Tungsten steel die insert binary surface machining method

Abstract

A tungsten steel die core binary surface processing method comprises the following steps: step one, connecting a diamond grinding stone, a first clamp and a CNC processing shaft in a Y-axis direction, the diamond grinding stone having a sharp periphery and an inclined surface, the sharp periphery being used to process the tungsten steel die core along a Z-axis direction, and the processing shaft being able to drive the diamond grinding stone to adjust a posture; step two, connecting a tungsten steel die core, a second clamp and a CNC workpiece shaft in a Z-axis direction; step three, rotating the CNC workpiece shaft; step four, aligning the periphery of the diamond grinding stone with the center of the tungsten steel die core; step five, according to an even-order aspheric surface formula, the diamond grinding stone performs aspheric surface processing on the tungsten steel die core; step six, according to an optical binary surface condition and based on a whole half radius formula of the binary surface, calculating a position difference between each point of the binary surface and each point on the aspheric surface that has been processed on the tungsten steel die core, and determining an actual feed amount of the diamond grinding stone for each position point; and step seven, based on the actual feed amount, performing ring belt processing on the binary surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of binary surface optical glass lens molding, and more particularly to a binary surface processing method of tungsten steel mold core. BACKGROUND

[0002] Binary surface optical glass lens molding often requires very precise molds, which are generally difficult to complete by mechanical processing. Tungsten steel molds have a service life of tens of times or even hundreds of times that of steel molds. Tungsten steel molds have high hardness, high strength, corrosion resistance, high temperature resistance, and a small expansion coefficient, and are particularly suitable as molds for binary surface lens molding. However, the current method for processing binary surfaces of tungsten steel mold cores is very harsh, and only foreign countries have mature processing methods. Generally, turning methods are used in combination with laser-assisted processing. This method causes severe tool wear, is complex, and is expensive to process. SUMMARY

[0003] In view of the problems in the background art, an object of the present disclosure is to provide a binary surface processing method of a tungsten steel mold core, which can simplify the binary surface processing technology of the tungsten steel mold core.

[0004] Another object of the present disclosure is to provide a binary surface processing method of a tungsten steel mold core, which can reduce the processing cost of the binary surface of the tungsten steel mold core.

[0005] Still another object of the present disclosure is to provide a binary surface processing method of a tungsten steel mold core, which can reduce tool wear compared to turning.

[0006] Still another object of the present disclosure is to provide a binary surface processing method of a tungsten steel mold core, which can ensure the precision of the binary surface of the processed tungsten steel mold core.

[0007] Thus, a binary surface processing method of a tungsten steel mold core includes the following steps: step one, connecting a diamond grinding stone, a first clamp, and a CNC processing shaft in the Y-axis direction in sequence, the diamond grinding stone having a sharp periphery and a bevel on both sides of the Y-axis direction connected to the periphery, the sharp periphery being used to process the tungsten steel mold core in the Z-axis direction, and the processing shaft being able to drive the diamond grinding stone to adjust the posture; step two, connecting a tungsten steel mold core to be processed, a second clamp, and a CNC workpiece shaft in the Z-axis direction in sequence; step three, rotating the CNC workpiece shaft; step four, aligning the periphery of the diamond grinding stone with the center of the tungsten steel mold core in the X-axis direction and the Z-axis direction by the processing shaft; step five, performing aspheric processing on the tungsten steel mold core by the diamond grinding stone according to an even aspheric surface formula; step six, calculating the position difference between each point of the binary surface and each point on the aspheric surface of the processed tungsten steel mold core based on the entire half radius formula of the binary surface, and determining the actual feed amount of the diamond grinding stone for each position point according to the optical binary surface condition; and step seven, performing ring band processing on the binary surface based on the actual feed amount to process the binary surface of the tungsten steel mold core.

