Design method of milling and grinding wheel and elastic clamp

Abstract

The invention discloses a design method of a milling grinding wheel and an elastic clamp, and relates to the technical field of optical part machining, the method comprises the following steps: 1, collecting information: rmin, hmin, t, Dt and R; step 2, judging whether h = 2r is true or not, if so, entering step 3, and if not, entering step 4; 3, obtaining a first value range of r, and selecting r0, D0 and a clamping groove depth design value; step 4, judging whether r is greater than or equal to 0.5 D, if so, entering step 5, and otherwise, entering step 6; 5, obtaining a second value range of r, and selecting r0, D0, h0 and a clamping groove depth design value; step 6, obtaining a third value range of r, and selecting r0, D0, h0 and a clamping groove depth design value; according to the method, the structures of the grinding wheel and the clamp are theoretically designed, and the grinding wheel is prevented from abrading the clamp during grinding wheel machining.

Description

Technical Field

[0001] The invention belongs to the technical field of optical parts processing, and in particular relates to a design method of a milling grinding wheel and an elastic clamp. Background Art

[0002] With the rapid development of smart phones and unmanned driving industries, the demand for small-diameter optical parts is increasing, and new requirements are put forward for the processing efficiency of optical parts. Milling and grinding (Fancheng method processing) is one of the important processes in the processing of optical parts. The quality of optical parts after milling and grinding directly affects product quality and production efficiency. Therefore, reasonable grinding wheel and fixture design is particularly important.

[0003] In the milling and grinding of optical parts, elastic clamps can accurately fix optical parts and absorb the vibration generated during the processing. In addition, elastic clamps have the characteristics of low cost, long service life, strong versatility, and convenient installation and disassembly of parts. Therefore, they are widely used in the milling and grinding production of optical parts. However, in the milling and grinding of small-diameter convex optical parts, especially when the radius of curvature of the processed surface is small, it is impossible to quickly and reasonably select the size of the grinding wheel or the size of the elastic clamp, which can easily cause the grinding wheel to wear the clamp, affecting its service life and the accuracy of the processed parts. Summary of the invention

[0004] The purpose of the present invention is to provide a design method of a milling grinding wheel and an elastic clamp with a simple structure and reasonable design in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A design method for a milling grinding wheel and an elastic clamp comprises the following steps:

[0007] Step 1: Collect the following information: The minimum radius of the arc of the grinding wheel head end face is r min , the minimum thickness of the grinding wheel head is h min , the edge thickness t of the part, the expected diameter D of the optical part after milling t and the expected radius of curvature R of the spherical surface of the milled optical part;

[0008] Step 2: Determine whether the thickness of the grinding wheel head is equal to twice the radius of the arc of the end face of the grinding wheel head. If it is equal, proceed to step 3; if not, proceed to step 4.

[0009] Step 3: At this time r min ≤r≤0.5D max , according to D max With R, r, t, D t , H minThe functional relationship of is obtained by inequality 1, and the first value range of r is obtained by solving inequality 1;

[0010] Select the design radius r0 of the arc on the end face of the grinding wheel head. The design radius r0 of the arc on the end face of the grinding wheel head belongs to the first value range and satisfies r min ≤r≤0.5D max conditions;

[0011] Then select the design value D0 of the grinding wheel diameter;

[0012] According to the maximum value of the groove depth and R, r, t, D t The maximum value of the groove depth is calculated by the relationship between and D, and the design value of the groove depth is selected within the maximum value range of the groove depth;

[0013] Step 4: Determine whether r≥0.5D. If yes, proceed to step 5; otherwise, proceed to step 6.

[0014] Step 5: r ≥ 0.5D, D ≥ D min , so 0.5D min ≤r, according to D min With R, r, D t , H min The functional relationship of is obtained by inequality 2, and the second value range of r is obtained by solving inequality 2;

[0015] Selecting a design radius r0 of the arc on the end face of the grinding wheel head, the design radius r0 of the arc on the end face of the grinding wheel head belongs to the second value range and satisfies the condition of r≥0.5D;

[0016] Then select the design value D0 of the grinding wheel diameter;

[0017] Select the design value h0 of the grinding wheel head thickness to satisfy and the condition of h0≤D0;

[0018] Step 6: Since r<0.5D, D≤D max , so r <D max , according to D max With R, r, t, D t , H min The functional relationship of is obtained by inequality 3, and the third value range of r is obtained by solving inequality 3;

[0019] Select the design radius r0 of the arc on the end face of the grinding wheel head, which is within the third value range and satisfies r min ≤r <D max ;

[0020] Then select the design value D0 of the grinding wheel diameter;

[0021] In this step, r0 and D0 are selected to satisfy the condition r0+R≥0.5D0;

[0022] Select the design value h0 of the grinding wheel head thickness to satisfy and h min ≤h0≤2r0 condition.

