Micro abrasive water jet polishing system and method for special-shaped inner cavity structure

Abstract

The present invention provides a micro abrasive water jet polishing system and method for special-shaped inner cavity structures. The system includes a control cabinet, a low / high pressure jet generation assembly, an autonomous feeding assembly, a waste collection assembly, an industrial robot actuator, and a workbench main frame. The low / high pressure jet generation assembly includes a high pressure jet generation device, a low pressure jet generation device, a high / low pressure conversion switch, a low / high pressure water inlet pipe, and a water inlet. The high pressure jet generation device and the low pressure jet generation device are integrally arranged and switched by means of the high / low pressure conversion switch. The jet polishing system of the present invention can meet the micro abrasive water jet polishing of complex special-shaped inner cavity structures, and can select the optimal path spacing value according to the processing requirements to generate the optimal path. The industrial robot works according to the optimal path to ensure the polishing accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of micro abrasive water jet polishing, and particularly relates to a micro abrasive water jet polishing system and method for special-shaped inner cavity structures. Background Art

[0002] Components such as hydraulic manifolds, heat exchange pipes, automotive engines, etc., which have complex special-shaped inner cavity structures, have been widely used in our daily life and industrial production. Due to the complexity of their structures, the polishing of their inner surfaces is difficult. Excessive surface roughness will cause unnecessary energy consumption. Therefore, how to achieve the polishing of the inner surfaces of complex special-shaped inner cavity structures is particularly important. Currently, the polishing techniques mainly used for complex special-shaped inner cavities are as follows: abrasive flow machining technology, mechanical polishing technology, and electrolytic polishing technology. However, these processing technologies have some deficiencies: 1. Under-polishing and over-polishing are likely to occur; 2. It is impossible to polish the curved inner surface with a large aspect ratio; 3. There are requirements for the size and shape of the processed components; 4. There are requirements for the initial surface roughness.

[0003] The micro abrasive water jet machining technology is a new type of special precision machining technology developed on the basis of the traditional abrasive water jet technology. In addition to having the advantages of the traditional abrasive water jet technology, such as small processing force, no heat affected zone, high processing efficiency, wide adaptability, and environmental friendliness, it is also particularly suitable for precision machining of small and complex inner cavity parts because the jet pressure used is lower, the abrasive particle size is smaller, and the mass flow rate and material removal rate are lower than those of the conventional abrasive water jet.

[0004] Therefore, it is particularly important to study a polishing method suitable for complex special-shaped inner cavity structures to achieve high-efficiency and precision forming of complex special-shaped inner cavity structures. Summary of the Invention

[0005] In order to solve the above deficiencies of the prior art, the purpose of the present invention is to provide a micro abrasive water jet polishing system and method for special-shaped inner cavity structures, which can meet the micro abrasive water jet polishing of complex special-shaped inner cavity structures through the setting of a bending flow channel.

[0006] Specifically, on the one hand, the present invention provides a micro abrasive water jet polishing system for special-shaped inner cavity structures, which includes a control cabinet, a low / high-pressure jet generation component, an autonomous feeding component, a waste collection component, an industrial robot actuator, and a workbench main frame; the low / high-pressure jet generation component includes a high-pressure jet generation device, a low-pressure jet generation device, a high-low pressure conversion switch, a low / high-pressure water inlet pipe, and a water inlet; the high-pressure jet generation device and the low-pressure jet generation device are integrally arranged and switched by means of the high-low pressure conversion switch; the high-pressure jet generation device includes a first water source, an oil source, a first water inlet filter, an oil inlet / return filter, an oil pump, a first silencer, an overflow valve, an oil inlet pressure gauge, a first reversing valve, a hydraulic piston pump, a first check valve, a first low-pressure water pressure gauge, and a first water pump, and the low-pressure jet generation device includes a second water source, an air pump, a second water inlet filter, an air filter, a safety valve, a gas pressure gauge, an air stop valve, a second silencer, a second reversing valve, a gas-liquid booster pump, a second check valve, a second low-pressure water pressure gauge, and a second water pump;

[0007] The autonomous feeding component includes an autonomous feeding tank and an abrasive feeding pipe; the first end of the abrasive feeding pipe is connected to the output end of the autonomous feeding tank, and the second end of the abrasive feeding pipe is connected to the nozzle of the industrial robot actuator;

[0008] The waste collection component includes a waste liquid collection control box, a waste liquid collection tank, and a waste liquid collection power motor, and the waste liquid collection tank is located below the industrial robot actuator; the waste liquid collection control box and the waste liquid collection power motor are arranged at the bottom of the waste liquid collection tank;

