A pps plate grinding process

Abstract

The application discloses a pps plate grinding process and relates to the field of precise material processing. The pps plate grinding process adopts a wide sand belt to replace traditional grinding tools to grind the pps plate, a ladder grinding scheme with a grinding time as a scheme expected control benchmark is designed, and the mesh span of multiple sand belt grinders and the speed adjustment control of the sand belt are designed according to different plate grinding amounts, so that small-amplitude fine grinding is realized, the time error is small, in each grinding stage, double-sided alternating grinding is realized, the thickness is detected by using a sensor, the thickness gradually approaches the preset value, the machining precision is high, over-grinding is avoided, the continuous grinding is avoided to prevent the plate surface from being damaged due to heat melting, and when the wide sand belt is ground, a swing module is used to make the grinding traces more random, elastic downward pressing is realized to realize mean value grinding, and the pps plate grinding speed and precision are improved.

Description

Technical Field

[0001] This invention relates to the field of precision material processing technology, specifically a PPS plate grinding process. Background Technology

[0002] In the PCB board testing process, the pin fixture is a key tool, and its core component is PPS board. Due to the excellent dimensional stability, high temperature resistance and insulation of PPS material, it has become the preferred material for manufacturing such fixtures. However, commercially available imported PPS boards are usually only available in standard thickness, while fixture manufacturing requires a variety of thinner specifications.

[0003] Currently, the closest existing technology in the industry is to use CNC milling machines for thinning. This involves fixing the PPS sheet to the milling machine table using a pressure plate or vacuum adsorption, then using a small-diameter milling cutter to perform single-sided milling with a very small depth of cut. After completing one milling cycle on one side, the sheet is removed, flipped, and refixed. The other side is then milled with the same parameters, and finally, double-sided milling is completed. Finally, the sheet is ground. This technical solution is widely used in existing production practices, but it has the following technical problems.

[0004] 1. Extremely low processing efficiency and high cost: Since the milling cutter only cuts to a depth of 0.02mm each time and needs to be flipped frequently, it takes about 10 hours to process a 500mm×500mm×6mm plate to a thickness of 1.5mm. The processing cost (mainly equipment depreciation, labor and tool wear) is as high as 900 yuan, which is even higher than the cost of raw materials (800 yuan). The fundamental reason is that milling is a "point-line-surface" processing method, with a small contact area between the tool and the material and a low material removal rate.

[0005] 2. Secondary defects (tool marks) exist, affecting subsequent processes: Milling inevitably leaves microscopic, directional, periodic tool marks on the surface of the sheet metal. These tool marks disrupt the surface homogeneity, causing the subsequent micro-drill bit to deviate in positioning (hole deviation) when it contacts the beveled surface of the tool marks, seriously affecting the accuracy of the fixture. To solve this problem, it is necessary to add an additional manual grinding process, further increasing time and labor costs.

[0006] 3. Quality stability relies on human experience and is prone to deformation: Although repeated milling can control stress to some extent, the process still heavily depends on the operator's experience. Even minor inaccuracies in milling parameters or poor timing of flipping can lead to uneven stress release, ultimately causing slight warping of the sheet metal and affecting the flatness of the fixture. The force and uniformity of manual sanding are also difficult to guarantee, potentially introducing new unevenness.

[0007] Therefore, during the research and development process, the feasibility of using belt abrasive technology was considered. After studying the belt abrasive technology, it was found that during belt abrasive ...

[0008] However, due to the unique characteristics of PPS materials, there is a lack of practical application precedents. When using belt grinding, there is a lack of corresponding implementation plans for the grinding speed, pressure, grinding time, belt mesh size design, and grinding cycle control. As a result, the traditional belt grinding process often results in over-grinding, inconsistent grinding effects across the entire board, and heat accumulation caused by belt grinding, leading to thermal deformation of PPS boards. To solve the above problems, a PPS board grinding process is provided. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a PPS board grinding process that solves the problems of long cycle time, high cost, and insufficient quality stability in existing PPS board grinding solutions.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a PPS board grinding process, comprising the following steps:

[0011] S1. Clamp the plate, measure the initial thickness, and set the target grinding thickness at the same time;

[0012] S2. The control system automatically sets the stepped grinding scheme according to the target grinding thickness;

[0013] S3. The grinding assembly moves down to grind one side of the board. During the process, the sensor continuously monitors the current thickness of the board. When the first stage grinding thickness is reached, the machine stops and waits for thickness detection.

