Resin binder diamond centerless grinding wheel and machining method thereof

Abstract

The invention relates to the technical field of hard alloy machining, in particular to a resin binder diamond centerless grinding wheel and a machining method thereof.According to the grinding wheel, a plurality of thin grinding wheel pieces are connected through a step type seamless assembly structure, and different diamond concentrations are set for the grinding wheel pieces at the two ends and the middle according to grinding characteristics; and the overall stability, the wear resistance and the shape keeping capability of the grinding wheel are effectively improved. The processing method comprises an optimized material mixing process, the holding force of a binding agent is enhanced through a process of pre-wrapping diamond with resin powder, and a special scraping device with rotation, radial movement and alternate inserting and scraping compound motion is adopted to carry out deep treatment on a die-filling mixture, so that the density uniformity is ensured. The problems of internal defects, uneven density and inconsistent abrasion of a traditional grinding wheel are systematically solved from the three aspects of structural design, the mixing technology and forming equipment, the machining consistency and dynamic balance performance of the grinding wheel are remarkably improved, and the service life of the grinding wheel is remarkably prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hard alloy processing, in particular to a resin bond diamond centerless grinding wheel and a processing method thereof. BACKGROUND

[0002] The resin bond diamond centerless grinding wheel is an important tool in modern precision grinding processing, and is widely used in the processes of ribbing, rough grinding and fine grinding of alloy rods. In the process of efficient grinding, the grinding wheel needs to have good self-sharpening, shape maintaining ability and stable grinding performance at the same time, which puts high requirements on the structure design and manufacturing process of the grinding wheel.

[0003] At present, the Chinese patent application No. CN201920065242.7 discloses an integrally formed resin bond diamond centerless grinding wheel, which comprises a positioning disc, the outer surface of the positioning disc is connected with a combined grinding wheel, a connecting hole is formed at the center position of the positioning disc, an upper connecting hole and a lower connecting hole are formed in the combined grinding wheel, a buckle hole is formed at the top end of the first outer screw, and an inner sliding hole is formed below the center line of the first outer screw. By means of the combined grinding wheel, the first outer screw and the miscellaneous arc plate, the size of the centerless grinding wheel can be adjusted according to the size of the parts to be polished, so that the two can be better matched, and the generated debris can be scraped in time during the polishing operation.

[0004] However, the grinding wheel of the prior art is mostly in the form of a thick sheet, which is prone to insufficient curing of the resin bond due to uneven temperature distribution during heat pressing and curing, and the internal gas and moisture are difficult to effectively discharge, resulting in defects such as bulging and cracking of the product. In addition, the conventional mixing process cannot ensure the uniform distribution of diamonds in the bond, and the holding force of the bond on the abrasive is insufficient, resulting in poor wear resistance and short service life of the grinding wheel. In addition, the existing molding process can only simply scrape the surface of the mixed material, and it is not convenient to eliminate the internal cavities, resulting in uneven density distribution and poor dynamic balance performance of the grinding wheel, which is prone to vibration during high-speed grinding, seriously affecting the processing precision. SUMMARY

[0005] The present application aims to provide a resin bond diamond centerless grinding wheel and a processing method thereof to solve the problems raised in the background art.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: a resin bond diamond centerless grinding wheel, comprising a plurality of grinding wheel pieces, the plurality of grinding wheel pieces are connected by stepless assembly, and the tight fit is realized by adopting the principle of thermal expansion and cold contraction to form a whole grinding wheel. The number of the plurality of grinding wheels is 6 or 8. When the diamond grit size is finer than 800 mesh, an 8-wheel combination is used, and when the diamond grit size is coarser than 800 mesh, a 6-wheel combination is used. The integral grinding wheel has an outer diameter of 450mm, a thickness of 205mm, a mounting hole diameter of 228.6mm, and a ring width of 10mm. Of the plurality of grinding wheels, the grinding wheels at both ends have a higher diamond concentration than the grinding wheels in the middle, wherein the diamond concentration of the grinding wheels at both ends is 150% and the diamond concentration of the grinding wheels in the middle is 125%. The grinding wheel is made of a resin binder and diamond, wherein the resin binder includes phenolic resin or imide resin.

