A method for precise dressing of small-sized surfaces of super-hard abrasive grinding wheels

Abstract

The present invention discloses a method for precise dressing of small-sized surfaces of super-hard abrasive grinding wheels. A small grinding wheel (D≤100mm) made of fine-grained ordinary abrasive is used as a dressing tool. The tool wheel axis and the axis of the grinding wheel to be dressed are spatially crossed and vertically arranged. The grinding wheel to be dressed rotates at high speed, while the tool wheel rotates at low speed and moves back and forth up and down at high speed to achieve dressing operation. Circular interpolation is intermittently performed at the upper and lower ends of the movement. As the dressing is performed and the circular interpolation radius is continuously reduced as the movement is up and down, the points are finally gathered into a circle to meet the preset requirements of the small circular arc of the grinding wheel. The method can reduce the dressing force, improve the dressing accuracy, quality, efficiency, etc., and can solve the shortcomings of existing dressing technology.

Description

Technical Field

[0001] The invention belongs to the technical field of grinding, and in particular relates to a method for precisely dressing a small-sized surface of a super-hard abrasive grinding wheel. Background Art

[0002] Superabrasive grinding tools are widely recognized in the field of mechanical processing for their excellent grinding performance and are widely used for grinding various difficult-to-machine materials and special-shaped parts. For the machining of key micro-grooves of parts with large curvature (small curvature radius) such as precision mold cores, punches, slices, combs, threads, microstructures, etc., usually small diameter D < 100mm, small size surface (tip width < 0.3mm, tip bevel angle θ < 10mm) are used. 0 , tip arc radius <0.1mm) super-hard abrasive grinding wheel for point grinding.

[0003] However, such grinding wheels, such as Figure 1 The thin structure, poor lateral rigidity, easy application of unbalanced load, rapid wear, and poor shape accuracy retention have brought bottlenecks to its dressing and forming. First, super-hard abrasives are hard and wear-resistant. Compared with ordinary abrasive grinding wheels, super-hard abrasive grinding wheels have the characteristics of high dressing resistance, long dressing time, low efficiency, and low precision. Second, small-sized surface dressing is difficult. Because the grinding wheel is sharp and thin and weak in strength, the abrasive grains at the tip are easy to fall off, resulting in chipping, serrations, burrs and other morphologies.

[0004] At present, a lot of research has been conducted on the arc dressing of superabrasive grinding wheels at home and abroad, and some progress has been made. The main research methods include interpolation dressing with dressing pens, rolling dressing with forming wheels, swing dressing with cup wheels, and ELID electrolytic dressing. However, dressing with dressing pens causes rapid tool wear; rolling dressing requires high force; cup wheel dressing requires a large contact area; and electrolytic dressing and electric spark dressing require the grinding wheel to be conductive. The double arc interpolation grinding method (such as 201610994908.8) has large dressing resistance and is only suitable for dressing ball-end grinding wheels; the CG rod interpolation dressing method (such as 201410280620.5) causes uneven wear of the tool wheel and cannot be precisely dressed; the roller and grinding wheel spiral dressing method (such as 201610120685.2) or interpolation dressing method (such as 201810930250.3) causes unreasonable force on the grinding wheel and is not suitable for dressing small-sized surface grinding wheels; laser dressing method (such as 201910604282.9) has some technical deficiencies, such as beam characteristics, energy distribution, Problems such as remelting layer and accuracy cannot be used for precision dressing in engineering at present; the efficient and precise in-situ dressing method and device for cup-shaped arc grinding wheels (such as 202110534615.2) organically combines the three-axis linkage CNC machine tool and the single-rotary axis grinding wheel dresser for cup-shaped arc grinding wheel dressing. The machine tool CNC system controls the X-linear axis and Z-linear axis of the machine tool to perform arc envelope interpolation, which can realize efficient and high-precision in-situ dressing of any angle arc of the cup-shaped grinding wheel. However, it belongs to interpolation dressing and adopts spiral continuous dressing. The dressing trajectory is spiral and the force is unreasonable, which is not suitable for dressing small-sized surface grinding wheels.

