Method for producing reflector molding die, method for producing reflector, and cutting tool

Abstract

This method for producing a die for molding a reflector that reflects light comprises a cutting step for performing cutting so as to form a plurality of recesses on the inner surface of the die for forming protrusions and recesses on the reflective surface of the reflector. The cutting step has a shaper step for cutting each of the plurality of recesses through a relative movement of a tool with respect to the die without rotation or vibration of the tool.

Description

Manufacturing method of mold for reflector molding, manufacturing method of reflector, and cutting tool

[0001] The present disclosure relates to a method for manufacturing a mold for molding a reflector, a method for manufacturing a reflector, and a cutting tool.

[0002] Reflectors that reflect light are known that have irregularities on their reflective surfaces. Specific examples include retroreflectors (sometimes called reflex reflectors in Japan; hereinafter, retroreflectors may be referred to as "RRs") that are installed at the rear of a vehicle and reflect light from other vehicles. Such reflectors are molded, for example, by filling a mold with a molding material (e.g., resin). Patent Documents 1 to 3 disclose techniques for forming irregularities in a mold that correspond to the irregularities of the RRs, or similar irregularities, by cutting with a tool.

[0003] Patent Document 1 discloses a technique for cutting a recess in a mold using a tool with a rounded tip. Although not explicitly stated in Patent Document 1, in light of the shape of the illustrated tool and common technical knowledge, the tool is rotated around its axis when used. Patent Document 2 discloses a technique for cutting a recess in a mold by vibrating the tool. Patent Document 3 discloses a technique for cutting a recess using a tool with a cutting edge located on the center line. The tool is used while being rotated or while being vibrated. Patent Documents 1 and 2 also disclose molds with concave and convex surfaces formed on them.

[0004] JP 2012-108213 A JP 2013-202750 A JP 2022-87422 A

[0005] There is a need for a manufacturing method of a mold for forming a reflector, a manufacturing method of a reflector, and a cutting tool that improves the ease and / or accuracy of forming unevenness by cutting.

[0006] A manufacturing method of a mold for molding a reflector according to one aspect of the present disclosure is a manufacturing method of a mold for molding a reflector that reflects light, and includes a cutting step of forming a plurality of recesses on the inner surface of the mold by cutting to form irregularities on the reflective surface of the reflector, and the cutting step includes a shaper step of cutting each of the plurality of recesses by moving the tool relative to the mold without rotating or vibrating the tool.

[0007] A method for manufacturing a reflector according to one aspect of the present disclosure includes molding the reflector using the mold manufactured by the above-described method for manufacturing a mold for molding a reflector.

[0008] A method for manufacturing a reflector according to one aspect of the present disclosure is a method for manufacturing a reflector that reflects light, and includes a cutting step in which a plurality of recesses that constitute the reflective surface of the reflector are formed by cutting, and the cutting step includes a shaper step in which each of the plurality of recesses is cut by relative movement of the tool with respect to the reflector without rotation or vibration of the tool.

[0009] A cutting tool according to one aspect of the present disclosure has a cutting edge extending in a direction intersecting the center line of a shank, and when both ends of the cutting edge are referred to as a first end and a second end, the distance from the center line to the first end is shorter than the distance from the center line to the second end, and the ridge extending from the first end toward the shank is inclined so that the closer it is to the shank, the closer it is to the second end.

[0010] According to the above-described procedure and configuration, the ease and / or accuracy of forming the irregularities is improved in the manufacturing method of the reflector molding die and the manufacturing method of the reflector.

[0011] 7 is a plan view showing an example of the shape of a reflecting surface of a reflector; a cross-sectional view showing an example of a manufacturing method of a reflector; a perspective view showing an example of a processing machine for manufacturing a reflector molding die used in the manufacturing method of FIG. 2; a side view showing an example of a tool attached to the processing machine of FIG. 3; a perspective view showing an example of a blade portion of the tool of FIG. 4; a side view showing an example of a tip of the blade portion of FIG. 5; a perspective view showing an example of a cutting method using the tip of FIG. 6; a perspective view showing an example of a procedure for forming three flat surfaces of an RR by the cutting method of FIG. 7; a view showing a first example of a concave-convex shape of a die formed by cutting; a view showing a second example of a concave-convex shape of a die formed by cutting; a view showing a third example of a concave-convex shape of a die formed by cutting; a plan view showing a fourth example of a concave-convex shape of a die formed by cutting; a cross-sectional view showing the fourth example; a plan view showing a fifth example of a concave-convex shape of a die formed by cutting.

[0012] In the following description, for convenience, the term "tool position" may refer to the position relative to the workpiece (e.g., a mold) or to the position in an absolute coordinate system. Unless otherwise specified or unless a contradiction arises, the tool position may be considered either a relative position or an absolute position. The same applies to the term "tool movement." The term "center line of a tool shank" refers to a straight line that includes not only a line segment within the shank but also a portion extended outside the shank in the longitudinal direction.

[0013] The term "axis" in relation to a processing machine can refer to an axis (or, from another perspective, a virtual line) that defines a coordinate system, or to a drive mechanism that realizes movement along such an axis. Furthermore, the term "axis" in relation to a processing machine can refer not only to an axis related to linear movement (translation) (sometimes referred to as a "linear axis"), but also to an axis related to rotational movement (sometimes referred to as a "rotational axis"). The rotation here does not necessarily have to be rotatable within an angular range of 360° (i.e., it includes tilt).

[0014] 1 is a plan view showing a partial area of ​​a reflecting surface 113 of a reflector 111 according to an embodiment. The reflecting surface 113 has a plurality of recesses 115 (or, from another perspective, a plurality of protrusions 117 located between the recesses 115). In the illustrated example, the reflector 111 is configured as a so-called corner cube RR.

[0015] 1 is a view of the surface (outer surface) of the reflector 111 as viewed from the outside of the reflector 111. The reflector 111 may be made of a light-transmitting material (e.g., resin or glass) and may reflect light that has passed through the reflector 111 from the depth of the page toward the depth of the page by a reflective surface 113. And / or, the reflector 111 may reflect light that has come from the front side of the page (outside the reflector 111) toward the front side of the page by a reflective surface 113.

[0016] It should be noted that the convex portions 117 can be regarded as concave portions for light that passes through the reflector 111 from the depth side of the page and reaches the reflecting surface 113. However, in the description of the embodiments, unless otherwise specified or unless a contradiction occurs, the terms convex portion and concave portion related to the reflector 111 refer to the shape of the reflector 111 as seen from the outside.

[0017] 2 is a cross-sectional view showing an example of a manufacturing method for reflector 111. In this example, reflector 111 is formed by filling a molding material (e.g., resin) into the space between mold 120 and mold 121. Mold 121 has an inner surface 123 that forms reflecting surface 113. Inner surface 123 has recesses 125 that correspond to protrusions 117 (or, from another perspective, protrusions 127 that correspond to recesses 115).

[0018] 3 is a perspective view showing an example of a manufacturing method of the mold 121. This figure is illustrated with an orthogonal coordinate system XYZ, which is a machine coordinate system (which may be considered an absolute coordinate system). The +Z side is, for example, vertically upward.

[0019] In this example, a processing machine 1 (e.g., a machine tool) cuts an inner surface 123 of a mold 121, thereby forming a plurality of recesses 125 (not shown in FIG. 3 ) in the inner surface 123. In the example shown, the processing machine 1 is configured by a machine tool capable of performing cutting (i.e., milling) by rotating a rotary tool (not a rotary tool, but see tool 101) around its axis. In FIG. 3 , tool 101 used to form the recesses 125 is attached to the processing machine 1.