[0008] The beneficial effects of the present disclosure are as follows: compared with the background art, in the tungsten steel die core binary surface processing method according to the present disclosure, the tungsten steel die core binary surface processing is carried out in a grinding single mode by the diamond dresser, which can simplify the tungsten steel die core binary surface processing process, reduce the tool wear compared with turning, and reduce the cost of tungsten steel die core binary surface processing. In the tungsten steel die core binary surface processing method according to the present disclosure, the aspherical surface processing of the tungsten steel die core by the diamond dresser according to the even aspherical surface formula in step five is equivalent to rough processing, and the difference and ring band processing in steps six and seven is equivalent to fine processing. The processing ring band of the annular surface expressed by the even aspherical surface formula in step five and the binary surface expressed by the whole half radius formula in step six form a good rough processing molding and further fine processing molding relationship in shape, which is more suitable for diamond dresser grinding processing, and thus the precision of the binary surface of the processed tungsten steel die core can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic view of the corresponding equipment components of the tungsten steel die core binary surface processing method according to the present disclosure.

[0010] Figure 2 is a top view of a part of the diamond dresser and the first clamp.

[0011] Figure 3 is a schematic view of the relationship between the positions of the points of the binary surface and the points of the processed aspherical surface of the tungsten steel die core, wherein only a part of the aspherical surface and the binary surface is shown, Z1 is the aspherical surface coordinate, and Z2 is the binary surface coordinate.

[0012] Figure 4 is a part of Figure 3 is a part of

[0013] Figure 5 is a schematic view of the adjustment of the diamond dresser to avoid interference.

[0014] Figure 6 is a tungsten steel die core aspherical surface type detection diagram.

[0015] Figure 7 is a tungsten steel die core binary surface type detection diagram.

[0016] In the drawings, the reference numerals are explained as follows:

[0017] 1 diamond dresser

[0018] 11 periphery

[0019] 12 inclined surface

[0020] 2 first clamp

[0021] 3 CNC machining shaft

[0022] 4 Tungsten steel die core

[0023] 5 Second clamp

[0024] 6 CNC workpiece shaft DETAILED DESCRIPTION

[0025] The accompanying drawings illustrate embodiments of the present disclosure and, it is to be understood that the disclosed embodiments are merely examples of the present disclosure, the present disclosure can be implemented in various forms, therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching a person of ordinary skill in the art to implement the present disclosure in various ways.

[0026] Reference Figures 1 to 5 , the tungsten steel die core binary surface machining method according to the present disclosure includes the steps of:

[0027] Step one, sequentially connect the diamond grinding stone 1, the first clamp 2, and the CNC machining shaft 3 in the Y-axis direction, the diamond grinding stone 1 has a sharp periphery 11 and a bevel 12 connected to the periphery 11 on both sides of the Y-axis direction, the sharp periphery 11 is used to machine the tungsten steel die core along the Z-axis direction, and the machining shaft 3 can drive the diamond grinding stone 1 to adjust the posture;

[0028] Step two, sequentially connect the tungsten steel die core 4 to be machined, the second clamp 5, and the CNC workpiece shaft 6 in the Z-axis direction;

[0029] Step three, rotate the CNC workpiece shaft 6;

[0030] Step four, align the periphery 11 of the diamond grinding stone 1 with the center of the tungsten steel die core 4 in the X-axis and Z-axis directions through the machining shaft 3;

[0031] Step five, according to the even-order aspheric surface formula, the diamond grinding stone 1 performs aspheric surface machining on the tungsten steel die core 4;

[0032] Step six, according to the optical binary surface condition and based on the entire half radius formula of the binary surface, calculate the position difference between each point of the binary surface and each point on the machined aspheric surface of the tungsten steel die core 4, and determine the actual feed amount of the diamond grinding stone 1 for each position point;

[0033] Step seven, based on the actual feed amount, perform ring belt machining on the binary surface to machine the binary surface of the tungsten steel die core.