[0009] The industrial robot actuator includes an industrial robot, a robot support frame, and a nozzle, the nozzle is arranged at the end of the industrial robot, and the industrial robot is installed by means of the robot support frame; the abrasive in the autonomous feeding tank is conveyed to the mixing chamber of the nozzle through the abrasive feeding pipe;

[0010] The robot support frame includes a guide rail, a rolling bearing, a bearing seat, a slider, a lead screw guide rail, a support plate, a robot moving device base, a double universal joint, a first synchronous pulley, a transmission belt, a second synchronous pulley, and a driving motor; the robot support frame is fixed on the support plate, the support plate is connected to the guide rail through the slider, and the lead screw guide rail is fixedly connected to the robot moving device base; the first synchronous pulley and the second synchronous pulley are connected by the transmission belt, the rolling bearing is arranged on both sides of the double universal joint and the lead screw guide rail through the bearing seat, the first synchronous pulley is connected to the output end of the driving motor, the second synchronous pulley is fixed at one end of the rolling bearing, and the driving motor is fixedly connected to the robot moving device base;

[0011] The control cabinet is connected to the upper control computer, and the upper control computer is provided with a path planning module. The path planning module is used to plan the polishing path of the industrial robot. The specific planning process is as follows:

[0012] S1. Perform reverse modeling on the parts with complex special-shaped inner cavity structures to obtain the geometric model of the complex curved surface;

[0013] S2. Select the optimal path spacing value L. Assume that the polishing trajectory is a circle with a radius R, and select L = 5 / 4R to ensure that all areas of the curved surface are traversed and polished, and generate a polishing spiral path. In the polishing spiral path, the spiral equation is:

[0014] x = a×cos(θ)

[0015] y = a×sin(θ)

[0016] z = b×θ

[0017] where a is the radius of the spiral, θ is the rotation angle of the nozzle, and b is the pitch of the spiral;

[0018] S3. Determine the optimal spiral pitch b and the optimal nozzle rotation angle θ. The optimal spiral pitch b is where d is the diameter of the micro abrasive water jet polishing trajectory; the optimal nozzle rotation angle θ is where R is the radius of the polishing trajectory of the complex special-shaped inner cavity to be processed.

[0019] Preferably, the main frame of the workbench includes a frame mechanism, a workbench, a support frame, and a coordinate grid; the workbench is located inside the frame structure, the coordinate grid is arranged on the upper surface of the workbench, and the support frame is arranged at the bottom of the frame structure.

[0020] Preferably, the coordinate grid is a hollow structure, and the waste liquid flows into the waste liquid collection box through the coordinate grid.

[0021] Preferably, the drive motor is a stepping motor.

[0022] Preferably, mounting brackets are respectively arranged at the four corners of the bottom of the workbench.

[0023] Preferably, the high-low voltage conversion switch is connected to a three-way conversion switch valve.

[0024] Preferably, a screen and a heating plate are arranged inside the waste liquid collection box. The screen is used to filter the wet abrasive, the heating plate is used to dry the wet abrasive, the bottom of the waste liquid collection box is connected to a waste water treatment device by means of a pumping device, and the waste water treatment device is used to treat the waste liquid.

[0025] Preferably, the robot support frame is fixed on the support plate by hexagon socket head cap screws.

[0026] Preferably, both the first synchronous pulley and the second synchronous pulley are high-torque synchronous pulleys.

[0027] On the other hand, the present invention also provides a polishing method for a micro abrasive water jet polishing system for a special-shaped inner cavity structure, which includes the following steps:

[0028] S1. Perform polishing path planning for the complex special-shaped inner cavity structure, which includes the following sub-steps:

[0029] S11. Perform reverse modeling on the parts with a complex special-shaped inner cavity structure to obtain the geometric model of the complex curved surface;

[0030] S12. Select the optimal path spacing value L. Assume that the polishing trajectory is a circle with a radius R, and select L = 5 / 4R to ensure that all areas of the curved surface are traversed and polished, and generate a polishing spiral path. In the polishing spiral path, the spiral equation is:

[0031] x = a×cos(θ)

[0032] y = a×sin(θ)

[0033] z = b×θ

[0034] where a is the radius of the spiral, θ is the nozzle rotation angle, and b is the pitch of the spiral;