[0007] Preferably, the stepped seamless assembly structure interface is a snap-fit ​​structure with concave and convex parts, and the contact surface is ground with high precision and assembled by thermal expansion and contraction to ensure the concentricity and assembly accuracy of the grinding wheel as a whole.

[0008] Preferably, the thickness of a single grinding wheel is in the range of 30mm to 35mm.

[0009] In addition, the present invention also provides a method for processing a resin-bonded diamond centerless grinding wheel, which is used to prepare the above-mentioned resin-bonded diamond centerless grinding wheel, comprising the following steps: S1. Ingredients: Weigh out the resin powder, diamond and filler according to the formula; S2. Mixing: Reserve a portion of the resin powder, mix the remaining binder powder and sieve; treat the diamond with a liquid wetting agent; premix the reserved resin powder with the wetting diamond so that the resin powder coats the diamond surface, and sieve to obtain the premix; mix the premix with the binder powder in a mixer and sieve again. S3. Molding and scraping: The mixed material is loaded into the molding mold, and the inside of the mixture deep in the molding mold is scraped repeatedly with a scraping device to reduce internal voids. S4. Hot pressing: The mixture in the mold is heated and pressed to form a mold. The hot pressing temperature is 190℃~235℃. S5. Curing: The pressed and shaped grinding wheel blank is placed in a constant temperature furnace for heat treatment to completely cure the resin and form a grinding wheel. S6. Post-processing: Drilling, tapping, and grinding of the outer diameter and end face of the cured grinding wheel. S7. Assembly: Depending on the grit size, 6 or 8 processed grinding wheel discs are used to assemble the whole grinding wheel through stepped thermal expansion and contraction. S8. Dynamic balancing: Perform dynamic balancing correction on the assembled grinding wheel.

[0010] Preferably, in step S2, the mesh size of the sieve used for sieving is two particle size numbers coarser than the diamond particle size.

[0011] Preferably, in step S2, the liquid wetting agent is a liquid resin, and its amount is 1%-2% of the diamond mass; the proportion of the reserved resin powder is 10% of the total weight of the resin powder in the binder.

[0012] Preferably, in step S3, the scraping device includes a pad for installation and positioning. A lifting unit is fixedly connected to the top of the pad. A crossbar is locked and fixed to the top middle side of the lifting unit. A worm gear drive is connected to the lower front side of the crossbar. The lifting unit is driven to lift by a cylinder. The worm gear drive includes a drive motor, a worm, and a worm wheel. The worm is connected to the output end of the drive motor, and the rear side of the worm wheel meshes with the worm. The top middle side of the worm wheel is rotatably connected to the crossbar, and a scraping structure is coaxially rotatable at the bottom of the worm wheel.

[0013] Preferably, the scraping structure includes a frame that rotates coaxially with the worm gear on one side of its top. A groove is provided on the bottom side of the frame, and a screw is rotatably connected to the inside of the groove. One end of the screw has a rotating head integrally formed and rotates through the inside of the frame. An internally threaded slider is threadedly connected to the outer surface of the screw. The top side of the internally threaded slider is slidably connected to the groove, and a support block is installed at the bottom of the internally threaded slider. A power component is locked and fixed at the bottom of the support block. A first toothed plate and a second toothed plate are locked and fixed on the left and right sides of the bottom of the power component, respectively. The first toothed plate is located in front of the second toothed plate.