[0005] In short, the existing technology generally has defects such as large dressing force, easy deformation, low precision, poor quality, poor appearance, and poor practicality, and is not suitable for precise dressing of small arc surfaces of superabrasive grinding wheels. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for precisely dressing a small-sized surface of a superabrasive grinding wheel in view of the above-mentioned deficiencies in the prior art, which is beneficial to precisely dressing a small-arc surface of a superabrasive grinding wheel.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A method for precision dressing of a small-sized surface of a superabrasive grinding wheel comprises the following steps:

[0009] 1) Select the trimming tool

[0010] Select dressing tools according to the characteristics of the grinding wheel to be dressed;

[0011] 2) System preset adjustment

[0012] The radial runout of the main shaft and auxiliary shaft of the equipment shall not exceed 0.005mm;

[0013] The grinding wheel to be dressed is installed on the main shaft of the equipment, and the tool wheel is installed on the secondary shaft. After installation, the radial runout of the two is no more than 0.01mm;

[0014] Determine the preset arc radius R of the grinding wheel, the current radius R1 of the tool wheel and the length b;

[0015] Adjust the tool wheel's reciprocating stroke to ensure that both ends of the stroke do not contact the grinding wheel being dressed;

[0016] Adjust the CCD system to facilitate online monitoring of the contact status of the dressing point;

[0017] Adjust the displacement sensor to ensure online monitoring of the wear of the tool wheel radius R1;

[0018] 3) Tool setting and positioning

[0019] Under the state of double-wheel rotation and CCD monitoring, the double-wheel four-point tool setting is completed on both sides of the dressing wheel; then the theoretical intersection point A and tangent points B and C of the grinding wheel on both sides and the position of the preset arc center O of the grinding wheel are calculated based on the four-point position;

[0020] 4) Repair plan

[0021] (1) After the grinding wheel arc center O is determined, point O is used as the arc base point in the XY plane, and the tool wheel is retracted by a distance d equal to the abrasive particle size of the dressed grinding wheel, that is, the tool wheel is retracted by 2d;

[0022] (2) Setting parameters:

[0023] Including grinding wheel speed, tool wheel speed, up and down reciprocating speed, interpolation arc radius R2, interpolation speed, circular interpolation amount c, radial feed amount a;

[0024] (3) The dressing process adopts the method of high-speed rotation of the grinding wheel to be dressed and low-speed rotation of the tool wheel and moving up and down for dressing;

[0025] At the intervals at both ends of the Z-axis travel, the XY-axis no-load circular interpolation is performed with point O as the base point. The single interpolation amount c is used to complete the interpolation trajectory arc.

[0026] As the tool wheel continues to reciprocate and interpolate, the interpolation radius R2 is gradually reduced until the preset arc radius R and arc length of the grinding wheel are reached.

[0027] 5) Trimming

[0028] Start the dressing system and dress the grinding wheel according to the dressing plan in 4);

[0029] 6) Detection

[0030] Based on the current grinding wheel arc interpolation radius R2, the current tool wheel radius R1 is measured and converted to the current actual arc radius r = R2-R1 of the dressing wheel. If r reaches the tolerance range of the preset value R of the grinding wheel, the dressing work is stopped.

[0031] If the current r does not reach the preset R tolerance of the grinding wheel arc, proceed to step 7);

[0032] 7) Re-trim

[0033] Repeat steps 4) to 6) and continue dressing until the arc radius r of the grinding wheel reaches the preset value R tolerance range.

[0034] In step 1), the tool wheel is a parallel grinding wheel with a diameter of D≤100 mm, a grit size of F230-F2000, a hardness of A-N, and a grinding wheel length of 10-30 mm.

[0035] In step 4), each interpolation is based on point O and the interpolation radius R2 is gradually reduced;

[0036] Starting interpolation radius R2 = R1 + R + 2d,

[0037] The second interpolation radius R2 = R1 + R + 2d - a;

[0038] …;

[0039] With continuous interpolation feeding, the radial feed of the grinding wheel arc accumulates to a distance of 2d, and the final interpolation radius R2=R1+R, which theoretically meets the preset R requirement of the grinding wheel.