[0035] S13. Determine the optimal spiral pitch b and the optimal nozzle rotation angle θ. The optimal spiral parameter b is where d is the diameter of the micro abrasive water jet polishing trajectory; the optimal nozzle rotation angle θ is where R is the radius of the polishing trajectory of the complex special-shaped inner cavity to be processed;

[0036] S2. Input the polishing path into the industrial robot. The industrial robot starts the polishing work and adjusts the parameters of the polishing path in real time according to the surface roughness of the polished surface during the processing;

[0037] S3. Fix the nozzle at any required coordinate point (X, Y) to start the polishing process, and at the same time turn on the waste liquid collection control box to collect the waste liquid.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] (1) The present invention provides a micro abrasive water jet polishing system and method for a special-shaped inner cavity structure. Through the setting of the nozzle deflection angle, it can meet the micro abrasive water jet polishing of the complex special-shaped inner cavity structure.

[0040] (2) The path production module of the present invention can select the optimal path spacing value according to the processing requirements and generate the optimal path. The industrial robot works according to the optimal path to ensure the polishing accuracy and guarantee the polishing quality. The polishing path is adjusted according to the nozzle deflection angle and the helix pitch to obtain a spiral path, which has better surface quality after polishing compared to other paths and can ensure the accuracy of polishing complex inner cavity structures.

[0041] (3) The present invention provides a micro abrasive water jet polishing system for special-shaped inner cavity structures, which combines an industrial robot with a micro abrasive water jet processing device. The two cooperate to achieve a wide reachable space range, fewer dead angles and blind spots, and can well adapt to polishing in complex special-shaped inner cavity structures. At the same time, the present invention proposes an abrasive water jet booster pump group that can include low, medium, high, and ultra-high pressure distribution ranges, which can solve the problem of low adjustment accuracy of traditional high-pressure piston pumps, achieve high jet pressure adjustment accuracy at low pressure, enable high / low pressure polishing and repair functions, and can realize high / low pressure automatic switching.

[0042] (4) The robot support frame of the present invention is a high-precision movable guide rail platform, driven by a high-power stepping motor. The industrial robot is installed on the moving working platform and can move in the horizontal left and right directions, increasing the working range of the industrial robot and better adapting to the processing of complex special-shaped parts by the industrial robot.

[0043] (5) The present invention is provided with a waste liquid collection box, which can collect abrasive grains and process waste liquid. A screen is placed in the middle of the waste liquid collection box. The waste liquid generated after processing will first pass through the placed screen, and the abrasive grains and the removed materials of the workpiece will remain on the screen. After processing, the heating plates on both sides of the waste liquid collection box will dry the wet abrasive grains remaining on the screen for secondary use. The waste liquid flowing to the bottom of the waste liquid collection box will be pumped by the waste liquid collection power motor-driven water pump to the waste water treatment equipment for waste liquid recovery treatment. At the same time, by using different mesh screens and placing them in layers and vibrating the screens in sequence, the abrasive grains of the required mesh can be screened. Description of the Drawings

[0044] Figure 1 is a schematic structural diagram of the low / high pressure jet generation component of the micro abrasive water jet polishing system for special-shaped inner cavity structures of the present invention;

[0045] Figure 2 is one of the working principle diagrams of the low / high pressure jet generation component of the micro abrasive water jet polishing system for special-shaped inner cavity structures of the present invention;

[0046] Figure 3 is the second working principle diagram of the low / high pressure jet generation component of the micro abrasive water jet polishing system for special-shaped inner cavity structures of the present invention;

[0047] Figure 4 This is a schematic diagram of the overall structure of the micro abrasive water jet polishing system for special-shaped inner cavity structures of the present invention;

[0048] Figure 5 This is a schematic diagram of the structure of the robot support frame of the present invention;

[0049] Figure 6 This is a schematic flow chart of the polishing method of the micro abrasive water jet polishing system for special-shaped inner cavity structures of the present invention;

[0050] Some of the reference numerals are as follows:

[0051] 1 - High-pressure jet generating device; 2 - Low-pressure jet generating device; 3 - High-low pressure conversion switch; 4 - Accumulator; 5 - High-pressure water pressure gauge; 6 - High-pressure overflow valve; 7 - Stop valve; 8 - Throttle valve; 9 - Flow indicator; 10 - Check valve; 11 - Stop valve; 12 - Flow meter; 13 - Check valve; 14 - Self-feeding tank; 15 - High-frequency switching valve; 16 - Air source pressure gauge; 17 - Pressure regulating valve; 18 - Power air source; 19 - Jet beam pressure gauge; 20 - High-pressure outlet stop valve; 21 - Nozzle; 22 - Workbench; 23 - Waste liquid collection tank; 101 - First water source; 102 - Oil source; 103 - First water inlet filter; 104 - Inlet / return oil filter; 105 - Oil pump; 106 - First silencer; 107 - Overflow valve; 108 - Inlet oil pressure gauge; 109 - First reversing valve; 1010 - Hydraulic piston pump; 1011 - First check valve; 1012 - First low-pressure water pressure gauge; 1013 - First water pump; 201 - Second water source; 202 - Air pump; 203 - Second water inlet filter; 204 - Air filter; 205 - Safety valve; 206 - Gas pressure gauge; 207 - Air stop valve; 208 - Second silencer; 209 - Second reversing valve; 2010 - Air-liquid booster pump; 2011 - Second check valve; 2012 - Second low-pressure water pressure gauge; 2013 - Second water pump;

[0052] 24 - Low / high-pressure water inlet pipe; 25 - Abrasive feed pipe; 26 - Industrial robot; 27 - Robot support frame; 28 - Waste liquid collection control box; 29 - Waste liquid collection power motor; 30 - Control cabinet; 31 - Floor feet; 32 - Water inlet; 33 - Coordinate grid; 34 - First hexagon socket head cap screw; 35 - Guide rail; 36 - Rolling bearing; 37 - Bearing seat; 38 - Slide block; 39 - Lead screw guide rail; 40 - Support plate; 41 - Robot moving device base; 42 - Second hexagon socket head cap screw; 43 - Double universal joint; 44 - Second high-torque synchronous pulley; 45 - Transmission belt; 46 - First high-torque synchronous pulley; 47 - Stepper motor. Detailed implementation manners

[0053] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0054] As Figures 1 to 5 shown, on the one hand, the present invention provides a micro abrasive water jet polishing method and device for the inner surface of a complex special-shaped inner cavity structure, including a low / high pressure jet generation component, an independent feeding component, a waste collection component, an industrial robot actuator, a workbench main frame, and a control cabinet 30; the low / high pressure jet generation part includes a high pressure jet generation device 1, a low pressure jet generation device 2, a high / low pressure conversion switch 3, a low / high pressure water inlet pipe 24, and a water inlet 32. The high pressure jet generation device 1 and the low pressure jet generation device 2 are sequentially connected to an accumulator 4, a high pressure water pressure gauge 5, a high pressure overflow valve 6, a stop valve 7, a throttle valve 8, a flow indicator 9, a check valve 10, a stop valve 11, a flow meter 12, a check valve 13, an independent feeding tank 14, a high frequency switch valve 15, a gas source pressure gauge 16, a pressure regulating valve 17, a power gas source 18, a jet beam pressure gauge 19, and a high pressure outlet stop valve 20 by means of the high / low pressure conversion switch 3. The rear end of the high pressure outlet stop valve 20 is connected to a nozzle.

[0055] The high pressure jet generation device includes a first water source 101, an oil source 102, a first water inlet filter 103, an oil inlet / return filter 104, an oil pump 105, a first silencer 106, an overflow valve 107, an oil inlet pressure gauge 108, a first reversing valve 109, a hydraulic piston pump 1010, a first check valve 1011, a first low pressure water pressure gauge 1012, and a first water pump 1013. The low pressure jet generation device includes a second water source 201, an air pump 202, a second water inlet filter 203, an air filter 204, a safety valve 205, a gas pressure gauge 206, an air stop valve 207, a second silencer 208, a second reversing valve 209, a gas-liquid booster pump 2010, a second check valve 2011, a second low pressure water pressure gauge 2012, and a second water pump 2013.

[0056] The low pressure jet generation device and the high pressure jet generation device are integrated, and the conversion between the high and low pressure jets is adjusted by the high / low pressure conversion switch.

[0057] The independent feeding component includes an independent feeding tank 14 and an abrasive feeding pipe 25; the first end of the abrasive feeding pipe 25 is connected to the independent feeding tank 14, the second end of the abrasive feeding pipe is connected to the nozzle of the industrial robot, and the abrasive in the independent feeding tank 14 is conveyed to the nozzle 21 mixing chamber through the abrasive feeding pipe 25.