[0014] S4. Detect the current thickness of the board. Flip the board over to achieve alternating grinding on both sides until both sides reach the first stage of grinding amount.

[0015] S5. Grind step by step according to the preset step grinding scheme until the workpiece thickness reaches the preset grinding effect.

[0016] S6. Reset the grinding assembly and unload the material;

[0017] The grinding assembly includes multiple belt abrasives, and the mesh size of the belt abrasives of the multiple belt abrasives is designed to increase progressively. In the stepped grinding scheme, the number of steps is the same as the number of belt abrasives.

[0018] The grinding assembly adopts an elastic pressing design, which allows the belt abrasive to be elastically pressed against the plate, and the pressure is monitored by a pressure sensor to ensure that the pressure is at a preset value.

[0019] The grinding assembly is equipped with a swing module to make the belt grinder oscillate horizontally during the grinding process, so as to avoid the fixed grinding path causing obvious grinding marks on the board.

[0020] Preferably, the contact area between the belt abrasive and the plate is larger than the plate area, so that the belt abrasive, under the action of the oscillating module, always effectively covers the grinding surface of the plate.

[0021] Preferably, in the stepped grinding scheme, the grinding time is used as the expected control benchmark for the scheme, wherein;

[0022] By designing multiple grinding amount thresholds, including Hmax and Hmin;

[0023] Meanwhile, the belt abrasives are labeled L1, L2, L3...Ln-2, ​​Ln-1, Ln according to their mesh size gradient;

[0024] If the target grinding amount is ≥ Hmax, then among the multiple belt abrasives, the mesh size range of the belts from L1 to Ln-2 is designed to be a large gradient; the mesh size range of the belts from Ln-2 to Ln is designed to be a small gradient, so as to achieve rapid grinding in the early stage.

[0025] If Hmin ≤ target grinding amount ≤ Hmax, then among multiple belt abrasives, the mesh size range of belts from L1 to L2 is designed to be a large gradient; the mesh size range of belts from L2 to Ln is designed to be a small gradient; thus ensuring a uniform grinding effect.

[0026] If the target grinding amount is ≤Hmin, then among multiple belt abrasives, the mesh size span of belts from L1 to Ln is designed as a constant gradient to achieve fine grinding with small amplitude.

[0027] This ensures that the time error of the entire stepped grinding process is controlled within ±20% of the preset time.

[0028] Preferably, the belt abrasive is driven by a servo motor, and the grinding speed of the multiple belt abrasives decreases at different stages to achieve high-speed grinding in the early stage to quickly approach the preset thickness, and low-speed grinding in the later stage to refine the abrasive, avoid over-grinding, and prevent the high temperature caused by high-speed grinding from causing the thermal deformation thickness of the board surface to exceed the final preset grinding thickness.

[0029] Preferably, in step S3, during continuous monitoring of the plate thickness, the sensors include a displacement sensor mounted on the grinding assembly and a laser sensor mounted on the side of the plate. The displacement sensor enables dynamic monitoring of plate thickness changes, while the laser sensor detects vertical height changes at fixed points on the plate during shutdown, reflecting static detection of the average thickness change of the entire plate. Furthermore, by designing a thickness threshold approximation scheme, the accurate thickness value is statically detected through multiple shutdowns within a single grinding stage. As the actual thickness gets closer to the grinding amount of that grinding stage, the shutdown interval is further shortened, thereby avoiding over-grinding.

[0030] Preferably, within a single grinding stage, the plate is alternately ground on both sides, and a single-gradient flipping thickness threshold Hf is designed.

[0031] When the thickness change of the plate during grinding does not reach Hf, the plate is flipped over once each time the machine stops, so as to avoid heat accumulation, deformation and melting caused by continuous grinding.

[0032] When the thickness of the plate reaches Hf during grinding, but does not reach the thickness threshold of that stage, a single-sided intermittent grinding scheme is executed until the thickness on one side reaches the thickness threshold of that stage before flipping the plate. This avoids frequent flipping in the later stages from affecting the processing speed, thereby achieving double-sided gradient grinding of the plate.

