TWI416291B

TWI416291B - Method for processing an aspheric lens mold

Info

Publication number: TWI416291B
Application number: TW97126268A
Authority: TW
Inventors: Wen Ssu Chiu; Kun Jung Tsai
Original assignee: Hon Hai Prec Ind Co Ltd
Priority date: 2008-07-11
Filing date: 2008-07-11
Publication date: 2013-11-21
Also published as: TW201003343A

Abstract

The invention provides a method for processing an aspheric lens mold, The method includes the following steps: providing a processing equipment for processing a mold, fixing the mold on a main axis of the processing equipment; driving a knife of the processing equipment to the zero point position of a workpiece coordinate; a numerical control unit of the processing equipment transforms a polar coordinates value of the knife to a workpiece coordinate value, and determines the working point on the mold for the knife; the numerical control unit gets the workpiece coordinate value of a mold hole's the geometric center according to the workpiece coordinate value of the knife, calculating the face shape of the mold hole by according to the polar coordinates value of the knife and the workpiece coordinate value of geometric center of the mold hole and an aspheric formula, and determining immediate feeding quantity of the knife; Supplements emendation to the cutting tool way according to the mold hole's face shape, completes the process of the aspheric surface lens mold.

Description

非球面透鏡模具加工方法 Aspheric lens mold processing method

本發明涉及一種加工方法，特別涉及一種非球面透鏡模具加工方法。 The invention relates to a processing method, in particular to a method for processing an aspherical lens mold.

光學零件注射成型技術中之模具要達到很高之要求，用一般之機械加工方法無法達到。目前國外大多數模具製造商均採用超精密單點金剛石車床進行車削或磨削，再用金剛石研磨膏進行手工拋光來加工模具表面(請參見“非球面透鏡模具之製造”，張松，《記錄媒體技術》，2007年第6期，62-64頁)，但是此種方法效率低，不利於非球面透鏡模具之批量生產。然而，其他之方法，如：電火花加工、電鑄複製及光學修磨等，加工精度很低，因此非球面透鏡模具之加工變得十分困難。 The molds in the optical part injection molding technology have to meet high requirements and cannot be achieved by general mechanical processing methods. At present, most foreign mold manufacturers use ultra-precision single-point diamond lathes for turning or grinding, and then use diamond polishing paste for manual polishing to process the mold surface (see "Manufacture of aspherical lens molds", Zhang Song," Recording Media Technology, No. 6, 2007, pp. 62-64), but this method is inefficient and is not conducive to mass production of aspheric lens molds. However, other methods, such as EDM, electroforming, and optical grinding, have low processing accuracy, so processing of aspherical lens molds becomes very difficult.

有鑑於此，有必要提供一種加工精度好且加工效率高之非球面透鏡模具加工方法。 In view of this, it is necessary to provide an aspherical lens mold processing method with high processing precision and high processing efficiency.

一種非球面透鏡模具加工方法，其包括以下步驟：提供一加工裝置，其用於對待加工模具進行加工，將待加工模具固定在加工裝置之主軸上，所述主軸帶動加工模具轉動；驅動加工裝置之刀具進入工件坐標系之原點位置；加工裝置之數控單元將刀具之極座標值轉化為工件座標值，並確定刀具在待加工模具上之加工點；數控單元根據刀具之工件座標值得出待加工模具之一模穴之幾何中心工件座標值，通過將刀具之極座標值及模穴之幾何中心工件座標值代入到非球面面型公式計算出待加工模具模穴之面型，並確定刀具之即時進刀量；根據待加工模具模穴之面型對刀具路徑補正，完成非球面透鏡模具之加工。 An aspherical lens mold processing method, comprising the steps of: providing a processing device for processing a mold to be processed, fixing the mold to be processed on a main shaft of the processing device, the spindle driving the processing mold to rotate; driving the processing device The tool enters the origin position of the workpiece coordinate system; the numerical control unit of the processing device takes the pole of the tool The standard value is converted into the workpiece coordinate value, and the machining point of the tool on the mold to be processed is determined; the numerical control unit is worth according to the workpiece coordinate of the tool, and the coordinate value of the geometric center workpiece of one of the mold holes to be processed is obtained, and the polar coordinate value of the tool is The geometric center of the cavity is substituted into the aspherical surface formula to calculate the surface shape of the mold cavity to be processed, and the instantaneous feed amount of the tool is determined; the tool path is corrected according to the shape of the mold cavity to be processed, and the completion is completed. Processing of aspheric lens molds.

