CN102513899A - Single-direction inclined-shaft profiling precision grinding method of array optical elements of micro circular troughs - Google Patents

Abstract

The invention discloses a single-direction oblique-axis profiling precision grinding method for a micro-arc groove array optical element, which relates to a precision grinding method for a micro-arc groove array optical element. The invention aims to solve the problems that the surface roughness of the micro-arc grooves ground in different feeding directions by the existing micro-arc groove array optical element grinding method is quite different, the grinding wheel is easy to wear during processing, and the grinding processing efficiency is low. Step 1. Make the rotation axis of the profiling grinding wheel form an angle of 45 degrees with the upper surface of the workpiece to be ground, so that the first lowest point of the profiling grinding wheel becomes the grinding center point; Step 2. Make the workpiece to be ground follow the precision grinding machine table Feed along the X-axis in the opposite direction and process all micro-arc grooves of the array in one direction; Step 3: Make the rotation axis of the grinding wheel form an angle of 135 degrees with the plane where the workpiece surface is located, so that the second lowest point of the grinding wheel becomes the grinding center point, and then Process arc grooves as described in Step 2. The precision grinding method of the invention is used for processing the micro-arc groove array optical element.

Description

Single-direction oblique-axis profiling precision grinding method for micro-arc groove array optical elements

technical field

The invention relates to a precision grinding method for micro-arc groove array optical elements.

Background technique

The micro-arc groove array optical element is a key element in the manufacture of high-energy diode laser generators, high-performance backlight components for mobile phones, and high-end projectors. The arc-shaped lens array can adjust the optical path through refraction, and finally achieve a collimated optical path. role. Replication processing technology is a common method for manufacturing high-performance micro-arc groove array optical components, in which the precision machining quality of the mold with micro-arc groove array surface plays a decisive role in the final product performance and cost control.

At present, the micro-arc groove array optical element mold is processed by a double-direction parallel axis profiling grinding method, that is, the rotational axis of the profiling grinding wheel is parallel to the surface of the workpiece to be processed during processing. During processing, the diamond grinding wheel first feeds and grinds the first arc groove along the cutting direction of the abrasive grains. After the first arc groove is ground, the grinding wheel moves axially to the second arc groove, and then cuts along the abrasive grains. Grind the second arc groove in the opposite direction, and process all the arc grooves sequentially in the same way, as shown in Figure 2. When profiling the micro-arc groove array, the rotation axis of the grinding wheel is arranged parallel to the surface to be machined, and the cutting tracks of the abrasive grains distributed in the axial direction on the grinding wheel are always parallel to each other, resulting in the ups and downs of the abrasive cutting micro-edges on the grinding wheel will be directly copied to the surface of the arc groove, so that the grinding marks on the surface of the arc groove after processing are obvious, and the surface roughness is high; at the same time, the grinding wheel always grinds the arc groove with the maximum diameter point A as the center. After the grinding wheel is worn, it needs to be immediately Trimming is required to continue processing.

In summary, the existing micro-arc groove array optical element grinding method has obvious grinding marks and high surface roughness, and the surface roughness of the micro-arc grooves ground in different feeding directions varies greatly, reaching 14%~ 55%; the grinding wheel is easy to wear during processing, and needs to be trimmed many times, and the grinding efficiency is low.

Contents of the invention

The present invention aims to solve the problems that the surface roughness of the micro-arc grooves ground in different feeding directions by the existing micro-arc groove array optical element grinding method is relatively different, the grinding wheel is easy to wear during processing, and the grinding processing efficiency is low, and further A single-direction oblique-axis profiling precision grinding method for micro-arc groove array optical elements is provided.

The technical scheme that the present invention takes for solving the problems of the technologies described above is:

The single-direction oblique-axis profiling precision grinding method of the micro-arc groove array optical element of the present invention is realized according to the following steps:

Step 1. Fix the workpiece to be ground on the upper surface of the precision grinding machine table, rotate the profiling grinding wheel so that the rotation axis of the profiling grinding wheel forms an angle of 45 degrees with the plane of the surface of the workpiece to be ground, so that the first The lowest point becomes the grinding center point;

Step 2. Adjust the profiling grinding wheel to the initial point of the first arc groove to be processed, so that the workpiece to be ground is fed along the X-axis in the opposite direction with the worktable of the precision grinding machine, and the rotation direction of the profiling grinding wheel is controlled to rotate counterclockwise. When processing After finishing the first arc groove to be processed, lift the profiling grinding wheel along the Y axis and move it back to the initial point of the first arc groove to be processed, then move the profiling grinding wheel to the opposite direction along the Z axis. At the initial point of the adjacent second groove to be processed, the workpiece to be ground is fed along the X-axis in the opposite direction with the worktable of the precision grinding machine, and the rotation direction of the profiling grinding wheel is controlled to rotate counterclockwise, and the second groove to be processed is processed. Process the next arc groove to be processed sequentially;

