CN102156314A - Isosceles micro prism and method for manufacturing mold - Google Patents

Abstract

The invention belongs to the technical field of retroreflective material manufacture, and relates to an isosceles micro prism. A micro prism unit constituting the isosceles micro prism is a tetrahedron; the bottom surface of the tetrahedron is an isosceles triangle; one of the three side surfaces is an isosceles triangle, the rest two side surfaces are the same hypotenuse triangles, and the three surfaces are perpendicular to one another and intersect at a structural vertex; and included angles between the side surfaces of the two hypotenuse triangles and the adjacent units are equal. The invention also provides a method for manufacturing a mold of the isosceles micro prism. By the micro prism structure provided by the invention, the retroreflective performance of the micro prism is reduced with the increase of an incidence angle.

Description

The method of a kind of isosceles microprism and mfg. moulding die

Technical field

The invention belongs to reflecting material manufacturing technology field, relate to a kind of microprism and mould thereof.

Background technology

Reflectorized material is also referred to as retroreflecting material or reflecting material, comprises reflective membrane, reflective printing ink, reflector marking, reflective cloth, reflective leather, reflective ribbon and reflection safety sex pilus fabric etc.Reflecting material has the advantage of saving the energy, environmental protection, is not subjected to environmental impacts such as sunshine, weather simultaneously, is the important embodiment of national communication sign and safety assurance.

Chinese descendant in America doctor Dong Qifang at first develops the glass microballoon oriented reflection film in nineteen fifty, has opened the road of the research and development of reflectorized material, develops reflective cloth series material subsequently again.Microprism (microprism) structure is the primary structure of reflecting material, compares with traditional micropearl array structure, and good characteristic such as have that reflective area is big, reflex reflection efficient height, safety are wear-resisting has become the important development direction of reflecting material.The array that microprism is made up of similar prism of corner cube structure is the important method that prism of corner cube microminiaturization and array are used, and its specification is equal to, and arranges accurately.Its cellular construction is still by three orthogonal surface compositions.Can be divided into two classes according to shape: a class is the triangle microprism, and end face cuts three faces mutually by the plane usually and forms triangle, and the side also is a triangle; Another kind of is the cube microprism, and three sides are square.Its optical property and the prism of corner cube of this class microprism are similar, all utilize the reflection of three sides to produce the reflex reflection phenomenon.Total can be made all-sealed device by the optical plastic injection moulding, after refraction and total reflection phenomenon take place in structure light, realizes retroreflectivity.

Nineteen sixty-eight U.S. ROWLAND brother invention and patent registration microprism reflex reflection technology, and set up U.S. Reflexite (auspicious flying) company, produce the microprism series of products specially.U.S. 3M, AVERY DENNISON subsequently, Japanese calcium carbide, carbonide Industrial Co., Ltd etc. has also begun the research and development of Related product.United States Patent (USP) 4478769 discloses the manufacturing process of a common microprism, and the mould V-shaped groove has 70.53 ° of angles, and the angle of three groups of grooves is 60 °.But it is bigger that the reflex reflection performance of this microprism increases decline scope with incident angle, and the reflex reflection when being unfavorable for big incident angle is used.For this reason, a large amount of patents have been carried out correlative study, as: patent 02811691.7 discloses a kind of mould, and the V-type groove is vibration relatively between cutter and the workpiece in process, and mould has controlled and wideer dispersing; Patent 01804407.7 discloses a kind of mould, and the degree of depth of three groups of V-shaped grooves has at least two not wait in fact, after the solution incident angle increases, can not satisfy the inner full-reflection condition, in the problem of side piercing elements, thereby increases available ranges of incidence angles; Patent 00817106.8 provides a kind of mould, and three hand-delivers point is higher or lower than calibrated altitude, has improved incident angle and rotation angle characteristic.

Summary of the invention

The present invention proposes a kind of novel micro-prism structure, and this kind structure has the reflex reflection performance that makes microprism to be increased to slow down with incident angle and reduce trend, proposes a kind of method of making this kind structure microprism mold simultaneously.The present invention adopts following technical scheme:

A kind of isosceles microprism, the microprism unit that constitutes the isosceles microprism is a tetrahedron, tetrahedral bottom surface is an isosceles triangle; Three sides have one to be isosceles triangle, and all the other two is identical hypotenuse triangle, and three faces vertically meet at the structure summit mutually; Two hypotenuse triangle sides equate that with the adjacent cells angle angle is between 40 °～100 °, and isosceles triangle side and adjacent cells angle are also between 40 °～100 °.