相較於先前技術，所述之非球面透鏡模具加工方法通過非球面面型公式得出非球面模具模穴面型，然後驅動刀具根據非球面面型對待加工模具進行即時切削，可有效提高加工精度和生產效率。 Compared with the prior art, the aspherical lens mold processing method obtains the aspherical mold cavity surface shape by the aspherical surface type formula, and then drives the tool to perform the cutting according to the aspherical surface type to process the mold, which can effectively improve the processing. Accuracy and productivity.

圖1係本發明實施方式非球面透鏡模具加工方法流程圖；圖2係本發明實施方式非球面透鏡模具加工方法之加工裝置示意圖；圖3係本發明實施方式非球面透鏡模具加工方法原理示意圖。 1 is a flow chart of a method for processing an aspherical lens mold according to an embodiment of the present invention; FIG. 2 is a schematic view of a processing device for processing an aspherical lens mold according to an embodiment of the present invention; and FIG. 3 is a schematic view showing a principle of a method for processing an aspherical lens mold according to an embodiment of the present invention.

下面將結合附圖與實施例對本技術方案作進一步詳細說明。 The technical solution will be further described in detail below with reference to the accompanying drawings and embodiments.

如圖1及圖2所示，本發明之非球面透鏡模具加工方法包括以下步驟： As shown in FIG. 1 and FIG. 2, the aspherical lens mold processing method of the present invention comprises the following steps:

S101，提供一加工裝置，其用於對待加工模具100進行加工，將待加工模具100固定在加工裝置之主軸22上，所述主軸22帶動待加工模具100轉動。所述之非球面透鏡模具加工裝置還包括：一數控裝置10、一刀具12、一壓電驅動軸14、一Z軸導軌16、一電機20、一X軸導軌24。在Z軸導軌16上有一固定壓電驅動軸14。在該壓電驅動軸14相對於待加工模具100之一端固定有一刀具12，所述刀具12為鑽石刀頭，具有較強之耐磨性。在垂直於Z軸導軌18之方向設置有一X軸導軌24，一電機20位於X軸導軌24上，在X軸導軌24內有一驅動裝置可驅動該電機20在X軸方向上移動，實現待加工模具100被加工點之變換。在電機20內有一主軸22，該主軸22帶動模具進行旋轉。 S101, a processing device is provided for processing the mold 100 to be processed, and the mold 100 to be processed is fixed on the main shaft 22 of the processing device, and the spindle 22 drives the mold 100 to be processed to rotate. The aspherical lens mold processing device further includes: a numerical control device 10, a cutter 12, a piezoelectric drive shaft 14, a Z-axis guide rail 16, and an electric Machine 20, an X-axis guide rail 24. A fixed piezoelectric drive shaft 14 is mounted on the Z-axis guide 16. A cutter 12 is fixed to one end of the piezoelectric drive shaft 14 with respect to the mold 100 to be processed. The cutter 12 is a diamond cutter head and has strong wear resistance. An X-axis guide rail 24 is disposed in a direction perpendicular to the Z-axis guide rail 18. A motor 20 is disposed on the X-axis guide rail 24, and a driving device is driven in the X-axis guide rail 24 to drive the motor 20 to move in the X-axis direction to be processed. The mold 100 is transformed by the machining point. Inside the motor 20 is a spindle 22 that drives the mold for rotation.

定義刀具12與待加工模具100之接觸點為刀具12之中心點，刀具12中心點在以工件坐標系原點為極點，以工件坐標系之X軸正方向為極軸之極坐標系中之極座標值為(ρ，θ)，所述工件坐標系採用標準右手笛卡兒直角坐標系，符合右手法則，所述刀具12之極座標值(ρ，θ)轉化後之工件座標值為(Xm，Ym)；每個模穴100之幾何中心點在工件坐標系中之座標值為(Xn，Yn)。 The contact point between the tool 12 and the mold to be processed 100 is defined as the center point of the tool 12, and the center point of the tool 12 is in the polar coordinate system with the origin of the workpiece coordinate system as the pole point, and the positive direction of the X coordinate of the workpiece coordinate system is the polar axis. The polar coordinate value is (ρ, θ), and the workpiece coordinate system adopts a standard right-handed Cartesian Cartesian coordinate system, which conforms to the right-hand rule, and the coordinate value of the workpiece after the transformation of the polar coordinate value (ρ, θ) of the tool 12 is (Xm, Ym); the geometric center point of each cavity 100 has a coordinate value (Xn, Yn) in the workpiece coordinate system.