[0014] Preferably, the power assembly includes a housing that is fastened to the support block at the top center. A servo motor is locked and fixed inside the housing on the right side. A drive gear is connected to the output end of the servo motor on the left side, and a driven gear is meshed with the drive gear on the front side. A shaft is fixed through the center side inside the driven gear. The shaft is rotatably connected to the inside of a bearing block, and a first turntable and a second turntable are wrapped around the left side of the outer surface of the shaft. The first turntable and the second turntable are fixed as one piece. A first slide rod is connected to the lower left side of the first turntable, and a second slide rod is connected to the lower right side of the second turntable. The driven gear, the first turntable, and the second turntable all pass through the front side of the housing. The first slide rod and the second slide rod slide longitudinally through the left and right sides of the sleeve, respectively, and the rear side of the sleeve is fixed to the housing. The bottom of the first slide rod is locked and fixed to the first toothed plate, and the bottom of the second slide rod is locked and fixed to the second toothed plate.

[0015] Preferably, the first turntable has a first cam groove on its left side and the second turntable has a second cam groove on its right side. The first cam groove and the second cam groove are symmetrically distributed at the central axis of the two turntables. The upper right part of the first slide rod slides on the bottom side of the first cam groove through a roller, and the upper left part of the second slide rod slides on the bottom side of the second cam groove through a roller.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention, through the combined design of multiple thin grinding wheels and a high-precision stepped embedding structure, not only effectively improves the stress distribution inside the grinding wheel but also ensures the compactness and stability of the overall structure. Furthermore, based on the grinding process characteristics, the grinding wheel is designed with a concentration gradient, giving the end grinding wheel, which bears the main impact, higher wear resistance, while the middle part maintains suitable grinding characteristics. This fundamentally enhances the shape retention capability of the grinding wheel under high-speed and heavy-load conditions, significantly extends its service life, and ensures the consistency of workpiece dimensions and the stability of surface quality.

[0017] This invention optimizes the mixing and molding processes. By using a "resin powder pre-coating" mixing process, the order of material addition and the mixing method are changed, which enhances the binding force of the binder on the diamond abrasive at the microscopic level and solves the key problem of uneven abrasive distribution in traditional mixing. On this basis, a scraping device with compound motion function is developed. Through the synergistic effect of rotational scraping, radial adjustment and alternating scraping, it can completely destroy the accumulation bridges and internal voids formed by the mixture in the mold, ensuring the high uniformity of the grinding wheel blank density. This improves the dynamic balance performance and mechanical strength of the final product from the source, laying a solid foundation for the reliable performance of the grinding wheel in high-speed precision grinding.

[0018] This invention integrates a specific grinding wheel structure, a precisely matched mixing method, and dedicated molding equipment into an organic whole. It overcomes the problems of internal defects caused by uneven curing, excessive vibration caused by poor density distribution, and morphological distortion caused by different wear rates in traditional thick grinding wheels from a mechanistic perspective. It provides a mature, reliable, and efficient complete solution for the manufacture of high-performance resin diamond grinding wheels. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the 6-piece combined integral grinding wheel of the present invention; Figure 2 This is a schematic diagram of the structure of the 8-piece combined integral grinding wheel of the present invention; Figure 3 This is a schematic diagram of the scraping device of the present invention; Figure 4 This is a schematic diagram of the scraping structure of the present invention; Figure 5 This is a schematic diagram of the connection between the screw and the internally threaded slider of the present invention; Figure 6 This is a schematic diagram of the power component of the present invention; Figure 7 For the present invention Figure 6 A partial left-side view of the connection between the central storage cover and the first turntable; Figure 8 For the present invention Figure 6 A partial right-side view of the structure connecting the central storage cover and the second turntable.