[0020] 7 is a perspective view showing an example of a cutting method for forming a recess 125 using a tool 101 (more specifically, a tip 103 at the tip of the tool 101). This figure specifically shows the state in which a first plane 129A of the three planes (129A to 129C) of one recess 125 is being formed. In this figure, the tip 103 at a given point in time is shown by a solid line, and the tip 103 at other points in its movement thereafter is shown by a two-dot chain line. Arrow a1 indicates the trajectory of the movement of the tip 103.

[0021] As can be seen from this diagram, the tool 101 cuts the mold 121 while moving in a parallel direction without rotation, thereby forming the first flat surface 129A. At this time, no vibration (intentional) is applied to the tool 101. That is, the tool 101 cuts the mold 121 only by moving in a parallel direction. In other words, the mold 121 is chipped (in other words, shaping is performed). The second flat surface 129B and the third flat surface 129C are also formed by shaping. The tool 101 has a shape suitable for such cutting.

[0022] As described above, forming the plurality of recesses 125 by shaping improves the ease and / or accuracy of forming the plurality of recesses 125. Specifically, this is as follows.

[0023] For example, in a configuration in which the recess 125 is formed by rotating a rotary tool (e.g., an end mill) (i.e., by normal milling) (see, for example, Patent Document 1), even if it is not desired to round the corners (in other words, concave corners or valleys) where the planes (129A to 129C) intersect with each other, the corners are rounded to a degree equivalent to the radius of the rotary tool. In other words, the machining accuracy of the corners is limited by the radius of the rotary tool. However, in this embodiment, because the tool 101 is not rotated, such limitations on machining accuracy do not arise. In other words, machining accuracy is improved.

[0024] Furthermore, for example, in an embodiment in which the recess 125 is formed by applying vibration to a tool (see, for example, Patent Document 2), a vibration mechanism is required to apply vibration to the tool. However, in this embodiment, a vibration mechanism is not required. In other words, the ease of processing is improved. For clarity, in this disclosure, when the tool is moved without vibrating it, the vibration refers to intentional vibration and does not include unavoidable error.

[0025] Furthermore, for example, in an embodiment in which the recess 125 is formed by rotating the tool in synchronization with the translation of the tool (see, for example, Patent Document 3), the translation and rotation are controlled taking into account the effects of both the translation and rotation on the position and orientation of the cutting edge, which complicates the control. However, in the embodiment, such control is not necessary. In other words, the ease of processing is improved.

[0026] Just to be clear, normal milling, vibration-based milling, and / or milling with synchronized translation and rotation may be performed before or after the shaping process. For example, the rough shape of the recess 125 may be formed by normal milling, and the shaping process according to the embodiment may be performed for finishing. From another perspective, the recess 125 may be formed solely by shaping, or may be formed by a combination of shaping and other types of processing (including not only other types of cutting, but also grinding and polishing, etc.).

[0027] In the above description, an example is taken of a mode in which recess 125 of mold 121 for molding the reflector is formed by cutting. Unlike the above description, recess 115 of reflector 111 may be formed directly by cutting. However, for convenience, the description of the embodiment takes an example in which mold 121 is used. Unless otherwise specified or unless a contradiction arises, the description related to cutting recess 125 may be applied to cutting recess 115.

[0028] The above is an overview of the embodiment. Below, the embodiment will be roughly described as follows: 1. Reflector (FIGS. 1 and 2) 2. Mold (FIG. 2) 3. Processing machine (FIG. 3) 4. Tool (FIGS. 4 to 6) 4.1. Tool in general (FIG. 4) 4.2. Tip (FIGS. 5 and 6) 4.3. Tip of body (FIG. 5) 4.4. Other examples of tool 5. Cutting method (FIGS. 7 and 8) 6. Processing examples 6.1. First processing example (FIG. 9) 6.2. Second processing example (FIG. 10) 6.3. Third processing example (FIG. 11) 6.4. Fourth processing example, and supplementary information regarding the orientation and size of the recess (FIGS. 12 and 13) 6.5. Fifth processing example (FIG. 14) 7. Summary of the embodiment

[0029] (1. Reflector) The reflector 111 (FIGS. 1 and 2) may be a variety of reflectors used for a variety of applications, and its specific shape, size, and material are optional. FIG. 1 and FIG. 2 merely show a schematic representation of the reflector 111 having a relatively simple shape.

[0030] For example, the reflector 111 may be provided on an automobile, a road sign, or an advertising medium. The shape, dimensions, and material of the reflector 111 may be determined according to the intended use. For example, the reflector 111 may be a plate-shaped member or a block-shaped member. The length of the ridge line of the convex portion 117 (the valley line of the concave portion 115) is, for example, 0.01 mm or more and 10 mm or less.

[0031] As described above, the reflector 111 illustrated in Fig. 1 is a corner cube type reflector. Taking the example of a configuration in which light transmitted through the reflector 111 from the depth of the page in Fig. 1 is reflected by the reflective surface 113, the outer surface of the convex portion 117 is configured in a triangular pyramid shape with three mutually orthogonal flat surfaces. The three flat surfaces contribute to reflecting light back in the incident direction (retroreflection).

[0032] In the above, an example was taken in which the reflector 111 reflects light from the depth of the page, but the same applies to an example in which the reflector 111 reflects light from the front of the page. That is, the inner surface of the recess 115 is configured in a triangular pyramid shape with three planes that are perpendicular to each other. The three planes contribute to retroreflection.

[0033] Unlike the example shown in FIG. 1 , the reflector 111 does not necessarily have to produce retroreflection. From another perspective, the outer surface of the convex portion 117 and / or the inner surface of the concave portion 115 are not limited to being formed by three mutually orthogonal planes. For example, the three planes may not be orthogonal to each other, or one convex portion 117 (or concave portion 115) may have four or more planes, or may have a curved surface. Such multiple convex portions 117 and / or multiple concave portions 115 may contribute to, for example, dispersing and / or homogenizing light, or to focusing light.

[0034] As described above, the reflector 111 may be transparent or non-transparent. Examples of materials for the former mode include resin and glass. Examples of materials for the latter mode include metal. In either case, the reflector 111 may be formed using a mold, or the recess 115 may be formed by cutting.

[0035] The surfaces of the convex portions 117 (or, from another point of view, the concave portions 115) of the reflector 111 formed by the mold 121 may directly constitute the reflective surface 113, or may be overlaid with a reflective film (for example, a metal film) to improve reflectivity. In other words, the multiple concave portions 125 formed in the mold 121 by cutting in order to form concaves and convexes on the reflective surface 113 of the reflector 111 may or may not directly form the reflective surface 113.

[0036] Similarly, in an aspect in which the mold 121 is not used and the reflector 111 is directly cut, the surfaces of the cut convex portions 117 (or, from another point of view, the concave portions 115) may directly constitute the reflective surface 113, or a reflective film (for example, a metal film) may be superimposed thereon to improve reflectivity. In other words, the step of forming the multiple concave portions 115 that constitute the reflective surface 113 by cutting does not have to be the step of finally forming the reflective surface 113.

[0037] The term "reflector 111" may refer to the entire component having the reflective surface 113, or may refer to a portion of the component having the reflective surface 113 that includes the reflective surface 113. In the description of the embodiment, for convenience, unless otherwise specified or unless a contradiction occurs, the former term will be used. The term "reflective surface 113" may refer to the entire reflective surface having multiple convex portions 117 (or multiple concave portions 115), or may refer to a partial region. In the description of the embodiment, for convenience, unless otherwise specified or unless a contradiction occurs, the former term will be used. The term "multiple convex portions 117" may refer to all convex portions 117 of the reflective surface 113, or may refer to some of the convex portions 117. In the description of the embodiment, for convenience, unless otherwise specified or unless a contradiction occurs, the former term will be used. The same applies to the multiple concave portions 115. The terms reflecting surface 113, multiple convex portions 117, and multiple concave portions 115 have been mentioned, but the same applies to the corresponding terms inner surface 123 of mold 121, multiple concave portions 125, and multiple convex portions 127.