Step 3. When the grinding work area centered on the first lowest point on the profiling grinding wheel needs to be trimmed due to wear, rotate the profiling grinding wheel again so that the rotation axis of the grinding wheel forms an included angle of 135 degrees with the plane of the surface of the workpiece to be ground , so that the first lowest point of the profiling grinding wheel becomes the second lowest point symmetrical to the first lowest point as the grinding center point, and then process the arc groove according to step 2, and the second lowest point on the profiling grinding wheel When the grinding work area centered at the center also needs to be trimmed due to wear, the profiling grinding wheel is then trimmed. After the profiling grinding wheel is trimmed, continue to grind according to steps 1 to 3 until the entire array of arc grooves is ground.

The present invention has the following beneficial effects: the single-direction oblique-axis profiling precision grinding method of the arc groove array optical element of the present invention adopts the single direction grinding method, and changes the reciprocating type from the existing micro-arc groove array optical element mold Compared with the advanced grinding method, it is guaranteed that each arc groove is ground by the grinding wheel feeding along the cutting direction of the abrasive grains, and the surface roughness is reduced by 10% to 15%, which greatly improves the machining accuracy;

In the precision grinding method of the present invention, the rotation axis of the grinding wheel maintains an angle of 45 degrees with the surface of the workpiece to be processed, and the grinding wheel grinds the arc groove centered on point B, and continues to grind the arc groove centered on point C after the grinding wheel is worn. Carry out the grinding process, and then trim after the grinding wheel is worn at point B and point C, one trimming and two grindings, thereby reducing the trimming times during the precision grinding process of the micro-arc groove array optical element mold, and the grinding process efficiency doubled.

Description of drawings

Fig. 1 is a schematic diagram of the principle of the single-direction oblique-axis profiling precision grinding method of the micro-arc groove array optical element of the present invention, and Fig. 2 is a schematic diagram of the principle of the existing micro-arc groove array optical element grinding method.

Detailed ways

Specific embodiment 1: In conjunction with Fig. 1, the single-direction oblique-axis profiling precision grinding method of the micro-arc groove array optical element described in this embodiment is realized according to the following steps:

Step 1. Fix the workpiece 4 to be ground on the upper surface of the workbench 5 of the precision grinding machine, and rotate the profiling grinding wheel 3 so that the rotation axis 1 of the profiling grinding wheel 3 forms an angle of 45 degrees with the plane where the surface of the workpiece 4 to be ground is located, so that The first lowest point B of the profiling grinding wheel 3 becomes the grinding center point;

Step 2. Adjust the profiling grinding wheel 3 to the initial point of the first arc groove to be processed, so that the workpiece 4 to be ground is fed in the opposite direction of the X axis along with the precision grinding machine table 5, and the rotation direction of the profiling grinding wheel 3 is controlled counterclockwise Rotate, when the first arc groove to be processed is finished, then the profiling grinding wheel 3 is lifted along the Y axis and moved back to the initial point of the first arc groove to be processed, and then the profiling grinding wheel 3 is moved along the Z axis The axis moves in the opposite direction to the initial point of the adjacent second groove to be processed, so that the workpiece 4 to be ground is fed along the X-axis in the opposite direction with the precision grinding machine table 5, and the rotation direction of the profiling grinding wheel 3 is controlled to rotate counterclockwise. Complete the second groove to be processed, and process the next arc groove to be processed in sequence in the same way;

Step 3. When the grinding work area centered on the first lowest point B on the profiling grinding wheel 3 needs to be trimmed due to wear, the profiling grinding wheel 3 is rotated again so that the axis of rotation of the grinding wheel 1 is in the same plane as the surface of the workpiece 4 to be ground. Form an included angle of 135 degrees, so that the first lowest point B of the profiling grinding wheel 3 becomes the second lowest point C symmetrical to the first lowest point B and becomes the grinding center point, and then process the arc groove according to step 2. When the grinding work area centered on the second lowest point C on the profiling grinding wheel 3 also needs to be trimmed due to wear, the profiling grinding wheel 3 is then trimmed, and after the profiling grinding wheel 3 is trimmed, continue to grind according to steps 1 to 3 Machining until all arc groove arrays are ground.

