A device for processing thin-walled parts at low temperature

Abstract

A low-temperature processing device for thin-walled parts belongs to the technical field of milling equipment for thin-walled components of alloys that are difficult to process, and in particular, relates to a low-temperature processing device for thin-walled parts. The present invention provides a low-temperature processing device for thin-walled parts with better working effect. The low-temperature processing device for thin-walled parts of the present invention comprises a tool handle outer ring 1.5, which is characterized in that the upper inner wall of the tool handle outer ring 1.5 is expanded outward to form an upper sealing ring placement groove and an upper bearing placement groove, an upper sealing ring 1.4 is arranged in the upper sealing ring placement groove, an upper threaded fastening washer 1.3 is arranged at the upper end of the upper sealing ring 1.4, the upper bearing placement groove is located at the upper end of the upper sealing ring placement groove, and the diameter of the upper bearing placement groove is greater than the diameter of the upper sealing ring placement groove; an upper bearing 1.2 is arranged in the upper bearing placement groove; the lower inner wall of the tool handle outer ring 1.5 is expanded outward to form a lower sealing ring placement groove and a lower bearing placement groove, a lower sealing ring 1.6 is arranged in the lower sealing ring placement groove, and a lower threaded fastening washer 1.7 is arranged at the lower end of the lower sealing ring 1.6.

Description

Technical Field

[0001] The invention belongs to the technical field of milling equipment for difficult-to-process alloy thin-wall components, and in particular relates to a low-temperature processing device for thin-wall components. Background Art

[0002] Thin-walled titanium alloys, nickel-based high-temperature alloys and other difficult-to-process components have good mechanical properties, high thermal strength, high specific strength, good corrosion resistance and other advantages, and are widely used in important fields such as aerospace, military industry and national defense. However, due to the poor stiffness and high toughness of such thin-walled components, high dimensional accuracy and form and position tolerance requirements, the use of traditional cutting fluid cooling milling technology will inevitably lead to defects such as burrs, easy deformation, and large dimensional errors. In addition, the thermal conductivity of difficult-to-process materials such as titanium alloys is lower than that of steel, and the cooling capacity and effect of the cutting fluid are not ideal. When processing at high speed, it is very easy to cause serious thermal deformation defects, especially when the milling amount is large, the processing defects are more serious. The milling defects of thin-walled difficult-to-process alloy materials are the result of the combined effect of heat and force coupling. The cooling efficiency should be improved and the cutting force load should be reduced during cutting.

[0003] Northwestern Polytechnical University has disclosed a robust process control method for the surface state of titanium alloy thin-walled structure precision milling, and applied for a domestic patent, application number: CN202111129812.2, invention name: robust process control method for the surface state of titanium alloy thin-walled structure precision milling. This method compensates for the sudden change of the surface state of the structural parts caused by the uncontrollable factors during processing by adjusting the controllable process parameters, ensuring that the fatigue performance of the structural parts reaches the expected effect, and improving the size and shape accuracy of titanium alloy thin-walled structural parts. Jiangsu Xianglin Jiayu Machinery Co., Ltd. has disclosed a chip position cooling device in the processing of thin-walled parts, and applied for a domestic patent, application number: CN202121806849.X, patent name: A chip position cooling device in the processing of thin-walled parts. This patent can spray water on the processing position of thin-walled parts through a water spray interface during processing, thereby achieving a cooling effect. Dalian Dongxing Forging Co., Ltd. has disclosed a cooling device for processing thin-walled ring parts and applied for a domestic patent, application number: CN202022435303.X. Invention name: A cooling device for processing thin-walled ring parts. The device can effectively cool the grinding disc and can continuously grind the inner and outer walls of thin-walled ring parts.

[0004] The above inventions are all based on cutting stability, machining error compensation and using cutting fluid to reduce the temperature of the cutting zone to improve the processing defects of thin-walled parts. However, for large cutting amount processing, high temperature thermal deformation and other defects are still inevitable, affecting the size and shape accuracy of the workpiece. Summary of the invention

[0005] The present invention aims at solving the above problems and provides a low-temperature processing device for thin-walled parts with better working effect.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme. The low-temperature processing device for thin-walled parts of the present invention comprises a tool handle outer ring 1.5, which is characterized in that the inner wall of the upper part of the tool handle outer ring 1.5 is expanded outward to form an upper sealing ring placement groove and an upper bearing placement groove, an upper sealing ring 1.4 is arranged in the upper sealing ring placement groove, an upper threaded fastening washer 1.3 is arranged at the upper end of the upper sealing ring placement groove, and the upper bearing placement groove is located at the upper end of the upper sealing ring placement groove, and the diameter of the upper bearing placement groove is greater than the diameter of the upper sealing ring placement groove; an upper bearing 1.2 is arranged in the upper bearing placement groove;

[0007] The inner wall of the lower part of the outer ring 1.5 of the tool handle is expanded outward to form a lower sealing ring placement groove and a lower bearing placement groove. A lower sealing ring 1.6 is arranged in the lower sealing ring placement groove, and a lower threaded fastening washer 1.7 is arranged at the lower end of the lower sealing ring 1.6. The lower bearing placement groove is located at the lower end of the lower sealing ring placement groove, and the diameter of the lower bearing placement groove is larger than the diameter of the lower sealing ring placement groove; a lower bearing 1.8 is arranged in the lower bearing placement groove, and a stop washer 1.9 is arranged at the lower end of the lower bearing 1.8;

[0008] The knife handle 1.1 passes through the center hole of the knife handle outer ring 1.5, and the upper outer wall of the knife handle 1.1 has a flange extending outward, and the lower end surface of the flange is connected to the upper end surface of the upper bearing 1.2; a fastening nut 1.10 is screwed on the lower outer wall of the knife handle 1.1, and the upper end of the fastening nut 1.10 is connected to the lower end of the stop washer 1.9;

[0009] The lower end of the knife handle 1.1 is provided with a left blade 1.11 and a right blade 1.13, and the left blade 1.11 and the right blade 1.13 are symmetrically arranged on both sides of the lower end of the knife handle 1.1;

[0010] The left side of the tool handle outer ring 1.5 bulges upward to form a left coolant inlet 1.15, and the right side of the tool handle outer ring 1.5 bulges upward to form a right lubricating liquid inlet 1.16; the left coolant inlet 1.15 and the right lubricating liquid inlet 1.16 are connected to the coolant channel in the tool handle outer ring 1.5, and the coolant channel is connected to the left blade 1.11 and the right blade 1.13.