S102，驅動加工裝置之刀具12進入工件坐標系之原點位置，此時，刀具12之極座標值為(0，0)。當轉動主軸22及移動位於X軸導軌24上之電機20時，刀具12之極座標值發生改變。 S102, the tool 12 that drives the processing device enters the origin position of the workpiece coordinate system. At this time, the pole coordinate value of the tool 12 is (0, 0). When the spindle 22 is rotated and the motor 20 on the X-axis rail 24 is moved, the polar coordinate value of the tool 12 changes.

S103，在加工過程中，數控裝置10將刀具12之極座標值轉化為工件座標值，Xm=ρ cos θ，Ym=ρ sin θ，其中，Xm為刀具12在工件坐標系中之橫坐標值，Ym為刀具12在工件坐標系中之縱坐標值，ρ為刀具12在極坐標系中之極徑，θ為刀具12在極坐標系中之極角。數控裝置10根據刀具12之工件座標值確定刀具12在待加工模具100上之加工點。 S103, during the machining process, the numerical control device 10 converts the polar coordinate value of the tool 12 into a workpiece coordinate value, Xm = ρ cos θ , Ym = ρ sin θ , where Xm is the abscissa value of the tool 12 in the workpiece coordinate system, Ym is the ordinate value of the tool 12 in the workpiece coordinate system, ρ is the polar diameter of the tool 12 in the polar coordinate system, and θ is the polar angle of the tool 12 in the polar coordinate system. The numerical control device 10 determines the machining point of the tool 12 on the mold to be processed 100 based on the workpiece coordinate value of the tool 12.

S104，當刀具12進入待加工模具100之模穴101區域時，數控裝置10通過將刀具12之工件座標值與模穴101之工件座標值範圍之對比，得出待加工模具100之模穴101幾何中心座標值(Xn，Yn)。如圖3所示，當待加工模具100不斷旋轉時，刀具12先後經過模穴101上兩個不同工件座標值之加工點A和加工點B，在這個過程中刀具12之極座標值發生改變，數控裝置10不斷之將刀具12之極座標值轉化為工件座標值，當刀具12經過加工點A時，轉化後之刀具12之工件座標值就是加工點A之工件座標值，同理，當刀具12經過加工點B時，轉化後之刀具12之工件座標值就是加工點B之工件座標值，刀具12之轉化後之每一個工件座標值與待加工模具100上之加工點一一相對應；數控裝置10將刀具12之工件座標值與模穴101之工件座標值範圍進行比對，就可判斷出刀具12進入了哪一個模穴101之加工範圍，以及這個模穴101之幾何中心座標值，數控裝置10就可以準確之根據模穴101幾何中心座標值(Xn，Yn)、刀具12之極座標值(ρ，θ)及一非球面面型公式計算出刀具12之進刀量。 S104, when the tool 12 enters the cavity 101 area of the mold 100 to be processed, the numerical control device 10 obtains the cavity 101 of the mold to be processed 100 by comparing the workpiece coordinate value of the tool 12 with the workpiece coordinate value range of the cavity 101. Geometric center coordinate value (Xn, Yn). As shown in FIG. 3, when the mold 100 to be processed is continuously rotated, the cutter 12 passes through the processing point A and the processing point B of two different workpiece coordinate values on the cavity 101, and the polar coordinate value of the cutter 12 changes during this process. The numerical control device 10 continuously converts the polar coordinate value of the tool 12 into the workpiece coordinate value. When the tool 12 passes the machining point A, the workpiece coordinate value of the converted tool 12 is the workpiece coordinate value of the machining point A. Similarly, when the tool 12 After the processing point B, the workpiece coordinate value of the converted tool 12 is the workpiece coordinate value of the processing point B, and each workpiece coordinate value after the conversion of the tool 12 corresponds to the processing point on the mold 100 to be processed; The device 10 compares the workpiece coordinate value of the tool 12 with the workpiece coordinate value range of the cavity 101, and determines the processing range of which cavity 101 the tool 12 has entered, and the geometric center coordinate value of the cavity 101. The numerical control device 10 can accurately calculate the infeed amount of the tool 12 according to the geometric center coordinate value (Xn, Yn) of the cavity 101, the polar coordinate value (ρ, θ) of the tool 12, and an aspherical surface type formula.

非球面面型公式： Aspherical surface formula:

其中，Z是以垂直於光軸且經過透鏡光學中心之平面為參考面，垂直方向上距離光軸為R處沿光軸方向之位移值，C是曲率半徑，R為鏡片高度，K為圓錐定數(Coin Constant)，Ai為i次之非球面係數(i-th order Aspherical Coefficient)。 Wherein, Z is a plane perpendicular to the optical axis and passing through the optical center of the lens as a reference surface, and a displacement value in the vertical direction from the optical axis is R along the optical axis direction, C is a radius of curvature, R is a lens height, and K is a cone Coin Constant, Ai is the second time I-th order Aspherical Coefficient.

