JP2016070918A - Molded product manufacturing method, shape measuring method and shape measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape measurement method that effectively prevents occurrence of measurement errors based on a change in shape of an irradiation surface due to a difference in a measurement position even when a molding is shaped into a surge, and can precisely measure the shape of a measurement object, and to provide a molding manufacturing method employing the shape measurement method.SOLUTION: A shape measurement device comprises: a light source 11 that generates broad band light; an optical system 20 that branches the broad band light into measurement light and reference light, which are different in a route, and causes the measurement light to be reflected by irradiating a measurement object with the measurement light; a phase shift mirror 41 that is arranged in an optical path of the reference light, and causes a reflection surface to be formed into a step to change an optical path length in accordance with a position of a Y-direction in the reference light; and a camera unit 50 that receives reflection light of the measurement light with which the measurement object is irradiated, and the reference light having the optical path length modulated by the phase shift mirror 41. A shape of a molding 1 is measured by the shape measurement device 3 in which the measurement light with which the measurement object is irradiated is parallel light.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a molded product manufacturing method, a shape measuring method, and a shape measuring apparatus for measuring the shape of a measurement object using an interferometer.

  In the method for manufacturing a molded product, the shape of the molded product may be measured in order to determine whether the surface of the molded product satisfies a predetermined quality standard. As a method of measuring the shape of a molded product, an interferometer that branches light such as a Michelson interferometer or a Mach-Zehnder interferometer into measurement light and reference light and measures the shape using the light interference is used. Methods are conventionally known. There exists patent document 1 as what discloses this kind of interferometer. In Patent Document 1, the shape of a measurement object is measured by changing the optical path length by using a stepped shift phase mirror without performing a complicated operation such as a movable mechanism for moving the mirror or Fourier transform. A method is disclosed.

International Publication No. 2010/113985

  As shown in FIG. 8, the interferometer irradiates the measurement target with the measurement light narrowed by an optical system such as a lens. However, when the surface of the measurement target has a wavy shape, the distance from the optical system to the measurement target varies depending on the measurement position, and the measurement light may not be appropriately irradiated to the measurement target. For example, when scanning measurement light irradiated in a line shape (when scanning from the left side to the right side in FIG. 8), the shape of the measurement light irradiation surface varies depending on the measurement position, and the measurement light and the reference light It may adversely affect the multiplexing and interfere with accurate measurement. As one method for solving this problem, it is conceivable to adjust the distance from the optical system to the measurement object for each measurement position. However, in this method, it takes time to adjust the distance for each measurement position, or it is necessary to provide an adjustment mechanism for adjusting the distance to the measurement target. Even in the configuration disclosed in Patent Document 1, it is possible to omit a movable mechanism that moves the mirror by changing the optical path length using a phase shift mirror, but measurement of a shape in which the surface undulates greatly is possible. Then, it may be necessary to separately adjust the distance from the optical system to the measurement target.

  The present invention can effectively prevent the occurrence of a measurement error based on the change in the shape of the irradiated surface due to the difference in measurement position even when the surface of the measurement target is wavy, and can accurately measure the shape of the measurement target. It is an object of the present invention to provide a shape measuring method, a shape measuring device, and a method for producing a molded product using the same.

  The present invention includes a molding process for molding a material into a predetermined shape, a measurement process for measuring the shape of a molded article (for example, molded article 1 described later) formed in the molding process as a measurement object, and the measurement. A determination step of determining whether a non-defective product is a defective product based on shape information of the molded product measured in the step and reference shape information based on a predetermined shape, and the measurement step includes broadband light A light source to be generated (for example, a light source 11 to be described later) and an optical system (for example, an optical system to be described later) that divides the broadband light into measurement light and reference light having different paths and irradiates the measurement target with the measurement light and reflects it. 20 or the optical system 320) and a reflection surface disposed in the optical path of the reference light and formed in a step shape, the optical path length is changed according to the position of the reference light in a predetermined direction (for example, Y direction described later). Phase shift mirror (For example, a phase shift mirror 41 to be described later), a detector (for example, a camera to be described later) that receives the reflected light of the measurement light irradiated on the measurement object and the reference light whose optical path length is modulated by the phase shift mirror Unit 50), and a method of manufacturing a molded article that measures the shape of the measurement object using an interferometer in which the measurement light applied to the measurement object is parallel light.

  Thereby, since the measurement light irradiated to the measurement object becomes parallel light, the distance from the optical system to the measurement light varies depending on the measurement position, so that a situation where the shape of the measurement light irradiation surface is not constant can be prevented. Therefore, the measurement depth can be accurately measured even for a measurement object having a large measurement depth and a wavy shape. In addition to not having to adjust the optical path length to the measurement target, the mechanism for adjusting the optical path length on the reference light side by the phase shift mirror can be omitted, so the structure of the interferometer can be improved while improving measurement accuracy. It can be simplified. Furthermore, since it is determined whether it is a non-defective product or a defective product based on the accurately measured shape information, quality inspection can be performed strictly, and high-quality molded products can be manufactured.

