A solid-liquid phase change heat storage segmented grinding wheel magnetic workbench auxiliary grinding system

Abstract

The invention discloses a solid-liquid phase change heat storage node grinding wheel magnetic workbench assisted grinding system, which belongs to the technical field of grinding equipment, and comprises a grinding component, wherein the grinding component is placed above the magnetic workbench; the grinding component comprises a phase change heat storage grinding wheel, wherein the phase change heat storage grinding wheel comprises a grinding wheel base, and a plurality of heat storage nodes are fixedly arranged on the periphery of the grinding wheel base; the heat storage node comprises a node housing, wherein the node housing has a fan-shaped cavity, wherein a plurality of heat-conducting fins are fixedly arranged, and a solid-liquid phase change working medium is filled between adjacent heat-conducting fins.

Description

Technical Field

[0001] The invention belongs to the technical field of grinding equipment, and in particular relates to a solid-liquid phase change heat storage segmented grinding wheel magnetic workbench auxiliary grinding system. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Grinding is one of the important methods of precision machining. It can achieve high surface quality and dimensional accuracy and plays an important role in many manufacturing fields. However, in the grinding process, especially in the face of difficult-to-machine materials or high-speed grinding, most of the heat generated accumulates in the grinding zone. If it cannot be discharged in time, it will cause surface burns, oxidation, residual stress, etc. for the workpiece; for the grinding wheel, it will cause abrasive blockage, passivation, and damage to the part combined with the substrate. The commonly used cooling method is to use a large amount of grinding fluid to cool the grinding zone, but the effect is often not effective enough. On the one hand, the grinding zone itself is a relatively sealed area. The airflow barrier formed by the high-speed rotation of the grinding wheel hinders the grinding fluid from entering the grinding zone for heat exchange. On the other hand, due to the film boiling of the grinding fluid, it is difficult for the grinding fluid to achieve the ideal cooling effect. In addition, the large-scale use of grinding fluid is costly and energy-intensive, which will affect the health of the staff, pollute the environment, increase the cost of subsequent treatment, and is not in line with the concept of green processing and manufacturing. Therefore, how to effectively control the temperature of the grinding zone is a hot issue that needs to be solved.

[0004] Nowadays, people have begun to improve the thermal properties of the grinding wheel to increase the heat transfer in the grinding area. By improving the heat capacity and thermal conductivity of the grinding wheel, more heat in the grinding area can be conducted through the grinding wheel, reducing the temperature of the grinding area, thereby reducing the use of grinding fluid and ensuring the surface processing quality of the workpiece.

[0005] At present, one research direction is to combine heat pipes with grinding wheels, and use the phase change process of the working fluid in the heat pipe to increase the heat transfer capacity of the grinding wheel, reduce the thermal conductivity, and increase the heat capacity of the grinding wheel. The phase change working fluid is liquid-gas phase change material, but there are other types of phase change materials.

[0006] Phase change materials have the ability to reversibly absorb or release a large amount of heat within a certain temperature range. They can change from one phase (such as solid) to another phase (such as liquid or gas), absorbing or releasing latent heat during the phase change process, thereby regulating the temperature of their surroundings. Phase change materials have a wide range of applications in many fields, mainly including thermal energy storage, temperature regulation, and energy conservation and emission reduction. Phase change materials have many advantages and are expected to be more widely used and developed in the future.

[0007] After searching, Fu Yucan and others from Nanjing University of Aeronautics and Astronautics invented a heat pipe grinding wheel and manufacturing method for dry grinding of difficult-to-process materials (patent number: ZL 201310059826.0). The abrasive particles are set on the end cover, and a heat pipe is formed between the end cover and the base. The base is provided with an exhaust hole connected to the heat pipe cavity. The exhaust hole is provided with an inner and outer plug. The heat pipe cavity is provided with a working medium, and the outer surface of the condensation section of the cavity is provided with a condensation groove. A large amount of grinding heat is generated in the contact arc area between the workpiece and the grinding wheel. The grinding heat is transferred to the inside of the grinding wheel through the abrasive particles and the grinding wheel matrix. The liquid working medium has a low boiling point under vacuum. It forms an airflow when it encounters heat, releases heat when it encounters the cold end, and condenses into a liquid. Under the action of centrifugal force, the liquid flows back to the evaporation end to form a liquid film, which continues to absorb the grinding heat, thereby achieving a heat exchange effect.

[0008] After searching, Fu Yucan and others from Nanjing University of Aeronautics and Astronautics invented a brazed diamond heat pipe grinding wheel (patent number: ZL 200710190139.7), which uses the excellent thermal conductivity of diamond abrasives to transfer the heat in the grinding area to the grinding wheel base, and then conducts the heat out through the heat pipe. The hot end of the heat pipe of the first brazed diamond heat pipe grinding wheel is inserted into the bottom of the blind hole of the segment, passes through the light hole of the grinding wheel base, and the cold end of the heat pipe is located in the groove of the grinding wheel base. The second brazed diamond heat pipe grinding wheel has an annular groove machined along the inner side of the outer cylindrical working surface of the grinding wheel base, and the heat pipe is buried in the annular groove on the grinding wheel base. The heat pipe section corresponding to the grinding arc zone serves as the hot end of the heat pipe. The heat generated by grinding is transferred to the substrate through the abrasive particles, and then transferred to the hot end of the heat pipe, causing the working fluid to evaporate. The heat pipe sections not in the grinding arc zone serve as the cold end of the heat pipe, which can be cooled by air or water. After the working fluid evaporates at the hot end, it enters the cold end, cools and liquefies, and then flows back to the hot end, completing a working cycle.

[0009] After searching, Fu Yucan and others from Nanjing University of Aeronautics and Astronautics invented an integral axially rotating oscillating heat pipe grinding wheel and a method for making it (patent number: ZL 202010180296.5). The interior of the grinding wheel body is processed with several axial oscillating heat pipe flow channels at a position close to the outer peripheral surface. The oscillating heat pipe flow channels are connected end to end in sequence through connecting flow channels to form a closed serpentine oscillating heat pipe structure. The oscillating heat pipe structure is evacuated and injected with cooling medium that does not fill the oscillating heat pipe flow channels, so that the lower part of the oscillating heat pipe flow channels is filled with cooling medium and the upper part is a cavity. Heat dissipation fins are fixedly installed on the upper outer peripheral surface of the grinding wheel body, and the heat dissipation fins are thermally connected to the upper part of the oscillating heat pipe flow channels. The integral axially rotating oscillating heat pipe grinding wheel can stably and continuously drain the grinding heat in the grinding arc zone effectively and quickly, thereby enhancing the heat exchange in the grinding arc zone, reducing the grinding temperature, and improving the grinding quality.

[0010] After searching, Fu Yucan and others from Nanjing University of Aeronautics and Astronautics invented a heat pipe grinding wheel and installation method for forming grinding (patent number: ZL 201410707834.6). The grinding wheel is provided with a heat pipe cavity filled with working medium, the inner wall of the evaporation end is close to the grinding surface of the grinding wheel, and the condensation end is far away from the grinding surface of the grinding wheel. The use of independently arranged sealing interfaces and vacuum interfaces simplifies the vacuuming and sealing operations and improves the reliability of the seal; the liquid wick structure arranged on the inner wall of the forming can achieve uniform distribution of the working medium on the entire forming surface, which can achieve uniform heat dissipation of forming grinding and avoid thermal damage to the workpiece and the grinding wheel due to excessive local temperature.