[0033] Preferably, the oscillating module drives the grinding component to perform high-frequency, small-amplitude horizontal oscillation motion on the horizontal plane through periodic or non-periodic speed changes. The horizontal oscillation motion breaks any possible fixed relative motion trajectory between the belt abrasive and the plate. In long-term operation, the horizontal oscillation motion can also ensure that the cutting path of the abrasive grains is more complex and random, actively avoiding any form of slight periodic marks caused by the uniformity of the motion trajectory, so as to achieve the ultimate surface uniformity.

[0034] Preferably, the elastic pressure design uses a flexible floating structure for the grinding component pressurization system, employing a cylinder in conjunction with a pressure sensor to achieve constant pressure grinding of the board material, rather than simple rigid displacement control. Since PPS boards may have slight thickness unevenness or flatness errors, constant pressure floating grinding ensures that the grinding head and the board surface always maintain uniform pressure contact, automatically adapting to the slight undulations of the surface. This avoids the situation where high points are over-grinded and low points are not ground under rigid control, achieving uniform material removal across the entire plane and obtaining extremely high flatness consistency.

[0035] Preferably, in step S1, the board is assembled on a processing table with a vacuum adsorption plate. The vacuum adsorption plate is made of a heat-conducting material and has vacuum adsorption holes. A continuous negative pressure vacuum scheme is adopted so that the board after being flipped can be heat-conducted downward through the vacuum adsorption plate into the vacuum negative pressure pipe. The heat is carried away by the continuous negative pressure airflow of the negative pressure pipe, which ensures stable adsorption while quickly removing the heat from the surface of the board.

[0036] Preferably, in step S4, when flipping the board, a robot arm is configured on the processing table, with a rotatable electric suction cup installed at the end of the robot arm. At the same time, a control host is configured on the processing table. The robot arm is moved by the control host, and then the board is flipped and placed on the vacuum suction plate after being adsorbed by the electric suction cup, thereby realizing the flipping process.

[0037] This invention discloses a grinding process for PPS boards, which has the following beneficial effects:

[0038] 1. This PPS board grinding process uses wide-width abrasive belts instead of traditional grinding tools to grind the PPS board. It employs a stepped grinding scheme with grinding time as the expected control benchmark. The number of grinding steps is equal to the number of abrasive belt grinders. Multiple abrasive belt grinders with different grit sizes gradually grind the board to the target thickness in a stepped ring. The grit size of the abrasive belt grinders increases towards the end, resulting in finer grinding. Furthermore, the grit size range of the multiple abrasive belt grinders and the belt speed are adjusted and controlled according to the different grinding volumes of the board, achieving fine grinding with small amplitude adjustments. Even for boards with large grinding volumes, it can achieve standard crystallization processing time, thereby increasing the grinding production speed.

[0039] 2. This PPS board grinding process involves alternating double-sided grinding of the board within a single grinding stage. By designing a single-gradient flipping thickness threshold, the board is flipped once every time the machine stops when the grinding thickness change does not reach the threshold. This avoids heat accumulation that could cause deformation and melting due to continuous grinding. When the grinding thickness change reaches the threshold, a single-sided intermittent grinding scheme is implemented until the thickness on one side reaches the threshold for that stage, at which point the board is flipped again. This avoids frequent flipping later on, which would affect the processing speed. This process achieves double-sided gradient grinding of the board, resulting in uniform grinding on both sides, effectively controlling the amount of grinding, and preventing heat-induced damage to the board surface caused by continuous grinding.

[0040] 3. This PPS board grinding process, based on belt grinding, incorporates an oscillating module. The oscillating module drives the grinding components to perform high-frequency, small-amplitude horizontal oscillation motion on a horizontal plane through periodic or non-periodic speed changes. This horizontal oscillation motion breaks any potentially fixed relative motion trajectory between the belt grinder and the board. During long-term operation, the horizontal oscillation motion also ensures that the cutting path of the abrasive grains is more complex and random, actively avoiding any form of slight periodic marks caused by a uniform motion trajectory, thus achieving the ultimate surface uniformity.