  It is preferable that the manufacturing method of the said molded object measures the shape of the said measuring object by moving the irradiation surface of the said measurement light irradiated to the said measuring object linearly in the direction orthogonal to an irradiation direction.

  As a result, the shape of the illuminated surface is unlikely to change due to the depth of parallel light, so accurate measurement can be efficiently performed with a simple mechanism that moves the illuminated surface in a straight line even for a measurement target with a wavy shape. Can do.

  In addition, the present invention is a shape measurement method using an interferometer, wherein a light source that generates broadband light (for example, a light source 11 described later), and the broadband light is branched into measurement light and reference light having different paths, and measurement is performed. An optical system (for example, an optical system 20 or an optical system 320 to be described later) that irradiates and reflects measurement light on an object (for example, a molded product 1 to be described later) and an optical path of the reference light, and is formed in a step shape. A phase shift mirror (for example, a phase shift mirror 41 described later) that changes an optical path length according to a position in a predetermined direction (for example, a Y direction described later) in the reference light, and the measurement target. A detector (for example, a camera unit 50 to be described later) that receives the reflected light of the measurement light and a reference light whose optical path length is modulated by the phase shift mirror, and the measurement light irradiated to the measurement object Relating to the shape measuring method for measuring the shape of the measurement object by using a parallel light interferometer.

  Thereby, since the measurement light irradiated to the measurement object becomes parallel light, the distance from the optical system to the measurement light varies depending on the measurement position, so that a situation where the shape of the measurement light irradiation surface is not constant can be prevented. Therefore, the measurement depth can be accurately measured even for a measurement object having a large measurement depth and a wavy shape. In addition to not having to adjust the optical path length to the measurement target, the mechanism for adjusting the optical path length on the reference light side by the phase shift mirror can be omitted, so the structure of the interferometer can be improved while improving measurement accuracy. It can be simplified.

  The present invention also includes a light source that generates broadband light (for example, a light source 11 to be described later), and the broadband light is branched into measurement light and reference light having different paths to be a measurement target (for example, a molded product 1 to be described later). An optical system that irradiates and reflects measurement light (for example, an optical system 20 or an optical system 320 to be described later) and a reflecting surface that is disposed in the optical path of the reference light and is formed in a step shape in a predetermined direction ( For example, a phase shift mirror (for example, a phase shift mirror 41 described later) that changes the optical path length according to a position in the Y direction (described later), reflected light of the measurement light irradiated on the measurement target, and the phase shift mirror A detector (for example, a camera unit 50 to be described later) that receives the reference light whose optical path length is modulated by the shape measuring device (for example, the measurement light irradiated to the measurement object is parallel light) Mentioned shape measuring device 3, the shape measurement device 203 or the shape measuring apparatus 300) relating to.

  Thereby, since the measurement light irradiated to the measurement object becomes parallel light, the distance from the optical system to the measurement light varies depending on the measurement position, so that a situation where the shape of the measurement light irradiation surface is not constant can be prevented. Therefore, the measurement depth can be accurately measured even for a measurement object having a large measurement depth and a wavy shape. In addition to not having to adjust the optical path length to the measurement target, the mechanism for adjusting the optical path length on the reference light side by the phase shift mirror can be omitted, so the structure of the interferometer can be improved while improving measurement accuracy. It can be simplified.

  It is preferable that the shape measuring apparatus further includes a moving device (for example, a stage unit 10 to be described later) that linearly moves an irradiation surface of the measurement light irradiated on the measurement target in a direction orthogonal to the irradiation direction.

  As a result, the shape of the illuminated surface is unlikely to change due to the depth of parallel light, so accurate measurement can be efficiently performed with a simple mechanism that moves the illuminated surface in a straight line even for a measurement target with a wavy shape. Can do.

  According to the molded product manufacturing method, shape measuring method, and shape measuring apparatus of the present invention, even when the surface of the object to be measured is wavy, a measurement error is generated based on a change in the shape of the irradiated surface due to a difference in measurement position. Can be effectively prevented, and the shape of the measurement object can be accurately measured.

It is the figure which showed typically the flow of the manufacturing process of the molding which concerns on one Embodiment of this invention. It is the figure which showed schematically the structure of the shape measuring apparatus. It is the figure which showed typically the external appearance of the phase shift mirror. It is the figure which showed typically the image information obtained by the multiplexing of measurement light and reference light. It is a figure which shows the image of the irradiation surface of the measurement light irradiated to the measuring object. It is the figure which compared the shape of the irradiation area for every measurement depth. It is a flow which shows the determination process of the quality inspection in a determination process. It is a figure which shows the image of the irradiation surface of the measurement light irradiated to the measuring object with the conventional interferometer. It is the figure which showed typically the structure of the shape measuring apparatus of a modification. It is the figure which showed typically the structure of the shape measuring apparatus of a 2nd modification.