[0040] The radial feed amount a and the single interpolation amount c are set according to the characteristics of the grinding wheel being dressed and the requirements of R. Step 4), the tool wheel reciprocates and interpolates by single-pass interpolation or double-pass interpolation.

[0041] In step 3), when setting the tool, it is necessary to set the tool from the center of the grinding wheel being dressed.

[0042] The tool wheel is a low hardness grinding wheel.

[0043] The particle size of the tool wheel is not greater than the particle size of the dressed grinding wheel.

[0044] The beneficial effects of the present invention are:

[0045] (1) The present invention discloses a method for precise dressing of small-sized surfaces of super-hard abrasive grinding wheels. A small grinding wheel with fine-grained ordinary abrasive, i.e., D≤100mm, is used as a dressing tool. The tool wheel axis and the axis of the grinding wheel to be dressed are arranged vertically and spatially. The grinding wheel to be dressed rotates at high speed, the tool wheel rotates at low speed, and moves back and forth up and down at high speed to achieve the dressing operation. Circular interpolation is performed intermittently at the upper and lower ends of the movement. As the dressing is performed up and down and the circular interpolation radius is continuously reduced, the points are finally gathered into a circle to meet the preset requirements of the small circular arc of the grinding wheel. The dressing force can be reduced, the dressing accuracy, quality, efficiency, etc. can be improved, and the shortcomings of the existing dressing technology can be solved.

[0046] (2) The purpose of the reciprocating movement of the tool wheel is to dress the grinding wheel, while the circular interpolation movement is only a position adjustment without performing any dressing operation; that is, dressing does not involve interpolation, and interpolation does not involve dressing. This is a discontinuous axial movement circular interpolation periodic dressing technology. With reciprocating movement, intermittent interpolation, and gradually reducing the interpolation radius, the preset arc of the grinding wheel is finally reached.

[0047] (3) Select dressing tools and try to reduce the dressing force; the tool wheel axis and the axis of the grinding wheel to be dressed are set vertically in a spatial cross to reduce the contact area; four-point tool setting can achieve precise positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structure of the grinding wheel to be dressed;

[0049] Figure 2 It is a schematic diagram of the trimming principle of the present invention;

[0050] Figure 3 This is a schematic diagram of tool setting and positioning according to the present invention;

[0051] Figure 4 It is a schematic diagram of the initial interpolation of the present invention. DETAILED DESCRIPTION

[0052] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0053] See also Figure 1. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0054] The present invention provides a method for precise dressing of small-sized surfaces of super-hard abrasive grinding wheels. Figures 1 to 4 shown.

[0055] The dressed grinding wheel is Figure 1 , the present invention is shown as follows Figure 2 The dressing system is mainly composed of XYZ three-phase CNC axes. The Z axis is set to reciprocate up and down at high speed. A CCD monitoring screen is set above the contact point between the grinding wheel and the tool wheel. A laser displacement sensor is set on the radial outside of the tool wheel. The above five actuators are uniformly controlled by a computer. Among them, the high-speed rotation of the dressing wheel provides the main motion for dressing; the tool wheel rotates at a low speed so that its circumference participates in the dressing; at the same time, the tool wheel moves up and down along the Z axis so that its entire axis participates in the dressing; the XY two-axis linkage circular interpolation realizes non-contact position adjustment; the CCD is fixed to the grinding wheel frame to facilitate online focus monitoring of the contact status of the two wheels at the dressing point; the laser displacement sensor is used to monitor the current radius of the tool wheel online.

[0056] In order to realize the above technical solution, the following specific finishing steps are proposed:

[0057] 1) Select the trimming tool

[0058] Select the dressing tool according to the characteristics of the grinding wheel to be dressed; in order to obtain the ideal grinding wheel arc radius R, the tool wheel should be a parallel grinding wheel with a small diameter (D≤30mm), ordinary abrasive (silicon carbide, corundum), grit size (F230~F2000), hardness A~N, and grinding wheel length (width) of 10~30mm.