The present invention provides a kind of isosceles microprism mold manufacture method simultaneously, it is die needed that this method cutting flutes on the microprism substrate forms the electroforming molding, the micro-prism structure of manufacturing is: the microprism unit that constitutes the isosceles microprism is a tetrahedron, tetrahedral bottom surface is an isosceles triangle, the length of side on three limits is: end a, waist b, the triangle drift angle angle of end correspondence is α, two triangle drift angle angles of waist correspondence are β; Three sides have one to be isosceles triangle, and all the other two is identical hypotenuse triangle, and three faces vertically meet at the structure summit mutually; There are two different angles each microprism unit with the angle of adjacent cells, and isosceles triangle side and adjacent cells angle are t _α, oblique triangle side and adjacent cells angle are t _βIt is characterized in that utilize two to adopt the triangle cutter of different cutting angles to make mould, one cutting angle is t _β, be referred to as t _βCutter, another cutting angle are t _α, be referred to as t _αCutter; And adopt and to have five degree of freedom ultra-precise cutting lathes this microprism mold is flown to cut processing, stock-removing machine is provided with an X-axis translation stage that can move along X-axis, the X-axis translation stage is provided with the lifting table that moves along Y-axis, lifting table is provided with the rotary main shaft C of lathe, and described two triangle cutters are fixed on the main shaft C by knife rest; Also be provided with a Z axle translation stage that moves along the Z axle on the lathe, it is provided with along the universal stage of B axle rotation, and the microprism substrate is fixed on the universal stage, rotates by the B axle and controls the angle of cutter in on-chip each cutting direction; Working angles is as follows:

1) determines micro-prism structure, thereby determine the cutting angle t of two triangle cutters _αAnd t _β, determine the required working process parameter of cutting microstructure simultaneously, comprise cutting depth H, t _βDistance h between the each the line of cut of cutting-tool angle _b, t _αDistance h between the each the line of cut of cutter _a, angle [alpha] between the cutting direction and β, wherein,

α=2sin ^-1(2/2b), β=90-α/2;

2) with t _αAnd t _βCutter is assemblied on the knife rest, and guarantees t _βThe cutter turning radius is greater than t _αCutter makes radius difference greater than cutting depth H;

3) adopt vision measurement system to gather two tool positions, the position of adjusting and writing down two cutters;

4) adjust lifting table according to cutting depth H, and fixing lifting table position;

5) control rotary main shaft C at the uniform velocity rotates, and control X-axis motion feeding, utilizes t _βCutter carries out cut, and mobile Z axle translation stage carries out the distance control between each the line of cut after each the line of cut, and command range is h _b, rotate B axle α angle then, to cut after the same method, the distance between each the line of cut still is h _b

6) adjust lifting table and Z axle translation stage, remove t then _βCutter;

7) rotation B axle β angle, and adopt t _αCutter cuts, and the distance between each the line of cut is h _aThereby, finish the making of whole microprism mold.

Novel micro-prism structure provided by the invention, having the reflex reflection performance that makes microprism increases to slow down with incident angle and reduces trend, and the design of micro-prism structure and the general scheme of processing are equally applicable to traditional micro-prism structure.Obtain microprism optics simulated effect by contrasting 70.5288 ° of cuttings of tradition, as can be seen, reflex reflection efficient with new construction is lower, but in the incident angle variation range, its reflex reflection energy variation amount is low than traditional structure, especially under the situation of 30 ° big incident angle, it is high that the reflex reflection efficiency ratio traditional structure of new structure is wanted.In addition, the present invention also provides effective way for the processing of isosceles type microprism, simultaneously by the vision measurement technology, effectively controlled position relation between two cutters, thereby avoided the easy rigging error that occurs when changing cutter, even depth when having guaranteed to change cutter is cut, and has guaranteed the integrality of micro-prism structure.

Description of drawings

Fig. 1 micro-prism structure synoptic diagram.

The single microstructure synoptic diagram of Fig. 2.

Fig. 3 system of processing is formed synoptic diagram.

Two tool position instrumentation plans of Fig. 4.

Fig. 5 reflex reflection performance simulation result.