  Hereinafter, a preferred embodiment of a method for producing a molded article 1 using the shape measuring device 3 of the present invention will be described with reference to the drawings. The molded product 1 manufactured in the present embodiment is a vehicle body panel used by an automated person. Drawing 1 is a figure showing typically the flow of the manufacturing process of molding 1 concerning one embodiment of the present invention.

  First, the entire flow of the manufacturing method of the molded product 1 of this embodiment will be described. As shown in FIG. 1, the molded product 1 of this embodiment is manufactured through (a) a molding process, (b) a measurement process, and (c) a determination process.

  (A) The forming step is a step of forming a workpiece as a material into a predetermined shape. In the present embodiment, the workpiece is processed into the molded product 1 by press molding by the press molding apparatus 2. (B) The measurement step is a step of measuring the shape of the surface of the molded article 1 molded in the (a) molding step by the shape measuring device 3. In the present embodiment, the shape information of the molded product 1 measured by the shape measuring device 3 is transmitted to the control device 4. The detailed configuration of the shape measuring device 3 will be described later. (C) The determination step is a step in which the control device 4 performs quality inspection determination based on the shape information of the molded product 1 measured by the shape measuring device 3. This determination result is transmitted to the output device 5. The output device 5 outputs the determination result received from the control device 4 to an image display device or paper, and notifies the operator of the determination result. Note that a non-defective product and a defective product may be automatically selected by a robot based on the determination result without being output to the output device 5.

  Next, the detailed configuration of the shape measuring apparatus 3 used in the (b) measuring step will be described. FIG. 2 is a diagram schematically showing the configuration of the shape measuring apparatus 3. A plan view is shown in the center of the page of FIG. 2, and a side view is shown outside the double line frame. FIG. 3 is a diagram schematically showing the appearance of the phase shift mirror 41. FIG. 4 is a diagram schematically showing image information obtained by combining the measurement light and the reference light. FIG. 5 is a diagram illustrating an image of the irradiation surface of the measurement light irradiated on the measurement target. FIG. 6 is a diagram comparing the shape of the irradiation area for each measurement depth. In the following description, a plane orthogonal to the measurement light irradiation direction (a surface substantially parallel to the irradiation surface) is defined as an XY plane, and a depth direction of the measurement target (thickness direction of the measurement target) is a Z direction. Will be described.

  The shape measuring device 3 of the present embodiment is an interferometer that divides light from the light source 11 into measurement light and reference light having different paths, and performs shape measurement using light interference due to an optical path difference. As shown in FIG. 2, the shape measuring apparatus 3 includes a light source 11, an optical system 20 including various lenses and beam splitters, an optical path modulation unit 40 having a phase shift mirror 41 (see FIG. 3), a camera unit. 50 and the stage unit 10. In the following description, unless otherwise specified, the X direction and the Y direction are directions orthogonal to the irradiation direction of the measurement light to the measurement target, and the Z direction indicates the irradiation direction of the measurement light. .

  The light source 11 is an SC (Super continuum) light source that generates broadband light. The light generated by the light source 11 is divided into measurement light and reference light by the optical system 20.

  First, the structure arrange | positioned in the optical path from the light source 11 to the 1st beam splitter 15 among the optical systems 20 is demonstrated. The first rod lens 12, the second rod lens 13, and the first cylindrical lens 14 are arranged in this optical path in this order.

  The first rod lens 12 and the second rod lens 13 are arranged such that the axial direction is parallel to the Y direction. The second rod lens 13 is formed such that its diameter and axial height are larger than those of the first rod lens 12. The light emitted from the light source 11 passes through the first rod lens 12 and the second rod lens 13 and is expanded into an elongated light in the X direction. The first cylindrical lens 14 has a shape obtained by cutting out a part of the side surface of a cylinder, and its longitudinal direction (W) is parallel to the Y direction and its short direction (H) is parallel to the X direction. The curved surface portion faces the downstream side (+ Z direction) of the optical path (see the schematic diagram at the upper left of the paper surface of FIG. 2). The light that has passed through the first rod lens 12 and the second rod lens 13 becomes elongated parallel light (collimated light) by the first cylindrical lens 14.