[0059] 2) System preset adjustment

[0060] The radial runout of the main shaft and auxiliary shaft of the equipment is no more than 0.005mm; the main shaft is used to install the dressing grinding wheel, and the auxiliary shaft is used to install the tool wheel. After installation, ensure that the radial runout of the two is no more than 0.01mm; determine the preset arc radius R of the grinding wheel, the current radius R1 of the tool wheel and the length b; adjust the current reciprocating stroke of the tool wheel to ensure that the two ends of the stroke do not contact the dressing grinding wheel; adjust the CCD system to facilitate online monitoring of the contact status of the dressing point; adjust the displacement sensor to ensure that the wear of the tool wheel radius R1 can be monitored online.

[0061] 3) Tool setting and positioning

[0062] like Figure 3 With both wheels rotating and CCD monitoring in place, tool setting is performed at four points on both sides of the dressing wheel, based on visual inspection and audio. The four-point position is then used to calculate the theoretical intersection point A, tangent points B and C, and the center O of the preset arc. Tool setting must always be performed from the center of the dressing wheel, never from the tip.

[0063] 4) Repair plan

[0064] (1) After the grinding wheel arc center O is determined, take point O as the arc base point in the XY plane and move the tool wheel back by a distance d equal to two abrasive grains of the dressed grinding wheel, ensuring safety and avoiding interference such as burrs.

[0065] (2) Setting parameters: including grinding wheel speed, tool wheel speed, up and down reciprocating speed, interpolation arc radius R2, interpolation speed, circular interpolation amount c, radial feed amount a;

[0066] (3) The dressing process adopts the method of high-speed rotation of the grinding wheel to be dressed and low-speed rotation of the tool wheel and moving up and down;

[0067] At the intervals at both ends of the Z-axis travel, the XY-axis no-load circular interpolation is performed with point O as the base point. The single interpolation amount c is used to complete the interpolation trajectory arc.

[0068] As the tool wheel continues to reciprocate and interpolate, the interpolation radius R2 is gradually reduced until the preset arc radius R and arc length of the grinding wheel are reached.

[0069] In each interpolation, the interpolation radius R2 is gradually reduced with point O as the base point; the initial interpolation radius R2 = R1 + R + 2d, the second interpolation radius R2 = R1 + R + 2d - a; ...;

[0070] With continuous interpolation feeding, the radial feed of the grinding wheel arc accumulates to a distance of 2d, and the final interpolation radius R2=R1+R, which theoretically meets the preset R requirement of the grinding wheel.

[0071] 5) Trimming

[0072] Start the dressing system and dress the grinding wheel according to the dressing plan 4).

[0073] 6) Detection

[0074] In order to ensure product quality, the system retracts the tool after completing the above work, and uses a micrometer to check the tool wheel radius R1 for verification; based on the current grinding wheel arc interpolation radius R2, the current tool wheel radius R1 is measured, and the current actual arc radius of the dressed grinding wheel is converted to r = R2-R1. If r reaches the tolerance range of the preset value R of the grinding wheel, the dressing work is stopped.

[0075] For the dressing of small-sized, fine-grained, and small-arc grinding wheel surfaces, the tool wheel consumption is generally very small, and the preset requirements can be achieved through the above dressing steps.

[0076] 7) Re-trim

[0077] If the current r does not reach the preset R tolerance of the grinding wheel arc, it means that the tool wheel consumption is too large. According to the current tool wheel radius R1, redesign R2 and repeat the above 4) to 6) to continue dressing until the grinding wheel arc radius r reaches the preset R tolerance range.

[0078] It should be noted that: before the grinding wheel arc dressing, the grinding wheel has completed double-side dressing, and the present invention only refers to the dressing of the arc surface of the grinding wheel tip.