[0020] In the diagram: 1. 6-piece combined integral grinding wheel; 2. 8-piece combined integral grinding wheel; 3. Pad block; 4. Lifting unit; 5. Crossbar; 6. Worm gear drive component; 7. Scraper structure; 71. Frame; 72. Screw; 73. Rotating head; 74. Internal threaded slider; 75. Support block; 76. Power assembly; 77. First toothed plate; 78. Second toothed plate; 761. Compartment cover; 762. Servo motor; 763. Driven gear; 764. Shaft; 765. Bearing block; 766. First turntable; 767. Second turntable; 768. First slide bar; 769. Second slide bar; 7610. Sleeve; 7611. First cam groove; 7671. Second cam groove; 7681. Detailed Implementation

[0021] To further explain the technical solution of the present invention, a detailed description is provided below through specific embodiments.

[0022] Example 1, Grinding wheel structure: Please see Figure 1 and Figure 2 This invention provides a resin-bonded diamond centerless grinding wheel, comprising multiple grinding wheel blades connected by a stepped seamless assembly. The stepped seamless assembly has a snap-fit ​​structure with concave and convex interlocking. This structure is precision ground before assembly and assembled using the principle of thermal expansion and contraction, so that the grinding wheel blades achieve an interference fit, forming a seamless integral grinding wheel, ensuring the concentricity, rigidity and dynamic balance of the grinding wheel as a whole.

[0023] The number of grinding wheels is selected based on the diamond grit size: when the diamond grit size is finer than 800 mesh (e.g., 1000 mesh, 1200 mesh, etc.), 8 wheels are used to form an 8-wheel composite grinding wheel 2; when the diamond grit size is coarser than 800 mesh (e.g., 600 mesh, 400 mesh, etc.), 6 wheels are used to form a 6-wheel composite grinding wheel 1. This balances the high stability requirements of fine-grit grinding wheels with the processing efficiency of coarse-grit grinding wheels. The thickness of each grinding wheel is preferably between 30mm and 35mm, which facilitates the uniform conduction and dissipation of heat and volatile resin components during hot pressing and curing.

[0024] The specifications of the integral grinding wheel are: outer diameter 450mm, total thickness 205mm, mounting hole diameter 228.6mm, and ring width 10mm.

[0025] In this grinding wheel assembly, the wheels located at both ends of the integral grinding wheel have a diamond concentration of 150%, while the wheels in the middle have a diamond concentration of 125%. This design is an optimization tailored to the characteristics of the grinding process: the grinding initiation end needs to withstand greater impact and grinding volume, and a higher concentration enhances its wear resistance and prevents premature wear and deformation; the grinding end plays a decisive role in the dimensional accuracy and surface quality of the workpiece, and a higher concentration better maintains its shape, thus ensuring workpiece consistency. The entire grinding wheel is made of resin-bonded material and diamond, with the resin bonded material selected from phenolic resin or imide resin depending on performance requirements.

[0026] Example 2, Processing method: Please see Figures 1-3 This invention provides a method for processing a resin-bonded diamond centerless grinding wheel, used to prepare the aforementioned resin-bonded diamond centerless grinding wheel. The method includes the following steps: S1. Ingredients: Weigh out phenolic resin powder or imide resin powder, diamond of a specific particle size, and the required metal or non-metal fillers according to the formula.

[0027] S2. Mixing: First, reserve approximately 10% of the total resin powder. Mix the remaining 90% of the resin powder with all the fillers in a mixer for 3 hours, then pass it through a 200-mesh sieve to break up lumps and ensure the binder is initially evenly mixed. Simultaneously, use liquid resin as a wetting agent to wet the diamond, controlling the amount of wetting agent to 1%-2% (preferably 1.5%) of the total diamond mass. Next, premix the reserved 10% of the resin powder with the wetted diamond, stirring to ensure the resin powder is evenly coated on the diamond surface, then pass it through a sieve two sizes larger than the diamond particle size. This premixing step significantly improves the binding force of the binder on the diamond in the final product. Finally, put this premixed material and the previously mixed binder powder into a mixer, continue stirring for 1 hour, and sieve it three times using a sieve two sizes larger than the diamond particle size to ensure the diamond is highly dispersed in the binder.