[0011] After searching, Fu Yucan and others from Nanjing University of Aeronautics and Astronautics invented a combined axial rotating pulsating heat pipe grinding wheel and its preparation method (patent number: ZL 201811546278.3), the grinding wheel consists of a handle body and a plurality of grinding wheel segments that can be combined and fixed on the handle body, the outer surface of the lower end of the grinding wheel segment is provided with a working layer with abrasive grains, the upper part of the grinding wheel segment is provided with a heat exchange fin, and a closed single-loop pulsating heat pipe flow channel is provided inside the grinding wheel segment near the outer wall surface, and a vacuum injection hole is provided on the single-loop pulsating heat pipe flow channel. The vacuum device can evacuate the single-loop pulsating heat pipe flow channel, and the injection device can inject a preset working fluid into the single-loop pulsating heat pipe flow channel. The heat of the working layer can be transferred to the lower part of the single-loop pulsating heat pipe flow channel to heat the working fluid in the lower part of the single-loop pulsating heat pipe flow channel, and the working fluid in the lower part of the single-loop pulsating heat pipe flow channel can exchange heat with the working fluid in the upper part of the single-loop pulsating heat pipe flow channel, and the heat of the working fluid in the upper part of the single-loop pulsating heat pipe flow channel can be transferred to the heat exchange fins to achieve heat dissipation.

[0012] After searching, Fu Yucan and others from Nanjing University of Aeronautics and Astronautics invented an oscillating heat pipe segment grinding wheel and its manufacturing method (patent number: ZL 201610294681.6). The oscillating heat pipe segment is fixed to the grinding wheel base with fastening screws. The oscillating heat pipe cavity is filled with a preset working medium. When the grinding wheel rotates at high speed, the water and water vapor in the cavity form a vapor-liquid plug flow under the action of surface tension and the temperature difference between the hot and cold ends, and appear randomly in the loop. The grinding heat is transmitted to the inside of the grinding wheel, and the liquid plug evaporates and absorbs part of the heat. The water vapor increases, and the pressure in the bubble at the evaporation end increases. The pressure difference between the evaporation end and the condensation end drives the liquid plug and the bubble to move. When the condensation end releases heat, the pressure decreases, pushing the liquid plug and the bubble from the condensation end back to the evaporation end, enhancing the thermal conductivity of the grinding wheel, thereby achieving the effect of strengthening the heat exchange in the grinding arc zone.

[0013] After searching, Yao Jun and others from the Institute of Engineering Thermophysics, Chinese Academy of Sciences, invented an axially rotating heat pipe grinding wheel structure and its design method and manufacturing method (application number: 202311054098.4). The grinding wheel includes a grinding wheel head base, heat dissipation fins, a grinding wheel handle, a heat pipe capillary wick with a layered porous lattice structure, and other components. By designing a heat pipe capillary wick with a layered porous lattice structure, a heat pipe cavity with an inverted cone inner wall, and a reflux pipe structure with a right cone inner wall in the inner cavity of the heat pipe grinding wheel, the condensed liquid medium can quickly reflux, thereby improving the heat dissipation effect of the heat pipe grinding wheel. In addition, the use of additive manufacturing technology to integrate the heat pipe and the grinding wheel into a new processing and manufacturing method solves the problems of difficult processing and complex processes of traditional manufacturing technology, and realizes the integrated manufacturing of the complex inner cavity structure of the heat pipe grinding wheel.

[0014] After searching, Chen Jiajia and others from Nanjing Forestry University invented a targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel and its use method (application number: 202310734784.X). The grinding wheel includes a handle, a condensation part is provided below the handle, an insulation part is provided below the condensation part, and an evaporation part is provided below the insulation part. The three parts are provided with a heat pipe cavity loaded with nanofluids, and a focusing and dispersion device for disturbing the nanofluid is provided in the heat pipe cavity, which solves the problem of nanofluids deposited in the contact area between the grinding wheel and the workpiece to hinder heat exchange, and promotes the application of nanofluids as working fluids in the formed heat pipe grinding wheel.

[0015] After searching, Wu Ze and others from Southeast University invented a method for cooling grinding wheels with oscillating heat pipes and improving the heat dissipation of grinding wheels (application number: 201611024216.7). An oscillating heat pipe is installed in the grinding wheel body, which is a steel annular plate heat pipe. Three groups of oscillating heat pipes are symmetrically distributed in the grinding wheel body along the axial direction. Each group has 40 groups of elbow channels and includes a liquid exchange port for replacing the working medium. The oscillating heat pipe uses the thermal conductivity of the oscillating heat pipe to be much greater than that of metal, so that the working medium absorbs heat in the heat absorption section and vaporizes to form a bubble flow of "bubble liquid plug" to start oscillation, and finally conducts heat to the condensation section to liquefy and release heat.

[0016] After searching, He Qingshan and others from Henan University of Technology invented a phase change heat storage composite superhard abrasive grinding wheel (application number: 202211626661.6). An annular tube cavity is provided in the area near the outer end of the grinding wheel base, and heat dissipation fins are installed in the annular tube cavity. A thin layer of foam metal is laid on the outer wall of the annular tube cavity, and a low-boiling point working fluid is injected inside it. The convection heat transfer of the gas / liquid two-phase transition of the working fluid and the large surface area of ​​the foam metal and the fins are utilized to ensure rapid condensation, thereby achieving rapid heat exchange.

[0017] After searching, He Qingshan and others from Henan University of Technology invented a phase change heat storage grinding wheel for green dry grinding and a manufacturing method thereof (patent number: ZL 201610865211.0). An annular tube cavity is provided near the outer end of the grinding wheel base, and a circle of heat storage elements is provided in the base at the inner end of the annular tube cavity. The annular tube cavity is provided with a working medium that is liquid at room temperature. The phase change heat transfer effect of the annular heat pipe can ensure that the heat is quickly transferred to the heat storage element inside the grinding wheel. The heat storage element further absorbs and stores this part of the heat in itself, and then gradually transfers the heat to the external environment through the large heat exchange area of ​​the grinding wheel base itself, thereby realizing rapid heat dissipation in the grinding arc area of ​​the grinding wheel.

[0018] After searching, He Qingshan and others from Henan University of Technology invented a new type of high thermal conductivity phase change heat storage superhard abrasive grinding wheel and its preparation method (patent number: ZL 201811635039.5). An annular tube cavity is provided near the outer end of the grinding wheel base, and the annular tube cavity is filled with an annular foam metal. The annular tube cavity is also provided with a gas-liquid phase change heat transfer medium. The porous structure and heat storage effect of the foam metal are used to improve the gas-liquid two-phase conversion efficiency of the medium in the annular tube cavity part of the grinding wheel base, thereby reducing the thermal resistance of the annular tube cavity part of the grinding wheel base. Finally, the heat control of the grinding area is achieved.

[0019] After searching, Li Yili and Huang Biao of Huizhou Jem Composite Materials Co., Ltd. invented a grinding wheel machine based on gas phase change cooling (patent number: ZL 202110875050.4). The cooling fluid is input from the input pipe in liquid state, passes through the second inner tube and the first inner tube in turn, and enters the flow gap. In the flow gap and the first annular cavity, the heat of the grinding wheel body is absorbed, the temperature is increased and vaporized, and then the vaporization latent heat is used to take away a large amount of heat from the end face and side curved surface of the grinding wheel body, and then passes through the second annular cavity and the output pipe in turn, enters the heat exchange equipment, and re-condenses into liquid. Even when the grinding wheel body rotates at a high speed, the grinding wheel body can be effectively cooled.