[0058] The waste collection assembly includes a waste liquid collection control box 28, a waste liquid collection box 23, and a waste liquid collection power motor 29; the main frame of the workbench includes a workbench 22 and a coordinate grid 33. An installation frame is provided at the bottom of the workbench 22. In this embodiment, the installation frame is a floor footing 31. The waste liquid collection box 23 is installed inside the workbench 22, and the waste liquid collection control box 28 and the waste liquid collection power motor 29 are installed outside the workbench 22.

[0059] In specific applications, a filter screen and a heating plate can be provided inside the waste liquid collection box 23. The waste liquid generated after processing will first pass through the placed screen, and the abrasive and the removed materials of the workpiece will remain on the screen. After the processing is completed, the heating plates on both sides of the waste liquid collection box will dry the wet abrasive remaining on the screen for secondary use. The waste liquid flowing to the bottom of the waste liquid collection box will be pumped by the waste liquid collection power motor-driven water pump to the waste water treatment equipment for waste liquid recovery treatment. At the same time, different mesh screens are placed in layers and the mesh screens are vibrated in sequence to screen the abrasive grains of the required mesh number. This process is to manually process the dried abrasive using different mesh screens.

[0060] Four fixed floor footings 31 are provided at the bottom of the workbench 22, and a coordinate grid 33 is provided on the workbench 22. The coordinate grid 33 is a hollow structure, which allows the generated waste liquid to flow through the coordinate grid 33 into the waste liquid collection box 23.

[0061] The industrial robot actuator part includes an industrial robot 26, a robot support frame 27, and a nozzle 21; the industrial robot 26 is installed on the robot support frame 27 and drives the nozzle 21 to move.

[0062] The robot support frame 27 includes a first hexagon socket head cap screw 34, a guide rail 35, a rolling bearing 36, a bearing seat 37, a slider 38, a lead screw guide rail 39, a support plate 40, a robot moving device base 41, a second hexagon socket head cap screw 42, a double cardan joint 43, a second high-torque synchronous pulley 44, a transmission belt 45, a first high-torque synchronous pulley 46, and a stepping motor 47; the robot support frame is fixed on the support plate 40, the support plate 40 is connected to the lead screw guide rail 39 through the slider 38, and the lead screw guide rail 39 is fixedly connected to the robot moving device base 41; the first high-torque synchronous pulley 46 and the second high-torque synchronous pulley 44 are connected by the transmission belt 45, the rolling bearing 36 is arranged on both sides of the double cardan joint 43 and the lead screw guide rail 39 through the bearing seat 37, the first high-torque synchronous pulley 46 is connected to the output end of the stepping motor 47, the second high-torque synchronous pulley 44 is fixed at one end of the rolling bearing 36, and the stepping motor 47 is fixedly connected to the robot moving device base.

[0063] The control cabinet is connected to the upper control computer, and the upper control computer is provided with a path planning module. The path planning module is used to plan the polishing path of the robot. The specific planning process is as follows:

[0064] S1. Perform reverse modeling on the parts with complex and irregular inner cavity structures to obtain the geometric model of the complex surface;

[0065] S2. Select the optimal path spacing value L. Assume that the polishing trajectory is a circle with a radius R, and select L = 5 / 4R to ensure that all areas of the surface are traversed and polished, and generate a polishing spiral path. In the polishing spiral path, the spiral equation is:

[0066] x = a×cos(θ)

[0067] y = a×sin(θ)

[0068] z = b×θ

[0069] where a is the radius of the spiral, θ is the rotation angle of the nozzle, and b is the pitch of the spiral;

[0070] S3. Determine the optimal spiral pitch b and the optimal nozzle rotation angle θ. The optimal spiral pitch b is where d is the diameter of the micro abrasive water jet polishing trajectory; the optimal nozzle rotation angle θ is where R is the radius of the polishing trajectory of the complex and irregular inner cavity to be processed.

[0071] On the other hand, the present invention also provides a micro abrasive water jet polishing method for complex and irregular inner cavity structures, as Figure 6 shown, which includes the following steps:

[0072] S1. Plan the polishing path for the complex and irregular inner cavity structure, which includes the following sub-steps:

[0073] S11. Perform reverse modeling on the parts with complex and irregular inner cavity structures to obtain the geometric model of the complex surface. The specific process of reverse modeling is to use equipment such as 3D laser scanners to collect the parameters of the parts on site, and use software to interpret the data and automatically or semi-automatically establish a three-dimensional model.