[0038] (2. Mold) The molds 120 and 121 (FIG. 2) are made of metal. The specific type of metal is arbitrary. Unlike the embodiment, molds other than metal molds (molds made of materials other than metal) may be used. The specific form of the mold is arbitrary. For example, the mold may be a direct-carving type mold in which the entire mold is basically formed as an integral unit, or a nested type mold having a nest that directly contributes to molding and a mother mold into which the nest is fitted. Furthermore, the combination of molds may consist of two molds facing each other (as in the illustrated example), or may consist of three or more molds. In other words, the number of divisions of the mold is arbitrary. Furthermore, the mold may be combined with a core.

[0039] (3. Processing Machine) The processing machine 1 (FIG. 3) has a machine section 3 that performs mechanical operations and a control device 5 that controls the machine section 3. The structure of the machine section 3 may be of various types, including known structures. The hardware of the control device 5 may be of various types, including known hardware. The operation (control) of the control device 5 may be of various types, including known operations, except for the control related to the shaper processing described above.

[0040] The configuration of the machine unit 3 is arbitrary as long as it is capable of performing the shaper machining described above. For example, the configuration of the machine unit 3 may be a configuration generally used in the machine unit of a machine tool (as in the illustrated example), a configuration generally used in the machine unit of an industrial robot, or a configuration that cannot be classified as such. The machine unit 3 in the illustrated example is configured to be capable of milling, but it may also be configured to be incapable of milling. In other words, the machine unit 3 may be configured without a spindle 7 (described below) that can rotate a tool around its axis.

[0041] The machine unit 3 may be configured to relatively translate the tool 101 and the mold 121 in three mutually orthogonal axes (X-axis, Y-axis, and Z-axis). Furthermore, the machine unit 3 may (but does not have to) have one or more linear axes and / or one or more rotational axes in addition to the three linear axes. The rotational axis may be any of the A-axis (axis around the X-axis), the B-axis (axis around the Y-axis), and the C-axis (axis around the Z-axis). For example, the processing machine 1 may be a five-axis processing machine having three linear axes and two rotational axes (in the illustrated example). The two rotational axes referred to here exclude rotation around the axis of the spindle 7 that holds the tool 101.

[0042] The specific configuration for realizing the processing machine 1 having three or more axes as described above is arbitrary. For example, the relative movement of each axis (linear axis or rotation axis) may be realized by movement in the absolute coordinate system of the tool 101 or the absolute coordinate system of the mold 121.

[0043] 3 is merely an example of a configuration that realizes three linear axes and two rotational axes. However, for reference, the configuration of the illustrated mechanical unit 3 will be briefly described below.

[0044] The machine unit 3 is capable of moving the tool 101 and the mold 121 relative to each other along the X-axis, Y-axis, Z-axis, A-axis, and C-axis. The tool 101 is held by the spindle 7, and the mold 121 is held by the table 9. Therefore, from another perspective, the machine unit 3 is capable of moving the spindle 7 and the table 9 relative to each other along the three linear axes and two rotational axes.

[0045] Relative movement along the Y-axis, Z-axis, and A-axis is realized by movement of the tool 101 along these axes in an absolute coordinate system. To realize this movement (absolute coordinate system), the machine unit 3 has, for example, the following components: A Y-axis movable unit 11 that is supported by fixed components (reference numerals omitted) so as to be movable in the Y-axis direction; A Z-axis movable unit 13 that is supported by the Y-axis movable unit 11 so as to be movable in the Z-axis direction; and A spindle head 15 that is supported by the Z-axis movable unit 13 so as to be movable in the A-axis direction (rotatable around the X-axis). The spindle head 15 holds the spindle 7 so that the axis of the spindle 7 is perpendicular to the X-axis.

[0046] Relative movement along the X-axis and C-axis is realized by movement of the mold 121 along these axes in an absolute coordinate system. To realize this movement (absolute coordinate system), the machine unit 3 has, for example, the following components: An X-axis movable unit 17 that is supported by a fixed component (reference numeral omitted) so that it can move in the X-axis direction; and a table 9 that is supported by the X-axis movable unit 17 so that it can move in the C-axis direction (rotatable around the Z-axis). The table 9 holds the mold 121 so that, for example, the inner surface 123 of the mold 121 faces the +Z-axis direction. However, the table 9 may hold the mold 121 in an orientation different from the above.

[0047] The following are examples of typical configurations of a five-axis machining center other than the configuration shown in the figure. One in which the spindle 7 moves along the X-axis, Y-axis, and Z-axis, and the table 9 moves along the A-axis and C-axis. One in which the spindle 7 moves along the Y-axis, Z-axis, A-axis, and B-axis, and the table 9 moves along the X-axis. One in which the spindle 7 moves along the Y-axis, Z-axis, and B-axis, and the table 9 moves along the X-axis and C-axis.

[0048] The drive source of each axis (including the main shaft 7) may be an electric motor, a hydraulic device, or a pneumatic device. The electric motor may be a rotary electric motor or a linear motor. When the drive source of the linear axis is a linear motor, it is easy to improve the machining accuracy. The drive source of the main shaft 7 may be, for example, an electric motor that can rotate at a relatively high speed (e.g., 20,000 rpm or more). This makes it easy to, for example, roughly machine the recess 125 using a normal rotary tool (a tool different from the tool 101) or to form the shape of the portion of the mold 121 other than the recess 125.

[0049] The linear guides or bearings of each shaft (including the main shaft 7) may be sliding guides in which a movable part and a fixed part slide against each other, rolling guides in which a rolling element rolls between the movable part and the fixed part, hydrostatic guides in which air or oil is interposed between the movable part and the fixed part, or a combination of two or more of these. Note that when the bearing of the main shaft 7 is an air hydrostatic bearing, it is easy to perform mirror finishing by milling.

[0050] Although not particularly shown, the machine unit 3 may have an automatic tool changer (ATC) that changes the tool to be used, which allows, for example, automatic cutting (as described above) to be performed using a tool different from the tool 101.

[0051] The machining accuracy (or, from another perspective, positioning accuracy) of the machine unit 3 (machine 1) may be set as appropriate. For example, the linear axes of the machine unit 3 may be positionable with submicrometer-order accuracy (error of less than 1 μm) or nanometer-order accuracy (error of less than 10 nm). Furthermore, for example, the rotary axes (including the spindle 7) may be positionable with an accuracy of 0.001°. Machine tools with such linear and / or rotary axis accuracy have already been put into practical use by the applicant (e.g., the UVM series, ULG series, and ULC series). Of course, the machining accuracy of the machine 1 may be lower than the above.

[0052] The control device 5 may perform control based on an NC program, control based on teaching, or other control methods. From another perspective, the processing machine 1 may be classified as a machine tool or a robot from the viewpoint of control, or may not be classified as such.

[0053] (4. Tools) (4.1. Tools in General) Figure 4 is a side view showing an example of a tool 101. For convenience, this figure is indicated by the Z axis, which is also indicated in Figure 3. A fixed Cartesian coordinate system xyz is also indicated for the tool 101. The Z axis and z axis are parallel to each other. The z direction is defined as being parallel to the center line CL1 of the shank 105s, which will be described later. The y direction is defined as being parallel to the cutting edge 103a, which will be described later. For convenience, the +z side is sometimes considered to be upward, and terms such as upper end are sometimes used.

[0054] The tool 101 has, for example, a generally axial shape extending in the z direction (the axial direction of the spindle 7). The tool 101 has a body 105 that occupies the majority of the tool 101 and the tip 103 fixed to the front end 105a of the body 105. The tip 103 is fixed by, for example, brazing.