[0020] In summary, the examples of combining phase change materials with grinding wheels currently only involve the use of solid-liquid phase change fluids, and the combination of other types of phase change fluids with grinding wheels is still blank. Existing cases of phase change heat storage grinding wheels mainly use the evaporation-condensation cycle of liquid-gas phase change fluids in the form of heat pipes to reduce the thermal resistance of the grinding wheel, thereby achieving the effect of quickly draining heat from the grinding area of ​​the grinding wheel. However, during the phase change process, the liquid-gas phase change material will undergo a phase change and its volume will increase dramatically, which will generate greater pressure on the inside of the grinding wheel. In addition, since the heat capacity of the phase change heat transfer part is small, once heat accumulates due to insufficient heat dissipation, it is easy to affect the heat transfer performance of the grinding wheel. Solid-liquid phase change material is a new type of material in recent years. The volume change during the phase change process is relatively small, and the heat capacity is large. It can also effectively drain the heat in the grinding area. However, there is no case combining solid-liquid phase change material with grinding wheel to design a new type of phase change heat storage grinding wheel, and there is no grinding device that combines phase change heat storage grinding wheel, micro-lubrication and magnetic worktable to assist grinding work and effectively cool the grinding area. Summary of the invention

[0021] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a solid-liquid phase change heat storage block grinding wheel magnetic worktable assisted grinding system, which effectively combines the solid-liquid phase change material with the grinding wheel through the design of the grinding wheel, reduces the thermal resistance of the grinding wheel and enhances the heat conductivity by designing heat-conducting fins and foam metal sheets inside the grinding wheel, places solid-liquid phase change materials in the grinding wheel, absorbs the heat of the grinding area by virtue of the characteristic of the material phase change process to absorb heat, reduces the temperature of the grinding area, and thus improves the surface processing quality of the workpiece. The grinding system is also assisted by a micro-lubrication component, which assists in cooling the grinding area by means of a micro-amount of grinding fluid and low-temperature cold air. The worktable adopts a magnetic worktable to reduce the difficulty of clamping and improve processing efficiency.

[0022] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0023] In the first aspect, the present invention provides a solid-liquid phase change heat storage node grinding wheel magnetic worktable assisted grinding system, including a grinding assembly, which is placed above the magnetic worktable; the grinding assembly includes a phase change heat storage grinding wheel, the phase change heat storage grinding wheel includes a grinding wheel base, and a plurality of heat storage nodes are fixedly arranged on the periphery of the grinding wheel base; the heat storage node includes a node shell, the node shell has a fan-shaped cavity, a plurality of heat-conducting fins are fixedly arranged in the fan-shaped cavity, and a solid-liquid phase change working medium is filled between adjacent heat-conducting fins.

[0024] As a further technical solution, the segment housing is connected to the segment cover plate to close the fan-shaped cavity; the heat-conducting fins are fixed in the fan-shaped cavity near the center of the grinding wheel base; the heat-conducting fins are arranged radially along the grinding wheel base, and adjacent heat-conducting fins are spaced apart.

[0025] As a further technical solution, a foam metal sheet is arranged outside the fan-shaped cavity, one end of the foam metal sheet contacts the heat-conducting fins, and the other end contacts the segment housing.

[0026] As a further technical solution, a circular hole is provided in the middle of the segment shell near the center of the grinding wheel base, which is connected to the interior of the fan-shaped cavity. A sealing air nozzle is fixedly provided at the circular hole to perform vacuum leak detection on the fan-shaped cavity, and the fan-shaped cavity is vacuumed after the leak detection. A rubber air nozzle plug is provided at the sealing air nozzle for sealing.

[0027] As a further technical solution, a rubber gasket is arranged between the heat storage node and the grinding wheel base; and an abrasive layer is fixed on the outer peripheral surface of the heat storage node.

[0028] As a further technical solution, the heat storage node is fan-shaped, and multiple heat storage nodes are installed around the periphery of the grinding wheel base; the node shell is provided with a positioning protrusion, and a groove is provided on the outside of the grinding wheel base to connect with the positioning protrusion.

[0029] As a further technical solution, a grinding wheel guard is installed on the outside of the phase change heat storage grinding wheel, and a lubricating component is fixed on the outside of the grinding wheel guard; the lubricating component includes a compressed air delivery pipe and a grinding fluid delivery pipe, and the bottoms of the compressed air delivery pipe and the grinding fluid delivery pipe are both connected to the lubrication nozzle, and the lubrication nozzle extends between the phase change heat storage grinding wheel and the workpiece; the compressed air delivery pipe is externally connected to a compressed air source, and the grinding fluid delivery pipe is externally connected to a cooling liquid source.

[0030] As a further technical solution, the magnetic workbench includes a suction cup body, the suction cup body has an internal space, a core body is arranged in the internal space of the suction cup body, a coil is wound around the outer periphery of the core body, and a cover plate is arranged on the top of the suction cup body; the cover plate includes S-pole magnetic blocks and N-pole magnetic blocks distributed alternately in sequence, and a magnetic insulating layer is sandwiched between adjacent S-pole magnetic blocks and N-pole magnetic blocks.

[0031] As a further technical solution, both sides of the bottom of the S-pole magnetic block and the N-pole magnetic block are fixed to the N-pole horizontal bar, and the N-pole horizontal bar is fixed to the top of the suction cup body; the S-pole magnetic block is connected to the core body, and a magnetic insulating layer is arranged between the S-pole magnetic block and the N-pole horizontal bar; a lead block is arranged between the bottom of the N-pole magnetic block and the core body to isolate magnetism; N-pole end plates are arranged at both ends of the N-pole horizontal bar, and the bottom of the N-pole end plate is fixed to the suction cup body.

[0032] As a further technical solution, a metal clamp is arranged on the magnetic workbench, and the clamp includes a clamp positioning frame for placing a workpiece; a tangential positioning bolt is passed through one side of the clamp positioning frame to tighten one side of the workpiece; an axial positioning bolt is passed through the other side of the clamp positioning frame to tighten the other side of the workpiece; and a positioning stopper can be arranged between the tangential positioning bolt, the axial positioning bolt and the workpiece.

[0033] The beneficial effects of the present invention are as follows:

[0034] The grinding system of the present invention, the phase change heat storage grinding wheel combines solid-liquid phase change material with the grinding wheel, utilizes the phase change heat absorption process of the phase change material, and uses the grinding wheel in contact with the grinding area to effectively transfer and absorb the heat of the grinding area, filling the gap in the relevant technology.

[0035] The grinding system of the present invention absorbs the heat in the grinding zone through the phase change process of the solid-liquid phase change material in the grinding wheel, thereby increasing the heat destination of the grinding zone, reducing the large-scale use of grinding fluid during grinding, reducing the impact of grinding fluid treatment on workers and harm to the environment, and conforming to the concept of green processing.

[0036] The grinding system of the present invention is provided with heat-conducting fins in the heat storage block, which can play a better role in heat conduction, and can transfer heat to the internal phase change material more quickly, thereby accelerating the transfer of heat in the grinding area; on the other hand, the heat-conducting fins have a relatively large specific heat capacity and have a certain heat storage capacity, and can temporarily store the heat that the phase change material fails to absorb in time inside the heat-conducting fins by heating. In addition, since the solid-liquid phase change material may affect the stability of the grinding wheel rotation after the material phase change, the heat-conducting fins can play a certain role in separation, and evenly distribute the phase change material to each compartment formed between the heat-conducting fins, thereby reducing the possibility of affecting the stability and dynamic balance of the grinding wheel due to the movement of the working medium.

