A composite contour grinding head for precision grinding of stepped lenses

Abstract

The utility model provides a kind of composite profile grinding head for with step lens fine carving, including handle and working section.Handle is cylindrical, for with fine carving machine main shaft clamping and limit, the outer surface of working section is thick and thin cylindrical staggered arrangement and is divided into four functional areas and consolidates diamond abrasive, area one: consolidates 250#‑380# diamond abrasive, for roughing;Area two: consolidates 250#‑350# diamond abrasive, for processing the profile of step;Area three: consolidates 800#‑1000# diamond abrasive, for side surface finishing;Area four: located working section bottom plane, consolidates 800#‑1000# diamond abrasive and is engraved cross heat dissipation groove, for platform surface finishing and heat dissipation.The new type is combined by "composite profile grinding head" and "zoned gradient sand particle arrangement", and the machining precision is significantly improved.

Description

Technical Field

[0001] This utility model belongs to the field of optical glass processing technology, specifically relating to a composite contour grinding head for precision engraving of stepped lenses. Background Technology

[0002] Insufficient adaptability of grinding head shape: In the processing of stepped lenses, existing grinding heads are mostly single cylindrical or conical structures, resulting in insufficient adaptability of the grinding head shape. They cannot form a close-fitting processing contact trajectory with the "step transition surface" of the stepped lens (such as the junction of the vertical surface and the curved surface of the step at the lens edge). This easily leads to "over-grinding" or "under-grinding" problems during processing. For example, at the root of the step, excess material may remain because the grinding head cannot penetrate deeply enough, causing a step accuracy deviation exceeding 0.05mm; at the top of the step, the grinding head edge may scrape against the lens surface, causing scratches, with a defect rate as high as 15% or more. Furthermore, the limited variety of abrasive grit design: Existing grinding heads mostly use fixed grit sizes (such as 800# or 1200#), which cannot match the processing requirements of different areas of stepped lenses. For the "non-functional support surface" of the step, fine-grained abrasive will reduce grinding efficiency, increasing the processing time per piece by 200%~300%.

[0003] Current industry attempts at improvement still have limitations: some manufacturers try to process in stages by changing grinding heads of different shapes, but frequent tool changes can lead to a shift in the machining reference and an increase in the coaxiality error of the steps; other manufacturers use grinding heads with a "mixed arrangement of coarse and fine abrasive grains," but the mixing of coarse and fine abrasive grains inevitably results in uneven coarseness. When designing toolpath programs, a large number of invalid and repetitive toolpaths are generated, resulting in long machining times, and the edges of the lens cannot be protected with chamfers, making it difficult to improve efficiency. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this utility model is to provide a composite contour grinding head for precision carving of stepped lenses, enabling full fit processing between the grinding head and the transition surface and end face of the lens steps.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A composite contour grinding head for precision engraving with stepped lenses includes: a shank and a working section; the shank is cylindrical and used for clamping and limiting the spindle of a precision engraving machine; the outer surface of the working section is divided into four functional areas with staggered coarse and fine cylindrical shapes and diamond abrasive grains bonded thereon: Area 1: occupies 40% of the working section surface area, bonded with 250#-380# diamond abrasive grains, used for roughing; Area 2: occupies 10% of the working section surface area, bonded with 250#-350# diamond abrasive grains, used for machining the contour of the steps; Area 3: occupies 50% of the working section surface area, bonded with 800#-1000# diamond abrasive grains, used for side finishing; Area 4: located on the bottom plane of the working section, bonded with 800#-1000# diamond abrasive grains and engraved with cross-shaped heat dissipation grooves, used for platform surface finishing and heat dissipation.

[0006] Furthermore, the second region is groove-shaped, with a step height of 0.5-5 mm and a step angle of 30°-90°, to accommodate stepped lenses of different specifications.

[0007] The abrasive layer in region three is formed by sintering diamond and a copper-based binder, with the binder having a hardness of HV180-200.

[0008] The cross-shaped heat dissipation groove has a depth of 0.5 mm and a width of 0.5 mm.

[0009] Compared with the prior art, the beneficial effects of this utility model are: This novel design, through the combination of a "composite contour grinding head" and "zonal gradient abrasive grain arrangement," has been verified through comparative experiments (test subject: a mobile phone lens with a stepped edge, a step height of 1.83mm, a step angle of 90°, and made of optical glass). It can achieve the following: Significantly improved processing accuracy: Compared with the existing single cylindrical grinding head, the step size deviation of the lens processed by the grinding head of the present invention is reduced from 0.05mm to 0.02mm, which fully meets the processing requirements of high-precision optical lenses.

[0010] Processing efficiency and cost optimization: The processing cycle of a single lens is shortened from 5 minutes in the existing technology to 3 minutes, improving efficiency by 40%; Extended grinding head life: After processing 500 lenses continuously, the wear of the grinding head in this invention is 0.008mm, which is only 16% of that of the existing grinding head (wear of 0.05mm), reducing the frequency of grinding head replacement by 60% and reducing the processing cost per batch by 25%.

[0011] Enhanced versatility: By adjusting the step height of the working section (0.5mm-5mm) and the grit size (such as 250#-380# ultra-fine matte finish processing), it can be adapted to different types of stepped lenses such as automotive camera lenses and smartwatch lenses, eliminating the need to design a separate grinding head for each type of lens and reducing the equipment investment cost for enterprises.