[0028] S3. Loading and Scraping: The uniformly mixed material is loaded into the molding mold. A special scraping device is used to scrape the mixture in the mold to level it. Unlike traditional flat scrapers that only level the surface, this device can penetrate deep into the material and scrape repeatedly, effectively destroying and reducing the voids formed by the accumulation inside the material. This ensures that the density distribution of the pressed grinding wheel blank is uniform, improving the dynamic balance performance and overall strength of the grinding wheel from the source.

[0029] S4. Hot pressing: The mold with the scraped material is transferred to a hot press for heating and pressing. The hot pressing temperature is set according to the selected resin type: 190℃ for phenolic resin and 235℃ for imide resin. Under this temperature and pressure, the binder reaches the predetermined density and achieves a firm encapsulation of the diamond.

[0030] S5. Curing: The hot-pressed grinding wheel blank is transferred to a constant temperature curing oven for post-curing heat treatment, so that the resin undergoes a full cross-linking reaction and is completely cured, thereby obtaining higher strength and hardness.

[0031] S6. Post-processing: Machining is performed on the fully cured grinding wheel, including drilling, tapping (for installation and fixing), and grinding the outer diameter and end face to ensure the dimensional accuracy and surface flatness of the grinding wheel.

[0032] S7. Assembly: According to the design, 6 or 8 pre-processed grinding wheels are stacked in a stepped structure, and then assembled using the principle of thermal expansion and contraction (for example, heating the grinding wheels or tooling to increase the fit clearance, and then shrinking and locking after cooling) to form the final integral grinding wheel.

[0033] S8. Dynamic balancing: The assembled grinding wheel is calibrated on a dynamic balancing machine to ensure its stability during high-speed rotation and meet the requirements of high-precision grinding.

[0034] Example 3, scraping device: Please see Figures 3-8 The scraping device includes a pad 3 for installation and positioning. A lifting unit 4 is fixedly connected to the top of the pad 3. The lifting unit 4 is driven by a cylinder to realize the lifting and lowering movement of the overall structure above it. A crossbar 5 is locked and fixed to the middle of the top of the lifting unit 4. A worm gear drive component 6 is connected to the lower front of the crossbar 5. The worm gear drive component 6 includes a drive motor, a worm and a worm wheel. The worm is connected to the output end of the drive motor, and the rear side of the worm wheel meshes with the worm. The middle of the top of the worm wheel is rotatably connected to the crossbar 5, and a scraping structure 7 is coaxially rotated at the bottom of the worm wheel. After the drive motor is started, it drives the scraping structure 7 to rotate with it, so that the scraping structure 7 can rotate 360 ​​degrees in the horizontal plane, thereby scraping the mixture in the mold in a comprehensive circular trajectory.

[0035] The scraper structure 7 includes a frame 71 that rotates coaxially with the worm gear on one side of its top. A groove is provided on the bottom side of the frame 71, and a screw 72 is rotatably connected to the inside of the groove. A rotating head 73 is integrally formed at one end of the screw 72 and rotates through the inside of the frame 71. An internally threaded slider 74 is threadedly connected to the outer surface of the screw 72. The top side of the internally threaded slider 74 is slidably connected to the groove, and a support block 75 is installed at the bottom of the internally threaded slider 74. A power assembly 76 is locked and fixed at the bottom of the support block 75. A first toothed plate 77 and a second toothed plate 78 are locked and fixed on the left and right sides of the bottom of the power assembly 76, respectively. The first toothed plate 77 is located in front of the second toothed plate 78. When the operator operates the rotating head 73 to rotate the screw 72, the internally threaded slider 74 converts the rotational motion of the screw 72 into its own linear motion, thereby realizing the radial adjustment of the position of the power assembly 76 and the two toothed plates.