[0023] Furthermore, the method for selecting the design value D0 of the grinding wheel diameter in step 5 is: calculate the minimum value D of the grinding wheel diameter according to the design radius r0 of the arc on the end face of the grinding wheel head min and the maximum value of the grinding wheel diameter D max , at the minimum value D of the grinding wheel diameter min Maximum value D of grinding wheel diameter max The design value D0 of the grinding wheel diameter is selected, and the design value D0 of the grinding wheel diameter needs to satisfy 2r0≥D0;

[0024] The method for selecting the design value D0 of the grinding wheel diameter in step 3 and step 6 is: calculate the minimum value D of the grinding wheel diameter according to the design radius r0 of the arc on the end face of the grinding wheel head min and the maximum value of the grinding wheel diameter D max , at the minimum value D of the grinding wheel diameter min Maximum value D of grinding wheel diameter max The design value D0 of the grinding wheel diameter is selected, and the design value D0 of the grinding wheel diameter needs to satisfy 2r0≤D0.

[0025] Furthermore, the initial value range of r is

[0026] Furthermore, D max With R, r, t, D t , H min The functional relationship is:

[0027]

[0028] Furthermore, we calculate D min The formula is:

[0029]

[0030] Furthermore, the maximum depth of the clamping groove is related to R, r, t, and D t The relationship between and D is:

[0031]

[0032] Furthermore, inequality 1 is as follows:

[0033]

[0034] Furthermore, inequality 2 is as follows:

[0035]

[0036] Furthermore, inequality 3 is as follows:

[0037]

[0038] Furthermore, when the grinding wheel obtained according to the design method is used to mill optical parts, the spherical surface of the grinding wheel head is tangent to the glass spherical surface of the processed optical part. At this time, the thickness h of the grinding wheel head satisfies the constraint condition h≥2rsinα.

[0039] The present invention has at least the following beneficial effects: through the above-mentioned six-step design method, through theoretical calculation and combined with production practice, when facing convex optical parts with thin edge thickness, small diameter and small curvature radius, the present invention can reasonably select the design values ​​of the radius r of the end face arc of the grinding wheel head and the center diameter D of the grinding wheel according to the actual application conditions, and also make a reasonable selection for the design value of the maximum clamping groove depth H'max of the fixture, thereby ensuring that under this condition, the grinding wheel will not wear the fixture when the optical part is milled by the grinding wheel, thereby increasing the service life of the fixture, improving the processing accuracy and reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the milling principle of optical parts in the prior art;

[0041] Figure 2 It is a schematic diagram of the comparative structure of the elastic abrasive tool before and after being worn in the prior art;

[0042] Figure 3 It is a flow chart of the steps of the design method of the milling grinding wheel and the elastic clamp provided by the present invention;

[0043] Figure 4 This is a schematic diagram of the milling principle of a convex part when the grinding wheel diameter provided by the present invention is the smallest;

[0044] Figure 5 This is a schematic diagram of the milling principle of a convex part when the clamping groove depth provided by the present invention is the largest;

[0045] Figure 6 It is a schematic diagram of the optical part after milling provided by the present invention. DETAILED DESCRIPTION

[0046] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0047] In the prior art, the specific working principle of spherical milling of optical parts is as follows: Figure 1 As shown. The diamond grinding wheel edge passes through the apex of the workpiece, the grinding wheel axis and the workpiece axis intersect at point O, and the angle between the two axes is α. The grinding wheel rotates at high speed around its own axis, and the workpiece rotates at low speed around its own axis. The envelope surface of this motion trajectory forms a spherical surface.

[0048] The size of the spherical radius is related to the angle α between the two axes. m The radius of the end arc r is a constant. By adjusting different angles α, spherical surfaces with different curvature radii R can be processed. The relationship between R and α is as follows:

[0049]

[0050] Conditions: ① The cutting edge of the diamond grinding wheel passes through the apex of the workpiece; ② The axis of the grinding wheel and the axis of the workpiece intersect at point O; ③ The angle between the two axes is α; ④ The grinding wheel rotates at high speed around its own axis, and the workpiece rotates at low speed around its own axis.