[0074] S12. Select the optimal path spacing value L. Assume that the polishing trajectory is a circle with a radius R, and select L = 5 / 4R to ensure that all areas of the surface are traversed and polished, and generate a polishing spiral path. In the polishing spiral path, the spiral equation is:

[0075] x = a×cos(θ)

[0076] y = a×sin(θ)

[0077] z = b×θ

[0078] Wherein, a is the radius of the spiral, θ is the rotation angle of the nozzle, and b is the pitch of the spiral;

[0079] S13. Determine the optimal spiral parameter b and the optimal nozzle rotation angle θ. The optimal spiral parameter b is where d is the diameter of the micro abrasive water jet polishing trajectory; The optimal nozzle rotation angle θ is where R is the radius of the complex-shaped inner cavity to be machined.

[0080] S2. Input the polishing path into the industrial robot. The industrial robot starts the polishing work and adjusts the parameters of the polishing path in real time according to the surface roughness of the polished surface during the machining process. During the actual machining process, the surface roughness of the polished surface is collected in real time and compared with the preset target roughness, and the difference is calculated. When the difference is positive, that is, the surface roughness of the polished surface collected in real time is lower than the preset target roughness, the spiral radius a, the nozzle rotation angle θ, or the spiral pitch b is adjusted until the surface roughness of the polished surface collected in real time reaches the preset target roughness.

[0081] S3. Fix the nozzle at any required (X, Y) coordinate point to start the polishing process, and at the same time, turn on the waste liquid collection control box to collect the waste liquid.

[0082] The specific working process of this embodiment is as follows: Place the workpiece with a complex-shaped inner cavity to be polished on the workbench 22. Before starting the work, first transmit the path planning of the industrial robot 26 during the machining to the micro abrasive water jet control cabinet 30. Use the micro abrasive water jet control cabinet 30 to fix the nozzle 21 at any required (X, Y) coordinate point to start the polishing process, and at the same time, turn on the waste liquid collection control box 28. After the equipment is started, the micro abrasive water jet control cabinet 30 transmits the path signal to the industrial robot 26, and the industrial robot 26 drives the nozzle 21 to move. At this time, the low / high-pressure jet generation part and the self-feeding tank 14 start to work to provide high-pressure water and abrasives for the nozzle 21. As the polishing work progresses, the mixed waste liquid generated by water, abrasives, and the removed workpiece material is pumped to the waste liquid collection tank 23 by the waste liquid collection power motor 29 through the coordinate grid 33.

[0083] Embodiment 1

[0084] The workpiece to be machined in this embodiment is a workpiece with a complex-shaped inner cavity, and the material is 316L stainless steel. The polishing equipment of this embodiment includes a low / high-pressure jet generation assembly, a self-feeding assembly, a waste collection assembly, an industrial robot actuator, a workbench main frame, and a control cabinet 30; The low / high-pressure jet generation part includes a high-pressure jet generation device 1, a low-pressure jet generation device 2, a high / low-pressure conversion switch 3, a low / high-pressure water inlet pipe 24, and a water inlet 32.

[0085] Among them, the high-pressure jet generating device includes a first water source 101, an oil source 102, a first water inlet filter 103, an oil inlet / return filter 104, an oil pump 105, a first silencer 106, a relief valve 107, an oil inlet pressure gauge 108, a first reversing valve 109, a hydraulic piston pump 1010, a first check valve 1011, a first low-pressure water pressure gauge 1012, and a first water pump 1013. The low-pressure jet generating device includes a second water source 201, an air pump 202, a second water inlet filter 203, an air filter 204, a safety valve 205, a gas pressure gauge 206, an air stop valve 207, a second silencer 208, a second reversing valve 209, a gas-liquid booster pump 2010, a second check valve 2011, a second low-pressure water pressure gauge 2012, and a second water pump 2013. The high-pressure jet generating device and the low-pressure jet generating device can be quickly switched through a switch.

[0086] According to the performance and processing requirements of the workpiece material, the micro abrasive water jet polishing process is selected as follows:

[0087] The jet pressure is 1 MPa; the type and size of the abrasive are CeO2 (10 μm); the abrasive concentration is 20 g / L.