[0037] The grinding system of the present invention has a foam metal sheet built into the grinding wheel. The foam metal has a large specific surface area. The foam metal sheet can increase the contact area between the solid-liquid phase change material and the outer surface of the grinding wheel cavity, which is beneficial to heat transfer. The thermal resistance during the grinding process is small, which is beneficial to the rapid start of the phase change process of the phase change medium in the grinding wheel, effectively conducts the heat in the grinding area, and accelerates the heat conduction speed.

[0038] The grinding system of the present invention is provided with a lubrication component, which combines the phase change heat storage grinding wheel with the micro-lubrication and low-temperature cold air technology. The lubrication component sprays a mist of micro-grinding fluid and low-temperature compressed cold air to the grinding area through a lubrication nozzle, thereby enhancing the lubrication and cooling of the grinding working area and jointly controlling the temperature of the grinding area.

[0039] In the grinding system of the present invention, after the magnetic workbench coil is energized, the core and the coil form an electromagnet with magnetism, and an alternating magnetic pole distribution is formed on the surface of the cover plate. The magnetic flux lines of the magnetic field formed by the electromagnet pass through the core, through the S-pole magnetic block on the cover plate, the workpiece, and then through the N-pole magnetic block on the cover plate and the suction cup body, and finally return to the core to form a complete closed magnetic flux line. The magnetic workbench generates magnetic force through the electromagnetic coil to adsorb and fix the magnetic material, which is convenient for the rapid fixation of the workpiece, reduces the difficulty of clamping, and thus improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0041] Figure 1 It is a solid-liquid phase change heat storage segmented grinding wheel magnetic workbench auxiliary grinding system in an embodiment of the present invention;

[0042] Figure 2 It is a schematic diagram of the interior of a phase change heat storage grinding wheel without an end cover in an embodiment of the present invention;

[0043] Figure 3a A side view of a phase change heat storage grinding wheel in an embodiment of the present invention;

[0044] Figure 3b for Figure 3a Middle AA section view;

[0045] Figure 4 Schematic diagram of the appearance of the phase change heat storage grinding wheel in the embodiment of the present invention;

[0046] Figure 5 for Figure 4 Sectional view of the middle BB part;

[0047] Figure 6 for Figure 5 A partial enlarged schematic diagram;

[0048] Figure 7 An exploded view of the heat storage node structure in the phase change heat storage grinding wheel in an embodiment of the present invention;

[0049] Figure 8 Schematic diagram of a gasket in a phase change heat storage grinding wheel in an embodiment of the present invention;

[0050] Fig. 9 Schematic diagram of the explosion of the phase change heat storage grinding wheel in the embodiment of the present invention;

[0051] Fig.10 Schematic diagram of heat conduction principle of phase change heat storage grinding wheel in an embodiment of the present invention;

[0052] Fig.11 for Fig.10 Partial magnification;

[0053] Fig.12 It is a schematic diagram of the manufacturing process of the phase change heat storage grinding wheel in an embodiment of the present invention;

[0054] Fig.13 It is a schematic diagram of the fixture-free operation of the solid-liquid phase change heat storage segmented grinding wheel magnetic worktable auxiliary grinding system in an embodiment of the present invention;

[0055] Fig.14 A schematic diagram of a fixture structure in an embodiment of the present invention;

[0056] Fig.15 This is a schematic diagram of a magnetic workbench in an embodiment of the present invention;

[0057] Fig.16 It is a top view of the magnetic workbench without a cover in an embodiment of the present invention;

[0058] Fig.17a This is a structural diagram of a magnetic workbench cover in an embodiment of the present invention;

[0059] Fig.17b for Fig.17a Middle FF section view;

[0060] Fig.17c for Fig.17a Middle GG section view;

[0061] Fig.17d for Fig.17a Middle CC section view;

[0062] Fig.17e for Fig.17a Middle DD section view;

[0063] Fig.17f for Fig.17a Middle EE section view;

[0064] In the figure: Ⅰ-grinding assembly, Ⅱ-magnetic workbench;

[0065] 1-grinding wheel base, 2-solid-liquid phase change medium, 3-block housing, 4-heat conducting fins, 5-fixing bolts, 6-abrasive layer, 7-foam metal sheet, 8-air nozzle rubber plug, 9-rubber gasket, 10-sealed air nozzle, 11-block cover, 12-washer, 13-phase change heat storage grinding wheel, 14-grinding wheel protective cover, 15-compressed air delivery pipe, 16-grinding fluid delivery pipe, 17-workbench fixing bolts, 18 pipeline fixing block, 19-lubricating nozzle, 20-workpiece, 21-clamp positioning frame, 22-tangential positioning bolts, 23-positioning stopper, 24-axial positioning bolts, 25-suction cup body, 26-cover plate, 27-magnetic insulation layer, 28-coil, 29-core body, 30-N pole horizontal bar, 31-S pole magnetic block, 32-N pole end plate, 33-N pole magnetic block.

[0066] In order to show the positions of various parts, the distances or sizes between them are exaggerated and the schematic diagram is for reference only. DETAILED DESCRIPTION

[0067] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0068] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise explicitly stated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof;

[0069] For the convenience of description, if the words "up", "down", "left" and "right" appear in the present invention, they only indicate that they are consistent with the up, down, left and right directions of the drawings themselves, and do not limit the structure. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0070] Terminology explanation section: If the terms "install", "connected", "connect", "fixed" and the like appear in the present invention, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements, or an interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0071] Example 1

[0072] In a typical embodiment of the present invention, Figure 1 As shown, a solid-liquid phase change heat storage segmented grinding wheel magnetic worktable assisted grinding system is proposed, which adopts the grinding process in grinding machine processing.

[0073] The grinding system comprises a grinding component I and a magnetic workbench II, wherein the grinding component I is arranged above the magnetic workbench II.

[0074] The main structure of grinding assembly I includes phase change heat storage grinding wheel and lubrication components. Phase change heat storage grinding wheel combines solid-liquid phase change material with grinding wheel, and uses the phase change heat absorption process of phase change material to transfer the heat of grinding area. The lubrication component sprays a mist of grinding fluid and low-temperature compressed cold air to the grinding area through the lubrication nozzle to enhance the lubrication and cooling of the grinding work area and control the temperature of the grinding area.

[0075] Magnetic workbench II mainly includes a suction cup body, a coil, a core body and a cover plate. The magnetic workbench generates magnetic force through the electromagnetic coil to adsorb and fix the magnetic material, which is convenient for the rapid fixation of the workpiece, reduces the difficulty of clamping, and thus improves work efficiency.

[0076] Specifically, Figures 2 to 9 As shown, the phase change heat storage grinding wheel mainly includes: a grinding wheel base 1, a solid-liquid phase change medium 2, a segment housing 3, a heat conducting fin 4, a grinding wheel fixing bolt 5, an abrasive layer 6, a foam metal sheet 7, an air nozzle rubber plug 8, a rubber gasket 9, a sealing air nozzle 10, a segment cover plate 11, a gasket 12, etc.

[0077] Among them, Figure 2 As shown, a mounting hole is provided in the middle of the grinding wheel base 1, and the grinding wheel base is in the shape of a circular ring; the grinding wheel base mainly plays a role in positioning and fixing, and connects the heat storage nodes together to form a grinding wheel. A plurality of heat storage nodes are fixedly arranged on the periphery of the grinding wheel base 1, and the heat storage nodes are in the shape of a fan ring. The plurality of heat storage nodes are installed around the grinding wheel base 1 located in the center, that is, the plurality of heat storage nodes are installed adjacent to each other in sequence on the periphery of the grinding wheel base 1, and the plurality of heat storage nodes are arranged in a ring shape. Mounting positions are evenly distributed on the periphery of the grinding wheel base 1, and the heat storage nodes are fixed to the grinding wheel base 1 by fixing bolts 5 corresponding to the mounting positions.