[0012] Improved processing stability: Due to the heat dissipation design at the bottom to disperse the grinding force, the vibration amplitude of the grinding head at high speed (20,000 r / min) is reduced from 0.02 mm to 0.008 mm, which reduces the lens processing error caused by vibration. In the test, the size fluctuation range of 100 consecutive lenses was ≤0.01 mm, and the stability is more than 3 times better than the existing technology. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a composite contour grinding head for precision engraving of stepped lenses according to this utility model; Figure 2 yes Figure 1 Side view; Figure 3 This is a schematic diagram of the processing state of a composite contour grinding head for precision engraving of stepped lenses according to this utility model. Detailed Implementation

[0014] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments.

[0015] See Figure 1-3 A composite contour grinding head for precision engraving with stepped lenses includes: a shank 5 and a working section; the shank is cylindrical and used for clamping and limiting the spindle of a precision engraving machine; the outer surface of the working section is divided into four functional areas with staggered coarse and fine cylindrical shapes and diamond abrasive grains bonded thereon. Area 1: occupies 40% of the working section surface area and is bonded with 250#-380# diamond abrasive grains for roughing; Area 2: occupies 10% of the working section surface area and is bonded with 250#-350# diamond abrasive grains for machining the contour of the steps; Area 3: occupies 50% of the working section surface area and is bonded with 800#-1000# diamond abrasive grains for side finishing; Area 4: located on the bottom plane of the working section, is bonded with 800#-1000# diamond abrasive grains and has cross-shaped heat dissipation grooves for platform surface finishing and heat dissipation.

[0016] The second area is groove-shaped, with a step height of 0.5-5 mm and a step angle of 30°-90°, to accommodate stepped lenses of different specifications.

[0017] The abrasive layer in region three is formed by sintering diamond and a copper-based binder, with the binder having a hardness of HV180-200.

[0018] The cross-shaped heat dissipation groove has a depth of 0.5 mm and a width of 0.5 mm. Example

[0019] A composite profile grinding head for precision engraving of stepped lenses, the object of which is a stepped lens for automotive headlight lenses.

[0020] Overall dimensions of the grinding head: Shank φ8mm×24mm, transition section 6-section inverted frustum shape (cone angle 45°, arc radius R1.5mm, length 5mm), working section φ15mm×22.09mm (including 1 grooved step, groove height 1.73mm, step end face width 1.7mm, bottom end with a 0.5*0.5mm cross-shaped groove). Abrasive grain arrangement: The working section step end face is made of 280# + 750# diamond abrasive grains; the shank and transition section base is 45# steel (hardness HRC28~32); the working section sintered layer is diamond abrasive grains + copper-based binder (binder hardness HV180~200).

[0021] The groove shank limit and fixation ensures that the grinding head is used at a similar height after installation, avoiding different cooling effects due to different installation heights. Φ15mm×22.09mm (including 1 groove step, groove height 1.73mm, step end face width 1.7mm, and a 0.5*0.5mm cross groove added to the bottom end: the groove wraps around the lens step in one piece, improving the lens processing efficiency. The groove at the bottom is added for heat dissipation, ensuring the smoothness of the lens platform and the service life of the grinding head.

[0022] When machining automotive headlight lenses (step height 1.83mm, material K9 optical glass), the single-piece machining time is 3 minutes (compared to 5 minutes in the existing technology), improving efficiency by 16%. After processing 500 pieces continuously, the grinding head wear was 0.008mm, the step size deviation was stable between 0.012mm and 0.018mm, the surface scratch defect rate was 1.8%, and there were no lens ablation or internal cracks.

Claims

1. A composite profile grinding head for precision engraving of stepped lenses, characterized in that, include: Handle and working section; The handle is cylindrical and used for clamping and limiting the spindle of the engraving machine. The outer surface of the working section is divided into four functional areas with staggered coarse and fine cylindrical shapes and diamond abrasive grains bonded to them. Area 1: occupies 40% of the working section surface area and is bonded with 250#-380# diamond abrasive grains for roughing. Area 2: occupies 10% of the working section surface area and is bonded with 250#-350# diamond abrasive grains for machining the contour of the steps. Area 3: occupies 50% of the working section surface area and is bonded with 800#-1000# diamond abrasive grains for side finishing. Area 4: located on the bottom plane of the working section, is bonded with 800#-1000# diamond abrasive grains and has cross-shaped heat dissipation grooves for platform surface finishing and heat dissipation.

2. A composite contour grinding head for precision engraving of stepped lenses according to claim 1, characterized in that, The second area is groove-shaped, with a step height of 0.5-5 mm and a step angle of 30°-90°, to accommodate stepped lenses of different specifications.

3. The composite contour grinding head for precision engraving of stepped lenses according to claim 1, characterized in that, The abrasive layer in region three is formed by sintering diamond and a copper-based binder, with the binder having a hardness of HV180-200.

4. A composite contour grinding head for precision engraving of stepped lenses according to claim 1, characterized in that, The cross-shaped heat dissipation groove has a depth of 0.5 mm and a width of 0.5 mm.

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