Finishing device, finishing method and sealing system

Abstract

The present invention relates to a finishing device, a finishing method, and a sealing system. The sealing finishing device includes a thrust system, a plurality of sealing systems, each of which has a piston and a cylinder block that fits with the piston, and a plurality of conveying pipeline systems, each of which conveys the finishing medium contained in the corresponding sealing system to a different port of an internal flow path work for finishing, and the plurality of sealing systems communicate with each other through the internal flow path work. In this regard, the thrust system of the finishing device includes a vertical plunger pump connected to the piston to provide a driving force so that the piston can move vertically relative to the cylinder block, and the multi-stage pipeline includes a first stage pipeline and a second stage pipeline connected adjacent to the downstream of the first stage pipeline, the first stage pipeline has an elbow structure connected to the outlet end of the cylinder block, and the elbow structure is connected to the second stage pipeline extending horizontally.

Description

[Technical Field]

[0001] The present invention relates to the field of precision machining of internal flow passages, and more particularly to a finishing device, a finishing method and a sealing system. [Background technology]

[0002] Components with fine and complex internal flow path structures are widely used in industrial fields such as aerospace, ships, nuclear, automobiles, and molds. In particular, components related to fluid power systems often have complex internal bore structures such as fine flow paths, small diameter deep holes, and connections between fine flow paths and small diameter deep holes, and perform functions such as transporting, exchanging, or applying hydraulic pressure to fluids, such as various engine fuel nozzles, heat exchangers, hydraulic modules, and oil passage control throttles in aerospace, ships, and automobiles.

[0003] Process technologies capable of fabricating fine and complex internal flow channels include precision machining, femtosecond / water jet guided / long pulse laser processing, spark machining, and additive manufacturing (3D printing), etc. Except for additive manufacturing technology, the fine and complex internal flow channel structures fabricated by other single processes are relatively simple and have a small length-to-diameter ratio, so they need to be combined with other combined processes such as welding to fabricate fine and complex internal flow channels. Precision machining can produce fine, complex internal flow passages with problems such as burrs, sharp corners, and uneven joints. Femtosecond laser machining can produce adhered residual particles and a "step" effect on the surface of internal flow passages. Guided water jet / long-pulse laser and spark machining can produce a remelted layer on the surface of internal flow passages. Additive manufacturing (3D printing) is a technology that separates complex 3D structured part models into 2D structures and then layers them together to form them. It enables the integrated molding of complex, fine, and intricate internal flow passage parts, and is therefore increasingly being applied in industrial fields such as aerospace, automotive, and molds. However, additive manufacturing technology has its own process characteristics, such as temperature gradients and layer-by-layer molding, which can cause semi-sintered or adhered powder particles and a "step" effect on the surface of the internal flow passages of parts.

[0004] Burrs during machining, particles sintered into internal flow passages during femtosecond laser processing, and adhesive powder on the surface of internal flow passages during additive manufacturing affect the performance and safety of components. When burrs, attached residual particles, or adhesive powder fall off due to high-speed friction between the fluid flowing into the internal flow passage and the surface, they become redundant and spread with the fluid, block the oil passage, or cause mechanical wear failure, resulting in serious safety hazards. Highly rough inner surfaces are prone to fatigue cracks during long-term use, and carbon accumulation is also likely to occur in high-temperature oil passage systems. Cutting edge marks on the flow passage surface during machining, sharp corners or steps at machined joints, and "step" phenomena on the surface of internal flow passages during femtosecond laser and additive manufacturing processes can cause turbulence, vortices, and a sudden increase in fluid frictional drag during fluid movement, leading to fluid runaway and vibration, shortening the service life of components. Rough surfaces can generate a large number of cavitation bubbles in the fluid, affecting combustion and hydraulic power, and can also cause cavitation corrosion. For internal flow channels and small connecting holes in parts made of specific materials, such as hollow blades, microcracks are likely to occur on the surface of the remelted layer, leading to early failure of the part. Therefore, it is necessary to reduce the thickness of the remelted layer or to prevent its appearance.

[0005] Therefore, when processing the internal flow passage surfaces of fluid power components using technologies such as precision machining, femtosecond / water jet guided / long pulse laser machining, spark machining, and additive manufacturing (3D printing), adverse issues such as burrs, adhesive powder, sintered particle residues, rough surfaces, and remelted layers can occur. Appropriate surface finishing techniques must be used to remove these adverse effects and meet the performance requirements of the product.

[0006] However, currently, there is no technology that can effectively finish the surfaces of fine and complex internal flow passages. Therefore, the roughness of the inner surface of fine and complex internal flow passage workpieces made by additive manufacturing generally only has an initial average roughness Ra of 6.3 μm or more after additive manufacturing. There are no products with an optimal surface roughness Ra of 1.6 μm or less for internal flow passages, and there are no products with an optimal surface roughness Ra of 0.8 μm or less for fine and complex internal flow passage workpieces made by laser processing or spark processing. In addition, with regard to machined workpieces with fine and complex internal flow paths, there are no products with an optimal surface roughness Ra of 0.4 μm or less for the internal flow paths. However, currently, when fine and complex internal flow paths have complex, irregularly shaped flow paths such as S-shaped, L-shaped, U-shaped, or O-shaped bends, this cannot be achieved with machining, which only allows for linear feed, and can only be achieved with methods such as additive manufacturing. Therefore, at present, there are no products with an optimal surface roughness Ra of 1.6 μm or less for fine, irregular, and complex internal flow paths produced by additive manufacturing. Summary of the Invention

[0007] SUMMARY OF THE INVENTION It is an object of the present application to provide a finishing device, a finishing method and a sealing system.

[0008] In a first aspect, the present application provides a finishing device, the finishing device comprising: a thrust system; a plurality of sealing systems, each of which has a piston and a cylinder block fitted with the piston to accommodate a finishing medium for finishing processing, the thrust system communicating with one end of the piston and providing a driving force to the sealing systems to extrude the finishing medium from an outlet end of the cylinder block; and a plurality of conveying pipeline systems, each of which conveys the finishing medium accommodated in a corresponding sealing system to a different port of an internal flow path work for finishing, the plurality of sealing systems communicating with each other via an internal flow path work, the upstream end of the conveying pipeline system being connected to an outlet port of the sealing system. the finishing device has a finishing medium conveying pipeline system having a length-to-diameter ratio greater than 10:1, an outlet end diameter greater than 3 mm, a multi-stage pipeline system having a cross-sectional area ratio between the upstream pipeline and the downstream pipeline of two adjacent pipeline stages greater than 1, a thrust system of the finishing device having a vertical plunger pump connected to the piston to provide driving force for vertically moving the piston relative to the cylinder block, the multi-stage pipeline having a first stage pipeline and a second stage pipeline connected adjacent to the downstream of the first stage pipeline, the first stage pipeline having an elbow structure connected to the outlet end of the cylinder block, the elbow structure connected to the horizontally extending second stage pipeline.

[0009] In the technical solution of this embodiment, the finishing device employs a vertical structure consisting of a vertical plunger pump and a vertically moving piston, and a horizontal conveying pipeline. The synergistic effects of these two elements ensure pressure stability during the finishing process of the finishing medium, achieving reliable finishing results. Specifically, the vertical structure of the vertical plunger pump, piston, and cylinder block, and the corresponding horizontal conveying pipeline and workpiece connected by an elbow structure—that is, the vertical-horizontal coupling structure of the finishing device—enables the vertical plunger pump, piston, and cylinder block to avoid the influence of gravity rolling force, effectively utilizes gravity to ensure highly stable pressure, and provides a larger operational table space for workpiece finishing. Furthermore, the conveying pipeline has a length-to-diameter ratio greater than 10:1, an outlet diameter greater than 3 mm, and a cross-sectional area ratio between the front and rear pipelines of two adjacent pipelines in a multi-stage pipeline structure greater than 1, achieving a saturated flow rate of the conveyed finishing medium and ensuring pressure stability in the conveying pipeline.