[0011] As a preferred solution, the left blade 1.11 and the right blade 1.13 of the present invention are rhombus-shaped blades, which are arranged obliquely with the lower ends of the rhombus-shaped blades facing outwards.

[0012] As another preferred embodiment, the rhombus blade has a back angle of 25°.

[0013] As another preferred embodiment, the middle portion of the left blade 1.11 of the present invention is fixed to the lower end of the handle 1.1 by a left blade fastening screw 1.12, and the middle portion of the right blade 1.13 is fixed to the lower end of the handle 1.1 by a right blade fastening screw 1.14.

[0014] As another preferred embodiment, the BT40 tapered handle portion 2.8 at the upper end of the tool handle 1.1 of the present invention is placed in a spindle box 3.8, a left swivel joint 2.4 is provided at the left side of the lower end of the spindle box 3.8, a right swivel joint 2.7 is provided at the right side of the lower end of the spindle box 3.8, a left sealing ring 2.3 is provided at the lower end outlet of the left swivel joint 2.4, and a right sealing ring 2.6 is provided at the lower end outlet of the right swivel joint 2.7;

[0015] The left end inlet of the left rotating joint 2.4 is connected to the left end of the left liquid inlet channel in the left rotating joint 2.4, and the lower end of the left liquid inlet channel is connected to the lower end outlet of the left rotating joint 2.4;

[0016] The inlet at the right end of the right rotating joint 2.7 is connected to the right end of the right liquid inlet channel in the right rotating joint 2.7, and the lower end of the right liquid inlet channel is connected to the outlet at the lower end of the right rotating joint 2.7;

[0017] The upper part of the left coolant inlet 1.15 is placed inside the lower outlet of the left swivel joint 2.4, and the left sealing ring 2.3 is placed between the upper outer wall of the left coolant inlet 1.15 and the lower outlet wall of the left swivel joint 2.4;

[0018] The upper part of the right lubricating liquid inlet 1.16 is placed inside the lower end outlet of the right rotating joint 2.7, and the right sealing ring 2.6 is placed between the upper outer wall of the right lubricating liquid inlet 1.16 and the lower end outlet wall of the right rotating joint 2.7.

[0019] As another preferred solution, the left swivel joint 2.4 of the present invention is provided with a left vertical connection hole, and the upper end of the left connection bolt 2.5 passes through the left vertical connection hole and is screwed into the left threaded hole at the lower end of the spindle box 3.8;

[0020] A right vertical connection hole is arranged on the right swivel joint 2.7, and the upper end of the right connection bolt 2.9 passes through the right vertical connection hole and is screwed into the right threaded hole at the lower end of the spindle box 3.8.

[0021] As another preferred embodiment, the coolant channel of the present invention comprises a left vertical coolant channel 1.17, a right vertical coolant channel 1.18, a middle horizontal coolant channel 1.19, a middle vertical coolant channel 1.20, a left lower oblique coolant channel 1.21 and a right lower oblique coolant channel 1.22, the upper end of the left vertical coolant channel 1.17 is connected to the left coolant inlet 1.15, and the upper end of the right vertical coolant channel 1.18 is connected to the right lubricating liquid inlet 1.16;

[0022] The lower end of the left vertical coolant channel 1.17 is connected to the left end of the middle horizontal coolant channel 1.19, the lower end of the right vertical coolant channel 1.18 is connected to the right end of the middle horizontal coolant channel 1.19, the middle part of the middle horizontal coolant channel 1.19 is connected to the upper end of the middle vertical coolant channel 1.20, the lower end of the middle vertical coolant channel 1.20 is respectively connected to the upper end of the left lower oblique coolant channel 1.21 and the upper end of the right lower oblique coolant channel 1.22, the lower end of the left lower oblique coolant channel 1.21 is connected to the upper end of the left blade 1.11, and the lower end of the right lower oblique coolant channel 1.22 is connected to the upper end of the right blade 1.13; the left lower oblique coolant channel 1.21 is inclined from the upper right to the lower left, and the right lower oblique coolant channel 1.22 is inclined from the upper left to the lower right.

[0023] As another preferred embodiment, the left coolant inlet 1.15 and the right lubricating liquid inlet 1.16 of the present invention are truncated cone-shaped ports, the center of which is the liquid inlet channel; the lower end outlet of the left rotating joint 2.4 and the lower end outlet of the right rotating joint 2.7 are truncated cone-shaped grooves corresponding to the truncated cone-shaped ports.

[0024] As another preferred solution, the upper threaded fastening washer 1.3 and the lower threaded fastening washer 1.7 of the present invention are glass fiber reinforced plastic washers.

[0025] Secondly, the upper threaded fastening washer 1.3 and the lower threaded fastening washer 1.7 of the present invention are provided with twisting sockets.

[0026] In addition, the diameter of the central vertical coolant channel 1.20 of the present invention is 3 mm, and the diameters of the lower left slanted coolant channel 1.21 and the lower right slanted coolant channel 1.22 are less than 2 mm.

[0027] The invention has beneficial effects.

[0028] The present invention is provided with a left coolant inlet 1.15 and a right lubricant inlet 1.16, which can simultaneously input two coolants (liquid nitrogen + CO 2-雪 ). Under ultra-low temperature, the cutting force will increase, and the elastic modulus of the material will increase significantly. The cutting force is related to the cutting lubrication effect. In order to reduce the ratio of cutting force and elastic modulus, the low-temperature processing device for thin-walled parts of the present invention can simultaneously input two coolants (liquid nitrogen + CO 2-雪 ) The hybrid cooling integral external and internal cooling tool holder device performs ultra-low temperature mixed lubrication cooling during the milling of thin-walled parts. During ultra-low temperature cooling processing, it simultaneously improves the cutting area rigidity and lubrication function, reduces friction, and reduces cutting loads; it effectively improves thin-walled parts processing defects and improves thin-walled parts milling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. The protection scope of the present invention is not limited to the following description.