Embodiment

Having the present invention relates to a kind of micro-prism structure bottom surface is the micro-prism structure design and the job operation of isosceles triangle.The micro-prism structure of design is easy to adopt diamond cutting or " fly cutter (fly-cutting) " processing mode to carry out ultraprecise processing, " convex " mould that obtains generates " matrix " entity microprism product of plastic material by hot-forming, injection mo(u)lding or other molding mode.Fig. 1 is a micro-prism structure of the present invention.The microprism unit is a tetrahedron, and tetrahedral bottom surface is an isosceles triangle, and the length of side on three limits is: end a, and waist b, the triangle drift angle angle of end correspondence is α, the triangle angle angle of waist correspondence is β; Have one to be isosceles triangle in three sides, all the other two is identical hypotenuse triangle, and three faces vertically meet at the structure summit mutually.There are two different angles this unit with the angle of adjacent cells, and isosceles triangle side and adjacent cells angle are t _α, oblique triangle side and adjacent cells angle are t _β

The general diamond cutting method that adopts is processed microprism.Adopt the V-type diamond cutter processing template of cutting flutes formation in the plane, adopt the electroforming mode to duplicate its surface structure and become the matrix working template, be directly used in and carry out hot-forming processing microprism finished product.This micro-prism structure can adopt the diamond cutting method that it is processed, and the shape of tool is a triangle, carries out little groove processing on workpiece.As shown in Figure 1, the triangle cutter that adopts two different angles along 1. 2. 3. three directions cut, 1. and 2. wherein the cutting tool angle of direction is t _β, the distance between each cutting path is h _b3. the cutting tool angle of direction is t _α, the distance between each cutting path is h _a2. and 3. 1. and 2. the angle of three directions is respectively: the angular separation is α, and cutting direction 1. and 3. angular separation is β, and the angular separation is β.

When known tetrahedron bottom surface length of side a and b, as shown in Figure 2, can be that isosceles triangle is found the solution by Δ ABC

$h_a=\sqrt{b^2-{(a/2)}^2}$ $h_b=\frac{a\sqrt{b^2-{(a/2)}^2}}{b}---\left(1\right)$

α＝2sin ^-1(2/2b) β＝90-α/2 (2)

Utilize Δ BCD, Δ ADE, Δ ADE to be right-angle triangle, obtain cutting required cutting-tool angle

$t_{\mathrm{\α}}=2{\sin }^{-1}\frac{a}{2\sqrt{b^2-{(a/2)}^2}}$ $t_{\mathrm{\β}}=2{\sin }^{-1}\frac{\sqrt{b^2-a^2/2}}{\sqrt{2}\sqrt{b^2-{(a/2)}^2}}---\left(3\right)$

Therefore, when bottom surface length of side a and b determine, can both determine with the relevant amount of processing, thereby can carry out the processing of microprism.The working depth H unanimity of while every the line of cut, for guaranteeing to obtain complete micro-prism structure, working depth H should satisfy:

$H\&GreaterEqual;\frac{a\sqrt{b^2-{\mathrm{<figure-callout\; id="2"\; label="a"\; filenames="HDA0000052246710000012.png,HDA0000052246710000021.png"\; state="\{\{state\}\}">a</figure-callout>}}^2/2}}{\sqrt{b^2-{(a/2)}^2}}---\left(4\right)$

For cutting obtains such microprism, need to adopt the cutter of two different angles to carry out the cutting of respective sequence.As shown in Figure 1, at first adopt t _β1. cutter 2 carries out and 2. direction cutting, and changing cutting tool then is t _αCutter 1 carries out 3. direction cutting.In order to guarantee to obtain complete structure, the Tool in Cutting degree of depth need guarantee unanimity, and cutting depth is generally about 100um.Can adopt five the degree of freedom ultra-precise cutting lathes that have as shown in Figure 3 that this microprism mold is flown to cut processing.System has rotary main shaft C, triangle diamond cutter is fixed on the main shaft C by cylindrical knife rest 3, main shaft drives cutter to carry out high speed rotating and cooperates translation stage X-axis (direction is perpendicular to paper) to fly to cut processing on microprism substrate 4 surfaces, can depict V-groove at substrate surface.System also has the lifting table that can carry out oscilaltion, i.e. Y-axis is used to control the degree of depth of cutting; System has rotation B axle, and the microprism substrate is mounted thereon, and rotates by the B axle and controls the angle of cutter in on-chip each cutting direction.Simultaneously, the B axle can be done directions X motion on translation stage, the distance when carrying out same direction cutting between the each cutting path of may command.