[0010] In some embodiments, the ratio of the cross-sectional area of ​​the first stage pipeline to the cross-sectional area of ​​the second stage pipeline is 1.2 to 1.8.

[0011] In some embodiments, the multi-stage pipeline further includes a third stage pipeline connected adjacent to the second stage pipeline downstream, and the cross-sectional area ratio between the second stage pipeline and the third stage pipeline is 1.2 to 1.8.

[0012] In some embodiments, the workpiece further includes a tool having a port, and a cross-sectional area ratio between the third stage pipeline and the port of the tool is 1.2 to 2.2. A cross-sectional area ratio between the port of the tool and the port of the workpiece internal flow path is 1.2 to 10.

[0013] In some embodiments, the piston has at least a first groove and a second groove from top to bottom, the sealing system further comprises a seal ring positioned between the piston and the cylinder block, the first seal ring being provided in the first groove and the second seal ring being provided in the second groove, and a radial gap between the piston and the cylinder block is 1 mm to 2.5 mm.

[0014] In some embodiments, the first groove is a separate structure, the top surface of the piston is flat, a cover plate is removably provided thereon, the cover plate has a slope on its outer periphery, and the slope forms a one-sided oblique groove with the top surface of the piston to form the first groove, the second groove is opened in a side wall of the piston, the first seal ring is made of a hard material, and the second seal ring is made of a soft material.

[0015] In some embodiments, the second groove comprises at least two grooves from top to bottom, including a first sub-groove and a second sub-groove, and the ratio of the depth of the second sub-groove to the depth of the first sub-groove is 1.2 to 1.5.

[0016] In some embodiments, the angle of inclination of the one-sided oblique groove is greater than 60°.

[0017] In some embodiments, the material of the first seal ring satisfies the following: a flexural modulus of 1.9 GPa to 3.6 GPa, an elongation of 60% to 120%, and a Knoop hardness of 90 Hk to 100 Hk; and the material of the second seal ring satisfies the following: a flexural modulus of 0.2 GPa to 0.25 GPa, an elongation of 300% to 380%, and a flexural strength of 80 MPa to 100 MPa.

[0018] In some embodiments, the material of the first seal ring is one of pp, polytetrafluoroethylene, nylon, and peek, and the material of the second seal ring is one of silica gel, rubber, and nitrile.

[0019] In some embodiments, the cylinder wall of the cylinder block has a coating, the coating having a thickness of 50 μm to 220 μm and a hardness of 1500 HV to 2200 HV, and made of one or a combination of oxide, carbide, boride, and nitride ceramics.

[0020] In some embodiments, the coating has a surface roughness Ra of 0.05 μm to 0.4 μm, a roundness of 100 μm or less, and a cylindricity of 200 μm or less.

[0021] In some embodiments, the finishing device further comprises a diagnostic device, the diagnostic device having a flow rate and / or flow rate sensor and a pressure sensor for sensing the flow rate and / or flow rate and pressure of the finishing medium.

[0022] In some embodiments, the finishing medium comprises a liquid phase and a solid phase, the liquid phase having a viscosity of less than 1000 cP, the solid phase comprising abrasive grains, and the workpiece to be finished is a fine internal channel material having a diameter of 3 mm or less and a length-to-diameter ratio of 50:1 or more.

[0023] In a second aspect, the present application provides a finishing method using the finishing apparatus described in the first aspect, wherein the finishing medium has a liquid phase and a solid phase, the viscosity of the liquid phase is less than 1000 cP, the solid phase comprises abrasive grains, the workpiece to be finished is a fine internal channel material, the diameter is 3 mm or less, and the length to diameter ratio is 50:1 or more, the thrust system of the finishing apparatus applies a predetermined pressure to the finishing medium so that the finishing medium flows through the fine internal channel at a flow velocity greater than 5 m / s, and the flow rate of the finishing medium flowing into the interior of the fine internal channel from one end thereof reaches a saturation value of the flow rate that can be accommodated by the diameter of the fine internal channel so that the hydraulic pressure inside the internal channel becomes a pressure-trapping state.

[0024] In a third aspect, the present application provides a sealing system, the sealing system including a piston, a cylinder block fitted with the piston, and a seal ring positioned therebetween to accommodate a finishing medium for performing finishing processing, the piston being reciprocally movable along an extension direction of a cylinder wall of the cylinder block, a thrust system communicating with one end of the piston and providing a driving force to the piston, the piston having at least a first groove and a second groove extending from a top to a bottom, the sealing system being configured to connect the piston and the cylinder block to each other, The piston further includes a seal ring positioned between the piston and a cylinder block, the seal ring including a first seal ring provided in the first groove and a second seal ring provided in the second groove, the radial gap between the piston and the cylinder block being 1 mm to 2.5 mm, the first groove being a separate structure, the top surface of the piston being flat, and a cover plate being removably provided thereon, the cover plate having a slope on its outer periphery, the slope forming a one-sided oblique groove with the top surface of the piston to form the first groove, and the second groove being opened in the side wall of the piston. [Brief explanation of the drawings]

[0025] The above and other features, properties and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings and embodiments, which should be noted that the accompanying drawings are illustrative only and are not drawn to scale, and should not be considered as limiting the scope of protection actually claimed by the present invention.

[0026] [Figure 1] 1 is a conceptual flow chart of a finishing method according to some embodiments of the present application; [Figure 2] 1 is a schematic diagram of a finishing device according to some embodiments of the present application; [Figure 3] Enlarged view of part A in Figure 2 [Figure 4] Enlarged view of part B in Figure 2 DETAILED DESCRIPTION OF THE INVENTION

[0027] Various embodiments or examples of implementing the above-mentioned technical proposal are disclosed below. To simplify the disclosure, specific examples of each element and arrangement are described below, but these are merely examples and do not limit the scope of protection of the present invention. The terms "one embodiment," "one embodiment," and / or "several embodiments" refer to features, structures, or special features associated with at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "alternative embodiments" mentioned more than once in different places in this specification do not necessarily refer to the same embodiment. Furthermore, some features, structures, or special features in expressions such as "several embodiments," "other embodiments," and "still other embodiments" of the present application may be appropriately combined.

[0028] Flowcharts are used herein to explain the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in precise order. Other operations may be added to these processes, or certain step or step operations may be removed from these processes.

[0029] Furthermore, the average roughness described below refers to the case where multiple areas on the surface to be measured are selected, measured, and the average value is taken to obtain the average roughness of the measured surface. The optimum roughness described below refers to the case where multiple areas on the surface to be measured are selected, measured, and the minimum value is taken to obtain the optimum roughness of the measured surface. For example, when performing roughness measurement, the area to be roughened is a pipe segment with a length of 8 mm, and multiple 8 mm pipe segments are selected and measured in the pipe to be measured, and the minimum value can be obtained.

[0030] Components with intricate and detailed internal flow passage structures are widely used in industries such as aerospace, marine, nuclear, automotive, and mold manufacturing. However, current machining processes, such as precision machining, femtosecond / waterjet guided / long-pulse laser machining, spark machining, and additive manufacturing (3D printing), can result in undesirable problems such as burrs, adhesive powder, sintered particle residues, rough surfaces, and remelted layers. Appropriate surface finishing techniques are required to eliminate these undesirable effects and ensure the product meets its performance requirements.