[0034] Compared with the background art, in the tungsten steel die core binary surface processing method according to the present disclosure, the tungsten steel die core binary surface processing is carried out in a grinding single mode by the diamond dresser 1, which can simplify the tungsten steel die core binary surface processing process, reduce the tool wear compared with turning, and reduce the cost of tungsten steel die core binary surface processing. In the tungsten steel die core binary surface processing method according to the present disclosure, the aspherical surface processing of the tungsten steel die core 4 by the diamond dresser 1 according to the even aspherical surface formula in step five is equivalent to rough processing, and the difference and ring band processing in steps six and seven is equivalent to fine processing. The processing ring band of the annular surface expressed by the even aspherical surface formula in step five and the binary surface expressed by the whole half radius formula in step six form a good rough processing molding and further fine processing molding relationship in shape, which is more suitable for the grinding processing of the diamond dresser 1, and thus the precision of the processed binary surface of the tungsten steel die core can be ensured.

[0035] In the tungsten steel die core binary surface processing method according to the present disclosure, the processing shaft 3 in step one can drive the diamond dresser 1 to adjust the posture, which is provided by the function of the CNC machine tool itself. Any known CNC machine tool currently has this function. The rotation of the CNC workpiece shaft 6 in step three facilitates the operator to visually operate the alignment in step four, that is, the periphery 11 of the diamond dresser 1 and the center of the tungsten steel die core 4 are aligned in the X-axis direction and the Z-axis direction, that is, the plane where the periphery 11 is located coincides with the plane formed by the X-axis direction and the Y-axis direction. Figure 3 and Figure 4 As shown in

[0036] Referring to Figure 1 , in step one, the included angle of the two inclined surfaces 12 on both sides of the diamond dresser 1 in the Y-axis direction is 20-40°. That is, the periphery 11 of the diamond dresser 1 and the two inclined surfaces 12 form a whole circle of sharp corner parts, which facilitates the ring band processing in step seven and reduces the risk of possible interference described below. Preferably, the two inclined surfaces are mirror symmetrical with respect to the plane where the periphery 11 is located.

[0037] In an embodiment, in step three, the rotation speed of the CNC workpiece shaft 6 is 100-300 RPM.

[0038] In an embodiment, in step five, the aspherical surface formula is:

[0039]

[0040] wherein R is the radius at the vertex of the aspherical surface,

[0041] is the conic coefficient of the quadratic curve,

[0042] A4, A6, A8, A 10 , A 12for aspherical surface order coefficient,

[0043] Y represents the incident height of the incident light on the aspherical surface.

[0044] In one embodiment, in step six, the binary surface entire half-radii formula is:

[0045]

[0046] where λ c is the design wavelength, N0 is the refractive index of the medium, (ρ) is the phase retardation function,

[0047]

[0048] where M is the diffraction order, N is the order of the phase function, A i is the coefficient of each order, and ρ is the normalized radial coordinate.

[0049] In one example, with reference Figure 5 to the peripheral edge 11 of the diamond grinding wheel 1 and the position relationship between each point on the two bevels 12 and the existing surface type on the tungsten steel die core 4 to be processed, it is determined whether there is interference between the diamond grinding wheel 1 and the existing surface type on the tungsten steel die core 4 to be processed. If there is interference, the diamond grinding wheel 1 is driven by the CNC machining shaft 3 to adjust the position of the peripheral edge 11 of the diamond grinding wheel 1 to avoid interference and to perform under-amount processing according to the maximum interference amount of each point of the diamond grinding wheel 1.

[0050] In one embodiment, the tungsten steel die core binary surface machining method further comprises step eight: using a Taylor profilometer to detect the binary surface surface type of the binary surface die core machined in step seven, as shown in Figure 7 .

[0051] In one embodiment, between step five and step six, there is also a step: using a Taylor profilometer to detect the aspherical surface surface type machined in step five, as shown in Figure 6 .