所述非球面高度值；(2)通過將公式(2)代入公式(1)得出一全部由已知量組成之非球面面型公式，數控裝置10根據刀具12極座標值和待加工模具100之模穴101之幾何中心座標值，計算出模穴101非球面面型，並驅動壓電驅動軸14作快速回應，帶動刀具12根據非球面面型對模穴101進行切削，所述之驅動壓電驅動軸14之最大移動頻率為400HZ，最大移動距離為70um。通過對模穴101非球面面型之計算，則確定了刀具12之進刀量，且壓電驅動軸14具有較快之移動頻率和較大之移動距離，可有效之減少刀具12之回應時間，提高切削精度。在本實施方式中，可以通過設定壓電驅動軸14之回應頻率，控制刀具12在對模穴101某一點加工一定之時間後自動退刀，準備對下一點進行加工，通過對某一點之多次進刀完成對其之加工。 The aspheric height value (2) By substituting the formula (2) into the formula (1) to obtain an aspherical surface type formula which is all composed of known quantities, the numerical control device 10 according to the polar coordinate value of the tool 12 and the geometry of the cavity 101 of the mold 100 to be processed The central coordinate value is used to calculate the aspherical surface of the cavity 101, and the piezoelectric drive shaft 14 is driven to respond quickly, and the cutter 12 is driven to cut the cavity 101 according to the aspherical surface shape, which drives the piezoelectric drive shaft 14 The maximum moving frequency is 400HZ and the maximum moving distance is 70um. By calculating the aspherical surface of the cavity 101, the amount of the tool 12 is determined, and the piezoelectric drive shaft 14 has a relatively fast moving frequency and a large moving distance, which can effectively reduce the response time of the tool 12. Improve cutting accuracy. In this embodiment, by setting the response frequency of the piezoelectric drive shaft 14, the control tool 12 can automatically retract after processing a certain point of the cavity 101 for a certain period of time, ready to process the next point, through a certain point. The secondary feed is completed and processed.

S105，通過路徑補正方法可進一步提高加工精度，所述路徑補正方法是由於刀具12之刀頭並非無限小，存在一定之半徑，當刀頭之切點與待加工模具100之模穴101相接觸時，刀頭四周之點可能會與模穴101之間存在一定之干涉而導致形狀精度變差，而對刀具12走刀路徑進行優化之一種方法。路徑補正方法就是通過非球面面型公式即時對刀頭四周之點進行計算，確定刀具12之進刀量，判斷是否會存在干涉現象，當刀頭四周存在一點之高度小於非球面面型上相對應之高度就說明存在干涉，於是就根據刀頭上各點最大干涉量進行退刀，所述干涉量為刀頭四周之高度與非球面面型上相對點之高度之差值。通過對干涉量之即時偵測可選擇一刀頭上各點都不存在干涉之切點對先前存在干涉之位置進行切削，通過對刀具12之路徑補正可有效提高形狀精度。 S105, the machining precision can be further improved by the path correction method, because the cutter head of the cutter 12 is not infinitely small, and there is a certain radius, when the cutting point of the cutter head is in contact with the cavity 101 of the mold 100 to be processed. A method in which the point around the cutter head may interfere with the cavity 101 to cause the shape accuracy to deteriorate, and the cutter 12 path is optimized. The path correction method is to calculate the point around the cutter head through the aspherical surface formula to determine the amount of the tool 12 to determine whether there will be interference. When there is a point around the cutter head, the height is smaller than the aspheric surface type. The corresponding height indicates that there is interference, so it is based on each The point of maximum interference is retracted, and the amount of interference is the difference between the height of the periphery of the cutter head and the height of the opposite point on the aspherical surface. By detecting the interference amount, the cutting point where there is no interference at each point on the cutter head can be selected to cut the position where the interference exists before, and the path precision can be effectively improved by correcting the path of the cutter 12.

通過本方法可實現對非球面之加工，並且可有效提高非球面模具之加工精度和加工效率。 The aspherical surface can be processed by the method, and the processing precision and processing efficiency of the aspherical mold can be effectively improved.