[0088] Install the workpiece with a complex and irregular inner cavity on the workbench 22. Before starting work, first use the upper computer to perform reverse modeling on the parts with a complex and irregular inner cavity structure to obtain the geometric model of the complex surface. The specific steps are as follows:

[0089] Select the optimal path spacing value L. Assume that the polishing trajectory is a circle with a radius R, and select L = 5 / 4R to ensure that all areas of the surface are traversed and polished, generating a polishing spiral path. In the polishing spiral path, the spiral equation is:

[0090] x = a×cos(θ)

[0091] y = a×sin(θ)

[0092] z = b×θ

[0093] Among them, a is the spiral radius, θ is the nozzle rotation angle, and b is the spiral pitch;

[0094] Determine the optimal spiral parameter b and the optimal nozzle rotation angle θ. The optimal spiral parameter b is where d is the diameter of the micro abrasive water jet polishing trajectory; the optimal nozzle rotation angle θ is where R is the radius of the complex and irregular inner cavity to be processed.

[0095] After the upper computer generates the optimal polishing path, the polishing path is transmitted to the control cabinet 30 in computer language. The control cabinet 30 is used to control the industrial robot 26 to drive the nozzle 21 to start polishing at the (X, Y) coordinate points of the set polishing path, and at the same time, the waste liquid collection control box 28 is turned on. After the equipment is started, the fine abrasive water jet control cabinet 30 transmits the path signal to the industrial robot 26, and the industrial robot 26 drives the nozzle 21 to move. At this time, the low / high pressure jet generation parts 1 and 2 and the self-feeding tank 14 start to work to provide high-pressure water and abrasives for the nozzle 21. As the polishing work progresses, the mixed waste liquid of water, abrasives, and removed workpiece materials is pumped to the waste liquid collection tank 23 by the waste liquid collection power motor 29 through the coordinate grid 33. During the polishing process, the surface roughness of the polished surface is collected in real time and compared with the preset target roughness and the difference is calculated. When the difference is positive, that is, the surface roughness of the polished surface collected in real time is lower than the preset target roughness, the spiral radius a, the nozzle rotation angle θ, or the spiral pitch b is adjusted until the surface roughness of the polished surface collected in real time reaches the preset target roughness.

[0096] In other embodiments, the low / high pressure jet generation part can also be replaced at any time according to specific processing conditions.

[0097] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A micro abrasive water jet polishing system for special-shaped inner cavity structures, characterized in that: It includes a control cabinet, a low / high-pressure jet generation component, an autonomous feeding component, a waste collection component, an industrial robot actuator, and a workbench main frame; the low / high-pressure jet generation component includes a high-pressure jet generation device, a low-pressure jet generation device, a high / low-pressure conversion switch, a low / high-pressure water inlet pipe, and a water inlet; the high-pressure jet generation device and the low-pressure jet generation device are integrally arranged and switched by means of the high / low-pressure conversion switch; the high-pressure jet generation device includes a first water source, an oil source, a first water inlet filter, an oil inlet / return filter, an oil pump, a first silencer, an overflow valve, an oil inlet pressure gauge, a first reversing valve, a hydraulic piston pump, a first check valve, a first low-pressure water pressure gauge, and a first water pump, and the low-pressure jet generation device includes a second water source, an air pump, a second water inlet filter, an air filter, a safety valve, a gas pressure gauge, an air stop valve, a second silencer, a second reversing valve, a gas-liquid booster pump, a second check valve, a second low-pressure water pressure gauge, and a second water pump; The autonomous feeding component includes an autonomous feeding tank and an abrasive feeding pipe; the first end of the abrasive feeding pipe is connected to the output end of the autonomous feeding tank, and the second end of the abrasive feeding pipe is connected to the nozzle of the industrial robot actuator; The waste collection component includes a waste liquid collection control box, a waste liquid collection tank, and a waste liquid collection power motor, and the waste liquid collection tank is located below the industrial robot actuator; the waste liquid collection control box and the waste liquid collection power motor are arranged at the bottom of the waste liquid collection tank; The industrial robot actuator includes an industrial robot, a robot support frame, and a nozzle, the nozzle is arranged at the end of the industrial robot, and the industrial robot is installed by means of the robot support frame; the abrasive in the autonomous feeding tank is conveyed to the mixing chamber of the nozzle through the abrasive feeding pipe; The robot support frame includes a guide rail, a rolling bearing, a bearing seat, a slider, a lead screw guide rail, a support plate, a robot moving device base, a double universal joint, a first synchronous pulley, a transmission belt, a second synchronous pulley, and a driving motor; the robot support frame is fixed on the support plate, the support plate is connected to the guide rail through the slider, and the lead screw guide rail is fixedly connected to the robot moving device base; the first synchronous pulley and the second synchronous pulley are connected by the transmission belt, the rolling bearing is arranged on both sides of the double universal joint and the lead screw guide rail through the bearing seat, the first synchronous pulley is connected to the output end of the driving motor, the second synchronous pulley is fixed at one end of the rolling bearing, and the driving motor is fixedly connected to the robot moving device base; The control cabinet is connected to an upper control computer, and the upper control computer is provided with a path planning module, and the path planning module is used to plan the polishing path of the industrial robot, and the specific planning process is as follows: S1. Perform reverse modeling on parts with complex special-shaped inner cavity structures to obtain the geometric model of the complex curved surface; S2. Select the optimal path spacing value L. Assume that the polishing trajectory is a circle with a radius R, and select L = 5 / 4R to ensure that all areas of the complex surface are traversed and polished, and generate a polishing spiral path. In the polishing spiral path, the helix equation is: x = a×cos(θ) y = a×sin(θ) z = b×θ where x, y, and z are the three-dimensional coordinates respectively, a is the radius of the helix, θ is the rotation angle of the nozzle, and b is the pitch of the helix; S3. Determine the optimal helix pitch b and the optimal nozzle rotation angle θ. The optimal helix pitch b is where d is the diameter of the micro abrasive water jet polishing trajectory; The optimal nozzle rotation angle θ is where R is the radius of the polishing trajectory of the complex-shaped inner cavity to be machined.