[0051] Therefore, in actual production, for convex optical parts with thin edge thickness, small diameter and small curvature radius, the values ​​of the center diameter D and r of the milling tool are completely based on experience. A slight deviation can easily cause the grinding wheel to damage the fixture, such as Figure 2 As shown, Figure 2 The left picture shows the unworn fixture structure. The center area is where the optical parts are placed. Figure 2 The figure on the right is a schematic diagram of the fixture structure after wear. After comparison, it can be seen that if the values ​​of D and r are not appropriate, a slight deviation will form the groove-type wear shown in the figure on the fixture. Grinding wheel damage to the fixture not only affects the service life of the fixture, but also affects the processing accuracy and increases the processing cost.

[0052] To solve the above problems, increase the service life of the fixture, improve processing accuracy, and reduce production costs, refer to Figure 3 The present invention provides a design method for a milling grinding wheel and an elastic clamp, comprising the following steps:

[0053] Step 1: Collect the following information: The minimum radius of the arc of the grinding wheel head end face is r min , the minimum thickness of the grinding wheel head is h min , the edge thickness t of the part, the expected diameter D of the optical part after milling t and the expected radius of curvature R of the spherical surface of the milled optical part;

[0054] Step 2: Determine whether the thickness of the grinding wheel head is equal to twice the radius of the arc of the end face of the grinding wheel head. If it is equal, proceed to step 3; if not, proceed to step 4.

[0055] Step 3: At this time r min ≤r≤0.5D max , according to D max With R, r, t, D t , H min The functional relationship of is obtained by inequality 1, and the first value range of r is obtained by solving inequality 1;

[0056] Select the design radius r0 of the arc on the end face of the grinding wheel head. The design radius r0 of the arc on the end face of the grinding wheel head belongs to the first value range and satisfies r min ≤r≤0.5D max conditions;

[0057] Then select the design value D0 of the grinding wheel diameter;

[0058] According to the maximum value of the groove depth and R, r, t, D t The maximum value of the groove depth is calculated by the relationship between and D, and the design value of the groove depth is selected within the maximum value range of the groove depth;

[0059] Step 4: Determine whether r≥0.5D. If yes, proceed to step 5; otherwise, proceed to step 6.

[0060] Step 5: r ≥ 0.5D, D ≥ D min , so 0.5D min ≤r, according to D min With R, r, D t , H min The functional relationship of is obtained by inequality 2, and the second value range of r is obtained by solving inequality 2;

[0061] Selecting a design radius r0 of the arc on the end face of the grinding wheel head, the design radius r0 of the arc on the end face of the grinding wheel head belongs to the second value range and satisfies the condition of r≥0.5D;

[0062] Then select the design value D0 of the grinding wheel diameter;

[0063] Select the design value h0 of the grinding wheel head thickness to satisfy and the condition of h0≤D0;

[0064] Step 6: Since r<0.5D, D≤D max , so r <D max , according to D max With R, r, t, D t , H min The functional relationship of is obtained by inequality 3, and the third value range of r is obtained by solving inequality 3;

[0065] Select the design radius r0 of the arc on the end face of the grinding wheel head, which is within the third value range and satisfies rmin ≤r <D max ;

[0066] Then select the design value D0 of the grinding wheel diameter;

[0067] In this step, r0 and D0 are selected to satisfy the condition r0+R≥0.5D0;

[0068] Select the design value h0 of the grinding wheel head thickness to satisfy and h min ≤h0≤2r0 condition.

[0069] In the above embodiment, through theoretical calculation and combined with production practice, when facing convex optical parts with thin edge thickness, small diameter and small curvature radius, the design values ​​of the radius r of the end face arc of the grinding wheel head and the center diameter D of the grinding wheel can be reasonably selected, and the design value of the maximum clamping groove depth H'max of the fixture can also be reasonably selected, so as to ensure that under this condition, the fixture will not be worn when the grinding wheel is used to mill and grind optical parts, thereby increasing the service life of the fixture, improving the processing accuracy and reducing the production cost.