[0078] The solid-liquid phase change working medium 2 is placed in the cavity inside the heat storage node, and the outer circles of n (n is generally an even number) heat storage nodes constitute a complete outer circle of the grinding wheel.

[0079] In this embodiment, various solid-liquid phase change fluids can be selectively filled, and different processing environments can be adapted according to the different characteristics of the different filled materials. Solid-liquid phase change materials can be mainly divided into organic and inorganic types. Organic materials include paraffin, fatty acids and other materials. Such materials have a lower phase change temperature and can absorb heat more quickly during grinding. With the assistance of processes such as low-temperature cold air with minimal lubrication, a lower grinding temperature can be maintained to meet the processing requirements of some special materials. Inorganic materials include low-melting point alloys, hydrated salts and hydroxides. Such phase change materials have a higher phase change temperature than organic materials and are more practical for materials that do not require strict processing temperatures.

[0080] Combination Figure 2-Figure 4 , Figure 7 , the structural composition of the phase change heat storage grinding wheel is explained in detail.

[0081] The phase change heat storage grinding wheel includes a grinding wheel base 1, and a plurality of heat storage nodes are arranged on the periphery of the grinding wheel base 1. The heat storage node includes a node shell 3, and the node shell 3 is made of alloy materials such as steel, aluminum alloy, and titanium alloy, which ensures the overall strength and stability of the grinding wheel. Four positioning protrusions are processed on the top of the node shell 3, which are used to better and more accurately fix the node shell 3 on the grinding wheel base 1. The four tangential inner wall surfaces of the positioning protrusions and the contact surface of the grinding wheel base 1 are clearance-matched to ensure the precise positioning of the heat storage node. The grinding wheel base 1 is correspondingly provided with a groove adapted to the positioning protrusion, the positioning protrusion is placed in the groove, and the positioning protrusion of the node shell 3 is fixed to the groove of the grinding wheel base 1 by a fixing bolt 5. The roughness of the contact surface between the node shell and the grinding wheel base is kept within Ra3.2μm, and the flatness error is controlled within 0.05mm, which is convenient for accurate fixing of the node. Through holes and countersunk holes are provided on the positioning protrusions for radially fixing the heat storage node and the grinding wheel base 1.

[0082] The segment housing 3 is processed with a fan-shaped cavity from one end for placing the solid-liquid phase change medium 2, and a sink is processed around the edge of the cavity for installing the segment cover plate 11. That is, the segment housing 3 has a fan-shaped cavity, and the segment housing 3 has an opening corresponding to one end of the fan-shaped cavity, and the segment cover plate 11 is installed at the opening to close the opening. The segment housing and the cover plate are welded together, and laser welding technology is used to reduce the influence of residual stress on the grinding wheel and improve welding accuracy.

[0083] The block housing 3 is provided with a heat conducting fin 4 on one side close to the grinding wheel center, and the heat conducting fin 4 is fixed to the block housing 3 by welding. Specifically, a plurality of heat conducting fins 4 are fixedly arranged in the fan-shaped cavity of the block housing 3 of each heat storage block, and the heat conducting fin 4 is fixed in the fan-shaped cavity on one side close to the grinding wheel center.

[0084] The heat-conducting fins 4 are arranged radially along the grinding wheel base 1 , and adjacent heat-conducting fins 4 are arranged at intervals, and the solid-liquid phase change medium 2 is filled between adjacent heat-conducting fins 4 of the fan-shaped cavity.

[0085] Since the thermal conductivity of the phase change material itself is relatively low, the heat-conducting fins 4 can play a better role in heat conduction, and can transfer heat to the internal phase change material faster, thereby accelerating the transfer of heat in the grinding area. On the other hand, the heat-conducting fins 4 themselves are made of high thermal conductivity materials such as copper alloys, and have a relatively large specific heat capacity. They have a certain heat storage capacity, and can temporarily store the heat that the phase change material fails to absorb in time in the form of temperature increase inside the heat-conducting fins 4. Moreover, since the solid-liquid phase change material is used, the material may affect the stability of the grinding wheel rotation after the phase change to liquid, and the heat-conducting fins 4 can play a certain role in separation, and evenly distribute the phase change material to each compartment formed between the heat-conducting fins 4, thereby reducing the possibility of affecting the stability and dynamic balance of the grinding wheel due to the movement of the working medium.

[0086] Some phase change materials may be corrosive. Depending on the selected material, the grooves, heat conducting fins, cover plates, etc. of the segment housing can be selectively sprayed with a heat conducting anti-corrosion layer to increase the service life of the grinding wheel.

[0087] In this embodiment, the thermal fins 4 are laser welded to the inner side of the fan-shaped cavity of the segment housing 3. Laser welding has higher welding accuracy and less residual stress. A certain gap is reserved between the thermal fins and the outer circular surface of the cavity. The gap size can be 3-5mm for placing the foam metal sheet.

[0088] A foam metal sheet 7 is placed on the outside of the fan-shaped cavity of the segment housing 3. The foam metal sheet 7 is made of materials such as foam copper. The foam metal sheet 7 is fixed in the gap formed by the heat-conducting fins 4 and the outer side of the fan-shaped cavity, and is fixed using a heat-conducting structural adhesive. One end of the foam metal sheet 7 contacts the heat-conducting fins 4, and the other end contacts the segment housing 3. The presence of the foam metal sheet 7 can increase the contact area between the solid-liquid phase change material and the outer surface of the grinding wheel cavity, and better transfer heat with the heat-conducting fins 4. At the same time, after the grinding wheel is used for the first time, some solid-liquid phase change medium will remain in the gap of the foam metal sheet 7. By utilizing the large specific surface area of ​​the foam metal, the next time grinding work is performed, the phase change medium can quickly begin to change phases, thereby accelerating the heat absorption rate.

[0089] A circular hole is provided in the middle of one side of the segment housing 3 near the center of the grinding wheel base 1, which is connected to the inside of the fan-shaped cavity, and a sealing air nozzle 10 with an outer diameter of 5-10 mm is welded at the circular hole. The sealing air nozzle 10 and the segment cover plate 11 are fixed by laser welding. The tightness of the welding needs to be ensured, and the cavity surrounded by the segment housing 3 and the segment cover plate 11 is vacuum leak-tested through the sealing air nozzle 10. When the leakage rate of the cavity satisfies S<0.2%, the sealing of the cavity meets the requirements, otherwise the sealing is improved by leak-testing and repairing the weld.

[0090] The leakage rate is calculated as follows:

[0091]

[0092] Where: S is the leakage rate, P1 is the system pressure at the beginning of the experiment, Pa; P2 is the system pressure after the end of the experiment, Pa; t1 is the system temperature at the beginning of the experiment, K; t2 is the system temperature after the end of the experiment, K.

[0093] After the heat storage block meets the sealing requirements, it is evacuated to reduce the pressure on the inside of the grinding wheel caused by the volume change of the working medium during phase change. After reaching the vacuum state, the sealing air nozzle 10 is sealed with the air nozzle rubber plug 8.

[0094] like Fig. 9As shown, the grinding wheel base 1 is made of alloy material, and a circle of grooves is processed on the outside of the grinding wheel base. The grooves are evenly distributed with the base axis as the center, and correspond to the positioning protrusions of the segment housing 3. The tangential surface of the groove needs to ensure high processing accuracy, so that the two contact surfaces are guaranteed to be a clearance fit, ensuring the tangential and precise positioning of the heat storage segment. An axial through hole is processed in the groove of the grinding wheel base 1, and threads are processed along the two plane directions of the grinding wheel, which are used for the fixed connection between the heat storage segment and the grinding wheel base 1. According to the size of the sealing air nozzle 10, a circle of blind holes is processed at the center of the outer cylindrical surface of the grinding wheel base 1 from the tangent surface to the center of the circle to accommodate the sealing air nozzle 10, and the depth of the blind hole is consistent with the sealing air nozzle 10, which can assist in fixing the rubber plug 8 and effectively prevent the rubber plug 8 from falling out when the pressure in the grinding wheel cavity increases.