For whole process, can be difficult to cutting depth and planform after cutter is changed in assurance because dismounting brings bigger error when changing cutter midway.For this reason, with two cutter (t _βCutter 2 and t _αCutter 1) is installed on symmetric position on the handle of a knife simultaneously, as shown in Figure 3, uses t respectively according to processing sequence _βCutter and t _αCutter is processed the microprism substrate.In order to guarantee t _βCutter cuts earlier, guarantees t when mounted _βThe cutter turning radius is greater than t _αCutter.And when needing to use t _αWhen cutter 1 cuts, need lifting table is fallen corresponding height, guarantee t _αCutter also can carry out the cutting of same depth, simultaneously with t _βThe cutter head of cutter 2 takes off and gets final product, like this t _βCutter 2 turning radius are just less than t _αCutter 1, thus t do not influenced _αCutter 1 carries out next step cutting.

In order specifically to obtain when changing cutting tool, lifting table specifically fall height, used vision measurement system, as shown in Figure 4, below rotary main shaft, place vision measurement system, comprise ccd video camera and the enlarging lens 5 that place in cutter the place ahead, and the LED-backlit plate 6 at cutter rear.Because cutter blocks, in CCD, become the photo of strong light intensity contrast, strengthen the outline of whole cutter, the summit that obtains the triangle cutter by image processing algorithm is with this point location tool position.And because the turning radius of two cutters is different, image space is also variant in vision system, obtains the tool position twice, and Δ y is the difference of two cutter turning radius among Fig. 4, just lifting table fall height, for fear of at t _βCutter 2 adds man-hour, t _αThe interference that 1 pair of processing of cutter causes, the turning radius deviation delta y that needs two cutters is greater than cutting depth H; Δ z is because cutter when assembling among Fig. 4, and two cutters after changing cutting tool, also need carry out the adjustment of Z direction by translation stage in the micro-deviation of Z-direction.

The working angles of the inventive method needs the triangle diamond cutter of two different angles, the parameter of cutter is by final microprism bottom surface triangular structure decision, can select in principle arbitrarily, but allow each cutting-tool angle between 40 °～100 °, to guarantee the good processing and forming of microstructure as far as possible.General the line of cut spacing is typically chosen between 20um～250um, selects appropriate cutting depth simultaneously, the reflex reflection effect that just can obtain.Can be widely used in traffic warning marks such as pavement marker and roadblock, safe clothes, material coil packing by the microprism product of implementing to obtain.

The concrete making flow process of microprism mold of the present invention is:

1) carries out the selection of micro-prism structure by computing formula (1)～(3), thereby determine suitable machining tool angle t _αAnd t _β, determine the required working process parameter of cutting microstructure simultaneously, comprise the distance between cutting depth, the line of cut, the angle between the cutting direction etc.;

2) with the t that chooses _αAnd t _βTwo cutters are assemblied on the knife rest, and guarantee t _βThe cutter turning radius is greater than t _αCutter guarantees that radius difference is greater than cutting depth H;

) adopt vision measurement system to gather two tool positions, and note the position deviation amount Δ y and the Δ x of cutter, if Δ y can carry out trace adjustment when excessive, and note suitable position deviation amount once more;

4) at first control lifting table motion and allow t _βThe Tool in Cutting degree of depth guarantees to meet the demands, and fixing lifting table position;

5) control rotary main shaft C at the uniform velocity rotates, and control X-axis motion feeding, allows t _βCutter carries out 1. direction cutting, and mobile Z axle carries out the distance control between each the line of cut after each the line of cut, and command range is h _b, rotate B axle α angle then, according to carry out 2. direction cutting with quadrat method, the distance between each the line of cut still is h _b

6) adjust lifting table and fall Δ y along Y direction, and control Z axle offset Δ z, t removed then _βThe cutter cutter head;

7) rotation B axle β angle, and adopt t _αCutter carries out 3. direction cutting, and the distance between each the line of cut is h _aThereby, finish the making of whole microprism mold.

The invention provides the general scheme of the design of micro-prism structure, be equally applicable to traditional micro-prism structure.For example: if the length of side of tetrahedron bottom surface equates that promptly a=b then brings formula (3) into and can obtain cutting microprism cutter t _α=t _β=70.5288 °, cutting just obtains positive tetrahedron.And when selecting t _β=60 °, can find the solution t _α=90 °, thus can calculate in the triangle on base: α=70.5288 ° and β=54.7356 °.Therefore, can utilize method of the present invention to obtain the combination of numerous cutting tool angles, these numerical value all are used for instructing all kinds of micro-prism structures of cutting.At t _β=60 ° and t _αThe micro-prism structure that=90 ° of cutters obtain carries out the optics simulation analysis, reflex reflection energy percentage value when obtaining different incidence angles, obtain microprism optics simulated effect by contrasting 70.5288 ° of cuttings of tradition, as can be seen, reflex reflection efficient with new construction is lower, but in the incident angle variation range, its reflex reflection energy variation amount is low than traditional structure, especially under the situation of 30 ° big incident angle, it is high that the reflex reflection efficiency ratio traditional structure of new structure is wanted.