[0031] Currently, there are no products with an optimum surface roughness Ra of 1.6 μm or less for fine internal flow passage workpieces made by additive manufacturing, no products with an optimum surface roughness Ra of 0.8 μm or less for fine internal flow passage workpieces made by laser processing or spark processing, and no products with an optimum surface roughness Ra of 0.4 μm or less for fine internal flow passage workpieces made by machining.However, if the fine internal flow passage has an irregular flow passage structure such as an S-shaped bend, L-shaped bend, U-shaped bend, or O-shaped bend, this cannot be achieved by linear feed machining and can only be achieved by additive manufacturing, and so there are currently no products with an optimum surface roughness Ra of 1.6 μm or less for fine internal flow passage workpieces made by additive manufacturing.

[0032] The inventors have conducted in-depth research and have tried and compared various methods for finishing the surfaces of internal flow passages, and have found that when the internal flow passages of a part have a large diameter (>3mm), a small length-to-diameter ratio (<50:1), and are generally linear, they can be finished using common methods such as manual polishing, chemical, electrochemical, plasma, magnetic, magnetorheological, abrasive flow, water jet, and ultrasonic. However, when it comes to fine internal flow passages with a small diameter (<3mm) and a large length-to-diameter ratio (>50:1), (1) Using abrasive flow technology, the inner cavity was finished using a press-grinding mechanism with a highly rigid semi-solid ointment finishing medium. However, the inventors discovered that this creep fluid, with its extremely low Reynolds number, makes it difficult to achieve uniform processing through complex, long-distance microchannels. It is prone to blockages at bends and dead corners, and forcing its passage through can cause the channel to deform or tear. Even if the fluid barely passes through an internal channel with a length-to-diameter ratio of 50:1 or more, the pressure and flow rate rapidly decrease with increasing fluid stroke, resulting in "excessive grinding" at the ports of the internal channel, while the pressure and flow rate losses are so great that the interior becomes "under-grinded." Furthermore, the water-insoluble colloidal abrasive flow medium tends to remain in the curves and dead corners of the internal channel, making it difficult or impossible to completely remove after processing. (2) Abrasive water jet technology, also known as fine abrasive slurry jet, high-velocity flow, or high-velocity water particle finishing, is used. By applying hydraulic pressure to the water jet nozzle, a water jet containing abrasive particles is ejected from the nozzle, and the impact kinetic energy washes away the surface material of the workpiece. However, because the distance between the water jet nozzle and the part surface is short, abrasive water jet technology is not effective on fine internal flow passages with small internal flow passage diameters (less than 3 mm) and large length-to-diameter ratios (more than 50:1). (3) Magnetic finishing technology can only produce a slight polishing effect on the surface of internal flow passages larger than 3 mm that extend in a roughly linear fashion. It cannot produce an effective surface finish on intricate, three-dimensional internal flow passages with diameters of 3 mm or less, such as S-, L-, U-, O-, or spiral bends. The reasons for this are as follows: Magnetic finishing is a flexible process that uses relatively large magnetic needle abrasive grains. It is based on the principle that convex and concave points on the surface are simultaneously processed under the action of an applied magnetic field. Therefore, these flexible processing methods can only produce a slight polishing effect on the surface. Even with a large amount of material removal, it cannot significantly improve the "step" effect on the surface, reduce surface roughness, significantly remove powder and particles adhering to the surface, or reduce burrs. Furthermore, because this method is limited by the movement of the magnetic field, it cannot be used to finish complex internal flow passages that extend in three dimensions in parts. (4) Although the chemical finishing method was adopted, the small diameter of the internal flow passages meant that only a small amount of corrosive solution could be accommodated, making the efficiency of the chemical finishing method extremely low, and even preventing finishing due to local accumulation of reactive bubbles. (5) Electrochemical, plasma finishing, and ultrasonic methods have been adopted, but they are unable to finish fine and complex internal flow paths because it is difficult to place tracing electrodes within the narrow, three-dimensionally stretched flow paths, including S-shaped bends, L-shaped bends, U-shaped bends, O-shaped bends, and spiral bends. Furthermore, with regard to (4) and (5), methods such as chemical, electrochemical, and plasma finishing can cause various corrosion and altered layer defects in the microstructure of the flow path substrate, and the corrosive liquid and reactive gases have adverse effects on the environment and equipment. At the same time, (4) and (5) are also flexible processing methods, and similarly have drawbacks to (3), in that they can only achieve a slight polishing improvement on the surface, and even if a large amount of material is removed, they cannot significantly improve the surface "step" effect, reduce surface roughness, or significantly remove powder, particles, and burrs adhering to the surface.

[0033] Based on the above, the inventors have conducted extensive research and discovered that the above-mentioned processing methods are not suitable for finishing fine internal flow paths because they all face problems such as difficulty in finishing the deep parts of the fine internal flow paths and / or the finishing quality is not ideal.

[0034] Based on the above, the inventors further researched and invented a surface finishing method for fine internal passages. This method uses a two-phase liquid finishing medium with a viscosity of less than 1000 cP, and the flow rate of the two-phase finishing medium within the fine internal passages is set to be greater than 5 m / s. The flow rate at one end of the fine internal passage is set to the saturation value that the diameter of the fine internal passage can accommodate. This creates a pressure-filled state within the internal passage, creating a means for the liquid to reach a saturation flow rate within the fine internal passages. In other words, the synergistic effects of the low-viscosity liquid phase, the fluid flow rate of the finishing medium, and the saturation flow rate solve the difficult problem of finishing fine internal passages. The principle behind this method is as follows. First, the synergistic effects of the low-viscosity liquid phase, fluid flow rate, and saturation flow rate allow the finishing medium to smoothly penetrate into the microscopic, complex internal flow channels and form a non-Newtonian-like state within the channel. The fluid boundary layer is parallel to the surface of the channel, and the abrasive grains in the "knife-like" hard non-Newtonian fluid achieve target machining of surface convexities through shear friction. Furthermore, the synergistic effects of these three factors create a micro-cutting force between the abrasive grains in the finishing medium and the surface of the microscopic, complex internal flow channels. This allows the optimal surface roughness to match the average contact length of the abrasive grain cutting edge, regardless of the material of the microscopic, complex internal flow channel. This enables the optimal surface roughness to be achieved within the range of the average contact length of the abrasive grain cutting edge, even achieving an ultra-mirror quality surface roughness of 0.05 μm, breaking through the limitations of abrasive flow and waterjet technologies. The cutting mechanism of abrasive flow technology relies on volume forces generated by the abrasive grains pressing against the surface, which can easily result in pits or indentations (Ra > 0.8 μm) when machining low-hardness metals and flexible polymer materials. The cutting force in abrasive waterjet technology is the erosion force caused by the impact of abrasive grains on the surface, and when machining soft metals, the surface is prone to roughening (Ra>0.8μm).

[0035] In order to develop a finishing device compatible with the above-mentioned surface finishing method, the inventors discovered that in order to ensure sufficient speed for the finishing medium to achieve shear friction and target processing of surface convex points using the hard fluid "like a blade," the finishing device must provide high pressure to the finishing medium. Furthermore, under high pressure conditions, there are high requirements for pressure precision and fluctuation range in order to avoid runaway polishing of the finishing medium and achieve an ideal finishing effect. Furthermore, the inventors discovered that the high-pressure two-phase flow of the finishing medium has a strong abrasive effect on the sealed system, and therefore the corresponding lifespan of the seals and sealed system of the finishing system is also an issue that must be resolved.