  The first beam splitter 15 is a splitting unit that splits the collimated light collimated by the first cylindrical lens 14. The first beam splitter 15 is inclined toward the light source 11 in the Z direction, and its coating surface is located on the light source 11 side. The parallel light that has reached the first beam splitter 15 branches into an optical path on the measurement light side and an optical path on the reference light side. In the present embodiment, since the light generated by the light source 11 is parallel light before the measurement light and the reference light are branched, the measurement light and the reference light branched by the first beam splitter 15 are Is also parallel light.

  Next, the structure arrange | positioned in the optical path by the side of the measurement light from the 1st beam splitter 15 to the camera unit 50 among the optical systems 20 is demonstrated. In the optical path on the measurement light side, the second cylindrical lens 16, the third cylindrical lens 17, the second beam splitter 18, the fourth cylindrical lens 21, the fifth cylindrical lens 22, the third rod lens 24, the sixth cylindrical lens 25, The third beam splitter 26 is arranged in order.

  The 2nd cylindrical lens 16 and the 3rd cylindrical lens 17 are comprised in the shape which cut out a part of side surface of a cylinder, The longitudinal direction (W) has faced the Y direction. The second cylindrical lens 16 is formed such that its diameter and axial length are smaller than those of the third cylindrical lens 17, and the curved surface portion faces the upstream side (−Z direction) of the optical path. On the other hand, the curved surface portion of the third cylindrical lens 17 faces the downstream side (+ Z direction) of the optical path.

  The measurement light split in the Z direction by the first beam splitter 15 passes through the second cylindrical lens 16 and the third cylindrical lens 17 and is expanded in the X direction. The enlargement ratio in the X direction is set based on the size of the measurement target (see FIG. 4). The shapes and positions of the second cylindrical lens 16 and the third cylindrical lens 17 are determined based on the enlargement ratio in the X direction.

  The second beam splitter 18 is inclined to the measurement target side when the X-direction reference is used, and the coating surface is disposed on the measurement target side. The measurement light that has reached the second beam splitter 18 passes through the second beam splitter 18 and reaches the measurement object. The measurement light reflected by the measurement object is reflected downstream of the optical path on the measurement light side by the second beam splitter 18.

  In the present embodiment, the light that has become parallel light by the first cylindrical lens 14 is branched by the first beam splitter and used as measurement light, and the irradiation surface irradiated on the measurement object is also parallel light (see FIGS. 4 and 4). 5). As shown in FIG. 6, since the parallel light can keep the shape of the irradiated surface constant even when the depth is different, even when the surface of the molded product 1 is wavy, the irradiated surface of the measurement light The shape of is kept constant.

  The fourth cylindrical lens 21 has a curved surface facing the upstream side (−X direction) of the optical path. On the other hand, the fifth cylindrical lens 22 is configured such that the curved surface portion is formed by a concave portion recessed on the downstream side (+ X direction) of the optical path.

  The measurement light reflected on the downstream side of the optical path by the second beam splitter 18 (measurement light reflected by the measurement object) passes through the fourth cylindrical lens 21 and the fifth cylindrical lens 22 and is reduced in the X direction (shape). Z direction in the coordinate system of the measuring device 3). The reduction ratio in the X direction is set based on the imaging range of the camera unit. The shapes and positions of the fourth cylindrical lens 21 and the fifth cylindrical lens 22 are determined by the reduction ratio in the X direction. Note that the reduction in the X direction here means reduction in the X direction at the time when an image is captured by a camera unit 50 described later (when the measurement light irradiation surface faces the camera unit 50).

  The third rod lens 24 is arranged so that the axial direction thereof is parallel to the Z direction (X direction with respect to the time point when the image is taken by the camera unit 50) in the coordinate system of the shape measuring apparatus 3. The measurement light reduced in the X direction by the fourth cylindrical lens 21 and the fifth cylindrical lens 22 is expanded in the Y direction through the third rod lens 24. The sixth cylindrical lens 25 has a shape obtained by cutting out a part of the side surface of the cylinder, and the curved surface portion faces the downstream side of the optical path. The measurement light is collimated in the Y direction through the sixth cylindrical lens 25.

  The third beam splitter 26 is a multiplexing unit that combines the measurement light and the reference light. The third beam splitter 26 is inclined to the optical path modulation unit 40 side (opposite side of the camera unit 50) with respect to the X direction, and the coating surface is located on the optical path modulation unit 40 side. As described above, the measurement light reaching the third beam splitter 26 is adjusted in size in the X direction and the Y direction by the optical system 20 arranged in the optical path on the measurement light side (see FIG. 4). In the present embodiment, the measurement light whose sizes in the X direction and the Y direction are adjusted is combined with the reference light by the third beam splitter 26. A part of the measurement light passes through the third beam splitter 26 and becomes leakage light.