[0079] The grinding wheel being dressed rotates at high speed, while the tool wheel rotates at low speed and reciprocates to perform dressing. Circular interpolation occurs during the dressing intervals at both ends of the reciprocating stroke. This is essentially non-contact circular interpolation, and no dressing is performed. In other words, reciprocation and differential compensation are performed sequentially, with intermittent interpolation and non-continuous cycles. Dressing is not performed without interpolation, and interpolation is not performed without dressing; in other words, they do not operate simultaneously. Circular interpolation occurs during the dressing intervals at both ends of the reciprocating stroke and does not involve dressing.

[0080] Reciprocating and interpolation can be single-pass interpolation or double-pass interpolation, which is generally determined based on the difficulty of dressing the grinding wheel and the rigidity of the equipment system.

[0081] When the tool wheel reciprocates, it must be ensured that both ends of the tool wheel's up and down reciprocating stroke are away from the grinding wheel being dressed to avoid double-wheel interference, so that the entire axial outer cylindrical surface of the tool wheel is involved in the dressing; at the same time, the tool wheel's grit size should not be larger than the grinding wheel being dressed, and the finer the grit size, the more conducive it is to improving the dressing accuracy; the softer the tool wheel, the more conducive it is to small arc dressing and improve the dressing accuracy of the grinding wheel; the tool wheel should use a medium or low hardness grinding wheel with a vitrified bond or resin bond, silicon carbide or alumina, which is conducive to reducing the dressing resistance.

[0082] The radial feed rate a is set according to the characteristics of the grinding wheel being dressed and the R requirements. Generally, a can be increased at first and then decreased. When the arc radius R is relatively small, a smaller feed rate must be selected to reduce the dressing resistance and improve the dressing accuracy. The single interpolation amount c is set according to the characteristics of the grinding wheel being dressed and the R requirements. Generally, c can be increased at first and then decreased. When the arc radius R is relatively small, a smaller interpolation amount must be selected to reduce the dressing resistance and improve the dressing accuracy.

[0083] More specific:

[0084] 1) Select the trimming tool

[0085] The grinding wheel being dressed is a single-bevel, metal-bonded diamond wheel with a diameter of 80 mm, a grit size of 325 / 400 (approximately 0.04 mm grit diameter), and a preset arc radius of 0.05 mm. It had already been double-sided dressed prior to this dressing process, leaving only the tip arc of the wheel to be dressed. To achieve the ideal arc radius, a resin-bonded, parallel-surface silicon carbide grinding wheel with a diameter of 15 × 20 mm, a grit size of F400, and a hardness of H was selected as the tool wheel.

[0086] 2) System preset adjustment

[0087] The radial runout of the main shaft and auxiliary shaft of the equipment is no more than 0.005mm; the main shaft is used to install the dressing grinding wheel, and the auxiliary shaft is used to install the tool wheel. After installation, ensure that the radial runout of the two is no more than 0.01mm; determine the preset arc radius of the grinding wheel R0.05 +0.005 mm, measure the current radius R17.488mm and length b20mm of the tool wheel; adjust the current reciprocating stroke of the tool wheel by 30mm to ensure that its two ends of the stroke do not contact the grinding wheel being dressed; adjust the CCD system to facilitate online monitoring of the contact status of the dressing point; adjust the laser displacement sensor to ensure that the wear of the tool wheel radius R1 can be monitored online.

[0088] 3) Tool setting and positioning

[0089] like Figure 3 , under the monitoring of double wheels rotating and CCD screen, the double-wheel four-point tool setting is completed on both sides of the dressing wheel based on AE and visual inspection; then the theoretical intersection point A and tangent points B and C of the grinding wheel on both sides and the position of the preset arc center O of the grinding wheel are calculated through the four-point position.

[0090] When setting the tool, be sure to set it from the middle of the grinding wheel and never from the tip of the grinding wheel.