[0036] Based on the above, the inventors conducted extensive research and designed a vertical-horizontal combination device structure. Specifically, a vertical thrust system and sealing system are used, along with a horizontal conveying pipeline system. The finishing device employs a vertical structure consisting of a vertical plunger pump and a vertically moving piston, and a horizontal conveying pipeline structure. The synergistic effects of these two elements ensure pressure stability during the finishing process of the finishing medium, achieving a reliable finishing effect. Specifically, the vertical structure of the vertical plunger pump, piston, and cylinder block, and the corresponding horizontal conveying pipeline and workpiece connected by an elbow structure, that is, the vertical-horizontal combination structure in the finishing device, prevents the vertical plunger pump, piston, and cylinder block from being affected by gravity rolling force, effectively utilizes gravity to ensure highly stable pressure delivery, and provides a larger table space for workpiece finishing. The conveying pipeline has a length-to-diameter ratio of greater than 10:1, an outlet diameter greater than 3 mm, and a cross-sectional area ratio between the upstream pipeline and the downstream pipeline of two adjacent pipelines in the multi-stage pipeline is greater than 1. This structure ensures a saturated flow rate of the conveyed finishing medium and ensures pressure stability of the finishing medium in the conveying pipeline. The sealing system's multiple grooves and corresponding sealing rings, combined with the 1-2.5 mm gap between the piston and cylinder block, ensure that the sealing system effectively seals the finishing medium and allows the piston to smoothly propel the finishing medium, achieving a balance between sealing performance, propulsion performance, and the sealing system's lifespan.

[0037] It can be understood that the internal flow channel surface finishing device disclosed in the embodiments of this application can provide stable and high pressure, which helps solve the problem of inability to finish the surface of fine internal flow channels with small internal flow channel diameters (3 mm or less) and large length-to-diameter ratios (50:1 or more), thereby achieving fine internal flow channel workpieces with an optimal inner surface roughness Ra of 1.6 μm or less. The workpieces may have fine and complex internal flow channel workpieces with three-dimensional extensions, including S-shaped, L-shaped, U-shaped, O-shaped, and spiral bends, such as fuel nozzles, heat exchangers, hydraulic units, and oil passage control throttles for various engines in aerospace, marine, and automobile industries. It can also be understood that the disclosed embodiments of this application can be applied not only to the surface finishing method introduced here, but also to other fluid processing methods requiring stable and high pressure.

[0038] It is important to clarify that the terms "diameter" and "length" in this context refer to equivalent diameter and equivalent length, and the ratio of length to diameter is the ratio of equivalent length to equivalent diameter. Regarding the equivalent diameter, the cross-sectional shape of the internal flow passage may be a circle, an ellipse, or the like, whose cross-sectional contour is formed by a closed curve (non-broken line). The cross-sectional shape of the internal flow passage may be a rectangle, a triangle, or the like, whose cross-sectional contour is formed by a closed broken line. Since the cross-sectional contour is formed by any closed curve (non-broken line) or a closed broken line, and the cross-sectional contour is an irregular shape, an equivalent diameter is introduced and defined as follows: For any cross-sectional shape, an ideal circle is taken to be equal to the actual cross-sectional area of ​​the cross-sectional shape, and the diameter of this ideal circle is the equivalent diameter. The equivalent length refers to the total distance that the fluid in the internal flow passage actually flows between the two ports of the internal flow passage.

[0039] First, in order to understand the effect of the finishing device of the present invention, a surface finishing method for fine internal flow passages to which the finishing device can be applied will be introduced.

[0040] Referring to FIG. 1 , the present application provides a method for surface finishing an internal flow passage, the method comprising: Using a liquid-solid two-phase flow finishing medium in which the viscosity of the liquid phase is less than 1000 cP and the solid phase is an abrasive; A predetermined pressure is applied to the finishing medium so that the finishing medium flows through the fine internal flow passage at a flow rate of greater than 5 m / s, the flow rate of the finishing medium flowing into the fine internal flow passage from one end thereof reaches the saturation value of the flow rate that can be accommodated by the diameter of the fine internal flow passage, and the liquid pressure inside the internal flow passage is in a pressure-trapping state.

[0041] The liquid herein has a viscosity of less than 1000 cP. All references to viscosity values ​​in this application refer to the Ubbelohde viscosity at room temperature (approximately 25°C). The optimal viscosity of the liquid phase for a finishing method for microscopic internal channels with different materials, dimensions, and initial average roughness can be achieved by continuously increasing the viscosity based on a lower limit. Currently, the lower limit of viscosity in the examples is approximately 50 cP. Through extensive testing, the inventors have determined that for microscopic internal channels in common materials such as titanium alloys, high-temperature alloys, steel, ceramics, aluminum alloys, and polymeric materials, the viscosity of the liquid phase must be at least 50 cP to achieve the target roughness after finishing. The critical value of 1000 cP is not generally an optimal value, but rather the limit at which the finishing medium can flow continuously, smoothly, and stably through the microscopic internal channels.

[0042] The liquid phase described in the examples is, for example, an aqueous liquid phase, in which a certain thickener is added to deionized water so that the aqueous liquid has a certain viscosity. The beneficial effects of using an aqueous liquid are that it is low cost, easy to obtain, environmentally friendly, and the finishing medium is easy to clean after finishing is completed. However, it is understood that the liquid phase here is not limited to an aqueous liquid, as long as it has a viscosity μ of less than 1000 cP.

[0043] The material of the solid-phase abrasive grains may be a common abrasive material, such as carbide ceramics including silicon carbide, tungsten carbide, etc., oxide ceramics including aluminum oxide, zirconium oxide, cerium oxide, etc., nitride ceramics including boron nitride, chromium nitride, etc., or natural minerals including diamond / sand, mica, quartz, olivine, etc. Preferably, the abrasive grains may be a combination of one or more of diamond / sand and oxide ceramics.

[0044] When selecting the grain size and mass concentration of abrasive grains, it is common to gradually increase them based on the lower limit to obtain an optimal range. If the grain size and mass concentration are below the lower limit, the expected finishing effect will not be achieved; that is, the fine internal flow passages will not achieve the target surface roughness. The principle is that if the grain size is too small, the mass of the abrasive grains themselves will be too low to generate enough kinetic energy to achieve effective polishing; if the mass concentration is too low, the grinding probability of the surface processing point will be reduced, making effective polishing impossible. The selection of the lower limit is generally conservative; for example, any lower limit can be selected conservatively, provided that it does not exceed the upper limit of the grain size. The lower limit for the ratio of the internal flow passage diameter to the abrasive grain size is usually 20. That is, the diameter of the internal flow passage must ensure that at least 20 abrasive grains can pass through in parallel without clogging. That is, the upper limit of the abrasive grain size is usually 1 / 20 of the internal flow passage diameter, and the lower limit of the abrasive grain size is generally 1 / 5 of the upper limit. The lower limit of the abrasive mass concentration is generally 10 g / L, and the selection of the lower limit is generally relatively conservative because the system pressure is relatively high, and clogging of the abrasive may result in the scrapping of the workpiece and the system, or even tearing and explosion. Therefore, the abrasive particle size and mass concentration are gradually increased based on the specified lower limit until the abrasive particle size or mass concentration is too large, causing significant flow resistance and reducing the flow rate, and mutual collisions between abrasive particles affect the flow rate, reducing the flow rate and grinding effect. That is, the optimum value can be obtained by testing based on the lower limit.