In addition, the present invention also provides effective way for the processing of isosceles type microprism, simultaneously by the vision measurement technology, effectively controlled position relation between two cutters, thereby avoided the easy rigging error that occurs when changing cutter, even depth when having guaranteed to change cutter is cut, and has guaranteed the integrality of micro-prism structure.

Claims (3)

1. isosceles microprism, the microprism unit that constitutes the isosceles microprism is a tetrahedron, tetrahedral bottom surface is an isosceles triangle; Three sides have one to be isosceles triangle, and all the other two is identical hypotenuse triangle, and three faces vertically meet at the structure summit mutually; Two hypotenuse triangle sides equate that with the adjacent cells angle angle is between 40 °～100 °, and isosceles triangle side and adjacent cells angle are also between 40 °～100 °.

2. isosceles microprism according to claim 1 is characterized in that, two hypotenuse triangle sides and adjacent cells angle are 90 °, and isosceles triangle side and adjacent cells angle are 60 °.

3. isosceles microprism mold manufacture method, it is die needed that this method cutting flutes on the microprism substrate forms the electroforming molding, the micro-prism structure of manufacturing is: the microprism unit that constitutes the isosceles microprism is a tetrahedron, tetrahedral bottom surface is an isosceles triangle, the length of side on three limits is: end a, waist b, the triangle drift angle angle of end correspondence is α, two triangle drift angle angles of waist correspondence are β; Three sides have one to be isosceles triangle, and all the other two is identical hypotenuse triangle, and three faces vertically meet at the structure summit mutually; There are two different angles each microprism unit with the angle of adjacent cells, and isosceles triangle side and adjacent cells angle are t _α, oblique triangle side and adjacent cells angle are t _βIt is characterized in that utilize two to adopt the triangle cutter of different cutting angles to make mould, one cutting angle is t _β, be referred to as t _βCutter, another cutting angle are t _α, be referred to as t _αCutter; And adopt and to have five degree of freedom ultra-precise cutting lathes this microprism mold is flown to cut processing, stock-removing machine is provided with an X-axis translation stage that can move along X-axis, the X-axis translation stage is provided with the lifting table that moves along Y-axis, lifting table is provided with the rotary main shaft C of lathe, and described two triangle cutters are fixed on the main shaft C by knife rest; Also be provided with a Z axle translation stage that moves along the Z axle on the lathe, it is provided with along the universal stage of B axle rotation, and the microprism substrate is fixed on the universal stage, rotates by the B axle and controls the angle of cutter in on-chip each cutting direction; Working angles is as follows:

1) determines micro-prism structure, thereby determine the cutting angle t of two triangle cutters _αAnd t _β, determine the required working process parameter of cutting microstructure simultaneously, comprise cutting depth H, t _βDistance h between the each the line of cut of cutting-tool angle _b, t _αDistance h between the each the line of cut of cutter _a, angle [alpha] between the cutting direction and β, wherein,

α=2sin ^-1(2/2b), β=90-α/2;

2) with t _αAnd t _βCutter is assemblied on the knife rest, and guarantees t _βThe cutter turning radius is greater than t _αCutter makes radius difference greater than cutting depth H;

3) adopt vision measurement system to gather two tool positions, the position of adjusting and writing down two cutters;

4) adjust lifting table according to cutting depth H, and fixing lifting table position;

5) control rotary main shaft C at the uniform velocity rotates, and control X-axis motion feeding, utilizes t _βCutter carries out cut, and mobile Z axle translation stage carries out the distance control between each the line of cut after each the line of cut, and command range is h _b, rotate B axle α angle then, to cut after the same method, the distance between each the line of cut still is h _b

6) adjust lifting table and Z axle translation stage, remove t then _βCutter;

7) rotation B axle β angle, and adopt t _αCutter cuts, and the distance between each the line of cut is h _aThereby, finish the making of whole microprism mold.

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