[0091] 4) Repair plan

[0092] (1) After the grinding wheel arc center O is determined, take point O as the arc base point in the XY plane and move the tool wheel back about 2 abrasive grain sizes d of the dressed grinding wheel, that is, 2×0.04=0.08mm. Figure 4 , safe and avoid burr interference;

[0093] (2) Setting parameters: grinding wheel speed 6000 rpm, tool wheel speed 100 rpm, up and down reciprocating speed 200 mm / min, preset arc radius R 0.05 mm, interpolation speed 100 mm / min, circumferential interpolation amount c 0.002 mm, radial feed a 0.001-0.01 mm;

[0094] (3) The dressing process adopts the method of high-speed rotation of the grinding wheel to be dressed and low-speed rotation of the tool wheel and up and down movement. At the intervals at both ends of the Z-axis stroke, XY two-axis arc interpolation is performed with point O as the base point, and the single interpolation amount c is used to complete the interpolation trajectory arc. As the tool wheel continues to reciprocate and interpolate, the interpolation radius R2 is gradually reduced until the preset arc radius R and arc length of the grinding wheel are reached.

[0095] The specific dressing process is to use point O as the arc base point, and the tool wheel reciprocates up and down, interpolating in one direction, and continuously reducing the interpolation radius R2. ① The grinding wheel being dressed rotates at high speed (6000rpm), while the tool wheel rotates at low speed (100rpm) and moves at high speed (200mm / min) along the Z axis to one end; ② The starting interpolation radius R2 = R1 + R + 2d = 7.488 + 0.05 + 0.08 = 7.618mm, and the interpolation amount c is 0.002mm. The first round of arc interpolation begins, and the interpolation continues until the arc is completed. ③ Move the tool wheel along the Z axis to the other end, set the interpolation radius R2 (decrease a0.01) mm, the interpolation amount c0.002 mm, and start the second round of interpolation and reciprocation. Gradually reduce the interpolation radius accordingly to complete 4 rounds of interpolation and reciprocation, and full arc rough machining; ④ Set the radial feed rate a0.005 mm again, reduce R2 by a0.005 mm, and the interpolation amount c0.002 mm to complete 4 rounds of interpolation and reciprocation, and full arc medium machining; ⑤ Set a0.002 mm again, reduce R2 by 0.002 mm, and the interpolation amount c0.002 mm to complete 5 rounds of interpolation and reciprocation, and full arc fine machining; ⑥ Set a0.001 mm again, reduce R2 by 0.001 mm, and the interpolation amount c0.002 mm to complete 10 rounds of interpolation and reciprocation, and full arc fine machining. Finally, through the four dressing stages of coarse, medium, fine and fine, the cumulative radial feed is 0.01×4+0.005×4+0.002×5+0.001×10=0.08mm, and the grinding wheel interpolation radius R2 reaches the preset R1+R=7.488+0.05=7.538mm, and the arc

[0096] 5) Trimming

[0097] Start the dressing system and dress the grinding wheel according to the above dressing plan until the above work is completed.

[0098] 6) Detection

[0099] To ensure quality, the system retracts the tool after completing the above work and verifies with a micrometer. Based on the current arc interpolation radius R2 = 7.538mm and the actual tool wheel radius R1 = 7.486mm, the actual arc radius of the grinding wheel is calculated to be r = R2-R1 = 7.538-7.486 = 0.052mm, which meets the preset tolerance R0.05. +0.005 mm, stop trimming work.

[0100] Due to the small size, fine grain, and small arc surface finishing, the machining allowance is very small, resulting in almost no consumption of the tool wheel, and the arc preset value R tolerance range is achieved through one processing.

[0101] This patent uses words such as "first" and "second" to limit process language. Those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description, and the above words have no special meaning.

[0102] The endpoints of the ranges disclosed herein and any values ​​are not limited to the exact ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0103] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications are possible without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the claimed invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0104] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "center", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the protection content of the present invention.