[0045] A predetermined pressure is applied to the finishing medium so that the finishing medium flows through the fine internal passages at a flow rate greater than 5 m / s. The "predetermined pressure" here refers to a pressure that allows the finishing medium to flow through the fine internal passages at a flow rate greater than 5 m / s even at the initial stage of the finishing process. As the finishing process progresses, the surface roughness of the internal passages decreases, and under the same pressure conditions, the flow rate of the finishing medium within the fine internal passages becomes increasingly faster. It should be noted that the realized flow rate is within a certain range, so the "predetermined pressure" here is a concept of a range, rather than a specific value that can only be applied to the finishing medium. To measure the flow rate of the finishing medium within the fine internal passages, immersion measurement cannot be used, otherwise abrasive particles may damage the sensor probe. Ultrasonic velocity measurement can be used, or indirect measurement can be performed using the Hagen-Poiseuille law of viscous fluids (see equation below). In the formula, D is the internal flow passage diameter, l is the length of the fine internal flow passage, p is the pressure difference acting on both ends of the fine internal flow passage, i.e., the hydraulic pressure p, Re is the Reynolds number, um is the liquid phase flow velocity in the aqueous two-phase flow, ρl is the density of the liquid phase, and the liquid phase flow velocity is approximately equal to the flow velocity of the completion medium.

number

[0046] The flow velocity of the finishing medium is greater than 5 m / s, based on the theoretical critical conditions for forming a non-Newtonian fluid and the critical value obtained by the inventors through long-term practice. According to engineering fluid mechanics data (e.g., Yang Shuren, Wang Zhiming, He Guangyu, et al., Engineering Fluid Mechanics [M]. Petroleum Industry Press, 2006), when pure water has a viscosity of 1 cP, the critical flow velocity of a non-Newtonian fluid is greater than 16.6 m / s. However, the lower limit of the viscosity of the liquid phase in this embodiment is 50 cP, which is greater than 1 cP, so the critical flow velocity of a non-Newtonian fluid is less than 16.6 m / s. At the same time, based on practical results, the inventors have found that a flow velocity less than 5 m / s does not achieve ideal processing results, so the critical value is set to 5 m / s.

[0047] The flow rate at which the finishing medium flows into one end of the fine internal flow passage reaches a saturation value of the flow rate that can be accommodated by the diameter of the fine internal flow passage, and the liquid pressure inside the internal flow passage becomes high, that is, the so-called saturated flow rate state in this field.

[0048] The saturated value of the flow rate and the state of saturated flow rate here mean that when a fluid flows into a pipe, the cross section of the pipe is filled and the cross section of the pipe can accommodate the maximum number of fluid molecules in parallel.

[0049] It can be seen that the beneficial effects of the finishing method of the above embodiment are as follows:

[0050] The viscosity of the liquid phase of the finishing medium is less than 1000 cP, and the flow rate of the two-phase finishing medium within the fine internal passages is greater than 5 m / s, so that the flow rate at one end of the fine internal passages reaches the saturation value that the diameter of the fine internal passages can accommodate. This creates a pressure-filled state within the internal passages, providing a means for the liquid to reach a saturation flow rate within the fine internal passages. In other words, the synergistic effects of the low-viscosity liquid phase, fluid flow rate, and saturation flow rate solve the difficult problem of finishing fine internal passages. The principle behind this is as follows. First, the synergistic effects of the low-viscosity liquid phase, fluid flow rate, and saturation flow rate create a low-viscosity, high-flow state for the finishing medium, allowing it to smoothly penetrate the microscopic internal channels and form a non-Newtonian fluid within the microscopic internal channels. The fluid boundary layer is parallel to the internal channel surface, and the abrasive grains in the "blade-like" hard liquid phase achieve targeted machining of convex surfaces through shear friction. This principle overcomes the problem of simultaneous machining of convex and concave surfaces during flexible machining, resulting in only a slight polish. At the same time, the small cutting force generated by friction between the abrasive grains in the finishing medium and the microscopic internal channel surface enables optimal surface roughness that matches the average contact length range of the abrasive cutting edge, regardless of the material of the microscopic internal channel. This breaks through the limitations of abrasive flow and waterjet technologies. The cutting mechanism of abrasive flow technology relies on volume forces generated by the pressure of the abrasive grains against the surface, which can easily result in pits (Ra > 0.8 μm) when machining low-hardness metals and flexible polymer materials. The cutting force in abrasive waterjet technology is the erosive force caused by the impact of abrasive particles on the surface. When machining soft metals, this can easily result in surface roughening (Ra > 0.8 μm). Furthermore, the low-viscosity, high-flow-rate, fluid-dynamic conformal machining method effectively polishes irregularities on the internal flow channel surface, such as steps, sharp corners, and geometric contour curvatures. This geometric streamlining of corners, sharp edges, internal flow channel contour curvatures, and hole shapes further improves the fluid dynamics of the internal flow channel. Furthermore, the above example proposed a critical flow velocity of 5 m / s for achieving a blade-like hard non-Newtonian fluid and target machining of convex surfaces through the shear friction of the abrasive particles.

[0051] Regarding the machining time of the finishing medium in the microscopic internal passage, the finishing medium may finish the microscopic internal passage during a reference period until the optimal surface roughness of the microscopic internal passage reaches a target value. The reference period may be a predetermined continuous period or a plurality of intermittent periods. The finishing process may automatically stop after a non-predetermined continuous period after starting, upon detecting that the flow rate of the finishing medium reaches a flow rate corresponding to the target value of the optimal surface roughness of the microscopic internal passage. For example, as described above, in some embodiments, after starting machining, the optimal surface roughness is indirectly characterized by measuring the flow rate or flow rate of the finishing medium in the microscopic internal passage. When the flow rate or flow rate reaches a predetermined value, the corresponding optimal surface roughness reaches the target value, and the finishing process is stopped manually or automatically. The term "optimum surface roughness" used here does not necessarily mean that the optimal surface roughness needs to be measured directly; it may be characterized indirectly, such as by characterizing the flow rate or flow rate of the finishing medium within the microscopic internal passage, as described above. The above target values ​​refer to the set optimum surface roughness values, and generally refer to the requirements for the final optimum surface roughness of the fine internal flow passages, but it is not excluded that further finishing may be carried out after the above finishing step, and what is set at this time is not the requirement for the final optimum surface roughness.

[0052] In summary, the finishing method introduced in the above examples solves the long-standing industry challenge of finishing fine internal passages with diameters of 3 mm or less and length-to-diameter ratios of 50:1 or more by combining measures such as establishing a hydraulic system at both ends of the internal passage to be machined, utilizing a low-viscosity, high-speed solid-liquid two-phase fluid, achieving a saturation flow rate in the internal passage to be machined, and utilizing a fine cutting mechanism generated by the high-speed friction of abrasive grains in the two-phase flow against the surface of the internal passage.

[0053] Referring to FIGS. 2-4, in some embodiments, the present invention provides a finishing apparatus 100 comprising a thrust system 101, a plurality of sealing systems 102, and a plurality of conveying pipeline systems 103.

[0054] Each sealing system 102 has a piston 21 and a cylinder block 18 that fits with the piston 21 to contain the finishing medium 8 for finishing, and the thrust system 101 communicates with one end of the piston 21 and provides a driving force to the piston 21 to push the finishing medium 8 out of the outlet end 190 of the cylinder block 18.

[0055] Each conveying pipeline system 103 conveys the finishing medium 8 contained in the corresponding sealing system 102 to a different port of the internal flow path workpiece 34 where finishing is performed. For example, one set of sealing systems 102 and conveying pipeline systems 103 shown in FIG. 2 corresponds to the inlet of the workpiece 34, and another set corresponds to the outlet, thereby communicating between the multiple sealing systems via the workpiece 34. The upstream end of the conveying pipeline system 103 is connected to the outlet end 190 of the sealing system 102, and the downstream end discharges the finishing medium 8 into the internal flow path workpiece 34 where finishing is performed. The conveying pipeline system 103 has a length-to-diameter ratio greater than 10:1, a diameter at the outlet end greater than 3 mm, and a multi-stage pipeline, where the ratio of the cross-sectional area of ​​the upstream pipeline to the downstream pipeline of two adjacent pipelines is greater than 1.

[0056] The thrust system 101 includes a vertical plunger pump 5 connected to the piston 21 to provide driving force for vertically moving the piston 21 relative to the cylinder block 18, and the multi-stage pipeline includes a first stage pipeline 22 and a second stage pipeline 23 connected adjacent to and downstream of the first stage pipeline, the first stage pipeline having an elbow structure connected to the outlet end 190 of the cylinder block 18, and the elbow structure is connected to the second stage pipeline 23 extending horizontally, thereby realizing a combination of a vertical structure and a horizontal structure.