綜上所述，本發明確已符合發明專利之要件，遂依法提出專利申請。惟，以上所述者僅為本發明之較佳實施方式，自不能以此限制本案之申請專利範圍。舉凡熟悉本案技藝之人士援依本發明之精神所作之等效修飾或變化，皆應涵蓋於以下申請專利範圍內。 In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

Claims

一種非球面透鏡模具加工方法，其包括以下步驟：提供一加工裝置，其用於對待加工模具進行加工，將待加工模具固定在加工裝置之主軸上，所述主軸帶動加工模具轉動；驅動加工裝置之刀具進入工件坐標系之原點位置；加工裝置之數控單元將刀具之極座標值轉化為工件座標值，並確定刀具在待加工模具上之加工點；數控單元根據刀具之工件座標值得出待加工模具之一模穴之幾何中心工件座標值，通過將刀具之極座標值及模穴之幾何中心工件座標值代入到非球面面型公式計算出待加工模具模穴之面型，並確定刀具之即時進刀量；通過非球面面型公式即時對刀頭四周之點進行計算，確定刀具之進刀量，判斷是否會存在干涉現象，當刀頭四周存在一點之高度小於非球面面型上相對應之高度就說明存在干涉，於是就根據刀頭上各點最大干涉量進行退刀，所述干涉量為刀頭四周之高度與非球面面型上相對點之高度之差值；通過對干涉量之即時偵測可選擇一刀頭上各點都不存在干涉之切點對先前存在干涉之位置進行切削，完成非球面透鏡模具之加工。 An aspherical lens mold processing method, comprising the steps of: providing a processing device for processing a mold to be processed, fixing the mold to be processed on a main shaft of the processing device, the spindle driving the processing mold to rotate; driving the processing device The tool enters the origin position of the workpiece coordinate system; the numerical control unit of the processing device converts the polar coordinate value of the tool into the workpiece coordinate value, and determines the machining point of the tool on the mold to be processed; the numerical control unit is worthy of processing according to the workpiece coordinate of the tool The geometric center workpiece coordinate value of one of the mold holes is calculated by substituting the polar coordinate value of the tool and the geometric center workpiece coordinate value of the cavity into the aspherical surface formula to calculate the shape of the mold cavity to be processed, and determining the instant of the tool. The amount of feed; the point around the cutter head is calculated by the aspherical surface formula to determine the amount of tool feed, and it is judged whether there will be interference phenomenon. When there is a point around the cutter head, the height is smaller than the aspherical surface type. The height indicates the presence of interference, so the retraction is performed according to the maximum amount of interference at each point on the cutter head. The amount of interference is the difference between the height of the periphery of the cutter head and the height of the opposite point on the aspherical surface type; by detecting the amount of interference, a point where there is no interference at each point on the cutter head can be selected for the position where the interference exists previously. Cutting, completing the processing of the aspherical lens mold.

如請求項1所述之非球面透鏡模具加工方法，其中：所述工件坐標系採用標準右手笛卡兒直角坐標系，符合右手法則；所述極坐標系，是以原點為極點，以工件坐標系之X軸正方向為極軸。 The method for processing an aspherical lens mold according to claim 1, wherein: the workpiece coordinate system adopts a standard right-handed Cartesian rectangular coordinate system, which conforms to a right-hand rule; and the polar coordinate system uses an origin as a pole to the workpiece. The positive direction of the X-axis of the coordinate system is the polar axis.

如請求項1所述之非球面透鏡模具加工方法，其中：通過公式Xm=ρ cos θ，Ym=ρ sin θ將刀具之極座標值轉化為工件座標值，其中，Xm、Ym分別為刀具在工件坐標系中之橫、縱坐標值，ρ為刀具在極坐標系中之極徑，θ為刀具在極坐標系中之極角。 The method for processing an aspherical lens mold according to claim 1, wherein: the coordinate value of the tool is converted into a workpiece coordinate value by a formula Xm = ρ cos θ , Ym = ρ sin θ , wherein Xm and Ym are respectively a tool in the workpiece The horizontal and vertical coordinate values in the coordinate system, ρ is the polar diameter of the tool in the polar coordinate system, and θ is the polar angle of the tool in the polar coordinate system.

如請求項1所述之非球面透鏡模具加工方法，其中：所述非球面面型公式中鏡片高度值，其中，Xm、Ym分別為刀具在工件坐標系中之橫、縱坐標值，Xn、Yn為每個待加工模穴之幾何中心在工件坐標系中之橫、縱坐標值。 The aspherical lens mold processing method according to claim 1, wherein: the lens height value in the aspherical surface formula Where Xm and Ym are the horizontal and vertical coordinate values of the tool in the workpiece coordinate system, and Xn and Yn are the horizontal and vertical coordinate values of the geometric center of each cavity to be processed in the workpiece coordinate system.