The arc radius of the micro-arc groove array of the present invention is 0.1 mm to 1.5 mm, and the groove depth is not greater than ((2 ^0.5 -1)R/2);

The grinding tool used in the present invention is a resin bonded or metal bonded diamond 14F1 or 1FF1 type profiling grinding wheel with a particle size of 400# to 2000#;

The micro-arc groove array optical element mold material of the present invention includes: precision silicon carbide ceramics, precision silicon nitride ceramics, tungsten carbide hard alloy and the like.

working principle:

Due to the hardness and brittleness of the micro-arc groove array optical element mold material, the micro-cracks caused during the grinding process will grow along with the cutting direction of the abrasive grains. surface, resulting in increased surface roughness, and the surface quality of micro-arc groove arrays ground in different feed directions is not the same. The single-directional grinding method avoids the damage of micro-cracks to the processed surface. Each arc in the array The grooves are all processed under the same grinding conditions, which eliminates the uneven surface quality of the micro-arc groove array, and the average surface roughness of two adjacent arc grooves after grinding is basically the same (the deviation is less than 10%);

The invention adopts the profiling precision grinding method. During the grinding process, with the feeding of the grinding wheel, the abrasive grain cutting tracks distributed in the axial direction of the grinding wheel will interfere with each other and superimpose, reducing the impact of the ups and downs of the abrasive grain cutting micro-blade on the grinding wheel on the circular arc. The impact of the groove grinding morphology, through the SEM observation after the test, the grinding marks are significantly weakened, compared with the existing processing method, the surface roughness is reduced by 10% to 15%, and the processing accuracy is improved; at the same time, the grinding wheel is B Point (C) as the center to grind the arc groove. After the grinding wheel is worn, you can continue to grind the arc groove centered at point C (B). After both points B and C of the grinding wheel are worn, proceed Trimming, one trimming and two grindings, thereby reducing the number of trimmings during the precision grinding process of micro-arc groove array optical element molds, and doubling the processing efficiency;

From the above, it can be seen that the present invention is a single-direction oblique-axis profiling precision grinding method for micro-arc groove array optical element molds, which can eliminate the phenomenon that the surface quality of micro-arc groove arrays is not the same, and effectively reduce the surface quality of the micro-arc groove array. Improve surface roughness, improve grinding marks, reduce grinding wheel dressing times, and obtain good processing quality and high processing efficiency.

Claims (1)

1. the folk prescription synclinal axis profiling precise grinding process of a little arc groove array optical element, it is characterized in that: the folk prescription synclinal axis profiling precise grinding process of said little arc groove array optical element is realized according to following steps:

Step 1, workpiece to be ground (4) is fixed on the upper surface of precision grinder workbench (5); Rotation profiling emery wheel (3) makes profiling emery wheel (3) rotation (1) and workpiece to be ground (4) surface belong to the plane in angle of 45 degrees, makes first minimum point (B) of profiling emery wheel (3) become the grinding center point;

Step 2, profiling emery wheel (3) is adjusted to article one arc groove initial point to be processed; Make workpiece to be ground (4) with precision grinder workbench (5) along the feeding in the other direction of X axle; Control profiling emery wheel (3) direction of rotation is rotated counterclockwise; After processing article one arc groove to be processed, then profiling emery wheel (3), Y direction is moved back into article one arc groove initial point to be processed place after mentioning, again profiling emery wheel (3) is moved to the second adjacent groove initial point to be processed place in the other direction along the Z axle; Make workpiece to be ground (4) with precision grinder workbench (5) along the feeding in the other direction of X axle; Control profiling emery wheel (3) direction of rotation is rotated counterclockwise, and machines second groove to be processed, in like manner processes next bar arc groove to be processed successively;

Step 3, when being that the grinding workspace at center is because wearing and tearing when need repairing with first minimum point (B) on the profiling emery wheel (3); Rotate profiling emery wheel (3) once more; Make emery wheel rotation (1) become 135 degree angles with plane, place, workpiece to be ground (4) surface; Second minimum point (C) that first minimum point (B) of profiling emery wheel (3) is become with first minimum point (B) symmetry becomes the grinding center point; Then according to the said processing arc groove of step 2; Treat that it be the grinding workspace at center when also needing finishing because of wearing and tearing that profiling emery wheel (3) is gone up with second minimum point (C), again profiling emery wheel (3) repaired that profiling emery wheel (3) is repaired continued and carried out grinding according to step 1～step 3 and finish whole arc groove arrays until grinding.

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