  Next, the optical system 20 and the optical path modulation unit 40 arranged in the optical path on the reference light side from the first beam splitter 15 to the camera unit 50 will be described. The optical path length of the reference light is appropriately adjusted by the optical system 20 arranged in the optical path on the reference light side. In the optical path on the reference light side, there are a fourth rod lens 32, a seventh cylindrical lens 33, a fourth beam splitter 34, an optical path modulation unit 40, a first spherical lens 51, a second spherical lens 52, and a third beam splitter 26. Arranged in order.

  The reference light split by the first beam splitter 15 passes through the fourth rod lens 32 and is expanded in the Y direction. The seventh cylindrical lens 33 is configured to have a shape obtained by cutting out a part of the side surface of the cylinder, and the longitudinal direction of the seventh cylindrical lens 33 is the Z direction in the coordinate system of the shape measuring device 3 (based on the time point when the camera unit 50 takes an image). X direction) and the curved surface portion faces the downstream side of the optical path. The reference light is collimated in the Y direction through the seventh cylindrical lens 33.

  The fourth beam splitter 34 is inclined to the camera unit 50 side with respect to the X direction, and the coating surface thereof is located on the optical path modulation unit 40 side. The fourth beam splitter 34 reflects the reference light that has passed through the seventh cylindrical lens 33 toward the optical path modulation unit 40 in the Z direction. In the present embodiment, the fourth beam splitter 34 is inclined 45 degrees toward the camera unit 50, and reflects a part of the incident reference light to the optical path modulation unit 40 side at right angles (see FIG. 2).

  The optical path modulation unit 40 includes a phase shift mirror 41, and reflects the reference light downstream of the optical path by the phase shift mirror 41. As shown in FIG. 3, the phase shift mirror 41 has a stepped reflection surface, and the reference light reflected by the phase shift mirror 41 changes in optical path length in a predetermined direction in the reference light. It will be in the state. The predetermined direction here is the Y direction based on the measurement object (see FIG. 4). In the present embodiment, the phase shift mirror 41 is disposed so as to reflect the reference light on the camera unit 50 side in the Z direction, and the reflection surface faces the camera unit 50 side. As described above, the light reflected by the fourth beam splitter 34 is incident on the reflection surface of the phase shift mirror 41 in the Z direction, which is a direction perpendicular to the Y direction, and the reference light is incident on the optical path modulation unit 40. The direction and the reflection direction coincide with each other. Therefore, the reference light applied to the phase shift mirror 41 is reflected downstream of the optical path as parallel light whose phases in the Y direction are stepwise different based on the step formed on the reflection surface of the phase shift mirror 41 ( (See FIG. 4). A part of the reference light reflected by the phase shift mirror 41 passes through the fourth beam splitter 34 and reaches the first spherical lens 51, and a part thereof is reflected at a right angle. As described above, the shape measuring apparatus 3 of the present embodiment is arranged on the upstream side of the phase shift mirror 41 in the optical path of the reference light, reflects the reference light that has passed through the optical path at a right angle, and reflects it to the phase shift mirror 41. A fourth beam splitter 34 is provided. The phase shift mirror 41 is arranged to reflect the reference light incident by the fourth beam splitter 34 in the same direction as the incident direction. This makes it easier to calculate the change in the optical path length based on the step formed on the reflection surface of the phase shift mirror 41, compared to the conventional configuration in which the reference light is incident obliquely on the phase shift mirror and reflected. Therefore, it is possible to simply perform device design and distance adjustment of each device.

  The first spherical lens 51 is arranged so that the spherical surface thereof faces the optical path modulation unit 40 side in the Z direction. The second spherical lens 52 is arranged so that the spherical surface thereof faces the camera unit 50 side in the Z direction.

  The reference light that has reached the third beam splitter 26 has been adjusted in size in the Y direction by the optical system 20 arranged in the optical path on the measurement light side as described above (see FIG. 4). A part of the reference light is reflected by the third beam splitter 26 and becomes leakage light.

  The measurement light that has passed through the optical path on the measurement light side and the reference light that has passed through the optical path on the reference light side are combined by the third beam splitter 26, and the combined light is imaged by the camera unit 50. Is done.

  The camera unit 50 will be described. The camera unit 50 acquires interference fringes caused by light interference as image information by a CCD camera. On the XY coordinate plane (X direction is horizontal, Y direction is vertical) in the light receiving element of the camera unit 50, there is no optical path difference between the reference light side and the measurement light side created by the phase shift mirror 41 at an arbitrary X position Xi. If there is (Zi position of the phase shift mirror 41), interference fringes are observed by the light receiving element Yi of the camera unit 50. Thereby, it can convert into the distance of Xi based on Y position Yi of a light receiving element, and the depth of a Z direction can be acquired. That is, the shape in the depth direction in the X direction can be specified based on the image information acquired by the camera unit 50. In the present embodiment, the control device 4 performs image processing based on the pixel information of the image acquired by the camera unit 50 to acquire the cross-sectional shape in the Z direction in the X direction (see FIG. 4).