[0070] For example, see Figure 4 , which is a schematic diagram of the milling principle of convex optical parts when the grinding wheel diameter is the smallest. It can be seen from the figure that when one side of the diamond grinding wheel head passes through the vertex of the workpiece, the spherical surface of the grinding wheel head on the other side is tangent to the spherical edge of the optical part, or the line connecting the center of the optical part and the center of the grinding wheel head passes through the outermost edge of the spherical surface of the optical part, at this time, the median diameter of the grinding wheel is the minimum value D of the median diameter of the grinding wheel min Specifically, calculate the minimum value D of the grinding wheel diameter min The formula is:

[0071]

[0072] From D min It can be seen from the expression that D min is an increasing function of r.

[0073] Continue reading Figure 5 , which is the milling principle diagram of convex parts when the groove depth is the largest. At this time, the calculated grinding wheel diameter takes the minimum value D min When the maximum depth of the clamping groove is H max The expression is:

[0074]

[0075] Limited by the mechanical properties, clamping stability and firmness of the fixture material, it is assumed that the minimum depth H in actual use minis a certain value. When the depth of the clamping groove is less than this value, the parts will be affected by the tangential force and steering force of the grinding wheel during processing, causing the parts to fall off the fixture, making it impossible to achieve normal processing, and even causing adverse consequences. Therefore, the depth of the clamping groove H needs to meet the condition H max ≥H min .

[0076] Therefore, based on the above-mentioned conditions for the groove depth H, the inequality of r is obtained, that is, the initial value range of r:

[0077]

[0078] According to the minimum depth of the clamping groove H min When a specific value is taken, the corresponding grinding wheel diameter D can reach the maximum value D max , specifically, D max With R, r, t, D t , H min The functional relationship is:

[0079]

[0080] For example, based on D min and D max The formula to obtain the maximum value of the groove depth and R, r, t, D t The relationship between and D is: The specific method of obtaining it is as follows:

[0081] (1) According to D min and D max The range of the grinding wheel center diameter D is calculated by the expression:

[0082]

[0083] (2) Take the derivative of ΔD with respect to r. When the derivative is 0,

[0084]

[0085] (3) When r is rd, ΔD has a maximum value, that is, the maximum range of the grinding wheel diameter. For any selected D value, the expression of the maximum depth H'max of the clamping groove at this time is:

[0086] Where t is the edge thickness of the optical component, D t is the diameter of the part after milling, R is the radius of curvature of the part, r is the arc radius of the end face of the grinding wheel, D is the median diameter of the grinding wheel, αD min Take the minimum value D for the grinding wheel diameter min When , the angle between the grinding wheel axis and the workpiece axis is a constant.

[0087] It should be noted that αD min It is only related to the size of the part. min is a constant, t is a constant, when r is selected, H' max is a decreasing function of D. When D is selected, H' max is an r-increasing function. When r is selected, although H' max The value of, but its value range can be determined, when D = D min Time H' max Take the maximum value when D=D max Time H' max Take the minimum value.

[0088] It should be noted that since the design of the grinding wheel head has a hemispherical shape and a non-hemispherical shape, it is necessary to analyze each case. Therefore, in step 2, it is necessary to determine whether the thickness h of the selected grinding wheel head is equal to twice the radius r of the arc of the end face of the grinding wheel head, and further design is performed based on the determination result.

[0089] For example, when h=2r, that is, the thickness of the grinding wheel head (metal part) under normal conditions is equal to twice the radius r of the end arc of the grinding wheel head (diamond grinding wheel part). Limited by the mechanical properties of the diamond grinding wheel material, it is assumed that the minimum radius of the end arc of the grinding wheel head in actual use is r min , the minimum thickness of the grinding wheel head is h min , both of which are specific values, the radius of the arc of the end face of the grinding wheel head r is less than r min When the material is processed, the wear resistance is poor, the bonding with the metal matrix is ​​not strong, it is easy to break or fall off from the metal matrix, and normal processing cannot be achieved, and even adverse consequences may occur. Therefore, in use, the value range of r meets the following conditions: min ≤r≤0.5D.