[0036] The power assembly 76 includes a housing 761 that is fastened to the support block 75 at the top center. A servo motor 762 is locked and fixed inside the housing 761 on the right side. The output end of the servo motor 762 is connected to a drive gear 763, and a driven gear 764 is meshed with the front side of the drive gear 763. A shaft 765 is fixed through the center side inside the driven gear 764. The shaft 765 is rotatably connected to the inside of the bearing block 766. The servo motor 762 serves as the power source. Through the cooperation of the drive gear 763 and the driven gear 764, the shaft 765 rotates stably under the support of the bearing block 766. A first turntable 767 and a second turntable 768 are wrapped around the left side of the outer surface of the shaft 765. The first turntable 767 and the second turntable 768 are fixed as one piece so that the two turntables rotate synchronously when the shaft 765 rotates. The first turntable 767 is connected to the lower left side of the first slide rod 769, and the second turntable 768 is connected to the lower right side of the second slide rod 7610, so that the two slide rods can be driven by the two turntables to produce a linear reciprocating motion according to a preset pattern. The driven gear 764, the first turntable 767 and the second turntable 768 all pass through the front side of the housing 761, which is convenient for connecting with the two slide rods and also convenient for observation and maintenance. The first slide rod 769 and the second slide rod 7610 slide longitudinally through the left and right sides of the sleeve 7611, and the rear side of the sleeve 7611 is fixed to the housing 761. The sleeve 7611 provides precise vertical guidance for the two slide rods, restricting them to only perform vertical linear motion. The bottom of the first slide rod 769 is locked and fixed to the first toothed plate 77, and the bottom of the second slide rod 7610 is locked and fixed to the second toothed plate 78, so that the vertical reciprocating motion of the two slide rods is directly and without delay transmitted to the two toothed plates, causing the two toothed plates to perform insertion and lifting actions.

[0037] The first turntable 767 has a first cam groove 7671 on its left side, and the second turntable 768 has a second cam groove 7681 on its right side. The first cam groove 7671 and the second cam groove 7681 are symmetrically distributed at the central axis of the two turntables to realize the alternating reciprocating motion of the first toothed plate 77 and the second toothed plate 78. That is, when one toothed plate is inserted, the other toothed plate is lifted, forming a continuous and alternating agitation of the material. The upper right part of the first slide rod 769 slides on the bottom side of the first cam groove 7671 through a roller, and the upper left part of the second slide rod 7610 slides on the bottom side of the second cam groove 7681 through a roller. The roller design reduces the friction and ultimately drives the two toothed plates to perform alternating insertion and scraping operations, which greatly optimizes the arch breaking and material uniformity effect.