  Next, scanning in the Y direction by the shape measuring apparatus 3 will be described. In the present embodiment, the stage unit 10 moves the measurement light irradiation surface in the Y direction to the measurement target. The stage unit 10 moves the optical system 20 relative to the measurement target by moving the molding 1 as the measurement target along the Y direction. The one-time moving distance by the stage unit 10 is appropriately set based on the measurement light irradiation area. The shape of the surface of the measurement target is acquired as three-dimensional shape information by continuously measuring the shape in the depth direction in the X direction in the Y direction.

  As described above, the measurement light applied to the measurement target is parallel light, and therefore the shape of the irradiation surface is constant even if the measurement position (depth) changes (see FIGS. 5 and 6). Therefore, even when the surface of the molded product 1 has a wavy shape, it is not necessary to adjust the distance to the measurement target, and the shape measurement of the XY plane is efficiently performed only by linear movement in the Y direction. It is possible.

  With the above flow, the shape measuring device 3 acquires the shape information of the molded article 1 that is the measurement target. Next, the quality inspection process by the control device 4 in the determination step (c) will be described. The quality inspection process is a determination process for inspecting the quality of the molded product 1 based on the shape information acquired by the shape measuring device 3. FIG. 7 is a flowchart showing the quality inspection determination process in the determination step.

  As shown in FIG. 7, when the control device 4 acquires a measurement value as shape information of the molded product 1 from the shape measurement device 3, the difference between the preset reference value and the acquired measurement value is equal to or less than a threshold value. Judgment processing is performed to determine whether or not (S101, S102). The reference value is reference shape information set based on the shape of the molded article 1 serving as a reference, and the threshold value is a determination reference set based on an allowable error. If the difference between the reference value and the measured value is less than or equal to the threshold value, the molded product 1 is determined as a non-defective product (S103), and if it exceeds the threshold value, it is determined as a defective product (S104). The determination result is output from the control device 4 to the output device 5. Since the measured value compared with the reference value is a value precisely measured by the shape measuring device 3, a strict quality inspection is performed based on the shape information of the molded product 1.

  According to the manufacturing method of the molded article 1 using the shape measuring apparatus 3 of the present embodiment described above, the following effects are obtained.

  The manufacturing method of the molded product 1 of this embodiment includes (a) a molding step, (b) a measurement step, and (c) a determination step. (A) In the forming step, a workpiece as a material is formed into a predetermined shape. (B) In the measurement process, the shape of the molded article 1 molded in the molding process is measured as a measurement target. (C) In the determination step, whether the non-defective product is defective is determined based on the measured value (shape information) of the molded product 1 measured in the measurement step and the reference value (reference shape information) based on a predetermined shape. judge. (B) A measurement process is measured by the shape measuring apparatus 3 comprised as follows. In other words, the shape measuring device 3 includes a light source 11 that generates broadband light, an optical system 20 that divides the broadband light into measurement light and reference light having different paths, irradiates the measurement target with the measurement light, and reflects the measurement target. The phase shift mirror 41 that is arranged in the optical path and changes the optical path length according to the position of the reference light in the Y direction by the reflecting surface formed in a step shape, and the reflected light and the phase shift of the measurement light irradiated on the measurement target A camera unit 50 that receives the reference light whose optical path length is modulated by the mirror 41, and the measurement light applied to the measurement object is parallel light.

  Thereby, since the measurement light with which the measurement object is irradiated becomes parallel light, the distance from the optical system 20 to the measurement light varies depending on the measurement position, so that the situation where the shape of the irradiation surface of the measurement light is not constant can be prevented. Therefore, the measurement depth can be accurately measured even for a measurement object having a large measurement depth and a wavy shape. Further, in addition to the necessity of adjusting the optical path length to the measurement target, a mechanism for adjusting the optical path length on the reference light side by the phase shift mirror 41 can be omitted, so that the accuracy of the shape measuring apparatus can be improved while improving the measurement accuracy. The structure can be simplified. Furthermore, since it is determined whether it is a non-defective product or a defective product based on the accurately measured shape information, quality inspection can be performed strictly, and high-quality molded products can be manufactured.

  The shape measuring apparatus 3 used in the method for manufacturing the molded article 1 of the present embodiment further includes a stage unit 10 that linearly moves the irradiation surface of the measurement light irradiated to the measurement object in a direction orthogonal to the irradiation direction. This stage unit 10 measures the shape of the measurement object while relatively moving the measurement object.

  Thereby, since the shape of the irradiated surface is hardly changed by the depth of parallel light, accurate measurement can be performed with a simple mechanism that moves the irradiated surface linearly even for a measurement target having a wavy shape.