Claims

1. A method for precision dressing of small-sized surfaces of superabrasive grinding wheels, characterized in that: The following steps are involved: 1) Select the trimming tool Select dressing tools according to the characteristics of the grinding wheel to be dressed; 2) System preset adjustment The radial runout of the main shaft and auxiliary shaft of the equipment shall not exceed 0.005mm; The grinding wheel to be dressed is installed on the main shaft of the equipment, and the tool wheel is installed on the secondary shaft. After installation, the radial runout of the two is no more than 0.01mm; Determine the preset arc radius R of the grinding wheel, the current radius R1 of the tool wheel and the length b; Adjust the tool wheel's reciprocating stroke to ensure that both ends of the stroke do not contact the grinding wheel being dressed; Adjust the CCD system to facilitate online monitoring of the contact status of the dressing point; Adjust the displacement sensor to ensure online monitoring of the wear of the tool wheel radius R1; 3) Tool setting and positioning Under the state of double-wheel rotation and CCD monitoring, the double-wheel four-point tool setting is completed on both sides of the dressing wheel; then the theoretical intersection point A and tangent points B and C of the grinding wheel on both sides and the position of the preset arc center O of the grinding wheel are calculated based on the four-point position; 4) Repair plan (1) After the grinding wheel arc center O is determined, point O is used as the arc base point in the XY plane, and the tool wheel is retracted from the position where the tool wheel arc surface contacts the grinding wheel arc surface by a distance d of two abrasive grain sizes of the dressed grinding wheel, that is, the tool wheel is retracted 2d; (2) Setting parameters: Including grinding wheel speed, tool wheel speed, up and down reciprocating speed, interpolation arc radius R2, interpolation speed, circular interpolation amount c, radial feed amount a; (3) The dressing process adopts the method of high-speed rotation of the grinding wheel to be dressed and low-speed rotation of the tool wheel and moving up and down for dressing; At the intervals at both ends of the Z-axis travel, the XY-axis no-load circular interpolation is performed with point O as the base point. The single interpolation amount c is used to complete the interpolation trajectory arc. As the tool wheel continues to reciprocate and interpolate, the interpolation radius R2 is gradually reduced until the preset arc radius R and arc length of the grinding wheel are reached. 5) Trimming Start the dressing system and dress the grinding wheel according to the dressing plan in 4); 6) Detection Based on the current grinding wheel arc interpolation radius R2, the current tool wheel radius R1 is measured and converted to the current actual arc radius r = R2-R1 of the dressing wheel. If r reaches the tolerance range of the preset value R of the grinding wheel, the dressing work is stopped. If the current r does not reach the preset R tolerance of the grinding wheel arc, proceed to step 7); 7) Re-trim Repeat steps 4) to 6) and continue dressing until the arc radius r of the grinding wheel reaches the preset value R tolerance range.

2. A method for precise dressing of small-sized surfaces of a superabrasive grinding wheel according to claim 1, characterized in that: In step 1), the tool wheel is a parallel grinding wheel with a diameter of D≤100 mm, a grit size of F230-F2000, a hardness of A-N, and a grinding wheel length of 10-30 mm.

3. The method for precise dressing of small-sized surfaces of a superabrasive grinding wheel according to claim 1, characterized in that: In step 4), each interpolation is based on point O and the interpolation radius R2 is gradually reduced; Starting interpolation radius R2 = R1 + R + 2d, The second interpolation radius R2 = R1 + R + 2d - a; …； With continuous interpolation feeding, the radial feed of the grinding wheel arc accumulates to a distance of 2d, and the final interpolation radius R2=R1+R, which theoretically meets the preset R requirement of the grinding wheel.

4. The method for precise dressing of small-sized surfaces of a superabrasive grinding wheel according to claim 1, characterized in that: The radial feed amount a and the single interpolation amount c are both set according to the characteristics of the dressed grinding wheel and the R requirements.

5. The method for precise dressing of small-sized surfaces of a superabrasive grinding wheel according to claim 1, characterized in that: Step 4): The tool wheel reciprocates and interpolates by single-pass interpolation or double-pass interpolation.

6. The method for precise dressing of small-sized surfaces of a superabrasive grinding wheel according to claim 1, characterized in that: In step 3), when setting the tool, it is necessary to set the tool from the center of the grinding wheel being dressed.

7. The method for precise dressing of small-sized surfaces of a superabrasive grinding wheel according to claim 1, characterized in that: The tool wheel is a low hardness grinding wheel.

8. The method for precise dressing of small-sized surfaces of a superabrasive grinding wheel according to claim 1, characterized in that: The particle size of the tool wheel is not greater than the particle size of the dressed grinding wheel.

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