[0030] Figure 1 Liquid nitrogen / CO 2-雪 Internally sprayed integral handle.

[0031] 1.1-handle, 1.2-upper bearing, 1.3-upper threaded fastening washer, 1.4-upper sealing ring, 1.5-handle outer ring, 1.6-lower sealing ring, 1.7-lower threaded fastening washer, 1.8-lower bearing, 1.9-stop washer, 1.10-fastening nut, 1.11-left blade, 1.12-left blade fastening screw, 1.13-right blade, 1.14-right blade fastening screw.

[0032] Figure 2 It is an integral toolholder machine tool connection.

[0033] 3.8-spindle box, 2.2-spindle, 2.3-left sealing ring, 2.4-left swivel joint, 2.5-left connecting bolt, 2.6-right sealing ring, 2.7-right swivel joint, 2.8-BT40 taper shank part.

[0034] Figure 3 It is a liquid nitrogen + CO2 delivery control system.

[0035] 3.1-Liquid nitrogen Dewar tank, 3.2-Liquid nitrogen delivery hose, 3.3-Cryogenic flow valve, 3.4-Electronic flow control valve, 3.5-Cryogenic pressure reducing valve, 3.6-Cryogenic throttle valve, 3.7-Cryogenic check valve, 3.8-Spindle, 3.9-Tool handle, 3.10-Workpiece, 3.11-Fixture, 3.12-Ultra-low temperature controller, 3.13-Thermocouple, 3.14-Tee connector, 3.15-Electric contact pressure gauge, 3.16-Wire, 3.17-PLC control module, 3.18-Cryogenic electromagnetic control valve, 3.19-Cryogenic flow valve, 3.20-CO2 Dewar tank.

[0036] Figure 4 It is a flow-temperature regulation scheme.

[0037] Figure 5 It is the PLC module control circuit (LED1 lights up to show the control working status, and LED2 lights up to show the PLC power-on status. Figure 5 The cryogenic solenoid control valve is Figure 3 Low temperature solenoid control valve 3.18). DETAILED DESCRIPTION

[0038] like Figure 1As shown, the low-temperature processing device for thin-walled parts of the present invention comprises a tool handle outer ring 1.5, the inner wall of the upper part of the tool handle outer ring 1.5 is expanded outward to form an upper sealing ring placement groove and an upper bearing placement groove, an upper sealing ring 1.4 is arranged in the upper sealing ring placement groove, and an upper threaded fastening washer 1.3 is arranged at the upper end of the upper sealing ring 1.4 (the outer wall of the washer 1.3 is an external thread, and the center hole of the tool handle outer ring 1.5 is an internal thread, 1.3 and 1.5 are rotated by 1.3, so that 1.3 moves downward and presses 1.4), the upper bearing placement groove is located at the upper end of the upper sealing ring placement groove, and the diameter of the upper bearing placement groove is larger than the diameter of the upper sealing ring placement groove; an upper bearing 1.2 is arranged in the upper bearing placement groove;

[0039] The inner wall of the lower part of the outer ring 1.5 of the tool handle is expanded outward to form a lower sealing ring placement groove and a lower bearing placement groove. A lower sealing ring 1.6 is arranged in the lower sealing ring placement groove, and a lower threaded fastening washer 1.7 is arranged at the lower end of the lower sealing ring 1.6. The lower bearing placement groove is located at the lower end of the lower sealing ring placement groove, and the diameter of the lower bearing placement groove is larger than the diameter of the lower sealing ring placement groove; a lower bearing 1.8 is arranged in the lower bearing placement groove, and a stop washer 1.9 is arranged at the lower end of the lower bearing 1.8;

[0040] The knife handle 1.1 passes through the center hole of the knife handle outer ring 1.5, and the upper outer wall of the knife handle 1.1 has a flange extending outward, and the lower end surface of the flange is connected to the upper end surface of the upper bearing 1.2; a fastening nut 1.10 is screwed on the lower outer wall of the knife handle 1.1, and the upper end of the fastening nut 1.10 is connected to the lower end of the stop washer 1.9;

[0041] The lower end of the knife handle 1.1 is provided with a left blade 1.11 and a right blade 1.13, and the left blade 1.11 and the right blade 1.13 are symmetrically arranged on both sides of the lower end of the knife handle 1.1;

[0042] The left side of the tool handle outer ring 1.5 bulges upward to form a left coolant inlet 1.15, and the right side of the tool handle outer ring 1.5 bulges upward to form a right lubricating liquid inlet 1.16; the left coolant inlet 1.15 and the right lubricating liquid inlet 1.16 are connected to the coolant channel in the tool handle outer ring 1.5, and the coolant channel is connected to the left blade 1.11 and the right blade 1.13.

[0043] The lower end of the tool handle 1.1 can adopt a standard machine clamp type end mill structure.

[0044] The left blade 1.11 and the right blade 1.13 are rhombus-shaped blades, which are arranged obliquely, with the lower ends of the rhombus-shaped blades facing outwards.

[0045] The rhombus blade has a back angle of 25° ( Figure 1 The lower end is marked) to reduce friction with the processed surface.

[0046] The middle portion of the left blade 1.11 is fixed to the lower end of the handle 1.1 via a left blade fastening screw 1.12, and the middle portion of the right blade 1.13 is fixed to the lower end of the handle 1.1 via a right blade fastening screw 1.14.