  As mentioned above, although preferable one Embodiment of the manufacturing method of the molded object 1 using the shape measuring apparatus 3 of this invention was described, this invention is not restrict | limited to the above-mentioned structure and can be changed suitably.

  Next, a modified example of the shape measuring apparatus 3 will be described. FIG. 9 is a diagram schematically showing the configuration of a modified shape measuring apparatus 203. A plan view is shown in the center of the page of FIG. 2, and a side view is shown outside the double line frame. In this modification, the same components as those in the above embodiment may be denoted by the same reference numerals and the description thereof may be omitted.

  As shown in FIG. 9, the shape measuring apparatus 203 of the present modified example does not include the second cylindrical lens 16, the third cylindrical lens 17, the fourth cylindrical lens 21, and the fifth cylindrical lens 22. The configuration is different. Therefore, in this modification, the measurement light reaches the camera unit 50 without being expanded in the X direction and reduced in the X direction. Since the reference light is not enlarged or reduced in the X direction, the size of the measurement light and the reference light in the X direction and the size in the Y direction match even when the measurement light passes through such a path. Shape measurement can be performed accurately. As described above, the number of lenses, beam splitters, reflection mirrors, and the like constituting the optical system 20 and the arrangement thereof can be appropriately changed according to circumstances.

  Next, a second modification of the shape measuring apparatus will be described. FIG. 10 is a diagram schematically showing the configuration of the shape measuring apparatus 300 of the second modified example. Also in this modification, the same configuration as the configuration of the above embodiment may be denoted by the same reference numeral, and the description thereof may be omitted.

  As shown in FIG. 10, the shape measuring apparatus 300 according to the second modified example includes the optical system 320 including various lenses and beam splitters, the layout of the optical path modulation unit 40, and the camera unit 50, etc. This is different from the shape measuring device.

  The layout of the optical system 320 will be described. First, a configuration of the optical system 320 that is disposed in the optical path from the light source 11 to the first beam splitter 315 will be described. In this optical path, a plano-convex lens 301, a plano-concave lens 302, a first rod lens 303, and a first cylindrical lens 304 are arranged in this order.

  The plano-convex lens 301 is a lens having a spherical surface, and is disposed so that the spherical portion faces the light source 11 side. The plano-concave lens 302 is disposed such that the concave portion formed in a spherical shape faces the downstream side of the optical path. The light emitted from the light source 11 passes through the plano-convex lens 301 and the plano-concave lens 302, and the beam diameter is reduced. The first rod lens 303 is arranged so that its axial direction is in the Y direction. The first cylindrical lens 304 has a shape obtained by cutting out a part of a side surface of a cylinder. The longitudinal direction of the first cylindrical lens 304 is parallel to the Y direction, and the curved surface portion faces the downstream side of the optical path. The light emitted from the light source 11 passes through the plano-convex lens 301, the plano-concave lens 302, the first rod lens 303, and the first cylindrical lens 304, and is expanded in the X direction (parallel light state). 315 is reached.

  The first beam splitter 315 will be described. The coating surface of the first beam splitter 315 is formed on the light source 11 side. The parallel light reaching the first beam splitter 315 is branched into an optical path on the measurement light side and an optical path on the reference light side. The measurement light in this modification is reflected light of the light irradiated onto the measurement object by the first beam splitter 315. The reference light is light that passes through the first beam splitter 315 and reaches the camera unit 50 via the optical path modulation unit 40.

  Next, the structure arrange | positioned in the optical path by the side of the measurement light from the 1st beam splitter 315 to the camera unit 50 among the optical systems 320 is demonstrated. A condensing lens 331, a second cylindrical lens 332, a third cylindrical lens 333, a second rod lens 334, a fourth cylindrical lens 335, and a second beam splitter 340 are sequentially arranged on the optical path on the measurement light side.

  The condensing lens 331 is a plano-convex cylindrical lens having a spherical surface, condenses the return scattered light of the measurement target (molded product 1) set on the stage unit 10, and the optical path on the measurement light side (the stage unit 10) The optical path between the measurement object and the camera unit 50) functions as an imaging lens for the 4f optical system.

  The 2nd cylindrical lens 332 and the 3rd cylindrical lens 333 are comprised by the shape which cut out a part of side surface of a cylinder, and the longitudinal direction has faced the Y direction. The second cylindrical lens 332 has a focal length longer than that of the third cylindrical lens 333, and the curved surface portion faces the upstream side of the optical path. On the other hand, the curved surface portion of the third cylindrical lens 333 faces the downstream side of the optical path. The measurement light is reduced in the X direction by the second cylindrical lens 332 and the third cylindrical lens 333.