[0055] The body 105 has a shank 105s that is detachably attached to the spindle 7. The body 105 may also have a neck (reference numeral omitted) between the shank 105s and the tip 105a, the diameter of which decreases toward the tip 105a. The configuration of the body 105 may be similar to a known configuration except for the shape of the tip 105a, and detailed description thereof will be omitted. The shape of the tip 105a will be described after the description of the tip 103.

[0056] (4.2. Tip) Fig. 5 is an enlarged perspective view showing the tip side portion of the tool 101. For convenience, this figure includes the Z axis and the Cartesian coordinate system xyz, which are also included in Fig. 4.

[0057] The tip 103 has a cutting edge 103a (in other words, a bottom cutting edge) facing the tip side (-z side). The surfaces that intersect with each other with the cutting edge 103a as a ridge line are a rake face 103b and a flank face 103c.

[0058] For example, when forming the first plane 129A in FIG. 7, the cutting edge 103a moves generally in the +x direction (to the right and near side of the paper in FIG. 5) to form the first plane 129A on the -z side. At this time, the third plane 129C is located on the -y side of the tip 103 (to the left and near side of the paper in FIG. 5). In other words, the first end 103e (FIG. 5) of the two ends of the cutting edge 103a is located on the side of the third plane 129C. The first end 103e may contribute to cutting to form a first corner 131A (FIG. 7) between the first plane 129A and the third plane 129C.

[0059] 7, the direction of movement of the cutting edge 103a during shaping may be inclined with respect to the x-direction (the direction perpendicular to the cutting edge 103a). However, in the description of the embodiment, for convenience, expressions are sometimes used assuming that the cutting edge 103a moves in the x-direction (parallel to the x-axis) without any particular mention.

[0060] The overall shape of the tip 103 is arbitrary as long as it has a cutting edge 103a, a rake face 103b, and a flank 103c. For example, the tip 103 may have an appropriate flat surface so that it can be suitably fixed to the body 105. Note that the shapes of the tip 103 shown in Figures 4 to 7 do not strictly match each other.

[0061] 5, the tip 103 has no cutting edge other than the cutting edge 103a. However, of the ridge 103h extending from the first end 103e toward the shank 105s (+z side), a portion near the first end 103e may function as a cutting edge. Also, unlike the illustrated example, the tip 103 may have two or more cutting edges.

[0062] The cutting edge 103a is, for example, linear and perpendicular to the center line CL1 ( FIG. 4 ) of the shank 105s. However, the cutting edge 103a may be inclined within a range of ±30°, ±10°, or ±5° relative to the center line CL1. The cutting edge 103a may also be curved when viewed in a direction perpendicular to the plane being cut. Unlike the description of the embodiment, the cutting edge 103a may be curved when viewed in the direction of its advancement, as long as it forms a curved surface. The length of the cutting edge 103a (or, from another perspective, the length of the tip 103 in the y direction) is optional. For example, the length of the cutting edge 103a is 0.005 mm or more and 30 mm or less.

[0063] The rake face 103b and the flank 103c are, for example, flat. However, they may be curved, have a combination of multiple flat surfaces, or have grooves. The rake angle, clearance angle, and cutting edge angle may be any value. The rake angle may be a negative value (example of FIG. 5), a positive value, or 0°. Just to be clear, in a configuration where the rake angle is a negative value, the rake face 103b is inclined so that it is positioned closer to the shank 105s (+z side) in the direction of travel of the cutting edge 103a (+x side). The various angles may be set taking into account machinability or the anisotropy of the material (e.g., diamond) of the tip 103.

[0064] 6 is a view of the tip 103 viewed in the x direction, which is, as described above, approximately the same as the direction in which the tip 103 moves during shaping.

[0065] The first end 103e is located, for example, on the center line CL1 of the shank 105s. As a result, even if an error occurs in the rotational position of the tool 101 (spindle 7), the effect of the error on the position of the first end 103e is reduced (theoretically, there is no effect). This in turn improves the positional accuracy of corners (131A, etc.) formed by the first end 103e. Note that even though the first end 103e is located on the center line CL1, it goes without saying that unavoidable errors, etc., may exist in the manufacturing process of the tool 101.

[0066] Consider a configuration in which the first distance from the center line CL1 of the first end 103e is the same as the second distance from the center line CL1 of the other end (second end 103f) of the cutting edge 103a (this configuration may also be included in the technology disclosed herein). Compared to this configuration, the above-described effect can be achieved to some extent if the first distance is slightly shorter than the second distance. Therefore, from another perspective, the first distance may be shorter than the second distance by an appropriate amount. For example, the first distance may be ½ or less, ⅕ or less, or 1 / 10 or less of the second distance.

[0067] The ridge line 103h extending from the first end 103e toward the shank 105s (+z side) is inclined with respect to the center line CL1 so as to move away from the center line CL1 as it approaches the shank 105s. From another perspective, the ridge line 103h is inclined so as to be positioned closer to the second end 103f as it approaches the shank 105s. From yet another perspective, when viewed in the movement direction of the tip 103 (for example, the x direction), the tip 103 does not have a portion positioned on the opposite side (-y side) from the second end 103f than the first end 103e.

[0068] This reduces the likelihood that the ridge 103h (or, from another perspective, the portion of the tip 103 other than the cutting edge 103a) will interfere with the third plane 129C when, for example, the cutting edge 103a is forming the first plane 129A and the first end 103e is forming the first corner portion 131A. Note that the term "ridge 103h" may refer to only a portion of the ridge extending from the first end 103e toward the shank 105s on the first end 103e side. However, for convenience in describing the embodiments, the term "ridge 103h" will refer to the entire ridge.

[0069] The inclination angle of the ridge line 103h is arbitrary. The ridge line 103h may be straight (as in the illustrated example) or curved. Unlike the illustrated example, the upper end (the end on the +z side) of the ridge line 103h does not have to reach the upper end of the chip 103 (the chip 103 may have a flat or curved surface facing the -y side above the ridge line 103h).

[0070] The material of the tip 103 is not limited, and may be, for example, diamond (single crystal or polycrystalline), CBN (Cubic Boron Nitrides), ceramics (e.g., alumina-based or silicon nitride-based), cermet, or cemented carbide.

[0071] 4 and 5 is located closer to the second end 103f (+y side) than the first end 103e (center line CL1 from another perspective) of the tip 103 when viewed in the movement direction (e.g., x direction) of the tip 103. This reduces the likelihood that the tip 105a will interfere with the third plane 129C when the first plane 129A is formed by the cutting edge 103a and the first corner portion 131A is formed by the first end 103e, as shown in FIG.

[0072] The specific shape of the tip 105a is arbitrary. In FIG. 5, the shape of the tip 105a is approximately a right columnar shape having a fan-shaped bottom surface with a central angle of 90°. However, the central angle of the fan shape does not have to be 90°. The shape of the bottom surface of the right columnar shape does not have to be fan-shaped, and may be, for example, rectangular or another polygonal shape. Furthermore, the tip 105a may not be a right columnar shape, but may be a truncated cone shape whose cross-sectional area decreases or increases toward the -z side.

[0073] As described above, the movement direction of the cutting edge 103a is not limited to the direction (x direction) perpendicular to the cutting edge 103a (y axis), but may be a direction inclined toward the x direction. The shape of the tip 105a may be determined taking into account the specific movement direction of the cutting edge 103a. For example, as illustrated in FIG. 7 , when the cutting edge 103a is used at an angle such that the first end 103e is positioned ahead in the direction of travel, the central angle may be smaller than 90° so that the tip 105a does not interfere with the third plane 129C.

[0074] (4.4. Other Examples of Tools) The shape of the tool 101 in the illustrated example is merely an example. Shaper processing can be performed using various tools other than the illustrated example. Examples are given below.

[0075] As already mentioned, the cutting edge 103a may straddle the center line CL1 or may be curved. The cutting edge 103a may not be a bottom cutting edge, but may be a peripheral cutting edge that runs along the center line CL1 (parallel to the center line CL1 or inclined to the center line CL1).