[0095] like Figure 5 , Figure 6 , the heat storage block and the grinding wheel base 1 pass through The countersunk hexagon socket bolt (i.e., fixing bolt 5) is used to fix it, and washers 12 are used when bolting to effectively prevent the bolts from loosening. A rubber gasket 9 is placed between the heat storage node and the grinding wheel base 1. On the one hand, the two contact surfaces are not in direct contact, reducing the difficulty of processing; on the other hand, the elasticity of the rubber gasket 9 and the bolt form a set of antagonistic forces to maintain a stable connection between the heat storage node and the grinding wheel base 1.

[0096] like Figure 5 The outer surface of the grinding wheel composed of the heat storage block (i.e. the outer peripheral surface of the heat storage block) is fixed with an abrasive layer 6 by brazing or electrolysis. The abrasive layer 6 is made of abrasives with high thermal conductivity such as diamond or cubic boron nitride, which is conducive to the rapid transfer of heat in the grinding area.

[0097] like Fig.10 The heat flow of the grinding wheel during operation is shown. The heat generated during grinding is transferred to the segment shell 3 of the grinding wheel through the abrasive layer, and then directly transferred to the solid-liquid phase change medium 2 through the foam metal sheet. When the phase change temperature is reached, the phase change of the medium is caused. During the heat transfer process, the thermal conductivity of the segment shell 3 is:

[0098]

[0099] Where: K——thermal conductivity of grinding wheel segment shell; λ s ——Heat transfer coefficient of segment shell material; D——outer diameter of grinding wheel; D1——outer diameter of segment shell cavity.

[0100] The phase change enthalpy of the phase change working fluid has different heat storage capacity according to the different phase change materials selected. Since the solid-liquid phase change changes from solid phase to liquid phase during the phase change process, the phase change process is complicated, so many numerical models need to be established to obtain accurate results. Based on the LB model, the numerical model of solid-liquid phase change enthalpy is briefly described:

[0101] The conservation equations describing the mass, momentum, and energy transfer of phase change materials by assuming Newtonian, laminar, and incompressible flow are:

[0102]

[0103] Where: ρ——phase change material density; C P ——Specific heat under constant pressure; k——Material thermal conductivity; μ——Material dynamic viscosity; u——Phase change material velocity; T——Temperature; p——Pressure; t——Unit time; x——Coordinate distance; F——Force term; q——Heat source term.

[0104]

[0105] Where: ΔH——latent heat enthalpy of phase change;

[0106] ΔH=h sl ψ (7);

[0107] Where: h sl ——latent heat of solid-liquid phase change; ψ——liquid phase fraction.

[0108] The total enthalpy of phase change is:

[0109] H=C P T+ΔH=C P T+h sl ψ (8).

[0110] like Fig.13 The system status during operation is shown. Lubrication components are arranged on the outside of the grinding wheel to assist the phase change heat storage grinding wheel in controlling the temperature of the grinding area.

[0111] Specifically, a grinding wheel guard 14 is installed on the outer side of the phase change heat storage grinding wheel 13 to block the splashing grinding chips and cutting fluid. The lubrication component of the system is installed on the grinding wheel guard 14. The lubrication component adopts low-temperature cold air micro-lubrication. The compressed air delivery pipe 15 and the grinding fluid delivery pipe 16 are fixed on the pipeline fixing block 18, and the pipeline fixing block 18 is fixed on the outer side of the grinding wheel guard 14.

[0112] The bottoms of the compressed air delivery pipe 15 and the grinding fluid delivery pipe 16 are both connected to the lubrication nozzle 19, and the lubrication nozzle 19 extends between the phase change heat storage grinding wheel 13 and the workpiece 20. Compressed low-temperature air and a trace amount of grinding fluid enter the lubrication nozzle 19 through the compressed air delivery pipe 15 and the grinding fluid delivery pipe 16 respectively, and are accelerated after being mixed in the lubrication nozzle 19, and are sprayed into the grinding area between the phase change heat storage grinding wheel 13 and the workpiece 20 in the form of low-temperature spray.

[0113] The compressed air delivery pipe 15 is connected to an external compressed air source, and the grinding fluid delivery pipe 16 is connected to an external coolant source. The coolant source can be realized by a coolant storage tank combined with a coolant pump, and the pressure cold air source can be realized by an air compressor, a low-temperature cold air jet machine, etc.

[0114] Furthermore, the magnetic workbench II is placed correspondingly below the phase change heat storage grinding wheel 13, and the magnetic workbench II is used to fix the workpiece 20. Magnetic materials can be directly adsorbed on the workbench by the magnetic force of the magnetic workbench for processing, but some non-magnetic materials or irregularly shaped workpieces require auxiliary clamping with a fixture. The magnetic workbench II is fixed to the base by the workbench fixing bolts 17.

[0115] like Fig.14 As shown in the figure, it is a structural diagram of the clamp of this embodiment, and the clamp is composed of a clamp positioning frame 21, a tangential positioning bolt 22, an axial positioning bolt 24 and a positioning block 23. All parts of the clamp are made of metal materials and can be directly adsorbed on the magnetic workbench. The clamp can be selectively used on the magnetic workbench as needed.

[0116] The fixture positioning frame 21 is a frame-shaped structure, which can be placed in and fixed to the workpiece 20. A tangential positioning bolt 22 is provided on one side of the fixture positioning frame 21, and the tangential positioning bolt 22 is inserted into the fixture positioning frame 21 to tighten one side of the workpiece 20; an axial positioning bolt 24 is provided on the other side of the fixture positioning frame 21, and the axial positioning bolt 24 is inserted into the fixture positioning frame 21 to tighten the other side of the workpiece 20. The tangential positioning bolt 22 and the axial positioning bolt 24 are arranged vertically in space to position and clamp the workpiece in two directions.

[0117] The tangential positioning bolt 22 and the axial positioning bolt 24 are both made of two positioning bolts, and the fixture positioning frame 21 is processed with threads. The positioning of the workpiece is controlled by controlling the tightening, loosening and screwing distance of the bolts. If the positioning bolt is not long enough or further precise positioning is required, the positioning block 23 can be used to assist in positioning. When using the positioning block 23, place the positioning block 23 between the corresponding positioning bolt and the workpiece 20.

[0118] like Fig.15The working principle diagram of the magnetic workbench. The magnetic workbench in this embodiment is an electromagnetic magnetic workbench, which is based on the magnetic effect of electric current. The magnetic workbench includes a suction cup body 25, a cover plate 26, a magnetic insulation layer 27, a coil 28, and a core body 29. Among them, the core body 29 is made of stacked silicon steel sheets, which is used to constrain and gather the magnetic field, and the coil 28 is wound around the outside to generate an electromagnetic field. The core body 29 and the coil 28 are placed in the internal space of the suction cup body 25, and a cover plate 26 is set on the top of the suction cup body 25. The cover plate 26 is also provided with a magnetic insulation layer 27. The gap between the cover plates is lead-cast to constrain the direction of the magnetic flux lines. The cover plate and the suction cup body are connected and fixed by hexagonal bolts.