[0090] Among them, because D min ≤D max , get r min ≤r≤0.5D max , and according to D max With R, r, t, D t , H min The functional relationship of is obtained by inequality 1, and the first value range of r is obtained by solving inequality 1, where inequality 1 is as follows:

[0091]

[0092] Combining inequalities That is, the initial value range of r, and the first value range of the radius r of the arc on the end face of the grinding wheel head is obtained. Among them, both sides of the above two inequalities about r are constants, so the value range of r obtained is wider and more certain. Therefore, within the specific value range constrained by the two inequalities, a suitable r0 can be selected. It should be noted that when selecting r0, it is also necessary to comprehensively consider the effect of r on ΔD and H' max The influence of the value, thus determining the final selected r0 as the preferred option;

[0093] The method steps for selecting the design value D0 of the grinding wheel diameter include: substituting r=r0 into D min and D max The expression of , and according to r≤0.5D, we can get 2r0≤D0 and D min ≤D0≤D max The constraint range is used to determine the design value D0 of the grinding wheel diameter D; when r0 is determined, D min With D max is a fixed value, so that in a certain D min With D max There exists a D0 greater than or equal to 2r0, that is, D0 ≥ 2r0, since r ≤ 0.5D max As long as r satisfies both the initial value range and the first value range, it can be max Find D0 between 2r0 and 2r0, so that 2r0≤D0; and, when choosing D0, we should also consider H' max The impact of value;

[0094] And the maximum value H' of the groove depth when the grinding wheel diameter is D0 max The steps for selecting the value of include: substituting r0 and D0 into H' max The expression of is used to calculate the design value of the corresponding maximum value of the groove depth.

[0095] When the design is carried out according to the above method, the grinding wheel can be prevented from wearing the elastic clamp, and at the same time, the clamp can be ensured to have sufficient clamping groove depth, and according to H' max The value can also provide technicians with a reference for the maximum groove depth to avoid excessive grooving in actual processing, which may cause the elastic clamp to be worn during subsequent grinding and milling.

[0096] Exemplarily, when the grinding wheel head is not hemispherical, the thickness h of the grinding wheel head is not equal to the radius r of the arc of the end face of the grinding wheel head.

[0097] In step 5, r≥0.5D, and further according to r≥0.5D≥0.5D min , according to D min With R, r, D t , H minThe functional relationship of inequality 2 is obtained:

[0098]

[0099] And continue based on the initial value range of r The solution yields the following second range of values ​​for r:

[0100]

[0101] The influence of r on the values ​​of ΔD and H'max can be comprehensively considered within the above specific constraints to select the design radius r0 of the arc on the end face of the grinding wheel head, wherein the design radius r0 of the arc on the end face of the grinding wheel head belongs to the second value range and satisfies the condition of r≥0.5D.

[0102] After r0 is determined, based on D min and D max The expression of D min and D max is a fixed value, and according to r≥0.5D, we can get 2r0≥D0 and D min ≤D0≤D max Therefore, as long as r satisfies both 2r≥D and D min ≤D≤D max The constraint can be between 2r0 and D min Find D0 between them so that 2r0≥D0.

[0103] It should be noted that when selecting D0, its effect on H' max The influence of the value, and under the condition and h min Under the constraint of ≤h≤D, obtain the constraint range of h and h min ≤h≤D0, and select the appropriate design value h0 of the grinding wheel head thickness within this constraint.

[0104] And the maximum value H' of the groove depth when the grinding wheel diameter is D0 max The steps for determining the design value of include: based on H' max The functional relationship expression of r0 and D0 is used to obtain the design value of the corresponding maximum groove depth.

[0105] Based on the above content, it can be known that under the conditions of h<2r and r≥0.5D, the structure design of the milling grinding wheel and the elastic clamp is carried out, so as to effectively avoid the grinding wheel from wearing the elastic clamp, and at the same time ensure that the elastic clamp has sufficient clamping groove depth. Moreover, according to the value of H'max, it can also provide technical personnel with a reference for the maximum clamping groove depth to avoid excessive grooving in actual processing, which will cause the grinding wheel to wear the elastic clamp during subsequent grinding and milling processing.

[0106] In step 6, since r<0.5D, according to the constraints of r<0.5D and r+R≥0.5D, and further according to D max With R, r, t, D t , H min The functional relationship of inequality 3 is obtained:

[0107] And based on the initial value range of r The third value range of r is obtained comprehensively.

[0108] Obtain the constraint range of the radius r of the end face arc of the grinding wheel head under this condition, and select the design radius value r0 of the end face arc r of the grinding wheel head. The design radius r0 of the end face arc of the grinding wheel head belongs to the third value range and satisfies r min ≤r <D max Then, the design value D0 of the grinding wheel center diameter D, the design value h0 of the grinding wheel head thickness, and the maximum value H' of the groove depth when the grinding wheel center diameter is D0 are determined. max design value.