[0057] The thrust system 101 may be a hydraulic system, and as shown in FIG. 2, includes a motor 1, a hydraulic tank 2, a hydraulic pump 3, a pressure booster device 6, a vertical plunger pump 5, and an oil pipe 4. The motor 1 drives the hydraulic pump 2 to extract hydraulic oil at a constant pressure from the oil tank 2, and the pressure oil increased by the pressure booster device 6 is delivered to the vertical plunger pump 5. The vertical plunger pump 5 is connected to a piston 21 via a ball head 13 and drives the piston 21 to discharge the finishing medium 8 from the discharge end 190 of the cylinder block 18. The motor-driven hydraulic system not only has a large thrust, but also high thrust precision.

[0058] Corresponding to the configuration of the vertical plunger pump 5, the sealed system 102 must also be configured vertically, in which the movement direction of the piston 21 relative to the cylinder block 18 is along the vertical direction, but the corresponding workpiece 34 must be horizontal, so that the change in direction can be completed by the conveying pipeline system.

[0059] The beneficial effect of adopting the above embodiment is that the finishing device adopts a vertical structure consisting of a vertical plunger pump and a vertically moving piston, and a horizontal structure for the conveying pipe, which works synergistically to ensure pressure stability during the finishing process of the finishing medium, thereby achieving a reliable finishing effect. Specifically, by adopting a vertical structure for the vertical plunger pump, piston, and cylinder block, and a correspondingly horizontal conveying pipe and workpiece connected by an elbow structure, that is, by adopting a vertical and horizontal combined structure in the finishing device, the vertical plunger pump, piston, and cylinder block are not affected by gravity rolling force, and the gravity effect can be cleverly utilized to ensure very stable pressure provided, and a larger operable table space can be provided for finishing the workpiece. In addition, the conveying pipeline has a length-to-diameter ratio greater than 10:1, an outlet end diameter greater than 3 mm, and a cross-sectional area ratio between the upstream pipeline and the downstream pipeline of two adjacent pipelines in the multi-stage pipeline is greater than 1, thereby realizing the transportation of the conveyed finishing medium at a saturated flow rate and ensuring the pressure stability of the finishing medium in the conveying pipeline.

[0060] The multiple sealed systems 102 are connected to the workpiece 34, i.e., the multiple sealed systems 102 are connected to each other via the workpiece 34 to realize fluid exchange, i.e., one sealed system 102 discharges finishing medium 8 to the workpiece 34, and another sealed system 102 receives the finishing medium 8 that has flowed out from the workpiece 34. When the finishing medium 8 in one sealed system 102 is all consumed, the other sealed system 102 can continue finishing the workpiece 34 in the opposite direction to the previous direction using the received finishing medium 8. In other words, this other sealed system 102 then discharges finishing medium 8 to the workpiece 34, and the sealed system 102 that has all consumed the finishing medium then receives the finishing medium 8 that has flowed out from the workpiece 34. This allows the finishing medium 8 contained in at least one sealed system 102 to be always provided to the workpiece 34, ensuring continuous finishing of the workpiece 34 and making the finishing process efficient.

[0061] As shown in FIG. 2, the finishing device 100 may further include an operation module having a touch operation display 10, a switch 9 for turning the device on / off, an emergency stop switch 11 for forcibly turning off the device, and an operation console 12 for connecting an external processing operation module.

[0062] The number of sealed systems 102 and conveying pipeline systems 103 is shown as two in the figure as an example, but is not limited to this, and the number of thrust systems 101 may be such that each sealed system 102 shown in the figure corresponds to one thrust system 101.

[0063] The cylinder block 18 defines a space via a bottom plate and a top plate 19, which are connected to the cylinder block 18 via bolts 7. The space between the piston 21 and the top plate 19 accommodates the finishing medium 8, and the opening in the top plate 19 is the outlet end 190 of the sealing system 102. The diameter ratio of the cylinder block 18 to the outlet end 190 is 10 to 32 to further increase the pressure of the finishing medium. As shown in FIG. 4, in some embodiments, the cross-sectional area ratio of the first-stage pipe 22 to the second-stage pipe 23 may be 1.2 to 1.8, which allows the finishing medium to be steadily and gradually increased in pressure and maintain a saturated flow rate. In some embodiments, the multi-stage pipeline further includes a third stage pipeline 32 connected adjacent to the downstream of the second stage pipeline 22, and the cross-sectional area ratio between the second stage pipeline 22 and the third stage pipeline 32 is 1.2 to 1.8. As shown, the length of the third stage pipeline 32 may be short, similar to the shape of the joint. The three-stage pipeline and the cross-sectional area ratio per stage of 1.2 to 1.8 allow for stable and gradual pressure buildup while maintaining a saturated flow rate. This not only ensures conditions for providing stable pressure to the finishing medium, but also ensures the strength reliability and service life of the conveying pipeline system 103.

[0064] Referring to FIG. 4 , in some embodiments, the finishing device may further include a tooling 31. The tooling 31 has at least two ports 310 corresponding to at least one inlet and at least one outlet of the workpiece 34. The tooling 31 is stably fixed via a three-axis clamp 33 on the table, and the workpiece 34 is clamped inside the tooling 31 using clamp bolts 30 of the tooling. The ratio of the diameter of the third conduit 32 to the cross-sectional area of ​​the port of the tooling 31 connected thereto may be 1.2 to 2.2, which has a similar beneficial effect as described above, namely, stable and gradual pressure increase while maintaining a saturated flow rate. The upper limit of the cross-sectional area ratio between the third conduit 32 and the port of the tooling 31 connected thereto may be 2.2, which is higher than the upper limit of the cross-sectional area ratio between the conduits (1.8). This is because the tooling 31 is generally replaced frequently and has less stringent service life requirements than the conduits, so the upper limit of the cross-sectional area ratio can be set higher. In some embodiments, the cross-sectional area ratio of the tooling port to the workpiece 34 port should be greater than 1 and less than 10. Both may be sealed with epoxy resin. A ratio greater than 1 allows the workpiece's internal flow path to reach saturation flow. However, the inventors discovered that a ratio too large results in excessive relief pressure on the workpiece 34 port, increasing the strength and sealing requirements for the connection between the port and the workpiece, potentially leading to safety hazards such as connection breakage. Therefore, the inventors discovered that the ratio should be less than 10. It should be understood that the tooling 31 may be provided with multiple spare ports 310 suitable for internal workpiece flow paths of different diameters. When one port is in use, the other unused port can be connected and blocked with bolts. The clamping bolts 30 of the tooling 31 include an upper clamping bolt and a lower clamping bolt, which can clamp workpieces 34 of different dimensions and align the tooling port and the workpiece's internal flow path port on the same axis as the tooling port and the multi-stage pipeline port.

[0065] The inventors have discovered that by adopting the multi-stage pipeline conveying pipeline system introduced in the above embodiment, a thrust system configuration combining a hydraulic pump and a vertical plunger pump, and a combined vertical and horizontal structure, high precision can be achieved even when providing a thrust of 50 MPa or more (the error is 0.01 MPa), and pressure fluctuations during operation are small, falling within ±0.1%, making it possible to very effectively realize the above-mentioned finishing method.

[0066] As shown in Figures 2 and 3, for the sealing system 102, the inventors have discovered that the issue of sealing between the piston 21 and the wall of the cylinder block 18 is particularly important because it is necessary to provide a large pressure to the finishing medium, and it is necessary to ensure sealing as well as smooth movement of the piston 21 along the inner wall of the cylinder block 18.