[0052] A number of exemplary embodiments are described above with the detail description, but the present document is not intended to be limited to the explicitly disclosed combinations. Therefore, unless otherwise specified, various features disclosed herein can be combined together to form a number of additional combinations which are not shown for the purpose of simplicity.

Claims

1. A method for machining the binary surface of a tungsten carbide mold core, characterized in that, Including the following steps: Step 1: Connect the diamond whetstone (1), the first fixture (2), and the CNC machining axis (3) in sequence along the Y-axis. The diamond whetstone (1) has a sharp periphery (11) and inclined surfaces (12) on both sides of the Y-axis that are connected to the periphery (11). The sharp periphery (11) is used to process the tungsten steel mold core along the Z-axis. The machining axis (3) can drive the diamond whetstone (1) to adjust its posture. Step 2: Connect the tungsten carbide mold core (4), the second fixture (5), and the CNC workpiece axis (6) in sequence along the Z-axis. Step 3: Rotate the CNC workpiece axis (6); Step 4: Align the periphery (11) of the diamond whetstone (1) with the center of the tungsten carbide mold core (4) in the X-axis and Z-axis directions by machining the shaft (3); Step 5: According to the even-order aspherical formula, the diamond whetstone (1) is used to perform aspherical processing on the tungsten carbide mold core (4); Step 6: Based on the optical binary surface conditions and the formula for the entire half-aperture of the binary surface, calculate the positional compensation between each point of the binary surface and each point on the aspherical surface of the tungsten carbide mold core (4) that has been processed, and determine the actual feed amount of the diamond whetstone (1) for each position point. Step 7: Based on the actual feed rate, perform ring-shaped machining according to the binary surface to produce the binary surface of the tungsten carbide mold core; In step one, the angle between the inclined planes (12) on both sides of the diamond whetstone (1) in the Y-axis direction is 20-40°.

2. The method for machining the binary surface of a tungsten carbide mold core according to claim 1, characterized in that, In step three, the rotation speed of the CNC workpiece axis (6) is 100-300 RPM.

3. The method for machining the binary surface of a tungsten carbide mold core according to claim 1, characterized in that, In step five, the formula for aspherical surfaces is: Formula (1) where R is the radius at the vertex of the non-spherical surface. k is the conic coefficient of the quadratic curve. A4, A6, A8, A 10 A 12 For aspherical order coefficients, Y represents the incident height of the incident ray on the aspherical surface.

4. The method for machining the binary surface of a tungsten carbide mold core according to claim 1, characterized in that, In step six, the formula for the entire half-aperture of the binary surface is: Where, λ c Where N0 is the design wavelength, N0 is the refractive index of the medium, and Φ(ρ) is the phase delay function. Where M is the diffraction order, N is the order of the phase function, and A i For each order, ρ represents the coefficient, and ρ is the normalized radial coordinate.

5. The method for machining the binary surface of a tungsten carbide mold core according to claim 1, characterized in that, In step seven: Based on the positional relationship between the periphery (11) of the diamond whetstone (1) and the points on the two inclined surfaces (12) and the existing surface on the tungsten carbide mold core (4) to be processed, it is determined whether there is interference between the diamond whetstone (1) and the existing surface on the tungsten carbide mold core (4) to be processed. If there is interference, the diamond whetstone (1) is driven by the machining axis (3) via the CNC machining axis (3) to adjust the position of the periphery (11) of the diamond whetstone (1) to avoid interference, and the reduction machining is performed according to the maximum interference amount of each point of the diamond whetstone (1).

6. The method for machining the binary surface of a tungsten carbide mold core according to claim 1, characterized in that, It also includes step eight: using a Taylor profiler to inspect the binary surface shape of the binary surface core processed in step seven.

7. The method for machining the binary surface of a tungsten carbide mold core according to claim 1, characterized in that, Between steps five and six, there is an additional step: inspecting the aspherical surface profile processed in step five using a Taylor profiler.

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