[0047] The BT40 taper shank part 2.8 at the upper end of the tool handle 1.1 is placed in the spindle box 3.8 (a pull nail can be added to the tail of the BT40 taper shank part 2.8, and the tool handle is clamped and connected by using the tool-beating cylinder and the spindle 2.2 of the spindle box 3.8.), a left swivel joint 2.4 is provided on the left side of the lower end of the spindle box 3.8, a right swivel joint 2.7 is provided on the right side of the lower end of the spindle box 3.8, a left sealing ring 2.3 is provided at the lower end outlet of the left swivel joint 2.4, and a right sealing ring 2.6 is provided at the lower end outlet of the right swivel joint 2.7;

[0048] The left end inlet of the left rotating joint 2.4 is connected to the left end of the left liquid inlet channel in the left rotating joint 2.4, and the lower end of the left liquid inlet channel is connected to the lower end outlet of the left rotating joint 2.4;

[0049] The inlet at the right end of the right rotating joint 2.7 is connected to the right end of the right liquid inlet channel in the right rotating joint 2.7, and the lower end of the right liquid inlet channel is connected to the outlet at the lower end of the right rotating joint 2.7;

[0050] The upper part of the left coolant inlet 1.15 is placed inside the lower outlet of the left swivel joint 2.4, and the left sealing ring 2.3 is placed between the upper outer wall of the left coolant inlet 1.15 and the lower outlet wall of the left swivel joint 2.4;

[0051] The upper part of the right lubricating liquid inlet 1.16 is placed inside the lower end outlet of the right rotating joint 2.7, and the right sealing ring 2.6 is placed between the upper outer wall of the right lubricating liquid inlet 1.16 and the lower end outlet wall of the right rotating joint 2.7.

[0052] The left swivel joint 2.4 is provided with a left vertical connection hole, and the upper end of the left connection bolt 2.5 passes through the left vertical connection hole and is screwed into the left threaded hole at the lower end of the spindle box 3.8;

[0053] A right vertical connection hole is arranged on the right swivel joint 2.7, and the upper end of the right connection bolt 2.9 passes through the right vertical connection hole and is screwed into the right threaded hole at the lower end of the spindle box 3.8.

[0054] The coolant channel comprises a left vertical coolant channel 1.17, a right vertical coolant channel 1.18, a middle horizontal coolant channel 1.19, a middle vertical coolant channel 1.20, a left lower oblique coolant channel 1.21 and a right lower oblique coolant channel 1.22, the upper end of the left vertical coolant channel 1.17 is connected to the left coolant inlet 1.15, and the upper end of the right vertical coolant channel 1.18 is connected to the right lubricating liquid inlet 1.16;

[0055] The lower end of the left vertical coolant channel 1.17 is connected to the left end of the middle horizontal coolant channel 1.19, the lower end of the right vertical coolant channel 1.18 is connected to the right end of the middle horizontal coolant channel 1.19, the middle part of the middle horizontal coolant channel 1.19 is connected to the upper end of the middle vertical coolant channel 1.20, the lower end of the middle vertical coolant channel 1.20 is respectively connected to the upper end of the left lower oblique coolant channel 1.21 and the upper end of the right lower oblique coolant channel 1.22, the lower end of the left lower oblique coolant channel 1.21 is connected to the upper end of the left blade 1.11, and the lower end of the right lower oblique coolant channel 1.22 is connected to the upper end of the right blade 1.13; the left lower oblique coolant channel 1.21 is inclined from the upper right to the lower left, and the right lower oblique coolant channel 1.22 is inclined from the upper left to the lower right.

[0056] The left coolant inlet 1.15 and the right lubricant inlet 1.16 are truncated cone-shaped ports, the centers of which are liquid inlet channels; the lower outlets of the left and right swivel joints 2.4 and 2.7 are truncated cone-shaped grooves corresponding to the truncated cone-shaped ports.

[0057] The upper threaded fastening washer 1.3 and the lower threaded fastening washer 1.7 are made of glass fiber reinforced plastic washers.

[0058] The upper threaded fastening washer 1.3 and the lower threaded fastening washer 1.7 are provided with a twisting jack 1.23. The head can be inserted into the twisting jack using pointed pliers to twist the threaded fastening washer, so as to compress the sealing ring.

[0059] The diameter of the middle vertical coolant channel 1.20 is 3 mm ( Figure 1 The lower part is marked) (i.e. the flow channel diameter in the tool handle is 3 mm), the diameters of the left lower inclined coolant channel 1.21 and the right lower inclined coolant channel 1.22 are less than 2 mm ( Figure 1 The lower end is marked) (i.e. the nozzle diameter is less than 2 mm).

[0060] The distance between the low temperature liquid nitrogen nozzle and the cutting edge of the milling cutter can be shortened to less than or equal to 5mm ( Figure 1 marked at the bottom).

[0061] The spraying direction of the nozzle (the left lower inclined coolant channel 1.21 and the right lower inclined coolant channel 1.22) is aimed at the cutting part of the tool tip.

[0062] The left lower inclined coolant channel 1.21 and the right lower inclined coolant channel 1.22 are conical holes, and standard machine clamped milling blades (left blade 1.11 and right blade 1.13) can be installed in the blade installation slot at the end of the tool bar. The coolant is sprayed from the lower ends of the lower inclined coolant channel 1.21 and the right lower inclined coolant channel 1.22.

[0063] The upper sealing ring 1.4 and the lower sealing ring 1.6 may be lip-shaped sealing rings.

[0064] The left blade 1.11 and the right blade 1.13 may be hard alloy milling blades.

[0065] The left end inlet of the left swivel joint 2.4 and the right end inlet of the right swivel joint 2.7 can be connected by a sealing pipe thread, and the head of the external hose is a joint that can be screwed together.

[0066] The outer ring 1.5 of the shank handle can be manufactured by 3D printing, and the material can be a glass fiber composite material; at the same time, in order to achieve the purpose of heat insulation, a layer of 0.5mm thick polytetrafluoroethylene emulsion is coated on the liquid nitrogen flow channel in the shank handle. The flow channel must be kept unobstructed during coating. After it dries, it will adhere to the inner hole of the shank handle and prevent the emulsion from blocking the flow channel.