[0076] The tip 103 may have two or more cutting edges. For example, the tip 103 may have one bottom cutting edge and one peripheral cutting edge. In this case, two intersecting planes (e.g., the first plane 129A and the third plane 129C) may be simultaneously formed by shaping. The bottom cutting edge and the peripheral cutting edge may be perpendicular to each other. In this case, two planes of a corner cube RR can be simultaneously formed. Of course, the bottom cutting edge and the peripheral cutting edge do not have to be perpendicular to each other.

[0077] The tip 103 may not be brazed to the body 105, but may be detachably attached to the body 105 with a screw or the like. Also, the tool 101 may not have the tip 103, but may have the cutting edge 103a and the shank 105s integrally formed. When such aspects are taken into consideration, the term tip 103 in the description of the embodiments may be replaced with the terms cutting portion or cutting edge, for example.

[0078] (5. Cutting Method) As described in the overview of the embodiment, for example, all flat surfaces (129A to 129C) of the recess 125 may be formed by shaping using the cutting edge 103a. Also, all corners (131A to 131C) between these flat surfaces may be formed by the first end 103e of the cutting edge 103a. Roughing and / or finishing may (or may not) be performed by a tool other than the tool 101 and / or by processing other than shaping (for example, milling).

[0079] As can be understood from the fact that rough machining and / or finishing machining may be performed, for example, when it is said that recess 125 is formed by shaping, the entire process of forming recess 125 does not have to be performed by shaping (although of course it can be performed).

[0080] Furthermore, for example, when all of the flat surfaces (129A to 129C) of the recess 125 are formed by shaping, the entire area of ​​each flat surface may be formed by shaping, or only a portion of each flat surface may be formed by shaping. As an example of the latter, for example, after the recess 125 is roughly formed by milling with a tool other than the tool 101, only the corners (131A to 131C) and their surrounding areas may be formed by shaping.

[0081] In the description of the embodiment, for convenience, expressions may be used that ignore machining other than the shaping machining performed by the tool 101. In addition, in the description of the embodiment, for convenience, expressions may be used that assume that the entirety of each plane is formed by the shaping machining, unless otherwise specified.

[0082] 7, the length of the cutting edge 103a is shorter than the width of the first plane 129A (the length of the second corner 131B) when viewed in the direction of travel of the cutting edge 103a. The cutting edge 103a may contribute to the formation of the entire area of ​​the first plane 129A by repeated shaping, or may contribute to the formation of only a portion of the area (e.g., the area around the first corner 131A as described above) by at least one shaping. The same applies to the other planes (129B and 129C).

[0083] Unlike the illustrated example, the length of the cutting edge 103a may be longer than the length of the second corner portion 131B. In this embodiment, the entire area of ​​the first flat surface 129A can be cut by a single shaping operation. However, even in this embodiment, the shaping operation may be repeated. In other words, the recess 125 may be gradually enlarged. The same applies to the other flat surfaces.

[0084] When forming the multiple recesses 125, the multiple first planes 129A may be formed, then the multiple second planes 129B may be formed, and then the multiple third planes 129C may be formed (hereinafter referred to as the "first procedure"). Alternatively, the multiple recesses 125 may be formed by repeating the operation of forming the three planes (129A to 129C) of one recess 125 (hereinafter referred to as the "second procedure"). That is, the multiple recesses 125 may be formed gradually as a whole (first procedure) or may be formed one by one (second procedure).

[0085] Note that the first procedure usually requires a shorter processing time, although this depends on the shape of the mold 121. Alternatively, after forming a first number (two or more) of recesses 125 in the first region by the first procedure, a second number (two or more) of recesses 125 may be formed in the second region that is inclined with respect to the first region by the first procedure.

[0086] FIG. 8 is a perspective view showing an example of more detailed matters of the cutting method.

[0087] In this figure, arrows a1 to a3 indicate the trajectory of the tip 103, similar to arrow a1 in Figure 7. The tip 103 moves, for example, in the order of arrows a1, a2, and a3. That is, in the illustrated example, the three planes are formed in the order of first plane 129A, second plane 129B, and third plane 129C.

[0088] The operations described with reference to Figure 8 (operations indicated by arrows a1 to a3) may be operations performed when focusing on one recess 125 in the process in which multiple recesses 125 are gradually formed by the first step described above, or may be operations performed in the process in which recesses 125 are formed one by one in sequence by the second step.

[0089] As can be understood from the above explanation, the shaper processing indicated by arrows a1 to a3 may or may not be repeated to form one recess 125. In the latter case, the operations of arrows a1, a2, and a3 may be repeated in order (hereinafter referred to as the "third procedure"), or the operations of arrow a1, a2, and a3 may be repeated in order (hereinafter referred to as the "fourth procedure"), or both may be combined.

[0090] It should be noted that either the first procedure or the second procedure may be combined with the third procedure or the fourth procedure. In addition, for convenience, in the description of the embodiments, expressions may be used assuming that there is no repetition unless otherwise specified.

[0091] When forming the first plane 129A, the tip 103 moves parallel to the first plane 129A (the imaginary plane where the first plane 129A is to be formed) toward the second plane 129B (the position where the second plane 129B is to be formed). At this time, the cutting edge 103a forms the first plane 129A, and the first end 103e forms the first corner 131A (the valley line between the third plane 129C and the first plane 129A). The tip 103 then retreats from the recess 125 (the imaginary space where the recess 125 is to be formed) along the second plane 129B (the imaginary plane where the first plane 129A is to be formed). The retreat path of the tip 103 may be different from that described above.

[0092] The formation of the second plane 129B and the third plane 129C is similar to the above. Just to be clear, a partial description will be given. When forming the second plane 129B, the tip 103 translates along the second plane 129B (the imaginary plane where the plane is planned to be formed) toward the next to be formed, the third plane 129C (the planned position of the plane). At this time, the cutting edge 103a forms the second plane 129B, and the first end 103e forms the second corner 131B (the valley line between the first plane 129A and the second plane 129B). When forming the third plane 129C, the tip 103 translates along the third plane 129C (the imaginary plane where the plane is planned to be formed) toward the first plane 129A. At this time, the cutting edge 103a forms the third plane 129C, and the first end 103e forms the third corner 131C (the valley line between the second plane 129B and the third plane 129C).

[0093] However, the procedure (or, from another point of view, the direction of movement) for sequentially forming the three planes may be different from that described above. For example, when forming the first plane 129A, the tip 103 may move toward the third plane 129C to be formed next.

[0094] (6. Machining Examples) When manufacturing a mold 121 using the tool 101, various shapes and dimensions of the recess 125 can be realized by controlling the cutting direction and cutting amount. Several examples are shown below. In the following description, for convenience, capital letters may be added to the symbols of the mold 121 and each part thereof to distinguish between several examples. The several examples described below may be combined with each other as long as no contradictions or the like arise. For example, two or more examples may be applied to one mold 121.

[0095] 9 is a cross-sectional view showing a mold 121A according to a first processing example. In the mold 121A, the recesses 125 (125A and 125B) include recesses 125A and 125B oriented in different directions. In the illustrated example, the recesses 125 have the same shape and dimensions.

[0096] More specifically, the plurality of recesses 125A are two-dimensionally arranged in a planar first region and face the same direction (more specifically, facing the normal direction of the first region). The plurality of recesses 125B are two-dimensionally arranged in a planar second region and face the same direction (more specifically, facing the normal direction of the second region). The orientations of the plurality of recesses 125A and the orientations of the plurality of recesses 125B are different from each other. From another perspective, the planar first region and the planar second region face in different directions from each other.