[0038] The working principle of this scraping device is as follows: First, when it is necessary to process the mixture in the mold, the lifting unit 4 is activated to move the crossbar 5, the worm gear drive 6 and the entire scraping structure 7 downward until the first toothed plate 77 and the second toothed plate 78 are inserted into the predetermined depth of the mixture in the forming mold, so as to ensure that the scraping tool can penetrate into the material and lay the foundation for subsequent internal stirring. Second, after the toothed plate is inserted into place, the drive motor in the worm gear drive 6 starts, driving the worm gear to rotate, which in turn drives the worm gear meshing with it to rotate slowly. The rotation of the worm gear eventually drives the entire scraping structure 7, which is coaxially connected to its bottom, to rotate 360 ​​degrees in the horizontal plane. This causes the first toothed plate 77 and the second toothed plate 78 to move along a circular trajectory in the mixture, achieving preliminary and large-scale stirring and leveling of the material. Third, while the first toothed plate 77 and the second toothed plate 78 move along the circular trajectory, the servo motor 762 in the power assembly 76 starts. Through the meshing of the drive gear 763 and the driven gear 764, the shaft 765 and the integrated first turntable 767 and second turntable 768 fixed on it rotate synchronously. Since the first cam groove 7671 and the second cam groove 7681 are symmetrically distributed, they drive the first slide rod 769 and the second slide rod 7610 to make up-down reciprocating linear motions with opposite phases under the constraint of the sleeve 7611 through the rollers that slide inside them respectively. Finally, this motion is transmitted to the first toothed plate 77 and the second toothed plate 78 at the bottom of the slide rod, so that the two toothed plates produce alternating "insertion" and "lifting" reciprocating motions. This alternating reciprocating motion, combined with the overall rotational motion, can effectively disperse the accumulation and voids inside the mixture, completely eliminate voids, and thus achieve a high degree of uniform distribution of the mixture in the mold. Fourth, in order to optimize the scraping effect and cover different radial areas of the mold, the operator can drive the screw 72 to rotate by rotating the rotating head 73. The rotation of the screw 72 will drive the internal thread slider 74, which is threaded to it, to move horizontally along the groove at the bottom of the frame 71. The movement of the internal thread slider 74 will drive the entire power assembly 76, the first toothed plate 77, and the second toothed plate 78 to move radially together through the support block 75. Thus, the effective radius of scraping can be adjusted as needed to ensure that the mixed material from the center to the edge area of ​​the mold can be effectively processed.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A resin-bonded diamond centerless grinding wheel, characterized in that: It includes multiple grinding wheels, which are connected by a stepped seamless assembly and are tightly fitted to form a whole grinding wheel by using the principle of thermal expansion and contraction. The number of the plurality of grinding wheels is 6 or 8. When the diamond grit size is finer than 800 mesh, an 8-wheel combination is used, and when the diamond grit size is coarser than 800 mesh, a 6-wheel combination is used. The integral grinding wheel has an outer diameter of 450mm, a thickness of 205mm, a mounting hole diameter of 228.6mm, and a ring width of 10mm. Of the plurality of grinding wheels, the grinding wheels at both ends have a higher diamond concentration than the grinding wheels in the middle, wherein the diamond concentration of the grinding wheels at both ends is 150% and the diamond concentration of the grinding wheels in the middle is 125%. The grinding wheel is made of a resin binder and diamond, wherein the resin binder includes phenolic resin or imide resin.

2. The resin-bonded diamond centerless grinding wheel according to claim 1, characterized in that: The stepped seamless assembly structure interface is a snap-fit ​​structure with concave and convex parts. The contact surfaces are ground with high precision and assembled by thermal expansion and contraction to ensure the concentricity and assembly accuracy of the grinding wheel as a whole.

3. The resin-bonded diamond centerless grinding wheel according to claim 1, characterized in that: The thickness of a single grinding wheel ranges from 30 mm to 35 mm.

4. A method for processing a resin-bonded diamond centerless grinding wheel, used to prepare the resin-bonded diamond centerless grinding wheel as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Ingredients: Weigh out phenolic resin powder or imide resin powder, diamond of a specific particle size, and the required metal or non-metal fillers according to the formula. S2. Mixing: Reserve a portion of the resin powder, mix the remaining binder powder and sieve; treat the diamond with a liquid wetting agent; premix the reserved resin powder with the wetting diamond so that the resin powder coats the diamond surface, and sieve to obtain the premix; mix the premix with the binder powder in a mixer and sieve again. S3. Molding and scraping: The mixed material is loaded into the molding mold, and the inside of the mixture deep in the molding mold is scraped repeatedly with a scraping device to reduce internal voids. S4. Hot pressing: The mixture in the mold is heated and pressed to form a mold. The hot pressing temperature is 190℃~235℃. S5. Curing: The pressed and shaped grinding wheel blank is placed in a constant temperature furnace for heat treatment to completely cure the resin and form a grinding wheel. S6. Post-processing: Drilling, tapping, and grinding of the outer diameter and end face of the cured grinding wheel. S7. Assembly: Depending on the grit size, 6 or 8 processed grinding wheel discs are used to assemble the whole grinding wheel through stepped thermal expansion and contraction. S8. Dynamic balancing: Perform dynamic balancing correction on the assembled grinding wheel.