[0067] The low temperature processing device for thin-walled parts of the present invention is an integral externally rotating internally cooling tool handle structure. The integral type is relative to the ordinary tool handle, in which the ordinary tool handle and the front end tool rod are separated, and the tool rod needs to be connected with the spring chuck, which increases the leakage of liquid nitrogen at the connection. The integral structure of the present invention is leak-free.

[0068] The thin-walled component cryogenic processing device of the present invention is a part of the thin-walled component cryogenic processing system. The thin-walled component cryogenic processing system includes a liquid nitrogen dewar tank 3.1. The outlet of the liquid nitrogen dewar tank 3.1 is connected to the inlet of a cryogenic flow valve 3.3 through a liquid nitrogen delivery hose 3.2. The outlet of the cryogenic flow valve 3.3 is connected to the inlet of an electronic flow control valve 3.4. The outlet of the electronic flow control valve 3.4 is connected to the inlet of a cryogenic pressure reducing valve 3.5. The outlet of the cryogenic pressure reducing valve 3.5 is connected to the inlet of a cryogenic throttle valve 3.6. The outlet of the cryogenic throttle valve 3.6 is connected to the inlet of a cryogenic check valve 3.7. , the outlet of the low-temperature one-way valve 3.7 is connected to the left inlet of the left rotating joint 2.4 on the machine tool spindle box 3.8; the control signal input port of the electronic flow control valve 3.4 is connected to the control signal output port of the ultra-low temperature temperature controller 3.12 (the ultra-low temperature temperature controller 3.12 can adopt AI-7028 / 7048 multi-channel PID temperature controller); the thermocouple 3.13 obtains the temperature signal from the tool terminal nozzle (i.e. the lower left oblique coolant channel 1.21 or the lower right oblique coolant channel 1.22), and transmits the temperature signal to the ultra-low temperature temperature controller 3.12 in the form of an electrical signal;

[0069] The right end inlet of the right turning joint 2.7 on the machine tool spindle box 3.8 is connected to the outlet of the three-way joint 3.14, the pressure detection port of the three-way joint 3.14 is connected to the inlet of the electric contact pressure gauge 3.15, the detection signal output port of the electric contact pressure gauge 3.15 is connected to the detection signal input port of the PLC control module (the PLC control module can adopt the Siemens S7-200PLC control module) 3.17 through the wire 3.16, the control signal output port of the PLC control module 3.17 is connected to the control signal input port of the cryogenic electromagnetic control valve 3.18, the outlet of the cryogenic electromagnetic control valve 3.18 is connected to the inlet of the three-way joint 3.14, the inlet of the cryogenic electromagnetic control valve 3.18 is connected to the outlet of the cryogenic flow valve 3.19, and the inlet of the cryogenic flow valve 3.19 is connected to the outlet of the CO2 Dewar tank 3.20.

[0070] The left end inlet of the left swivel joint 2.4 and the right end inlet of the right swivel joint 2.7 are tapered holes.

[0071] The temperature at both ends of the horizontal machining surface of the workpiece is set to T1, and the temperature in the middle is set to T2. The temperature change satisfies the following formula:

[0072]

[0073] Where y is the calculated set temperature of the nozzle, x is the feed direction coordinate, and L is the length of the workpiece in the feed direction. The tool position before cutting is 10 mm from the starting cutting end of the workpiece.

[0074] Divide the workpiece length L into 10 parts, and the above formula can be used to calculate the cooling temperature y1, y2…y required for each step along the processing feed x direction. 10 .

[0075] At the same time, the feeding time for each portion is

[0076]

[0077] Where t is the tool moving time (s), f z is the feed per tool tooth (mm / z), z is the number of tool teeth, and n is the spindle speed (r / min).

[0078] Preset needs to be changed in real time (set 10 y values ​​y1, y2…y in the ultra-low temperature controller 3.12 in succession) 10 , obtained by formula (1), the nozzle calculation setting temperature y is input into the ultra-low temperature controller 3.12 every time the calculation time t in formula (2) changes. On the basis of the adjusted temperature T1, T1 is the liquid nitrogen and CO at the outlet of the knife tip. 2-雪 The mixture reaches the required nozzle temperature; the tool enters the cutting state after feeding 10mm, and then the temperature is adjusted from the set temperature y1;

[0079] The temperature is controlled starting from the set temperature y1, and the temperature state changes according to the parabolic characteristic (the parabolic characteristic temperature state is a nonlinear temperature change process, which is smoother than the linear change, and prevents the temperature change gradient from increasing the cooling change speed of the workpiece and causing uneven cooling. When the thin-walled workpiece is optimized for cooling temperature experiments, the temperature measured at the temperature measuring points at the same step length position on the cutting surface is fitted into a parabolic curve). The temperature signal is converted into an electrical signal by the thermocouple 3.13 and transmitted to the ultra-low temperature controller 3.12, and the ultra-low temperature controller 3.12 converts the electrical signal through the PID signal amplifier in the electronic flow control valve 3.4. The signal is transmitted to the servo controller inside, which drives the servo motor to rotate forward or reverse (when the servo motor rotates forward, the opening of the electronic flow control valve 3.4 decreases, the flow decreases, and the temperature increases; otherwise, the servo motor reverses to reduce the temperature. Let K be the actual thermocouple collection temperature. When |yK|>5℃ and yK>0, it rotates forward, otherwise yK<0, it reverses; when |yK|≤5℃, it stops working, that is, the adjustment accuracy is less than or equal to 5℃). The reducer drives the regulating valve in the electronic flow control valve 3.4 to operate, open or close the valve, until the ultra-low temperature temperature controller 3.12 reaches the set nozzle temperature requirement, and the electronic flow control valve 3.4 stops working.

[0080] The set temperature y1 is -190°C to 153°C, T1 = -190°C, T2 = -153°C.