[0097] The angle formed between the first region and the second region is arbitrary. One or more recesses 125 may be interposed between the first region and the second region, with the orientation between the orientation of recess 125A and the orientation of recess 125B. Two or more planar regions may be provided. Note that whether the first region and the second region are planar may be determined, for example, by whether the opening surfaces of the multiple recesses 125A and 125B (virtual planes that block the openings of the recesses 125) are generally located in the same plane.

[0098] 10 is a cross-sectional view showing a mold 121B according to a second processing example. In the mold 121B, similar to the mold 121A, the recesses 125 include two or more recesses 125 that are oriented in different directions. However, the specific form is different from that of the mold 121A.

[0099] More specifically, the orientations of the multiple recesses 125 are different from adjacent recesses 125. From another perspective, the angle of the recesses 125 gradually changes in at least one arrangement direction of the two-dimensional arrangement. From yet another perspective, the multiple recesses 125 are arranged in a curved area so as to face the normal direction of each position. Whether the multiple recesses 125 are arranged along a curved surface may be determined, for example, by considering the opening surfaces of the multiple recesses 125 and determining whether the multiple opening surfaces are connected to form a generally curved surface (strictly speaking, a polygonal shape).

[0100] The degree and pattern of the change in orientation (or, from another perspective, the curvature and shape of the curved surface) are arbitrary. For example, the curvature may be constant (as in the illustrated example) or may vary. The curved surface of the second processing example may be located between two planar regions of different orientations in the mold 121A of the first processing example.

[0101] 11 is a cross-sectional view showing a mold 121C according to a third processing example. In the mold 121C, the recesses 125 include two or more recesses 125C and 125D of different sizes. In the illustrated example, the recesses 125 have the same shape.

[0102] More specifically, in the illustrated example, two types of recesses 125C and 125D having different sizes are two-dimensionally arranged on the same plane. The two types of recesses 125C and 125D are located in different regions.

[0103] Unlike the illustrated example, there may be three or more different sizes. The recesses 125 of different sizes may be mixed rather than being concentrated in different regions. The sizes of the multiple recesses 125 may gradually change in the arrangement direction, one by one or in a predetermined number.

[0104] The recesses 125 having different sizes may be combined with the first processing example and / or the second processing example. For example, the recesses 125 having different sizes may be oriented in different directions. More specifically, for example, in FIG. 9, the recess 125A may be larger or smaller than the recess 125B. And / or, the recesses 125 located on the curved surface between the recess 125A and the recess 125B as in the second processing example may be larger or smaller than the recess 125A and / or the recess 125B.

[0105] (6.4. Supplementary information regarding the fourth processing example and the orientation and size of the recesses) Fig. 12 is a plan view showing a mold 121D according to the fourth processing example. Fig. 13 is a cross-sectional view showing the mold 121D. Note that both figures are schematic, and therefore the shapes of the recesses 125 in Fig. 12 and Fig. 13 do not match.

[0106] In the mold 121D, the multiple recesses 125 include two or more recesses 125E that differ from one another in shape, size, and / or orientation. More specifically, the multiple recesses 125E have random shapes, sizes, and orientations. Note that the randomness in this case does not need to be strict, as in a pseudo-random number sequence. For example, it is sufficient if an average person or a person skilled in the art cannot find any regularity when looking at the mold 121D. The reflector 111 formed by such multiple recesses 125E can, for example, homogenize the distribution of radiant and / or photometric quantities in the cross section of the light when reflecting light from a light source.

[0107] In the first processing example (FIG. 9) and the second processing example (FIG. 10), the recesses 125 having different orientations have the same shape (although the sizes may be different), so it is easy to determine whether the orientations are the same. When the recesses 125 have different shapes, as in the fourth processing example, the orientations of the recesses 125 may be determined based on the orientation of the optical axis LA (FIG. 13), for example.

[0108] The direction of the optical axis LA may be defined as follows in the present disclosure, for example. Consider a situation in which parallel light is incident on one recess 125 and reflected. The direction in which the radiation amount of the reflected light (e.g., the radiant flux in a sufficiently wide plane parallel to the opening plane of the recess 125) is greatest may be selected as the incident direction of the parallel light. The direction in which the radiation amount of the reflected light (e.g., the radiation intensity) is greatest is defined as the direction of the optical axis LA. When the radiation intensity is greatest over a solid angle of a certain size, the direction of the center line thereof may be defined as the direction of the optical axis LA. Note that the optical axis LA of the corner cube RR recess 125 is a straight line equidistant from the three planes (129A to 129C).

[0109] The recess 125 is formed in the mold 121, and therefore, unlike the protrusion 117 (or recess 115) of the reflector 111, it is not intended to reflect light. However, for convenience, the optical axis LA is used to determine whether the orientation is the same. Furthermore, the determination of whether the orientation is the same here is solely based on the orientation of the shape of the recess. Therefore, it may be assumed that the surface properties related to reflection of the multiple flat surfaces (129A to 129C) that make up the inner surface of the recess are the same.

[0110] Furthermore, in the third processing example ( FIG. 11 ), the recesses 125 of different sizes have the same shape, making it easy to determine whether they are the same or different in size. When the recesses 125 have different shapes, as in the fourth processing example, the size of the recesses 125 may be determined based on, for example, the area of ​​the inner surface of the recesses 125. This is because, although it depends on the shape of the recess 125, the larger the area of ​​the inner surface, the greater the amount of light radiation reflected by one recess 125. Alternatively, the volume of the space within the recess 125 or the area of ​​the opening surface of the recess 125 may be compared.

[0111] Figure 12 also illustrates recesses 125 that are not triangular pyramidal. However, recesses 125 that are different from one another in shape, size, and orientation (or even random) may be triangular pyramidal, as shown in Figure 13. Also, although the shapes, sizes, and orientations are all random in Figures 12 and 13, only one or two of them may be random. Multiple recesses 125 with random shapes, sizes, and / or orientations may be provided along a curved surface rather than along a flat surface.

[0112] 14 is a cross-sectional view showing a mold 121E according to a fifth processing example. In the mold 121E, the recesses 125 include two or more recesses 125F and 125G that are oriented in different directions.

[0113] More specifically, the recesses 125F have the same shape, size, and orientation, and constitute a corner cube RR. The optical axis (not shown) is parallel to the normal (the vertical direction in the drawing) of the plane on which the recesses 125 are arranged. The recesses 125F are also evenly arranged two-dimensionally, similar to the example in FIG. 1.

[0114] Some of the recesses 125F are replaced with recesses 125G, which are oriented in a different direction from the recesses 125F. The recesses 125G are based on a triangular pyramid shape constituting a corner cube RR, for example. However, to avoid disrupting the arrangement of the recesses 125F, additional flat surfaces are added to the three flat surfaces constituting the triangular pyramid. The optical axis (not shown) of the triangular pyramid of the recess 125G is inclined toward the right side of the figure toward the top of the figure with respect to the normal to the plane on which the recesses 125 are arranged (or, from another perspective, the optical axis of the recesses 125F). The degree of inclination (tilt angle) may be appropriately set so as to obtain the effects described below.

[0115] Here, for convenience, it is assumed that the mold 121E is a reflector, and the effect of setting the orientation of the recess 125 as described above will be described. In the following description, strictness will be ignored for ease of understanding.

[0116] As shown by eye E1, assume that a plane on which multiple recesses 125 are arranged is viewed from above parallel to the normal direction of the plane (the direction of the optical axis of recess 125F). In this case, light incident on the plane in the line of sight is reflected upward by both recesses 125F and 125G parallel to the line of sight. As a result, reflected light is visible across the entire plane.

[0117] Next, as shown by eye E2, consider the case where a plane on which multiple recesses 125 are arranged is viewed from above parallel to the optical axis of recesses 125G. In this case, light incident on the plane in the line of sight is reflected upward by recesses 125G parallel to the line of sight. Meanwhile, the line of sight is outside the angular range in which recesses 125F produce retroreflection, and recesses 125F do not reflect light in the line of sight. As a result, (relatively strong) reflected light is visible only at the position of recesses 125G.