[0067] The piston 21 has at least a first groove 211 and a second groove 210 from top to bottom. The sealing system 102 further includes a seal ring located between the piston 21 and the cylinder block 18, the seal ring including a first seal ring 17 in the first groove 211 and a second seal ring 170 in the second groove 210. The radial gap between the piston 21 and the cylinder block 18 is 1mm to 2.5mm. By adopting a structure with multiple grooves and multiple seal rings and a gap between the piston and the cylinder block of 1mm to 2.5mm, the first seal ring can filter the abrasive grains in the two-phase flow, and the second seal ring can seal the pure liquid phase, such as the aqueous liquid phase, thereby achieving good sealing performance against the finishing medium. The inventors have discovered that a gap range of 1mm to 2.5mm can maintain a good sealing effect and ensure that the piston can move smoothly along the wall surface of the cylinder block 18 and push out the finishing medium 18.

[0068] Continuing with FIG. 3 , the first groove 211 of the piston 21 is a separate structure. The top surface 212 of the piston 21 body is flat, and a cover plate 20 is removably mounted thereon. The cover plate 20 has a slope 201 on its outer periphery, which forms a one-sided oblique groove with the top surface of the piston 21 to form the first groove 211. The second groove 210 is formed in the side wall of the piston. The first seal ring 17 is made of a hard polymer material, and the second seal ring 170 is made of a soft polymer material. The inventors discovered that under high pressure, no matter how well the first seal ring seals, abrasive particles will infiltrate the gap between the cylinder wall and the seal ring and damage the seal ring. Therefore, the one-sided oblique groove and hard seal ring structure are provided to actively guide the abrasive particles to infiltrate / slide into the first seal ring 17, forming a self-sealing structure. Therefore, the first seal ring 17 is made of a hard polymer material. On the other hand, after most of the abrasive grains are actively engaged in the first seal ring 17, the material that needs to be sealed by the second seal ring 170 becomes the liquid phase in the two-phase flow, so it is sealed using the soft second seal ring 170. The reason why the first groove 211 needs to be a separate structure is that the inventors discovered that the first seal ring 17, which is made of a hard polymer and is subjected to large pressures, would not be able to be secured if the groove were provided directly on the piston sidewall. Therefore, a separate structure is adopted, and during assembly, the first seal ring is first placed on the top surface 212 of the piston 21 body, and then the cover plate 20 is placed on top and tightened with the bolts 7. In some embodiments, the inclination angle of the one-sided oblique groove, i.e., the inclination angle of the inclined surface 201, is greater than 60° to provide sufficient clamping force.

[0069] In some embodiments, the polymer material of the first seal ring 17 and the second seal ring 170 may have a flexural modulus of 1.9 GPa to 3.6 GPa, an elongation of 60% to 120%, and a Knoop hardness of 90 Hk to 100 Hk. Therefore, the first seal ring 17 should have a certain rigidity and be resistant to obvious deformation, while also having relatively good surface self-lubrication, relatively low compression shrinkage, and allowing the abrasive grains to embed well in the material and continue to slide easily within the material after embedding. The polymer material of the second seal ring 170 should have a flexural modulus of 0.2 GPa to 0.25 GPa, an elongation rate of 300% to 380%, and a flexural strength of 80 to 100 MPa, so that the second seal ring 170 has relatively good elasticity and can undergo obvious expansion and contraction deformation. At the same time, it should have both the ability to seal aqueous substances with a significant compression contraction length and very high flexural strength; otherwise, it will be prone to breakage after bending during movement.

[0070] In some embodiments, the material of the first seal ring 17 may be one of pp, polytetrafluoroethylene, nylon, and peek, and the material of the second seal ring 170 may be one of silica gel, rubber, and nitrile, which are readily available and low in cost.

[0071] 3, the second groove 211 may have at least two grooves, including a first sub-groove 2111 and a second sub-groove 2111, from the top to the bottom, and the ratio of the depth of the second sub-groove 2112 to the depth of the first sub-groove 2111 is 1.2 to 1.5. Furthermore, a third sub-groove 2113 may be further formed toward the bottom of the second sub-groove 2112, or more sub-grooves may be further formed. The ratio of the depth of the second sub-groove 2112 to the depth of the third sub-groove 2113 is 1.2 to 1.5. The second seal rings 170 corresponding to the first sub-groove 2111, the second sub-groove 2112, and the third sub-groove 2113 are seal rings 16, 15, and 14, respectively, and their function is to seal out water. The groove shape may be trapezoidal, which is easier to process and to fix the seal rings. The depth of the second sub-groove 2112 is greater than that of the adjacent first sub-groove 2111 and third sub-groove 2113, and the beneficial effect is that it can provide reliable multi-stage sealing against the fluid phase of the finishing medium. The first sub-groove 2111 provides a basic seal, the second sub-groove 2112 provides a complete seal, and the third sub-groove 2113 provides a reliable seal.

[0072] Continuing with FIG. 3, in some embodiments, the cylinder wall of the cylinder block 18 is coated with a coating having a thickness of 50 μm to 220 μm and a hardness of 1500 HV to 2200 HV, made of one or a combination of oxide, carbide, boride, and nitride ceramics. Its beneficial effect is to ensure reliable sealing. The principle behind this coating is as follows: The inventors discovered that during operation, the high-speed two-phase flow of fluid and abrasive particles mixes with the gap between the seal ring and the cylinder block, causing friction against the cylinder wall. Scratches caused by this friction on the cylinder wall can lead to complete failure of the sealing system and leakage of the fluid phase. Therefore, the cylinder wall must be hardened. The process for achieving the coating described above can also address the wear resistance of the cylinder wall by thermally spraying a special WC coating onto the bore of the cylinder block. The specific composition of the WC coating sprayed on the cylinder block is 15-100μm in WC powder particle size, greater than 85% WC powder, 1%-4% molybdenum powder, 1%-5% silicon powder, and 1%-5% boron powder. After spraying and sintering, a molybdenum-silicon-boron alloy phase is formed in the WC coating. The molybdenum-silicon-boron alloy has a relatively low coefficient of friction and acts as a reinforcing phase to enhance the strength and hardness of the WC coating. The particle temperature during spraying is below 1500°C, which reduces thermal deformation of the cylinder block at low temperatures and ensures dimensional accuracy of the final cylinder block. The spraying distance is 10mm-50mm, ensuring a coating bond strength of greater than 100MPa due to the short spraying distance. In some embodiments, the surface roughness Ra of the coating is 0.05 μm to 0.4 μm, the cylinder block has a roundness of 100 μm or less and a cylindricity of 200 μm or less, and the diameter of the cylinder block is 100 mm to 400 mm, which prevents the relative movement of the piston and the cylinder block from generating a rolling force that scratches the coating and causes peeling, and further ensures the life of the sealing system and the reliability of the sealing effect.To achieve this effect, the coating may be subjected to surface honing, with a zirconia ceramic blade being used as the honing tool. The honing speed is less than 80 r / min, and the relatively low speed ensures that the coating does not peel, chip or fall off during the honing process.

[0073] As shown in FIG. 2, the finishing apparatus 10 may further include a diagnostic device, which includes a flow velocity and / or flow rate sensor and a pressure sensor for detecting the flow velocity and / or flow rate of the finishing medium and diagnosing the status of the finishing process. The sensors may be installed close to the upstream end of the workpiece 34, and the principle behind this is described below. The inventors discovered that when the finishing process is performed normally, the flow velocity, flow rate, and pressure of the finishing medium at the upstream end of the fine internal flow passage are affected only by the internal flow passage structure and the surface quality of the internal flow passage. The flow resistance and flow rate of the internal flow passage itself generate a reaction force that directly affects the flow velocity, flow rate, and pressure at the upstream end. Because the downstream end of the internal flow passage has a larger cross-sectional area than the internal flow passage, the polishing medium flows freely "empty" relative to the downstream end after flowing out of the internal flow passage, and the downstream end of the internal flow passage does not affect the flow velocity, flow rate, and pressure at the upstream end. Therefore, simply measuring the change in the inlet velocity at the upstream end can reflect the processing quality of the internal flow passage.