[0081] The adapters 2.4 and 2.7 in the present invention must ensure the perpendicularity accuracy of their horizontal and vertical tapered hole axes and end faces during processing (the end faces and bottom faces are processed according to the mutual reference principle during cutting to ensure their perpendicularity, and then the tapered holes are drilled with the end faces or bottom faces as references to ensure the perpendicularity accuracy of the tapered holes and the end faces and bottom faces). At the same time, when they are installed on the machine tool spindle box, the dimensional accuracy and parallelism accuracy of the vertical tapered hole axes of the two adapters and the axis of the spindle 2.2 must be ensured (since the spindle box end face and the spindle tapered hole in the CNC milling machine assembly have a high degree of perpendicularity, the two adapters with higher precision bottom faces are installed on the spindle box 3.8 end face, so the parallelism accuracy of the vertical tapered hole axis and the spindle 2.2 axis can be ensured, and then the dimensional accuracy of the adapters 2.4 and 2.7 and the axis of the spindle 2.2 is ensured by the threaded holes of the mounting screws 2.5 that are accurately drilled on the end face of the spindle box 3.8 in advance).

[0082] The clamp 3.11 can adopt an existing conventional pressing plate.

[0083] The low-temperature processing device for thin-walled parts of the present invention is a highly efficient, high-quality and low-damage milling processing equipment for weak-rigidity alloy materials.

[0084] The external transmission and internal cooling integral tool holder has a tool rod (the thinnest part of the tool rod at the lower end of the fastening nut 1.10 is the tool rod) and a tool holder body that are designed and manufactured as an integrated whole, and does not require a spring chuck (the spring chuck is a conventional structure in the field). The assembly solves the problem of transmission leakage of liquid nitrogen in the tool holder (the spring chuck has no seal and needs to be disassembled frequently).

[0085] The present invention controls the instantaneous temperature of the cutting zone by controlling the flow rate of liquid nitrogen, and controls the cutting lubrication performance by controlling CO2.

[0086] The liquid nitrogen circulation and control device outside the tool handle can refer to the previously authorized invention patent - a milling device (ZL201910319180.2).

[0087] The PLC control module at the CO2 end takes into account that the solidification temperature of CO2 is higher than that of liquid nitrogen. When the liquid nitrogen pressure exceeds the CO2 pressure, it prevents liquid nitrogen from flowing into the CO2 end circulation pipeline, causing CO2 to freeze and block the pipeline.

[0088] The working process of the present invention will be described below in conjunction with the accompanying drawings.

[0089] like Figure 1 As shown, first press the upper sealing ring 1.4 into the outer ring 1.5 of the handle, then screw in the upper threaded fastening washer 1.3, and then install the upper bearing 1.2 to ensure that the outer ring of the bearing is fully installed. Install the handle 1.1 along the open end of the upper bearing 1.2 of the handle outer ring 1.5, ensuring that the innermost shoulder of the handle 1.1 is closely fitted with the inner ring end face of the upper bearing 1.2; then install the lower sealing ring 1.6, the lower threaded fastening washer 1.7, the lower bearing 1.8, the stop washer 1.9 in sequence along the other end of the handle outer ring 1.5, and finally screw in the fastening nut 1.10; fix the left blade 1.11 and the right blade 1.13 to the tail of the tool rod at the end of the handle through the left blade fastening screw 1.12 and the right blade fastening screw 1.14.

[0090] like Figure 2 As shown, the left sealing ring 2.3 and the right sealing ring 2.6 are respectively installed into the left rotating joint 2.4 and the right rotating joint 2.7, and then the assembled left rotating joint 2.4 and the right rotating joint 2.7 are installed on the spindle box 3.8 by the left connecting bolt 2.5 and the right connecting bolt 2.9; the BT40 tapered shank part 2.8 of the tail of the assembled integral tool handle 1.1 is installed into the spindle box 3.8, and at the same time, the two coolant inlets of the outer ring component of the integral tool handle 1.1 are installed into the left rotating joint 2.4 and the right rotating joint 2.7 to realize the connection between the integral tool handle 1.1 and the spindle box 3.8.

[0091] like Figure 3As shown, the liquid nitrogen dewar 3.1, the cryogenic flow valve 3.3, the electronic flow control valve 3.4, the cryogenic pressure reducing valve 3.5, the cryogenic throttle valve 3.6, and the cryogenic check valve 3.7 are connected in series in sequence by using the liquid nitrogen delivery hose 3.2, and then connected to the adapter on the machine tool spindle box 3.8 ( Figure 2 Then use the liquid nitrogen delivery hose 3.2 to connect the CO2 Dewar tank 3.20, the cryogenic flow valve 3.19, the cryogenic electromagnetic control valve 3.18, the three-way connector 3.14 in sequence, and finally connect to the adapter ( Figure 2 The adapter 2.7 in the figure); connect the electronic flow control valve 3.4, the ultra-low temperature controller 3.12 and the thermocouple 3.13 with wires; connect the electric contact pressure gauge 3.15 to the third interface of the three-way connector 3.14 and seal it, and connect the electric contact pressure gauge 3.15, the PLC control module 3.17 and the electrical control unit of the low-temperature electromagnetic control valve 3.18 with wires 3.16; clamp the workpiece 3.10 with the fixture 3.11, and use the tool tip on the tool handle 3.9 installed on the spindle box 3.8 to align and cut the workpiece.

[0092] 1) Use the fixture 3.11 to position and clamp the thin-walled workpiece 3.10.

[0093] 2) Install the tapered shank of the tool holder 1.1 into the machine tool spindle 2.2, and align the two tapered holes of the tool holder outer ring 1.5 with the tapered holes with sealing rings of the adapter 2.4 and adapter 2.7 installed on the spindle box 3.8. Use rivets and tool-beating cylinders to install and fix the tool holder device on the machine tool spindle 2.2.

[0094] 3) Unscrew the valve on the CO2 Dewar tank 3.20, check the CO2 delivery pipeline, ensure that there is no leakage in the components on the series pipeline, and set the pressure rating of the electric contact pressure gauge 3.15. At the same time, the one-way valve 3.7 can prevent CO2 from flowing into the liquid nitrogen pipeline.