[0041] 4. In this PPS board grinding process, the swing module utilizes an elastic downward pressure design. By designing the grinding component pressurization system as an elastic floating structure and using a cylinder in conjunction with a pressure sensor, constant pressure grinding of the board is achieved. Constant pressure floating grinding ensures that the grinding head and the board surface always maintain uniform pressure contact, automatically adapting to the slight undulations of the surface, avoiding the situation of over-grinding at high points and under-grinding at low points under rigid control, achieving uniform material removal across the entire plane and obtaining extremely high flatness consistency. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flow chart of the PPS board grinding process of the present invention;

[0044] Figure 2 This is a schematic diagram of the actual execution device in the PPS board grinding process of the present invention;

[0045] Figure 3 This is a top view of the grinding components and oscillating module in the PPS board grinding process of the present invention.

[0046] In the diagram: 1. Processing table; 2. Vacuum adsorption plate; 3. Hydraulic lifting platform; 4. Rotary wheel; 5. Belt abrasive grinder; 6. Robotic arm; 7. Laser sensor; 8. Control host; 9. Swing module; 10. Constant pressure cylinder. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] This application provides a PPS board grinding process that solves the problems of long cycle time, high cost and insufficient quality stability in existing PPS board grinding solutions.

[0049] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0050] Example 1: This invention discloses a grinding process for PPS boards, according to the attached... Figures 1 to 2 As shown, it includes the following steps:

[0051] S1. Clamp the plate, measure the initial thickness, and set the target grinding thickness at the same time;

[0052] S2. The control system automatically sets the stepped grinding scheme according to the target grinding thickness;

[0053] S3. The grinding assembly moves down to grind one side of the board. During the process, the sensor continuously monitors the current thickness of the board. When the first stage grinding thickness is reached, the machine stops and waits for thickness detection.

[0054] S4. Detect the current thickness of the board. Flip the board over to achieve alternating grinding on both sides until both sides reach the first stage of grinding amount.

[0055] S5. Grind step by step according to the preset step grinding scheme until the workpiece thickness reaches the preset grinding effect.

[0056] S6. Reset the grinding assembly and unload the material;

[0057] The grinding assembly includes multiple belt abrasives 5, and the mesh size of the belt abrasives 5 is designed to increase progressively. In the stepped grinding scheme, the number of steps is the same as the number of belt abrasives 5.

[0058] The grinding assembly adopts an elastic downward pressure design, which allows the belt abrasive 5 to be elastically squeezed against the plate, and the pressure is monitored by a pressure sensor to ensure that the pressure is at a preset value;

[0059] The grinding assembly is equipped with an oscillating module 9 so that the belt abrasive grinder 5 oscillates horizontally during the grinding process, thereby avoiding the appearance of obvious grinding marks on the board due to a fixed grinding path.

[0060] The contact area between the belt abrasive 5 and the plate is larger than the plate area, so that the belt abrasive 5 can always effectively cover the grinding surface of the plate under the action of the oscillating module 9.

[0061] In the stepped grinding scheme, the grinding time is used as the expected control benchmark of the scheme, where;

[0062] By designing multiple grinding amount thresholds, including Hmax and Hmin;

[0063] Meanwhile, the belt abrasives 5 are labeled L1, L2, L3...Ln-2, ​​Ln-1, Ln according to the mesh size gradient;

[0064] If the target grinding amount is ≥ Hmax, then among the multiple belt abrasives 5, the mesh size range of the belts from L1 to Ln-2 is designed to be a large gradient; the mesh size range of the belts from Ln-2 to Ln is designed to be a small gradient, so as to achieve rapid grinding in the early stage.

[0065] If Hmin≤target grinding amount≤Hmax, then among the multiple belt abrasives 5, the mesh size range of the belts from L1 to L2 is designed to be a large gradient; the mesh size range of the belts from L2 to Ln is designed to be a small gradient; thus ensuring a uniform grinding effect.

[0066] If the target grinding amount is ≤Hmin, then among the multiple belt abrasives 5, the mesh size span of the belts from L1 to Ln is designed as a constant gradient to achieve fine grinding with small amplitude.

[0067] This ensures that the time error of the entire stepped grinding process is controlled within ±20% of the preset time.

