill 9 to penetrate a temperature measuring hole 5 and two process holes 4 on the outer arc surface 3 to respectively machine a temperature measuring hole 5 and a pilot hole of M20 thread 6 on the inner arc surface 2, as shown in FIG. Figure 6 As shown;

[0043] 5) On the machining center, a thermal expansion rod 10 is used to match a stepped drill 11 with a diameter of 7 mm and 14.1 mm to penetrate the temperature measuring hole 5 of the outer arc surface 3 to machine the depth size of the temperature measuring hole 5 of the inner arc surface, such as Figure 7 As shown;

[0044] 6) On the machining center, a thermal expansion rod 10 is used in conjunction with a 30.4 mm diameter drill 12 to expand the temperature measuring hole 5. Figure 8 As shown;

[0045] 7) Use a 7mm diameter drill bit 13 to make a through hole for the temperature measuring hole 5 on the machining center. Figure 9 As shown;

[0046] 8) Use a 30.6mm diameter inverted strip reamer 14 on the machining center to simultaneously ream the temperature measuring holes 5 of the outer arc surface 3 and the inner arc surface 2, as shown in the following example: Figure 10 As shown;

[0047] 9) Use a 17.5mm diameter high-speed steel deep hole drill 15 to machine the bottom hole of the M20 threaded hole 6 on the machining center. Figure 11 As shown;

[0048] 10) Manually tap the thread of M20 threaded hole 6;

[0049] 11) Install the angle head 16 on the machining center, and install a high-speed milling cutter 17 with a diameter of 20 mm on the angle head 16 to process the 45 mm wide bevel groove 7, such as Figure 2 、 Figure 12 As shown;

[0050] 12) Install the angle head 16 on the machining center, and install a 20mm diameter ball end cutter 18 on the angle head 16 to fine mill the R10 chamfer position of the inclined groove 7, as shown in the figure. Figure 2 、 Figure 13 shown.

[0051] The inverted strip reamer 14 used in step 8) is an integral segmented type. The inverted strip of the inverted strip reamer 14 used in step 8) can play a guiding and supporting role, and at the same time, the holes of the inner arc surface and the outer arc surface are reamed to ensure the coaxiality of the holes.

[0052] Step 2) The speed of the three-edge milling cutter is n = 160r / min ± 5r / min, the feed speed vf = 80mm / min ± 5mm / min, and the cutting depth ap = 6mm ± 1mm; Step 3) The speed of the plate drill is n = 800r / min ± 20r / min, the feed speed vf = 150mm / min ± 10mm / min; Step 4) The speed of the spot drill is n = 1000r / min ± 20r / min, the feed speed vf = 200mm / min ± 10mm / min; Step 5) The speed of the step drill is n = 900 r / min±20r / min, feed speed vf=90mm / min±5mm / min; step 6) drill speed n=80r / min±5r / min, feed speed vf=16mm / min±2mm / min; step 7) drill speed n=1550r / min±30r / min, feed speed vf=60mm / min±5mm / min; step 8) inverted reamer speed n=80r / min±5r / min, feed speed vf=20mm / min±2mm / min.

Claims

1. A process for processing deep holes and grooves of temperature measuring elements in the sealing chamber of a nuclear main pump, characterized by: The machining of deep holes and grooves on multiple levels of the sealing chamber is completed by equipping the machining center with an angle head, a three-face milling cutter, and a variety of tools. The following steps are included: 1) Fixing the sealing chamber (1) on a workbench (21) of a machining center; 2) Installing the angle head (16) on the machining center (20), installing a three-edge milling cutter (19) with a diameter of 100 mm on the angle head (16), and using the three-edge milling cutter (19) to machine the position of the temperature measuring hole (5) on the inner arc surface (2) into a flat surface; 3) Using a 30mm diameter plate drill (8) on a machining center, pre-machine a temperature measuring hole (5) and two process holes (4) on the outer arc surface (3); 4) On the machining center, a thermal expansion rod (10) is used in conjunction with a 16mm diameter centering drill (9) to penetrate a temperature measuring hole (5) and two process holes (4) on the outer arc surface (3), and respectively process a temperature measuring hole (5) and a centering hole of an M20 threaded hole (6) on the inner arc surface (2); 5) On the machining center, a thermal expansion rod (10) is used in conjunction with a stepped drill (11) with a diameter of 7 mm and 14.1 mm to penetrate the temperature measuring hole (5) on the outer arc surface (3) and machine the depth of the temperature measuring hole (5) on the inner arc surface; 6) On the machining center, a thermal expansion rod (10) is used in conjunction with a 30.4 mm diameter drill (12) to expand the temperature measuring hole (5); 7) Using a 7mm diameter drill bit (13) on a machining center, a through hole for the temperature measuring hole (5) is machined; 8) Using a 30.6mm diameter inverted strip reamer (14) on a machining center, the temperature measuring holes (5) on the outer arc surface (3) and the inner arc surface (2) are simultaneously reamed; 9) Using a high-speed steel deep hole drill (15) with a diameter of 17.5 mm, the bottom hole of the M20 threaded hole (6) is machined on a machining center; 10) Manually tap the threads of the M20 threaded hole (6); 11) An angle head (16) is mounted on a machining center (20), and a high-speed milling cutter (17) with a diameter of 20 mm is mounted on the angle head (16) to machine a 45 mm wide bevel groove (7); 12) An angle head (16) is mounted on a machining center (20), and a ball-end cutter (18) with a diameter of 20 mm is mounted on the angle head (16) to fine-mill the R10 chamfer position of the inclined groove (7).

2. The process for processing deep holes and grooves of temperature measuring elements in the sealing chamber of a nuclear main pump according to claim 1 is characterized by: The inverted strip reamer (14) used in step 8) is an integral segmented type. The inverted strip of the inverted strip reamer (14) used in step 8) can play a guiding and supporting role, and simultaneously hinge the holes of the inner layer arc surface and the outer layer arc surface to ensure the coaxiality of the holes.

3. The process for processing deep holes and grooves of temperature measuring elements in the sealing chamber of a nuclear main pump according to claim 1 is characterized by: Step 2) The speed of the three-edge milling cutter is n = 160r / min ± 5r / min, the feed speed vf = 80mm / min ± 5mm / min, and the cutting depth ap = 6mm ± 1mm; Step 3) The speed of the plate drill is n = 800r / min ± 20r / min, the feed speed vf = 150mm / min ± 10mm / min; Step 4) The speed of the spot drill is n = 1000r / min ± 20r / min, the feed speed vf = 200mm / min ± 10mm / min; Step 5) The speed of the step drill is n = 900 r / min±20r / min, feed speed vf=90mm / min±5mm / min; step 6) drill speed n=80r / min±5r / min, feed speed vf=16mm / min±2mm / min; step 7) drill speed n=1550r / min±30r / min, feed speed vf=60mm / min±5mm / min; step 8) inverted reamer speed n=80r / min±5r / min, feed speed vf=20mm / min±2mm / min.

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