[0095] 4) Unscrew the valve on the liquid nitrogen dewar tank 3.1, check the liquid nitrogen delivery pipeline, and ensure that there is no leakage in the components on the series pipeline. After 1 minute of spraying, use a low-temperature thermometer to measure the temperature at the tip of the tool, and adjust the valve on the dewar tank 3.1 to obtain a stable outlet temperature required by the tool.

[0096] 5) Wait for liquid nitrogen and CO to appear at the outlet of the knife tip. 2-雪 Mixture (mixing ratio is liquid nitrogen: CO 2-雪 =2:1~8:1, by replacing the joints of the liquid nitrogen delivery hose 3.2 with different inner diameters connected to the right rotating joint 2.7, the liquid nitrogen and CO 2-雪 After the flow rate is controlled proportionally) and the required nozzle temperature T1 is reached, the machine tool tool is in the processing state.

[0097] 6) Due to the uneven rigidity of the plane to be processed of the difficult-to-process alloy thin-walled components, that is, the rigidity at both ends is poor, and the rigidity is relatively larger towards the middle. In order to obtain a high-quality uniform processing surface, the cooling temperature should be controlled to achieve a reasonable change in the surface rigidity of the workpiece, thereby improving the overall processing deformation defects. In order to make the temperature change uniform, the change satisfies the parabolic trajectory, that is, it decreases first and then increases. For example, the temperature at both ends is set to T1 and the middle is T2. The temperature change satisfies the following formula

[0098]

[0099] Where y is the nozzle temperature, x is the feed direction coordinate, L is the length of the workpiece in the feed direction, and the tool position before cutting is 10 mm from the starting cutting end of the workpiece.

[0100] Divide the workpiece length L into 10 parts, and the above formula can be used to calculate the cooling temperature y1, y2…y required for each step along the processing feed x direction. 10 .

[0101] At the same time, the feeding time for each portion is

[0102]

[0103] Where t is the tool moving time (s), f z is the feed per tool tooth (mm / z), z is the number of tool teeth, and n is the spindle speed (r / min).

[0104] 7) Based on the pre-set nozzle temperature that needs to be changed in real time in step 6, the ultra-low temperature temperature controller 3.12 is inputted, and on the basis of the temperature T1 adjusted in step 5, the tool enters the cutting state after feeding 10mm, and then the temperature is adjusted from the set temperature y1. Specifically, the temperature state changes according to the parabolic characteristic, and the thermocouple 3.13 converts the temperature signal into an electrical signal and transmits it to the ultra-low temperature temperature controller 3.12, and the ultra-low temperature temperature controller 3.12 transmits the electrical signal to the servo controller in the electronic flow control valve 3.4 through the PID signal amplifier, which drives the servo motor to rotate forward and reverse, and drives the regulating valve in the electronic flow control valve 3.4 to operate through the reducer, and the valve is opened or closed, until the ultra-low temperature controller 3.12 reaches the set nozzle temperature requirement, and the electronic flow control valve 3.4 stops working.

[0105] 8) If the pressure of the liquid nitrogen delivery pipe is greater than the pressure in the CO2 pipeline, the electromagnetic contact in the electric contact pressure gauge 3.15 is activated, and the signal is fed back to the PLC control module 3.17. The PLC control module 3.17 processes the signal and sends an electrical signal to the low-temperature electromagnetic control valve 3.18 to close the control valve opening to achieve locking and prevent liquid nitrogen from flowing into the CO2 pipeline. After the pressure of the liquid nitrogen pipeline is lowered, the pressure of the electric contact pressure gauge 3.15 returns to the set pressure and controls the low-temperature electromagnetic control valve 3.18 to open the pipeline through the PLC control module 3.17.

[0106] The present invention aims at the milling deformation of thin-walled parts, which is mainly manifested as the deflection and rotation angle of the processed end. According to material mechanics, the deflection and rotation angle are affected by the cutting force load (directly proportional) and the elastic modulus (inversely proportional) of the material at the cutting end. At the same time, the cutting force will increase under ultra-low temperature, and the elastic modulus of the material will increase significantly. The cutting force is related to the cutting lubrication effect. Therefore, if you want to reduce the ratio of cutting force and elastic modulus, the present invention uses a liquid nitrogen + CO 2-雪 The hybrid cooling integral external transmission internal cooling toolholder device performs ultra-low temperature hybrid lubrication cooling in the milling of thin-walled parts. During ultra-low temperature cooling processing, it simultaneously improves the rigidity and lubrication function of the cutting area, reduces friction, and alleviates the cutting load.

[0107] The invention can be applied to thin-walled materials that are difficult to process, cut the thin-walled materials into regular rectangular blocks, clean the surface of the workpiece by strong wind, and position and clamp the workpiece on a linked CNC machine tool workbench according to positioning rules.

[0108] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A low temperature processing device for thin-walled parts, comprising a tool handle outer ring (1.5), characterized in that The inner wall of the upper part of the outer ring (1.5) of the tool handle is expanded outward to form an upper sealing ring placement groove and an upper bearing placement groove, an upper sealing ring (1.4) is arranged in the upper sealing ring placement groove, an upper threaded fastening washer (1.3) is arranged at the upper end of the upper sealing ring (1.4), the upper bearing placement groove is located at the upper end of the upper sealing ring placement groove, and the diameter of the upper bearing placement groove is larger than the diameter of the upper sealing ring placement groove; an upper bearing (1.2) is arranged in the upper bearing placement groove; The lower inner wall of the handle outer ring (1.5) is expanded outward to form a lower sealing ring placement groove and a lower bearing placement groove, a lower sealing ring (1.6) is arranged in the lower sealing ring placement groove, a lower threaded fastening washer (1.7) is arranged at the lower end of the lower sealing ring (1.6), the lower bearing placement groove is located at the lower end of the lower sealing ring placement groove, and the diameter of the lower bearing placement groove is larger than the diameter of the lower sealing ring placement groove; a lower bearing (1.8) is arranged in the lower bearing placement groove, and a stop washer (1.9) is arranged at the lower end of the lower bearing (1.8); The knife handle (1.1) passes through the center hole of the knife handle outer ring (1.5); the upper outer wall of the knife handle (1.1) has a flange extending outward, and the lower end surface of the flange is connected to the upper end surface of the upper bearing (1.2); a fastening nut (1.10) is screwed onto the lower outer wall of the knife handle (1.1), and the upper end of the fastening nut (1.10) is connected to the lower end of the stop washer (1.9); A left blade (1.11) and a right blade (1.13) are arranged at the lower end of the knife handle (1.1), and the left blade (1.11) and the right blade (1.13) are symmetrically arranged on both sides of the lower end of the knife handle (1.1); The left side of the tool handle outer ring (1.5) bulges upward to form a left coolant inlet (1.15), and the right side of the tool handle outer ring (1.5) bulges upward to form a right lubricant inlet (1.16); the left coolant inlet (1.15) and the right lubricant inlet (1.16) are connected to a coolant channel in the tool handle outer ring (1.5), and the coolant channel is connected to a left blade (1.11) and a right blade (1.13).