[0074] The pressure sensor uses a high-sensitivity piezoelectric quartz sensor 28 and a high-resolution multi-channel data collector 27 to monitor data from multi-port pressure gauges 29 in real time, fully recording the quasi-static and highly dynamic pressure processes during the completion process. This allows for accurate flow resistance data for each flow channel and ensuring optimal completion results. The flow velocity and / or flow rate sensors include a flow velocity meter 24, a flow velocity and flow rate piezoelectric sensor 25, and a flow velocity and flow rate data collector 26. They employ ultrasonic measurement principles, and the Doppler-based ultrasonic flowmeter synchronizes the flow velocity and flow rate of multiple ports. Ultrasonic measurement is non-contact, completely avoiding damage to the flow velocity meter caused by two-phase flow. This significantly improves the response sensitivity of the entire system and optimizes completion times.

[0075] Although the present invention has been disclosed in the above embodiments, the present invention is not limited to these embodiments, and those skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention and the content that does not deviate from the technical solution of the present invention fall within the scope of protection defined in the claims of the present invention.

Claims

1. 1. A finishing device comprising: a thrust system; a plurality of sealing systems, each having a piston and a cylinder block mating with the piston for containing a finishing medium for performing finishing processing, the thrust system communicating with one end of the piston and providing a driving force to the sealing systems to push the finishing medium out of an outlet end of the cylinder block; a plurality of conveying pipeline systems, each conveying the finishing medium contained in a corresponding sealed system to a different port of an internal flow path work for finishing, and the plurality of sealed systems communicate with each other via the internal flow path work, wherein the upstream end of the conveying pipeline system is connected to the outlet end of the sealed system, and the downstream end of the conveying pipeline system discharges the finishing medium to the internal flow path work for finishing, the ratio of the length to the diameter of the conveying pipeline system is greater than 10:1, and the diameter of the outlet end is greater than 3 mm, and the conveying pipeline system has multi-stage pipelines; wherein the finishing device thrust system includes a vertical plunger pump connected to the piston for providing a driving force for vertical movement of the piston relative to a cylinder block; the multi-stage piping includes a first stage piping and a second stage piping connected adjacent to the downstream of the first stage piping, wherein a ratio of a cross-sectional area of ​​the first stage piping to a cross-sectional area of ​​the second stage piping is greater than 1, the first stage piping has an elbow structure connected to an outlet end of the cylinder block, and the elbow structure is connected to the second stage piping extending horizontally; the piston has a flat top surface on which a cover plate is removably mounted, a first groove is formed between the top surface of the piston and the sloped outer peripheral surface of the cover plate, and a second groove is formed in a side wall of the piston between the top and bottom, the sealing system further comprises a seal ring positioned between the piston and a cylinder block, the seal ring including a first seal ring provided in the first groove and a second seal ring provided in the second groove, a radial gap between the piston and the cylinder block is 1 mm to 2.5 mm, and the first seal ring is made of a hard material and the second seal ring is made of a soft material.

2. 2. The finishing apparatus of claim 1, wherein a ratio of a cross-sectional area of ​​the first stage pipe to a cross-sectional area of ​​the second stage pipe is 1.2 to 1.

8.

3. 3. The finishing device according to claim 2, wherein the multi-stage pipeline further comprises a third stage pipeline connected adjacent to the second stage pipeline downstream, and the ratio of the cross-sectional area of ​​the second stage pipeline to the cross-sectional area of ​​the third stage pipeline is 1.2 to 1.

8.

4. The finishing device described in claim 3, further comprising a tool having a port, wherein the ratio of the cross-sectional area of ​​the port of the tool to the cross-sectional area of ​​the third stage pipeline is 1.2 to 2.2, and the ratio of the cross-sectional area of ​​the port of the tool to the cross-sectional area of ​​the port of the workpiece internal flow path is 1.2 to 10.

5. 2. The finishing device of claim 1, wherein the second groove comprises at least two grooves, including a first sub-groove and a second sub-groove, from top to bottom, and a ratio of a depth of the second sub-groove to a depth of the first sub-groove is between 1.2 and 1.

5.

6. 2. The finishing device according to claim 1, wherein an angle formed between the top surface of the piston that forms the first groove and the outer peripheral surface of the cover plate is greater than 60 degrees.

7. 2. The finishing device according to claim 1, wherein the material of the first seal ring satisfies the following: a flexural modulus of elasticity of 1.9 GPa to 3.6 GPa, an elongation rate of 60% to 120%, and a Knoop hardness of 90 Hk to 100 Hk; and the material of the second seal ring satisfies the following: a flexural modulus of elasticity of 0.2 GPa to 0.25 GPa, an elongation rate of 300% to 380%, and a flexural strength of 80 MPa to 100 MPa.

8. 8. The finishing device according to claim 7, wherein the material of the first seal ring is one of PP, polytetrafluoroethylene, nylon, and peek, and the material of the second seal ring is one of silica gel, rubber, and nitrile.

9. 2. The finishing device according to claim 1, wherein the cylinder wall of the cylinder block has a coating, the coating having a thickness of 50 μm to 220 μm and a hardness of 1500 HV to 2200 HV, and made of one or a combination of oxide, carbide, boride, and nitride ceramics.

10. 10. The finishing device according to claim 9, wherein the coating has a surface roughness Ra of 0.05 μm to 0.4 μm, a roundness of 100 μm or less, and a cylindricity of 200 μm or less.

11. 10. The finishing device of claim 1, further comprising a diagnostic device, the diagnostic device including a flow rate and / or flow rate sensor and a pressure sensor for sensing the flow rate and / or flow rate and pressure of the finishing medium.

12. 2. The finishing device of claim 1, wherein the finishing medium has a liquid phase and a solid phase, the viscosity of the liquid phase is less than 1000 cP, the solid phase comprises abrasive grains, and the workpiece to be finished is a fine internal channel material, the diameter of which is 3 mm or less, and the length-to-diameter ratio is 50:1 or more.

13. A method for finishing an internal flow path material, comprising: using a finishing device according to any one of claims 1 to 12; the finishing medium has a liquid phase and a solid phase; the viscosity of the liquid phase is less than 1000 cP; the solid phase comprises abrasive grains; the workpiece to be finished is a fine internal flow path material; the diameter is 3 mm or less; and the length-to-diameter ratio is 50:1 or more; the thrust system of the finishing device applies a predetermined pressure to the finishing medium so that the finishing medium flows through the fine internal flow path at a flow velocity greater than 5 m / s; and the flow rate of the finishing medium flowing into the interior of the fine internal flow path from one end thereof reaches a saturation value of the flow rate that can be accommodated by the diameter of the fine internal flow path so that the liquid pressure inside the internal flow path is trapped.

14. A sealing system for use in a finishing device according to any one of claims 1 to 12, comprising: a piston for receiving a finishing medium for performing finishing processing, a cylinder block fitted with the piston, and a seal ring positioned therebetween, the piston being reciprocally movable along an extension direction of a cylinder wall of the cylinder block; a thrust system communicating with one end of the piston and providing a driving force to the piston; In the sealing system, the piston has a flat top surface on which a cover plate is removably mounted, a first groove is formed between the top surface of the piston and the sloped outer peripheral surface of the cover plate, and a second groove is formed in a side wall of the piston between the top and bottom, the sealing system further includes a seal ring positioned between the piston and a cylinder block, the first seal ring being mounted in the first groove and the second seal ring being mounted in the second groove, and a radial gap between the piston and the cylinder block is 1 mm to 2.5 mm.

Images