[0109] Specifically, since r<0.5D, then 2r<D, and h min ≤h≤D, h<2r, so h min ≤h≤2r, and According to the sum h<2r, we get Solving this inequality yields: r+R≥0.5D.

[0110] Among them, after r0 is determined, based on D min and D max The expression of D min and D max is a fixed value, then in D min and D max Select D0 greater than or equal to 2r0.

[0111] It should be noted that when selecting D0, its effect on H' max When selecting r and D, we also need to consider whether r and D satisfy the inequality: r+R≥0.5D. min ≤h<2r0 and Select the design value h0 of the grinding wheel head thickness between.

[0112] The steps for determining the design value of the maximum value H'max of the groove depth when the grinding wheel diameter is D0 include: based on H' max The functional relationship expression of r0 and D0 is used to obtain the design value of the corresponding maximum groove depth.

[0113] Through the above steps, r0, D0 and h0 are determined, and the grinding wheel structure and the elastic fixture structure obtained by designing according to the above method based on the selected r0, D0 and h0 can avoid the grinding wheel from wearing the elastic fixture during milling and grinding. At the same time, it can ensure that the fixture has a sufficient clamping groove depth to achieve normal processing of optical parts.

[0114] For example, Figure 6 The figure shows the schematic diagram of the optical part after milling. The edge thickness of the part is t = 1.38 mm, and the diameter of the part is D t =11.6mm, convex curvature radius R = 10.485mm. Take the minimum value of the end face arc radius r min =0.2mm, the minimum thickness of the grinding wheel head is h min =0.4mm, minimum value of the groove depth H min =0.3mm.

[0115] t,D t , H min , r min , R is substituted into the following inequality:

[0116]

[0117] It turns out that: 0.2mm<r≤6.47mm.

[0118] Take the derivative of ΔD with respect to r. When the derivative is 0, t, D t , H min , r min , R is substituted into the following formula:

[0119]

[0120] When rd = -6.25mm (the value of r when ΔD takes the maximum value), ΔD takes the maximum value, and when r takes the value between 0.2mm and 6.47mm, ΔD is a decreasing function of r. R = 10.485mm, and When it reaches 6.47 mm, D min =D max , ΔD=0, when r is between 0.2mm and 6.47mm, ΔD is greater than or equal to zero.

[0121] When the grinding wheel head thickness h = 2r, solve the inequality:

[0122]

[0123] We get: -3.2mm≤r≤4.624mm. Combined with 0.2mm<r≤6.47mm, we determine the constraint range of r to be: 0.2mm<r≤4.624mm.

[0124] Appropriately increase the values ​​of ΔD and H'max. In actual operation and adjustment of process parameters, there is more room for adjustment. However, H'max is an increasing function of r. When r is between 0.2 and 4.624 mm, ΔD is a decreasing function of r. It is impossible to make both of them take the maximum value at the same time. Considering the durability of the grinding wheel, it is assumed that r0 = 1 mm (not unique, theoretically it can take any value between 0.2 and 4.624 mm), H' max The value range of ΔH' is 0.3~1.213mm, max =0.913mm, the value range of D is 6.64~8.06mm and ΔD=1.42mm.

[0125] When r0 = 1 mm, within the constraints of 6.64 mm ≤ D ≤ 8.06 mm and D ≥ 2r0 = 2 mm, the design value D0 of the grinding wheel median diameter D is selected. max It is a decreasing function of D. D should be selected as the minimum value of 6.64mm, H' max The maximum value is 1.21mm, but in actual operation, a slight error in the longitudinal movement (or the part is processed to the upper tolerance, and the grinding wheel is processed to the lower tolerance) may cause the edge of the part to not contact the grinding wheel, resulting in the machined surface not being a complete sphere, and the curvature radius of the machined surface cannot be measured online, so the process parameters cannot be adjusted according to the measured curvature radius. Therefore, the value of D can be appropriately increased on the basis of 6.64mm. Assuming that D = 7mm is selected (not unique, any value between 6.64 and 8.06mm can be selected in theory), the maximum depth of the clamping groove is: H' max =0.997mm. Substitute D, r, R into: The angle between the grinding wheel axis and the workpiece axis is α = 17.75 degrees. This allows the depth of the groove to not exceed H' max =0.997mm. Through the above-mentioned structural design of the milling grinding wheel and the design of the clamping groove depth of the elastic clamp, it can be ensured that the grinding wheel does not wear the elastic clamp during milling and grinding, thereby increasing the service life of the clamp, improving the processing accuracy and reducing the production cost.