[0118] Here, for example, the plurality of recesses 125G are arranged in a specific pattern (figures and / or letters, etc.), which realizes a gimmick in which a pattern that is not visible when the plane on which the plurality of recesses 125 are arranged is viewed from the front can be seen when the plane is viewed obliquely.

[0119] The above gimmick can be further developed. Specifically, for example, as follows. In the above gimmick, recess 125G is provided in which both eyes E1 and E2 are visible, and recess 125F is provided in which eye E1 is visible but eye E2 is not. In addition, although not specifically shown, recess 125 is provided in which both eyes E1 and E2 are not visible, and recess 125 in which eye E1 is not visible but eye E2 is visible. In this way, different patterns can be visible when the plane is viewed from the front and when viewed obliquely.

[0120] (7. Summary of the embodiment) As described above, the manufacturing method of the reflector molding die according to the embodiment is a manufacturing method of the die 121 that molds the reflector 111 that reflects light, and includes a cutting step ( FIG. 7 ) that forms a plurality of recesses 125 on the inner surface of the die 121 by cutting in order to form irregularities (recesses 115 and protrusions 117) on the reflective surface of the reflector 111. The cutting step includes a shaper step ( FIG. 7 ) that cuts each of the plurality of recesses 125 by moving the tool 101 relative to the die 121 without rotating or vibrating the tool 101.

[0121] From another point of view, in the manufacturing method of the reflector 111 according to the embodiment, the reflector 111 is molded using the mold 121 manufactured by the manufacturing method of the mold for molding a reflector according to the embodiment described above.

[0122] Therefore, as described in the overview of the embodiment, for example, the accuracy of the corners (131A to 131C) of the recess 125 can be improved compared to an embodiment in which the recess 125 is formed by cutting (milling) with a rotating rotary tool. The configuration of the processing machine 1 can be simplified compared to an embodiment in which the recess 125 is formed by cutting with a vibrating tool. Control can be simplified compared to an embodiment in which the translation and rotation of the tool are synchronized. From another perspective, the creation of an NC program or teaching program can be facilitated.

[0123] The tool 101 may have a cutting edge 103a extending in a direction intersecting a center line CL1 of the shank 105s. When both ends of the cutting edge 103a are referred to as a first end 103e and a second end 103f, the distance from the center line CL1 of the first end 103e may be shorter than the distance from the center line CL1 of the second end 103f. A ridge 103h extending from the first end 103e toward the shank 105s may be inclined so as to be positioned closer to the second end 103f as it approaches the shank 105s.

[0124] In this case, for example, as described above, when forming the first corner 131A with the first end 103e while forming the first plane 129A with the cutting edge 103a, the influence of positioning errors around the axis of the tool 101 on the accuracy of the first corner 131A is reduced. Furthermore, the likelihood of the ridge 103h interfering with the third plane 129C is reduced. As a result, for example, the likelihood of forming an unintended shape in the first corner 131A and / or the third plane 129C is reduced, thereby improving the accuracy of these areas. Furthermore, because the angle between the cutting edge 103a and the ridge 103h at the first end 103e is less than 90°, when forming the corners (131A-131C) with the first end 103e during shaping, it is easy to set the angle of the corner to any desired value.

[0125] The first end 103e may be located on the center line CL1. The ridge line 103h may be inclined so as to move away from the center line CL1 toward the shank 105s.

[0126] In this case, for example, the above-described effect (reduced influence of errors around the axis of the tool 101 on the accuracy of the first corner portion 131A) is improved.

[0127] In the shaper step, all of the surfaces (129A to 129C) of each of the plurality of recesses 125 may be cut by the same linear cutting edge 103a of the tool 101.

[0128] In this case, the cutting conditions for the two planes are closer than in a configuration in which two planes (e.g., first plane 129A and third plane 129C) are simultaneously formed using a bottom cutting edge and a peripheral cutting edge (this configuration may also be included in the technology disclosed herein). As a result, for example, the surface textures of the two planes of mold 121 are likely to be equivalent, and thus the surface textures of the two planes of reflector 111 corresponding to the two planes are likely to be equivalent. As a result, for example, the uniformity of light reflection is improved.

[0129] In each of the plurality of recesses 125, all corners (131A to 131C) between adjacent surfaces may be cut by the first end 103e of the first end 103e and the second end 103f of the cutting edge 103a.

[0130] In this case, for example, because all corners are cut by the same first end 103e, the microscopic roundness (unavoidable manufacturing errors) of all corners tends to be uniform. As a result, for example, the roundness of the ridges of the protrusions 117 of the reflector 111 corresponding to the corners of the mold 121 tends to be uniform. As a result, for example, the uniformity of light reflection is improved.

[0131] Each of the multiple recesses 125 may have a first plane 129A, a second plane 129B, and a third plane 129C that are perpendicular to one another. The shaper step may have a first step (arrow a1 in FIG. 8 ), a second step (arrow a2 in FIG. 8 ), and a third step (arrow a3 in FIG. 8 ). In the first step, the cutting edge 103 a may be moved relatively toward a position where the second plane 129B is to be formed, and the first end 103 e may form a first corner portion 131A between the third plane 129C and the first plane 129A while forming the first plane 129A with the cutting edge 103 a. In the second step, after the first step, the cutting edge 103a may be relatively moved toward the intended position for forming the third plane 129C, so that the second plane 129B is formed by the cutting edge 103a while the second corner 131B between the first plane 129A and the second plane 129B is formed by the first end 103e. In the third step, after the second step, the cutting edge 103a may be relatively moved toward the first plane 129A, so that the third plane 129C is formed by the cutting edge 103a while the third corner 131C between the second plane 129B and the third plane 129C is formed by the first end 103e.

[0132] In this case, for example, the flat surface and the corner portion are formed simultaneously, resulting in efficient machining. When the cutting edge 103a is moved toward the second flat surface 129B to form the first flat surface 129A (first step), chips may remain in the position that will become the second corner portion 131B. However, since the second corner portion 131B is formed in the subsequent second step, the chips can be removed.

[0133] The tool 101 may be attached to the spindle 7 of the processing machine 1 that is capable of simultaneously controlling three linear axes and two rotational axes.

[0134] In this case, for example, the orientation of the multiple recesses 125 can be made different from one another by changing the orientation of the tool 101 and the mold 121 using two rotational axes. Therefore, for example, when forming multiple recesses 125 with the same shape and dimensions, the amount of movement along the three linear axes when forming each recess 125 (excluding positioning depending on the differences in the positions of the multiple recesses 125) can be made the same for all multiple recesses 125. As a result, for example, the creation of NC programs or teaching data is facilitated. Also, for example, the variation in error among the multiple recesses 125 is likely to be reduced.

[0135] The plurality of recesses 125 may include two or more recesses 125 whose optical axes are oriented in different directions (FIGS. 9, 10, and 12 to 14).

[0136] A method for forming the plurality of recesses 125 that is different from the embodiment includes bundling a plurality of pins with triangular pyramidal tips and forming a mold at the tip of the bundle by electroforming. Compared to this method, the method for forming the plurality of recesses 125 according to the embodiment uses the tool 101 to individually form the plurality of recesses 125, and therefore can easily realize two or more recesses 125 that are oriented in different directions.

[0137] 9 and 10, a mold 121 including recesses 125 oriented differently from each other can be used to integrally form a rear reflector (RR) that is provided at the rear of an automobile and includes protrusions 117 capable of reflecting light from the rear and protrusions 117 capable of reflecting light from the side. Also, as can be seen from FIGS. 12 and 13, a mold 121 including recesses 125 oriented differently from each other can be used for a reflector that homogenizes light from a light source (e.g., a component that reflects light from an automobile lamp to the outside). Also, as can be seen from FIG. 14, a mold 121 including recesses 125 oriented differently from each other can be used to realize a technology that allows different patterns to be seen depending on the viewing direction, such as a lenticular lens.