2. A low temperature processing device for thin-walled parts according to claim 1, characterized in that The left blade (1.11) and the right blade (1.13) are rhombus-shaped blades, which are arranged obliquely, with the lower ends of the rhombus-shaped blades facing outwards.

3. A low temperature processing device for thin-walled parts according to claim 2, characterized in that The blade back angle of the diamond blade is 25 o .

4. A low temperature processing device for thin-walled parts according to claim 1, characterized in that The middle portion of the left blade (1.11) is fixed to the lower end of the blade handle (1.1) via a left blade fastening screw (1.12), and the middle portion of the right blade (1.13) is fixed to the lower end of the blade handle (1.1) via a right blade fastening screw (1.14).

5. A low temperature processing device for thin-walled parts according to claim 1, characterized in that The BT40 taper shank portion (2.8) at the upper end of the tool handle (1.1) is placed in a spindle box (3.8); a left swivel joint (2.4) is provided on the left side of the lower end of the spindle box (3.8); a right swivel joint (2.7) is provided on the right side of the lower end of the spindle box (3.8); a left sealing ring (2.3) is provided at the lower end outlet of the left swivel joint (2.4); and a right sealing ring (2.6) is provided at the lower end outlet of the right swivel joint (2.7); The inlet at the left end of the left rotating joint (2.4) is connected to the left end of the left liquid inlet channel in the left rotating joint (2.4), and the lower end of the left liquid inlet channel is connected to the outlet at the lower end of the left rotating joint (2.4); The inlet at the right end of the right rotating joint (2.7) is connected to the right end of the right liquid inlet channel in the right rotating joint (2.7), and the lower end of the right liquid inlet channel is connected to the outlet at the lower end of the right rotating joint (2.7); The upper portion of the left coolant inlet (1.15) is placed inside the lower outlet of the left swivel joint (2.4), and the left sealing ring (2.3) is placed between the upper outer wall of the left coolant inlet (1.15) and the lower outlet wall of the left swivel joint (2.4); The upper portion of the right lubricating liquid inlet (1.16) is placed inside the lower end outlet of the right rotating joint (2.7), and the right sealing ring (2.6) is placed between the upper outer wall of the right lubricating liquid inlet (1.16) and the lower end outlet wall of the right rotating joint (2.7).

6. A low temperature processing device for thin-walled parts according to claim 5, characterized in that The left swivel joint (2.4) is provided with a left vertical connection hole, and the upper end of the left connection bolt (2.5) passes through the left vertical connection hole and is screwed into the left threaded hole at the lower end of the spindle box (3.8); A right vertical connection hole is provided on the right swivel joint (2.7), and the upper end of the right connection bolt (2.9) passes through the right vertical connection hole and is screwed into the right threaded hole at the lower end of the spindle box (3.8).

7. A low temperature processing device for thin-walled parts according to claim 1, characterized in that The coolant channel comprises a left vertical coolant channel (1.17), a right vertical coolant channel (1.18), a middle horizontal coolant channel (1.19), a middle vertical coolant channel (1.20), a left lower oblique coolant channel (1.21) and a right lower oblique coolant channel (1.22); the upper end of the left vertical coolant channel (1.17) is connected to the left coolant inlet (1.15), and the upper end of the right vertical coolant channel (1.18) is connected to the right lubricating liquid inlet (1.16); The lower end of the left vertical coolant channel (1.17) is connected to the left end of the middle horizontal coolant channel (1.19), the lower end of the right vertical coolant channel (1.18) is connected to the right end of the middle horizontal coolant channel (1.19), the middle of the middle horizontal coolant channel (1.19) is connected to the upper end of the middle vertical coolant channel (1.20), the lower end of the middle vertical coolant channel (1.20) is respectively connected to the upper end of the left lower oblique coolant channel (1.21) and the upper end of the right lower oblique coolant channel (1.22), the lower end of the left lower oblique coolant channel (1.21) is connected to the upper end of the left blade (1.11), and the lower end of the right lower oblique coolant channel (1.22) is connected to the upper end of the right blade (1.13); the left lower oblique coolant channel (1.21) is inclined from the upper right to the lower left, and the right lower oblique coolant channel (1.22) is inclined from the upper left to the lower right.

8. A low temperature processing device for thin-walled parts according to claim 5, characterized in that The left coolant inlet (1.15) and the right lubricant inlet (1.16) are truncated cone-shaped ports, the centers of the truncated cone-shaped ports are liquid inlet channels; the lower end outlets of the left rotating joint (2.4) and the lower end outlets of the right rotating joint (2.7) are truncated cone-shaped grooves corresponding to the truncated cone-shaped ports.

9. A low temperature processing device for thin-walled parts according to claim 1, characterized in that The upper threaded fastening washer (1.3) and the lower threaded fastening washer (1.7) are glass fiber reinforced plastic washers.

10. The low temperature processing device for thin-walled parts according to claim 1, characterized in that The upper threaded fastening washer (1.3) and the lower threaded fastening washer (1.7) are provided with twisting sockets.

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