[0119] After the coil is energized, the core 29 and the coil 28 form an electromagnet with magnetism, and an alternating magnetic pole distribution is formed on the surface of the cover plate 26. The magnetic flux lines of the magnetic field formed by the electromagnet pass through the core 29, through the S-pole magnetic block and the workpiece 20 on the cover plate 26, and then through the N-pole magnetic block and the suction cup body 25 on the cover plate 26, and finally return to the core 29 to form a complete closed magnetic flux line. Among them, the magnetic insulation layer 27 has the function of isolating the magnetic field, so that most of the magnetic flux lines start from the S-pole magnetic block, pass through the workpiece 20, and then pass through the N-pole magnetic block, and return to the suction cup body 25 and the core 29 to form a closed magnetic flux line, and cannot directly go back from the cover plate. The magnetic insulation layer is made of Babbitt alloy non-magnetic material, and the width c is generally 2-4mm. It is clamped between the N-pole magnetic block and the S-pole magnetic block of the cover plate, dividing the cover plate into a state where the N-pole magnetic block and the S-pole magnetic block are alternately distributed.

[0120] It should be noted that Fig.15 The magnetic workbench is simplified to illustrate the principle of the magnetic workbench, and does not limit the specific arrangement of the structure. For example, the arrangement of the magnetic insulation layer 27 is not based on Fig.15 To set in the form, press Figure 17a-Figure 17c Make specific settings in the form.

[0121] Fig.16 The magnetic workbench is a partial structural diagram of the plate body, which is mainly composed of a suction cup body 25, a coil 28 and a core body 29. The coil 28 is wound on the core body 29 and poured with paint, and then placed in the coil groove in the suction cup body 25. The entire magnetic workbench is only equipped with a set of core body 29 and coil 28. The size of the core body 29 is a1×b1, where a1 is the core body width and b1 is the core body length; Fig.15 As shown, there is a certain tiny gap between the coil 28 and the core 29, a gap of size a is left between the coil 28 and the cover plate, and a gap of size b is left between the coil 28 and the coil slot. The sizes of a and b are both 4-8 cm, in preparation for pouring asphalt.

[0122] The size of the coil slot is a2×b2, where a2 is the width of the coil slot and b2 is the length of the coil slot. The size of the coil slot is determined by the number of turns of the designed coil and the diameter of the wire. The size of the suction cup body 25 is a3×b3, where a3 is the width of the suction cup body and b3 is the length of the suction cup body. The outer ring of the suction cup body 25 is processed with a certain number of threaded holes for connection with the cover plate.

[0123] Figure 17a-17f The structure diagram of the magnetic workbench cover is mainly composed of an insulating layer 27, an N-pole horizontal bar 30, an S-pole magnetic block 31, an N-pole end plate 32, and an N-pole magnetic block 33. The S-pole magnetic block 31 and the N-pole magnetic block 33 are alternately distributed and welded on the N-pole horizontal bar 30. The two ends of the N-pole horizontal bar 30 are N-pole end plates 32. An insulating layer 27 is sandwiched between each magnetic block to separate the two-pole magnetic blocks, so that the cover structure presents an alternating distribution of N poles and S poles. The width of the N-pole end plate 32 is h1, the width of the S-pole magnetic block 31 is h2, and the width of the N-pole magnetic block 33 is h3. The size relationship between the three is:

[0124] The N-pole horizontal bar 30 is disposed on both sides of the bottom of the cover plate, and the S-pole magnetic block 31 and the N-pole magnetic block 33 are both fixed to the N-pole horizontal bar 30. The N-pole horizontal bar 30 is fixed to the top of the suction cup body 25.

[0125] like Fig.17d As shown, combined Fig.15 As shown, the S-pole magnetic block 31 is only connected to the core 29, and is separated from the N-pole horizontal bar 30 by a magnetic insulation layer. That is, the bottom of the S-pole magnetic block 31 is connected to the core 29, and a magnetic insulation layer is set between the S-pole magnetic block 31 and the N-pole horizontal bar 30.

[0126] like Fig.17e As shown, the N-pole terminal plate 32 is connected to the N-pole horizontal bar 30 , and the N-pole terminal plate 32 is located at both ends of the cover plate, and the bottom thereof is fixed to the suction cup body 25 .

[0127] like Fig.17f As shown, combined Fig.15 As shown in FIG. 1 , the N-pole magnetic block 33 is only connected to the N-pole horizontal bar 30, and is further connected to the chuck body 25. That is, both sides of the bottom of the N-pole magnetic block 33 are connected to the N-pole horizontal bar 30, and are further connected to the chuck body 25; a lead block is set between the middle of the bottom of the N-pole magnetic block 33 and the core body 29 to isolate the magnetism, as shown in FIG. Fig.17f The fully filled section in the middle is lead-cast.

[0128] Since both ends of the cover plate are N pole end plates 32 , the number of the N pole magnetic blocks 33 in the middle is an even number, and the number of the S pole magnetic blocks 31 is an odd number.

[0129] Example 2

[0130] like Fig.12 As shown, the manufacturing process of the phase change heat storage grinding wheel of the present invention is:

[0131] 1. Use alloy materials to process the grinding wheel base, segment housing and segment cover;

[0132] 2. Use laser welding to weld the heat conducting fins into the fan-shaped cavity of the segment housing;

[0133] 3. Place the foam metal sheet in the gap between the outer side of the fan-shaped cavity of the segment housing and the heat-conducting fins and fix it with heat-conducting structural adhesive;

[0134] 4. Put equal amounts of solid-liquid phase change working fluid into the compartments divided by the heat conducting fins;

[0135] 5. Laser weld the node cover plate and the sealing gas nozzle to the node shell, and check the air tightness of the heat storage node through the sealing gas nozzle. If the air tightness does not meet the standard, repair the node cover plate and the sealing gas nozzle;

[0136] 6. Finish the heat storage node until the size and surface quality are qualified, then check the air tightness, and repeat the above steps until the air tightness is qualified;

[0137] 7. Evacuate the heat storage node and plug the sealing air nozzle with the air nozzle rubber plug;

[0138] 8. Assemble and fix the heat storage segment and the grinding wheel base, and process the outer cylindrical surface of the grinding wheel composed of the heat storage segment to make the outer cylindrical surface round;

[0139] 9. Use electrolysis or brazing to machine an abrasive layer on the outer circle of the grinding wheel;

[0140] 10. Perform dynamic balancing on the grinding wheel until it meets the requirements, thus completing the preparation of the phase change heat storage grinding wheel.

[0141] The specific working principle and working process of the grinding system of the present invention are as follows:

[0142] Temperature control in the grinding zone has always been an important research topic for relevant workers. In-depth research has been conducted from multiple aspects, such as abrasive tools, workpieces, cutting fluids, and the application of multi-energy fields. However, the surface quality of the machined surface is often not ideal during the machining process. The influence of temperature during grinding is multifaceted, including the impact on the surface quality and dimensional accuracy of the workpiece, the generation of residual stress, the impact on the performance and service life of the abrasive tools, and the increase in energy consumption. Therefore, it is necessary to continuously combine new methods to control the temperature of the grinding zone.

[0143] The grinding system of the present invention applies solid-liquid phase change materials to grinding wheels, combines and designs phase change heat storage grinding wheels, and utilizes the characteristics of solid-liquid phase change materials that produce phase change reactions when reaching phase change temperature, converting from solid to liquid and absorbing heat, to transfer heat from the grinding area. The grinding system is provided with a lubrication nozzle at the working position of the grinding wheel, combined with micro-lubrication technology and low-temperature cold air technology to assist in controlling the temperature of the grinding area. The system's workbench adopts a magnetic workbench, which effectively reduces the difficulty of clamping the workpiece and improves the processing efficiency of the grinding work.