[0126] When h<2r, h satisfies the following constraints: ,h min ≤h≤D, according to the above constraint condition of h, determine whether r≥0.5D holds.

[0127] When r≥0.5D,

[0128] t,D t , H min , substituting the parameter of R into the above inequality, we get: 4.26mm≤r≤6.47mm.

[0129] Increase ΔD and H' appropriately max In actual operation and during the process of adjusting process parameters, there is more room for adjustment, but H' max is an increasing function of r. When r is between 4.26 and 6.47 mm, ΔD is a decreasing function of r. It is impossible to make both of them reach the maximum value at the same time. Assuming that r0=5 mm (not unique, theoretically it can take any value between 4.26 and 6.47 mm), H' max The value range of ΔH' is 0.3~0.55mm, max =0.25mm, D range is 8.95~9.36mm and ΔD=0.41mm. According to D0≤2r0=10mm, and D range is 8.95~9.36mm, consider H' max The value of D0 is 9.2 mm (not unique, theoretically any value between 8.95 and 9.36 mm can be selected), H' max =0.4mm. At this time, Select h0=4mm.

[0130] Substitute the parameter values ​​of r0=5mm, D0=9.2mm, and R=10.485mm into The angle between the grinding wheel axis and the workpiece axis is α = 17.29 degrees. At this time, the depth of the groove during processing does not exceed H' max =0.4mm, which can prevent the grinding wheel from wearing the fixture.

[0131] When r<0.5D, solve the following inequality:

[0132]

[0133] Determine the constraint range of r: 0.2mm <r<4.624mm。

[0134] Increase ΔD and H' appropriately max In actual operation and during the process of adjusting process parameters, there is more room for adjustment, but H' max is an increasing function of r. When r is between 0.2 and 4.624 mm, ΔD is a decreasing function of r. It is impossible to make both of them take the maximum value at the same time. Considering the durability of the grinding wheel, it is assumed that r0 = 3.5 mm (not unique, theoretically it can take any value between 0.2 and 4.624 mm), H' max The value range of ΔH' is 0.30~0.80mm, max =0.5mm, the value range of D is 8.08~8.90mm and ΔD=0.82mm.

[0135] When r0 = 3.5 mm is selected, the value range of D is 8.08 mm ≤ D ≤ 8.90 mm, and R = 10.485 mm. It must satisfy r + R ≥ 0.5D, and at the same time, it must also satisfy D ≥ 2r0 = 7 mm. Since H’ max is a decreasing function of D, D should be selected as the minimum value of 8.08 mm, and H’ max takes the maximum value of 0.80 mm. However, in actual operation, there is a slight error in the longitudinal movement amount (or the part is machined to the upper tolerance and the grinding wheel is machined to the lower tolerance), which is very likely to cause the edge of the part not to contact the grinding wheel, resulting in the machined surface not being a complete spherical surface, and it is impossible to perform on-line measurement of the curvature radius of the machined surface. Therefore, it is impossible to adjust the process parameters according to the measured curvature radius. Therefore, the value of D can be appropriately increased on the basis of 8.08 mm. Assume that D = 8.5 mm is selected (not unique, any value between 8.08 and 8.90 mm can be selected theoretically). At this time, the maximum depth of the clamping groove is: H’ max = 0.55 mm. According to H min ≤ h < 2r0, the constraint range selects h0 = 5 mm (not unique, 2.13 mm < h0 < 7 mm). Substitute D = 8.5 mm, r = 3.5 mm, and R = 10.485 mm into to obtain the included angle α between the grinding wheel shaft and the workpiece shaft as 17.70 degrees. During machining, the depth of the clamping groove does not exceed H’ max = 0.55 mm. Through the above structural design of the milling and grinding wheel and the design of the clamping groove depth of the elastic fixture, the grinding wheel can be made not to wear the fixture during milling and grinding, increasing the service life of the fixture, improving the machining accuracy, and reducing the production cost.