2. The micro abrasive water jet polishing system for the special-shaped inner cavity structure according to claim 1, characterized in that: The main frame of the workbench includes a frame mechanism, a workbench, a support frame, and a coordinate grid; the workbench is located inside the frame mechanism, the coordinate grid is arranged on the upper surface of the workbench, and the support frame is arranged at the bottom of the frame structure.

3. The micro abrasive water jet polishing system for the special-shaped inner cavity structure according to claim 2, characterized in that: The coordinate grid is a hollow structure, and the waste liquid flows into the waste liquid collection box through the coordinate grid.

4. The micro abrasive water jet polishing system for special-shaped inner cavity structures according to claim 1, characterized in that: The drive motor is a stepping motor.

5. The micro abrasive water jet polishing system for a special-shaped inner cavity structure according to claim 1, characterized in that: Mounting brackets are respectively arranged at the four corners of the bottom of the workbench.

6. The micro abrasive water jet polishing system for special-shaped inner cavity structures according to claim 1, characterized in that: The high-low voltage conversion switch is connected with a three-way conversion switch valve.

7. The micro abrasive water jet polishing system for a special-shaped inner cavity structure according to claim 1, wherein: A screen and a heating plate are arranged inside the waste liquid collection box. The screen is used for filtering wet abrasives, the heating plate is used for drying the wet abrasives, the bottom of the waste liquid collection box is connected with a waste water treatment device by means of a pumping device, and the waste water treatment device is used for treating the waste liquid.

8. The micro abrasive water jet polishing system for a special-shaped inner cavity structure according to claim 1, characterized in that: The robot support frame is fixed on the support plate by hexagon socket head cap screws.

9. The micro abrasive water jet polishing system for special-shaped inner cavity structures according to claim 8, wherein: Both the first synchronous pulley and the second synchronous pulley are high-torque synchronous pulleys.

10. A polishing method for a micro abrasive water jet polishing system for special-shaped inner cavity structures according to claim 1, characterized in that: It includes the following steps: S1. Plan the polishing path for the complex special-shaped inner cavity structure, which includes the following sub-steps: S11. Perform reverse modeling on the parts with complex special-shaped inner cavity structures to obtain the geometric model of the complex surface; S12. Select the optimal path spacing value L. Assume that the polishing trajectory is a circle with a radius R, and select L = 5 / 4R to ensure that all areas of the surface are traversed and polished, and generate a polishing spiral path. In the polishing spiral path, the helix equation is: x = a×cos(θ) y = a×sin(θ) z = b×θ where a is the radius of the helix, θ is the rotation angle of the nozzle, and b is the pitch of the helix; S13. Determine the optimal helix pitch b and the optimal nozzle rotation angle θ. The optimal helix pitch b is where d is the diameter of the micro abrasive water jet polishing trajectory; The optimal nozzle rotation angle θ is where R is the radius of the polishing trajectory of the complex-shaped inner cavity to be machined; S2. Input the polishing path into the industrial robot. The industrial robot starts the polishing work and adjusts the parameters of the polishing path in real time according to the surface roughness of the polished surface during the processing; S3. Fix the nozzle at any required coordinate point (X, Y) to start the polishing process, and at the same time turn on the waste liquid collection control box to collect the waste liquid.

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