[0144] Before the grinding work begins, the surface of the magnetic worktable is first cleaned with compressed air to prevent grinding chips from affecting the fixation and positioning of the workpiece 20 .

[0145] For magnetically adsorbable workpieces 20, they are directly placed on the magnetic workbench. For magnetically non-adsorbable workpieces, they must first be clamped by a fixture, and the workpiece 20 is placed in the fixture positioning frame 21. The tangential positioning bolts 22 and axial positioning bolts 24 are adjusted to tighten the bolts against the workpiece, and the tightness of each bolt is adjusted to balance the force on the workpiece. If the positioning bolts are not fixed sufficiently, the positioning block 23 can be used for auxiliary clamping. After clamping, the whole is placed on the magnetic workbench.

[0146] After the workpiece 20 is placed, the power supply of the magnetic workbench is started. After the current passes through the coil 28, under the magnetic effect of the current, it forms a complete electromagnet with the core 29. During the working process, the working state of the magnetic workbench can be controlled by the on-off current, and the magnetic force of the magnetic workbench, that is, the size of the attraction to the workpiece 20, can be controlled by the magnitude of the current. After the magnetic workbench is started, the magnetic field formed by the electromagnet, most of the magnetic flux lines, under the constraint of the core, start from the core 29 at the center of the coil 28 and pass through the S-pole magnetic block 31. Since there is a magnetic insulation layer 27 between the N-pole magnetic block 33 and the S-pole magnetic block 31, the magnetic flux lines cannot directly enter the N-pole magnetic block 33 from the cover plate 26, but start from the S-pole magnetic block 31, cross the magnetic insulation layer 27, pass upward through the workpiece 20 or the fixture on the workbench, and then return to the N-pole magnetic block 33, and pass through the suction cup body 25 in contact with the N-pole magnetic block 33 from the bottom of the workbench back to the core 29, forming a closed magnetic flux line. Because the magnetic lines of force pass through the workpiece, the workpiece also becomes magnetic.

[0147] After the workpiece is fixed, align the grinding assembly with the workpiece 20. Connect the compressed air delivery pipe 15 fixed to the grinding wheel guard by the pipeline fixing block 18 to the low-temperature cold air jet machine as the compressed air source, and connect the grinding fluid delivery pipe 16 to the coolant pump as the grinding fluid source. After aligning the lubrication nozzle 19 with the working area, start the low-temperature cold air jet machine and the coolant pump, and the low-temperature cold air and the grinding fluid reach the lubrication nozzle 19 through the compressed air delivery pipe 15 and the grinding fluid delivery pipe 16 respectively. The grinding fluid becomes mist under the impact of the low-temperature cold air, and is accelerated in the lubrication nozzle 19, so that the mist of trace grinding fluid and low-temperature cold air is sprayed into the grinding working area, which plays a role in lubrication and cooling.

[0148] Start the grinding wheel, wait for the grinding wheel speed to stabilize, adjust the grinding wheel to the pre-processing position, and start grinding. After grinding, turn off the grinding wheel, move away from the workpiece, and turn off the low-temperature cold air jet machine and coolant pump. Turn off the power of the magnetic workbench, demagnetize the workpiece, and remove the workpiece. For the used grinding wheel, try to lay it flat, which is conducive to the uniform dispersion and cooling of the phase change working fluid, and can effectively prevent the problem of dynamic imbalance of the grinding wheel.

[0149] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A solid-liquid phase change heat storage segment grinding wheel magnetic workbench auxiliary grinding system, characterized in that: The invention comprises a grinding assembly, which is placed above a magnetic workbench; the grinding assembly comprises a phase-change heat storage grinding wheel, which comprises a grinding wheel base, and a plurality of heat storage nodes are fixedly arranged on the periphery of the grinding wheel base; the heat storage node comprises a node shell, which has a fan-shaped cavity, and a plurality of heat-conducting fins are fixedly arranged in the fan-shaped cavity, and a solid-liquid phase-change working medium is filled between adjacent heat-conducting fins; The segment housing is connected to the segment cover plate to close the fan-shaped cavity; the heat-conducting fins are fixed to one side of the fan-shaped cavity close to the center of the grinding wheel base; the heat-conducting fins are arranged along the radial direction of the grinding wheel base, and adjacent heat-conducting fins are arranged at intervals; A foam metal sheet is arranged outside the fan-shaped cavity, one end of the foam metal sheet contacts the heat-conducting fin, and the other end contacts the segment housing; The heat storage node is fan-shaped, and a plurality of heat storage nodes are installed around the outer periphery of the grinding wheel base; the node shell is provided with a positioning protrusion, and a groove is provided on the outer side of the grinding wheel base to connect with the positioning protrusion.

2. The grinding system according to claim 1, characterized in that: A circular hole is arranged in the middle of one side of the segment shell close to the center of the grinding wheel base body, which is communicated with the interior of the fan-shaped cavity. A sealing air nozzle is fixedly arranged at the circular hole to perform vacuum leak detection on the fan-shaped cavity. After the leak detection, the fan-shaped cavity is vacuumed. A rubber air nozzle plug is arranged at the sealing air nozzle for sealing.

3. The grinding system according to claim 1, characterized in that: A rubber gasket is arranged between the heat storage node and the grinding wheel base; and an abrasive grain layer is fixed on the outer peripheral surface of the heat storage node.

4. The grinding system according to claim 1, characterized in that: A grinding wheel protection cover is installed on the outside of the phase change heat storage grinding wheel, and a lubricating component is fixed on the outside of the grinding wheel protection cover; the lubricating component includes a compressed air delivery pipe and a grinding fluid delivery pipe, the bottoms of the compressed air delivery pipe and the grinding fluid delivery pipe are both connected to the lubrication nozzle, and the lubrication nozzle extends between the phase change heat storage grinding wheel and the workpiece; the compressed air delivery pipe is externally connected to a compressed air source, and the grinding fluid delivery pipe is externally connected to a cooling liquid source.

5. The grinding system according to claim 1, characterized in that: The magnetic workbench includes a suction cup body, which has an internal space. A core body is arranged in the internal space of the suction cup body, a coil is wound around the outer periphery of the core body, and a cover plate is arranged on the top of the suction cup body; the cover plate includes S-pole magnetic blocks and N-pole magnetic blocks distributed alternately in sequence, and a magnetic insulation layer is sandwiched between adjacent S-pole magnetic blocks and N-pole magnetic blocks.

6. The grinding system according to claim 5, characterized in that: Both sides of the bottom of the S-pole magnetic block and the N-pole magnetic block are fixed to the N-pole horizontal bar, and the N-pole horizontal bar is fixed to the top of the suction cup body; the S-pole magnetic block is connected to the core body, and a magnetic insulation layer is arranged between the S-pole magnetic block and the N-pole horizontal bar; a lead block is arranged between the bottom of the N-pole magnetic block and the core body to isolate magnetism; N-pole end plates are arranged at both ends of the N-pole horizontal bar, and the bottom of the N-pole end plate is fixed to the suction cup body.

7. The grinding system according to claim 1, characterized in that: A metal clamp is arranged on the magnetic workbench, and the clamp comprises a clamp positioning frame into which a workpiece can be placed; a tangential positioning bolt is passed through one side of the clamp positioning frame to tighten one side of the workpiece; an axial positioning bolt is passed through the other side of the clamp positioning frame to tighten the other side of the workpiece; positioning blocks are arranged between the tangential positioning bolt, the axial positioning bolt and the workpiece.

Images