[0136] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A design method for a milling grinding wheel and an elastic clamp, characterized in that: The steps include: Step 1: Collect the following information: The minimum radius of the arc of the grinding wheel head end face is r min , the minimum thickness of the grinding wheel head is h min , the edge thickness t of the part, the expected diameter D of the optical part after milling t and the expected radius of curvature R of the spherical surface of the milled optical part; Step 2: Determine whether the thickness of the grinding wheel head is equal to twice the radius of the arc of the end face of the grinding wheel head. If it is equal, proceed to step 3; if not, proceed to step 4. Step 3: At this time r min ≤r≤0.5D max , according to D max With R, r, t, D t , H min The functional relationship of is obtained by inequality 1, and the first value range of r is obtained by solving inequality 1; Select the design radius r0 of the arc on the end face of the grinding wheel head. The design radius r0 of the arc on the end face of the grinding wheel head belongs to the first value range and satisfies r min ≤r≤0.5D max conditions; Then select the design value D0 of the grinding wheel diameter; According to the maximum value of the groove depth and R, r, t, D t The maximum value of the groove depth is calculated by the relationship between and D, and the design value of the groove depth is selected within the maximum value range of the groove depth; Step 4: Determine whether r≥0.5D. If yes, proceed to step 5; otherwise, proceed to step 6. Step 5: r ≥ 0.5D, D ≥ D min , so 0.5D min ≤r, according to D min With R, r, D t , H min The functional relationship of is obtained by inequality 2, and the second value range of r is obtained by solving inequality 2; Selecting a design radius r0 of the arc on the end face of the grinding wheel head, the design radius r0 of the arc on the end face of the grinding wheel head belongs to the second value range and satisfies the condition of r≥0.5D; Then select the design value D0 of the grinding wheel diameter; Select the design value h0 of the grinding wheel head thickness to satisfy and the conditions h0≤D0; Step 6: Since r<0.5D, D≤D max , so r <D max , according to D max With R, r, t, D t , H min The functional relationship of is obtained by inequality 3, and the third value range of r is obtained by solving inequality 3; Select the design radius r0 of the arc on the end face of the grinding wheel head, which is within the third value range and satisfies r min ≤r <D max ; Then select the design value D0 of the grinding wheel diameter; In this step, r0 and D0 are selected to satisfy the condition r0+R≥0.5D0; Select the design value h0 of the grinding wheel head thickness to satisfy and h min ≤h0≤2r0 condition.

2. The design method of a milling grinding wheel and an elastic clamp according to claim 1, characterized in that: The method for selecting the design value D0 of the grinding wheel diameter in step 5 is: calculate the minimum value D of the grinding wheel diameter according to the design radius r0 of the arc on the end face of the grinding wheel head min and the maximum value of the grinding wheel diameter D max , at the minimum value D of the grinding wheel diameter min Maximum value D of grinding wheel diameter max The design value D0 of the grinding wheel diameter is selected, and the design value D0 of the grinding wheel diameter needs to satisfy 2r0≥D0; The method for selecting the design value D0 of the grinding wheel diameter in step 3 and step 6 is: calculate the minimum value D of the grinding wheel diameter according to the design radius r0 of the arc on the end face of the grinding wheel head min and the maximum value of the grinding wheel diameter D max , at the minimum value D of the grinding wheel diameter min Maximum value D of grinding wheel diameter max The design value D0 of the grinding wheel diameter is selected, and the design value D0 of the grinding wheel diameter needs to satisfy 2r0≤D0.

3. The design method of a milling grinding wheel and an elastic clamp according to claim 2, characterized in that: The initial value range of r is:

4. The design method of a milling grinding wheel and an elastic clamp according to claim 3, characterized in that: D max With R, r, t, D t , H min The functional relationship is:

5. The design method of a milling grinding wheel and an elastic clamp according to claim 4, characterized in that: Calculate D min The formula is:

6. The design method of a milling grinding wheel and an elastic clamp according to claim 5, characterized in that: Maximum clamping groove depth and R, r, t, D t The relationship between and D is:

7. The design method of a milling grinding wheel and an elastic clamp according to claim 6, characterized in that: Inequality 1 is as follows:

8. The design method of a milling grinding wheel and an elastic clamp according to claim 6, characterized in that: Inequality 2 is as follows:

9. The design method of a milling grinding wheel and an elastic clamp according to claim 8, characterized in that: Inequality 3 is as follows:

10. The design method of a milling grinding wheel and an elastic clamp according to claim 9, characterized in that: When the grinding wheel obtained according to the design method is used to mill optical parts, the spherical surface of the grinding wheel head is tangent to the glass spherical surface of the processed optical part. At this time, the thickness h of the grinding wheel head satisfies the constraint condition of h≥2rsinα.

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