5. The processing method of a resin-bonded diamond centerless grinding wheel according to claim 4, characterized in that: In step S2, the mesh size of the sieve used for sieving is two particle size numbers coarser than the diamond particle size.

6. The processing method of a resin-bonded diamond centerless grinding wheel according to claim 4, characterized in that: In step S2, the liquid wetting agent is a liquid resin, and its amount is 1%-2% of the diamond mass; the proportion of the reserved resin powder is 10% of the total weight of the resin powder in the binder.

7. The processing method of a resin-bonded diamond centerless grinding wheel according to claim 4, characterized in that: In step S3, the scraping device includes a pad (3) for installation and positioning. A lifting unit (4) is fixedly connected to the top of the pad (3). A crossbar (5) is locked and fixed to the middle side of the top of the lifting unit (4). A worm gear drive (6) is connected to the lower front side of the crossbar (5). The lifting unit (4) is driven to lift by a cylinder. The worm gear drive (6) includes a drive motor, a worm and a worm wheel. The worm is connected to the output end of the drive motor, and the rear side of the worm wheel meshes with the worm. The middle side of the top of the worm wheel is rotatably connected to the crossbar (5), and a scraping structure (7) is rotatably connected to the bottom of the worm wheel.

8. The processing method of a resin-bonded diamond centerless grinding wheel according to claim 7, characterized in that: The scraping structure (7) includes a frame (71) that rotates coaxially with the worm gear on one side of the top. The bottom side of the frame (71) is provided with a groove, and a screw (72) is rotatably connected to the inside of the groove. One end of the screw (72) is integrally formed with a rotating head (73), and the rotating head (73) rotates through the inside of the frame (71). The outer surface of the screw (72) is threaded with an internal thread slider (74). The top side of the internal thread slider (74) is slidably connected to the groove, and a support block (75) is installed at the bottom of the internal thread slider (74). A power assembly (76) is locked and fixed at the bottom of the support block (75). A first toothed plate (77) and a second toothed plate (78) are locked and fixed on the left and right sides of the bottom of the power assembly (76), respectively. The first toothed plate (77) is located in front of the second toothed plate (78).

9. The processing method of a resin-bonded diamond centerless grinding wheel according to claim 8, characterized in that: The power assembly (76) includes a housing (761) that is fastened to the support block (75) at the top center. A servo motor (762) is locked and fixed inside the housing (761) on the right side. A drive gear (763) is connected to the output end of the servo motor (762) on the left side. A driven gear (764) is meshed with the drive gear (763) on the front side. A shaft (765) is fixed through the center side inside the driven gear (764). The shaft (765) is rotatably connected to the bearing block (766). A first turntable (767) and a second turntable (768) are wrapped around the left side of the outer surface of the shaft (765). The first turntable (767) and the second turntable (768) are... 68) Fixed as one piece, and the first slide rod (769) is connected to the lower left side of the first turntable (767), and the second slide rod (7610) is connected to the lower right side of the second turntable (768). The driven gear (764), the first turntable (767) and the second turntable (768) all pass through the front side of the cover (761). The first slide rod (769) and the second slide rod (7610) slide longitudinally through the left and right sides of the sleeve (7611), and the rear side of the sleeve (7611) is fixed to the cover (761). The bottom of the first slide rod (769) is locked and fixed to the first toothed plate (77), and the bottom of the second slide rod (7610) is locked and fixed to the second toothed plate (78).

10. The processing method of a resin-bonded diamond centerless grinding wheel according to claim 9, characterized in that: The first turntable (767) has a first cam groove (7671) on its left side and the second turntable (768) has a second cam groove (7681) on its right side. The first cam groove (7671) and the second cam groove (7681) are symmetrically distributed at the central axis of the two turntables. The upper right part of the first slide rod (769) slides on the bottom side inside the first cam groove (7671) through a roller, and the upper left part of the second slide rod (7610) slides on the bottom side inside the second cam groove (7681) through a roller.

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