[0068] The belt abrasive grinder 5 is driven by a servo motor. The grinding speed of multiple belt abrasive grinders 5 decreases in different stages to achieve high-speed grinding in the early stage to quickly approach the preset thickness, and low-speed grinding in the later stage to refine the abrasive and avoid over-grinding and the high temperature caused by high-speed grinding, which would cause the thermal deformation thickness of the board surface to exceed the final preset grinding thickness.

[0069] In step S3, during continuous monitoring of the plate thickness, the sensors include a displacement sensor mounted on the grinding assembly and a laser sensor 7 mounted on the side of the plate. The displacement sensor enables dynamic monitoring of plate thickness changes, while the laser sensor 7 detects the vertical height change of fixed points on the plate when the machine stops, reflecting the static detection of the average thickness change of the entire plate. Furthermore, by designing a thickness threshold approximation scheme, the accurate thickness value is statically detected through multiple stops within a single grinding stage. When the actual thickness is closer to the grinding amount of that grinding stage, the stop interval is further shortened to avoid over-grinding.

[0070] Within a single grinding stage, the board is alternately ground on both sides, and a single-gradient flipping thickness threshold Hf is designed.

[0071] When the thickness change of the plate during grinding does not reach Hf, the plate is flipped over once each time the machine stops, so as to avoid heat accumulation, deformation and melting caused by continuous grinding.

[0072] When the thickness of the plate reaches Hf during grinding, but does not reach the thickness threshold of that stage, a single-sided intermittent grinding scheme is executed until the thickness on one side reaches the thickness threshold of that stage before flipping the plate. This avoids frequent flipping in the later stages from affecting the processing speed, thereby achieving double-sided gradient grinding of the plate.

[0073] The oscillating module 9 drives the grinding component to perform high-frequency, small-amplitude horizontal oscillation motion on the horizontal plane through periodic or non-periodic speed changes. The horizontal oscillation motion breaks any possible fixed relative motion trajectory between the belt abrasive 5 and the plate. During long-term operation, the horizontal oscillation motion also ensures that the cutting path of the abrasive grains is more complex and random, actively avoiding any form of slight periodic marks caused by the uniformity of the motion trajectory, so as to achieve the ultimate surface uniformity.

[0074] The elastic pressure design uses a flexible floating structure for the grinding component pressurization system, employing a cylinder in conjunction with a pressure sensor to achieve constant pressure grinding of the board material, rather than simple rigid displacement control. Since PPS boards may have slight thickness unevenness or flatness errors, constant pressure floating grinding ensures that the grinding head and the board surface always maintain uniform pressure contact, automatically adapting to the slight undulations of the surface. This avoids the situation of over-grinding high points and under-grinding low points under rigid control, achieving uniform material removal across the entire plane and obtaining extremely high flatness consistency.

[0075] In step S1, the board is assembled with a vacuum adsorption plate 2 on the processing table 1. The vacuum adsorption plate 2 is made of thermally conductive material and has vacuum adsorption holes. A continuous negative pressure vacuum scheme is adopted so that the board after being flipped can be heat-conducted downward through the vacuum adsorption plate 2 into the vacuum negative pressure pipe. The heat is carried away by the continuous negative pressure airflow of the negative pressure pipe, which ensures stable adsorption while quickly removing the heat from the surface of the board.

[0076] In step S4, when flipping the board, a robot arm 6 is configured on the processing table 1. The end of the robot arm 6 is equipped with a rotatable electric suction cup. At the same time, a control host 8 is configured on the processing table 1. The robot arm 6 is moved by the control host 8. Then, the board is flipped and placed on the vacuum suction plate 2 after being adsorbed by the electric suction cup, thereby realizing the flipping process.

[0077] Working Principle: This method proposes a technique to reduce the thickness of PPS sheets by replacing traditional milling cutters with abrasive belts. The theoretical basis of this method is that the surface of the abrasive belt is equivalent to the random action of countless cutting units. The abrasive belt can be regarded as a flexible cutting tool composed of millions or even hundreds of millions of tiny, sharp, and randomly distributed hard abrasive grains, such as silicon carbide or alumina. These abrasive grains, as "micro-cutting edges," have random and disordered geometry, size, and distribution. Furthermore, the wide abrasive belt makes full-area surface contact with the PPS sheet surface. During grinding, countless abrasive grains simultaneously contact the sheet surface, performing a large amount of random, micro-cutting, with a cutting level equivalent to the micrometer level. Due to the randomness of the abrasive grains, the grinding marks left on the sheet surface are disordered, interlaced, and non-directional. These grinding marks are extremely shallow and uniform in depth, and do not form periodic macro-patterns with a dominant direction. The final result is a "matte" surface with a uniform diffuse reflection effect, and its surface contour curve is a uniform undulating micro-grind, rather than a steep tool mark.