[0138] The plurality of recesses 125 may include two or more recesses 125 having different inner surface areas (FIGS. 11 to 14).

[0139] Similar to the two or more recesses 125 with different orientations as described above, the method for forming the multiple recesses 125 according to the embodiment involves individually forming the multiple recesses 125 using tool 101, and therefore, two or more recesses 125 with different sizes can be easily realized.

[0140] The mold 121 including the recesses 125 of different sizes can be used, for example, to integrally form a rear end (RR) that is provided at the rear of an automobile and includes protrusions 117 of different sizes. By making the sizes of the multiple protrusions 117 different from one another, it is possible to improve the design of the automobile, for example. Furthermore, by combining this with making the orientations different from one another, it is possible to separately set performance suitable for reflecting light from behind and performance suitable for reflecting light from the side.

[0141] The plurality of recesses 125 may include two or more recesses 125 having different shapes (FIGS. 12 to 14).

[0142] The method for forming the plurality of recesses 125 according to the embodiment involves individually forming the plurality of recesses 125 using the tool 101, which allows for easy realization of two or more recesses 125 with different shapes. The use of such recesses 125 facilitates, for example, imparting randomness to the reflection patterns of the plurality of recesses 125 ( FIGS. 12 and 13 ). Furthermore, for example, it facilitates making the optical axis directions of the plurality of recesses 125 different from one another while maintaining regularity in the arrangement of the plurality of recesses 125 ( FIG. 14 ).

[0143] The plurality of recesses 125 may include two or more recesses 125 aligned along the curved surface (FIG. 10).

[0144] The method for forming the plurality of recesses 125 according to the embodiment uses the tool 101 to individually form the plurality of recesses 125, and therefore, can easily realize two or more recesses 125 arranged along a curved surface. A mold 121 including the recesses 125 arranged along a curved surface can be used, for example, to integrally form a rear edge of an automobile that extends from the rear to the sides. In this case, for example, the rear edge of the automobile can be made into an arbitrary curved surface, which in turn facilitates improving the design of the automobile.

[0145] The optical axes of the recesses 125 may be oriented in random directions (FIGS. 12 and 13).

[0146] The method for forming the plurality of recesses 125 according to the embodiment involves individually forming the plurality of recesses 125 using the tool 101, and therefore can easily realize the plurality of recesses 125 with random orientations. The mold 121 including the plurality of recesses 125 with random orientations can be used, for example, to create a reflector for the purpose of uniformizing light.

[0147] In another example, a manufacturing method of a reflector 111 according to the embodiment is a manufacturing method of a reflector 111 that reflects light, and includes a cutting step of forming a plurality of recesses 115 that constitute a reflective surface 113 of the reflector 111 by cutting (see FIG. 7 for a diagram of cutting a mold 121). The cutting step includes a shaper step of cutting each of the plurality of recesses 115 by moving the tool 101 relative to the reflector 111 without rotating or vibrating the tool 101.

[0148] In this case, the same effect as in the case where the reflector 111 is formed via the mold 121 described above can be achieved.

[0149] In the above embodiment, the mold 121 is an example of a mold for forming a reflector, and the tool 101 is an example of a cutting tool.

[0150] The technology according to the present disclosure is not limited to the above embodiment and may be implemented in various ways. For example, only some of the multiple surfaces of the inner surface of the recess of the mold may be formed by shaping.

[0151] Inventions that do not require shaping, a reflector, or multiple recesses may be extracted from the present disclosure. For example, an invention may be extracted of a method for manufacturing a mold that forms two or more recesses 125 with different shapes and / or sizes by cutting that does not involve shaping. Also, for example, an invention may be extracted of a method for manufacturing a mold that uses the tool 101 of the embodiment for milling.

[0152] 111...reflector, 113...reflecting surface, 115...concave portion (of reflector), 117...convex portion (of reflector), 121...mold (mold for forming reflector), 123...inner surface (of mold), 125...concave portion (of mold).

Claims

1. A manufacturing method of a mold for molding a reflector that reflects light, comprising a cutting step of forming a plurality of recesses on the inner surface of the mold by cutting to create unevenness on the reflective surface of the reflector, the cutting step also comprising a shaper step of cutting each of the plurality of recesses by relative movement of the tool with respect to the mold without rotation or vibration of the tool.

2. The method for manufacturing a reflector molding die as described in claim 1, wherein the tool has a cutting edge extending in a direction intersecting the center line of a shank, and when both ends of the cutting edge are referred to as a first end and a second end, the distance from the center line to the first end is shorter than the distance from the center line to the second end, and a ridgeline extending from the first end toward the shank is inclined so as to be positioned closer to the second end as it approaches the shank.

3. A manufacturing method for a reflector molding die according to claim 2, wherein the first end is located on the center line, and the ridge line is inclined so as to move away from the center line as it approaches the shank.

4. The manufacturing method of a reflector molding die as described in claim 1, wherein in the shaping step, all of the faces of each of the plurality of recesses are cut by the same linear cutting edge of the tool.

5. A manufacturing method for a reflector molding die as described in claim 4, wherein in each of the plurality of recesses, all corners between adjacent faces are cut by the first end of the cutting edge, which has a first end and a second end.

6. A manufacturing method for a reflector molding die as claimed in claim 5, wherein each of the plurality of recesses has a first plane, a second plane and a third plane which are perpendicular to one another, and the shaper step includes: a first step of relatively moving the cutting edge towards a position where the second plane is scheduled to be formed, and forming the first plane with the cutting edge while forming a corner portion between the third plane and the first plane with the first end; a second step, after the first step, of relatively moving the cutting edge towards the position where the third plane is scheduled to be formed, and forming the second plane with the cutting edge while forming a corner portion between the first plane and the second plane with the first end; and a third step, after the second step, of relatively moving the cutting edge towards the first plane, and forming the third plane with the cutting edge while forming a corner portion between the second plane and the third plane with the first end.

7. The manufacturing method of the reflector molding die according to claim 4, wherein the tool is attached to the main spindle of a processing machine capable of simultaneously controlling three linear axes and two rotational axes.

8. The method for manufacturing a reflector molding die according to claim 1, wherein the plurality of recesses include two or more recesses whose optical axes are oriented in different directions.

9. The method for manufacturing a reflector molding die according to claim 1, wherein the plurality of recesses include two or more recesses having inner surface areas different from each other.

10. The method for manufacturing a reflector molding die according to claim 1, wherein the plurality of recesses include two or more recesses having different shapes.

11. The method for manufacturing a reflector molding die according to claim 1, wherein the plurality of recesses includes two or more recesses aligned along the curved surface.

12. The method for manufacturing a reflector molding die according to claim 1, wherein the optical axes of the plurality of recesses are oriented randomly.

13. A method for manufacturing a reflector, comprising the steps of: molding the reflector using the mold manufactured by the method for manufacturing a mold for molding a reflector according to claim 1.

14. A method for manufacturing a reflector that reflects light, comprising: a cutting step for forming a plurality of recesses that constitute the reflective surface of the reflector by cutting; the cutting step also comprises a shaper step for cutting each of the plurality of recesses by relative movement of the tool with respect to the reflector without rotation or vibration of the tool.

15. A cutting tool having a cutting edge extending in a direction intersecting a center line of a shank, wherein when both ends of the cutting edge are referred to as a first end and a second end, the distance from the center line to the first end is shorter than the distance from the center line to the second end, and a ridge extending from the first end toward the shank is inclined so as to be positioned closer to the second end as it approaches the shank.

Images