[0078] Meanwhile, to further improve surface quality and ensure the complete elimination of any potential uneven wear marks, this solution innovatively introduces technical improvements for PPS grinding:

[0079] First, by designing the belt abrasive grinder 5 as multiple sets of abrasive belts with different mesh sizes, and then setting a stepped grinding scheme according to the required cutting amount of the plate, the number of grinding steps in the scheme is equal to the number of belt abrasive grinders 5. In this way, multiple belt abrasive grinders 5 with different mesh sizes are used to gradually grind the target thickness in a stepped ring, and the mesh size of the belt abrasive grinders 5 that are further back is larger, making the grinding more refined.

[0080] However, the above is only a basic design. Based on this, due to the significant thickness differences between different PPS masterbatches, a uniform stepped grinding scheme would result in excessively long grinding times for materials with large grinding amounts. Therefore, this solution innovatively proposes a stepped grinding scheme with grinding time as the expected control benchmark. Multiple grinding amount thresholds are designed, including Hmax and Hmin. Simultaneously, the belt abrasives 5 are labeled L1, L2, L3…Ln-2, ​​Ln-1, Ln according to their mesh size gradient. If the target grinding amount is ≥ Hmax, then among the multiple belt abrasives 5, L1 to Ln… The abrasive belt mesh size range of L1-2 is designed as a large gradient; the abrasive belt mesh size range from Ln-2 to Ln is designed as a small gradient to achieve rapid grinding in the early stage; if Hmin≤target grinding amount≤Hmax, then among the multiple abrasive belt grinders 5, the abrasive belt mesh size range from L1 to L2 is designed as a large gradient; the abrasive belt mesh size range from L2 to Ln is designed as a small gradient; thus ensuring a balanced grinding effect; if the target grinding amount≤Hmin, then among the multiple abrasive belt grinders 5, the abrasive belt mesh size range from L1 to Ln is designed as a constant gradient to achieve fine grinding with small amplitude; thus ensuring that the time error of the entire stepped grinding scheme is controlled within ±20% of the preset time;

[0081] More importantly, during the entire grinding process, sensors are used to monitor the thickness of the board. Displacement sensors on the grinding assembly and laser sensors 7 installed on the side of the board are used to dynamically monitor changes in the board thickness. Laser sensors 7 are used to detect changes in the vertical height of fixed points on the board when the machine stops, reflecting static detection of changes in the average thickness of the entire board. Furthermore, by designing a thickness threshold approximation scheme, the accurate thickness value is statically detected through multiple stops within a single grinding stage. When the actual thickness is closer to the grinding amount of that grinding stage, the stop interval is further shortened to avoid over-grinding.

[0082] Furthermore, based on the above, the board is alternately ground on both sides within a single grinding stage, and a single-gradient flipping thickness threshold Hf is designed. When the grinding thickness change of the board does not reach Hf, the board is flipped once every time the machine stops, thus avoiding heat accumulation that could cause deformation and melting due to continuous grinding. When the grinding thickness change of the board reaches Hf but does not reach the thickness threshold of that stage, a single-sided intermittent grinding scheme is implemented until the thickness on one side reaches the thickness threshold of that stage before flipping. This avoids frequent flipping in the later stages, which would affect the processing speed, thereby achieving double-sided gradient grinding of the board. This achieves uniform grinding on both sides, effectively controls the amount of grinding, and avoids thermal melting damage to the board surface caused by continuous grinding.

[0083] Furthermore, this solution incorporates a swing module 9. This module drives the grinding assembly to perform high-frequency, small-amplitude horizontal oscillations on a horizontal surface through periodic or non-periodic speed changes. This horizontal oscillation breaks any potentially fixed relative motion trajectory between the belt abrasive 5 and the material. During long-term operation, the horizontal oscillation also ensures that the cutting path of the abrasive grains is more complex and random, actively avoiding any slight periodic marks caused by a uniform motion trajectory, thus maximizing surface uniformity. The swing module 9 utilizes an elastic downward pressure design, making the grinding assembly pressurization system an elastic floating structure. Using a cylinder and pressure sensor, it achieves constant pressure grinding of the material, rather than simple rigid displacement control. Since PPS materials may have slight thickness variations or flatness errors, constant pressure floating grinding ensures that the grinding head maintains uniform pressure contact with the material surface, automatically adapting to minor surface undulations. This avoids over-grinding at high points and under-grinding at low points under rigid control, achieving uniform material removal across the entire plane and obtaining extremely high flatness consistency.

[0084] Example 2, see attached document Figure 2 To be continued Figure 3 This embodiment proposes a PPS board grinding device based on the PPS board grinding process. The device is used to perform the PPS board grinding process. The device includes a processing table 1 and a hydraulic lifting table 3 fixed on one side of the top of the processing table 1. A vacuum adsorption plate 2 is fixedly installed on the surface of the processing table 1. A pressure sensor is embedded on the surface of the vacuum adsorption plate 2. Robot arms 6 are respectively set on both sides of the vacuum adsorption plate 2. A flip-up electric suction cup is installed at the end of the robot arm 6. At the same time, a control host 8 is configured on the processing table 1. The control host 8 is pre-written with a control system. The robot arm 6 is moved by the control host 8. Then, the board is adsorbed by the electric suction cup and flipped and placed on the vacuum adsorption plate 2 to achieve the flipping process. A laser sensor 7 is also installed on one side of the vacuum adsorption plate 2. A rotating wheel 4 is rotatably set on the top of the hydraulic lifting table 3. Multiple ring-shaped abrasive belt grinders 5 are fixedly installed on the surface of the rotating wheel 4. A swing module 9 is installed on one side of the output end of the hydraulic lifting table 3. A constant pressure cylinder 10 is installed between the swing module 9 and the rotating wheel 4. A displacement sensor is also installed on the output end of the hydraulic lifting table 3.

[0085] During use, the rotating wheel 4 rotates, so that the target belt abrasive 5 is vertically downward and facing the board on the vacuum adsorption plate 2. Then, the hydraulic lifting platform 3 descends, so that the belt abrasive 5 comes into contact with the board. At the same time, the pressure sensor and the constant pressure cylinder 10 ensure that the belt abrasive 5 is flexibly squeezed with the board. Then, the belt abrasive 5 and the swing module 9 are started to continuously grind through the belt. At the same time, the swing module 9 makes the entire belt abrasive 5 swing, thereby avoiding the regular grinding marks caused by a fixed path. During the grinding process, the displacement sensor monitors the grinding amount in real time. When it approaches the grinding threshold, the robot arm 6 flips the board to achieve double-sided grinding, and finally completes the double-sided grinding process of the entire PPS board.

[0086] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A grinding process for PPS boards, characterized in that, Includes the following steps: S1. Clamp the plate, measure the initial thickness, and set the target grinding thickness at the same time; S2. The control system automatically sets the stepped grinding scheme according to the target grinding thickness; S3. The grinding assembly moves down to grind one side of the board. During the process, the sensor continuously monitors the current thickness of the board. When the first stage grinding thickness is reached, the machine stops and waits for thickness detection. S4. Detect the current thickness of the board. Flip the board over to achieve alternating grinding on both sides until both sides reach the first stage of grinding amount. S5. Grind step by step according to the preset step grinding scheme until the workpiece thickness reaches the preset grinding effect. S6. Reset the grinding assembly and unload the material; The grinding assembly includes multiple belt abrasives, and the mesh size of the belt abrasives of the multiple belt abrasives is designed to increase progressively. In the stepped grinding scheme, the number of steps is the same as the number of belt abrasives. The grinding assembly adopts an elastic pressing design, which allows the belt abrasive to be elastically pressed against the plate, and the pressure is monitored by a pressure sensor to ensure that the pressure is at a preset value. The grinding assembly is equipped with a swing module to make the belt grinder oscillate horizontally during the grinding process, so as to avoid the fixed grinding path causing obvious grinding marks on the board. In the aforementioned stepped grinding scheme, grinding time is used as the expected control benchmark for the scheme, wherein... By designing multiple grinding amount thresholds, including Hmax and Hmin; Meanwhile, the belt abrasives are labeled L1, L2, L3...Ln-2, ​​Ln-1, Ln according to their mesh size gradient; If the target grinding amount is ≥ Hmax, then among the multiple belt abrasives, the mesh size range of the belts from L1 to Ln-2 is designed to be a large gradient; the mesh size range of the belts from Ln-2 to Ln is designed to be a small gradient, so as to achieve rapid grinding in the early stage. If Hmin ≤ target grinding amount ≤ Hmax, then among multiple belt abrasives, the mesh size range of belts from L1 to L2 is designed to be a large gradient; the mesh size range of belts from L2 to Ln is designed to be a small gradient; thus ensuring a uniform grinding effect. If the target grinding amount is ≤Hmin, then among multiple belt abrasives, the mesh size span of belts from L1 to Ln is designed as a constant gradient to achieve fine grinding with small amplitude. This ensures that the time error of the entire stepped grinding process is controlled within ±20% of the preset time.

2. The PPS board grinding process according to claim 1, characterized in that, The belt abrasive is driven by a servo motor. The grinding speed of the multiple belt abrasives decreases at different stages to achieve high-speed grinding in the early stage to quickly approach the preset thickness, and low-speed grinding in the later stage to avoid over-grinding and the high temperature caused by high-speed grinding, which would cause the thermal deformation thickness of the board surface to exceed the final preset grinding thickness.

3. The PPS board grinding process according to claim 1, characterized in that, In step S3, during continuous monitoring of the plate thickness, the sensors include a displacement sensor mounted on the grinding assembly and a laser sensor mounted on the side of the plate. The displacement sensor enables dynamic monitoring of plate thickness changes, while the laser sensor detects vertical height changes at fixed points on the plate during shutdown, reflecting static detection of the average thickness change of the entire plate. Furthermore, by designing a thickness threshold approximation scheme, the accurate thickness value is statically detected through multiple shutdowns within a single grinding stage. As the actual thickness gets closer to the grinding amount of that grinding stage, the shutdown interval is further shortened to avoid over-grinding.

4. The PPS board grinding process according to claim 3, characterized in that, Within a single grinding stage, the plate is alternately ground on both sides, and a single-gradient flipping thickness threshold Hf is designed. When the thickness change of the plate during grinding does not reach Hf, the plate is flipped over once each time the machine stops, so as to avoid heat accumulation, deformation and melting caused by continuous grinding. When the thickness of the plate reaches Hf during grinding, but does not reach the thickness threshold of that stage, a single-sided intermittent grinding scheme is executed until the thickness on one side reaches the thickness threshold of that stage before flipping the plate. This avoids frequent flipping in the later stages from affecting the processing speed, thereby achieving double-sided gradient grinding of the plate.

5. The PPS board grinding process according to claim 1, characterized in that, The oscillating module drives the grinding component to perform high-frequency, small-amplitude horizontal oscillation motion on the horizontal plane through periodic or non-periodic speed changes, so as to avoid periodic grinding marks between the belt grinder and the plate.

6. The PPS board grinding process according to claim 1, characterized in that, The elastic pressure design incorporates a flexible floating structure in the grinding component pressurization system, using a cylinder in conjunction with a pressure sensor to ensure that the belt abrasive grinder applies constant pressure to the board. Since PPS boards may have slight thickness variations or flatness errors, constant pressure floating grinding ensures that the grinding head and the board surface always maintain uniform pressure contact, automatically adapting to minor surface undulations.

7. The PPS board grinding process according to claim 1, characterized in that, In step S1, the plate is assembled with a vacuum adsorption plate on a processing table. The vacuum adsorption plate is made of thermally conductive material and has vacuum adsorption holes, using a continuous negative pressure vacuum scheme.

8. The PPS board grinding process according to claim 7, characterized in that, In step S4, when flipping the board, a robot arm is configured on the processing table. A rotatable electric suction cup is installed at the end of the robot arm. At the same time, a control host is configured on the processing table. The robot arm is moved by the control host. Then, the board is flipped and placed on the vacuum suction plate after being adsorbed by the electric suction cup, thereby realizing the flipping process.

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