  The measurement light reduced in the X direction by the second cylindrical lens 332 and the third cylindrical lens 333 is expanded in the Y direction through the second rod lens 334. The fourth cylindrical lens 335 is formed in a shape obtained by cutting out a part of the side surface of the cylinder, and the curved surface portion faces the downstream side of the optical path. The measurement light is collimated in the Y direction through the fourth cylindrical lens 335.

  The coating surface of the second beam splitter 340 is located on the camera unit 50 side. The measurement light that has passed through the fourth cylindrical lens 335 passes through the second beam splitter 340 and reaches the camera unit 50. The second beam splitter 340 is a multiplexing unit that combines the measurement light and the reference light, and the measurement beam and the reference light are combined by the second beam splitter 340.

  Next, the optical system 320 and the optical path modulation unit 40 arranged in the optical path on the reference light side from the first beam splitter 315 to the camera unit 50 will be described. In the optical path on the reference light side, the fifth cylindrical lens 351, the sixth cylindrical lens 352, the reflection mirror 355, the third rod lens 356, the seventh cylindrical lens 357, the third beam splitter 360, the optical path modulation unit 40, the first A spherical lens 361, a second spherical lens 362, and a second beam splitter 340 are arranged in this order.

  The fifth cylindrical lens 351 has a curved surface portion facing the upstream side of the optical path. On the other hand, in the sixth cylindrical lens 352, the concave portion of the curved surface portion faces the downstream side of the optical path. The reference light from the first beam splitter 315 is reduced in the X direction by the fifth cylindrical lens 351 and the sixth cylindrical lens 352.

  The reflection mirror 355 is a reflection unit that totally reflects reference light in the Z direction in the Y direction. Therefore, the reference light that has passed through the fifth cylindrical lens 351 and the sixth cylindrical lens 352 is guided to the downstream side of the optical path by the reflection mirror 355 without causing leakage light.

  The third rod lens 356 is disposed so that its axial direction is parallel to the axial direction of the second rod lens 334. The reference light reflected by the reflection mirror 355 passes through the third rod lens 356 and is expanded in the Y direction. The seventh cylindrical lens 357 has a shape obtained by cutting out a part of a side surface of a cylinder. The longitudinal direction of the seventh cylindrical lens 357 faces the X direction, and the curved surface portion faces the downstream side of the optical path. The reference light is collimated in the Y direction through the seventh cylindrical lens 357.

  The third beam splitter 360 reflects the light that has passed through the seventh cylindrical lens 357 to the optical path modulation unit 40 and allows the reference light whose phase has been changed by the optical path modulation unit 40 to pass to the camera unit 50 side in the Y direction.

  The first spherical lens 361 is arranged so that the spherical surface thereof faces the optical path modulation unit 40 in the Z direction. The second spherical lens 362 is disposed so that the spherical surface faces the camera unit 50 side in the Z direction. The first spherical lens 361 and the second spherical lens 362 function as an imaging lens of the 4f optical system in the optical path on the reference light side (the optical path between the optical path modulation unit 40 and the camera unit 50).

  The second beam splitter 340 reflects the light that has passed through the first spherical lens 361 and the second spherical lens 362 to the camera unit 50 side in the Z direction by its coating surface. As described above, the measurement light is incident on the second beam splitter 340, and the measurement light and the reference light are combined to reach the camera unit 50. The image processing acquired by the camera unit 50 is the same as in the above embodiment.

  The main configuration of the shape measuring apparatus 300 of the second modification is as described above. In the second modification, the first beam splitter 315 is sandwiched between the first cylindrical lens 304 and the fifth cylindrical lens 351 in the Z direction, and is collected from the measurement target (molded product 1) in the X direction orthogonal to the Z direction. It arrange | positions so that it may be pinched | interposed into the optical lens 331. FIG. Thereby, when irradiating light to a measuring object, leak light does not arise. In addition, since no lens is disposed between the condenser lens 331 and the measurement target (stage unit 10), the measurement light reflected by the measurement target is condensed on the condenser lens 331 without being reflected by the lens. Is done. That is, the shape measuring apparatus 300 according to the second modification has a layout that can reduce the number of arranged lenses and effectively reduce the influence of ghosts. Thus, as also shown in the second modification, the layout of the optical system, the optical path modulation unit, and the camera unit of the shape measuring apparatus can be changed as appropriate according to circumstances.

  In the above embodiment, the light output from the light source 11 is converted into parallel light on the upstream side of the first beam splitter 15. However, the measurement light applied to the measurement target only needs to be parallel light. The position of light can be changed as appropriate. For example, parallel light can be made downstream of the first beam splitter 15. In this case, in order to match the sizes of the measurement light and the reference light, it is preferable to arrange means for making the parallel light in the path on the reference light side.

  In the above embodiment, a cylindrical lens or a spherical lens is used as the lens of the optical system, but the lens to be used can be changed as appropriate. For example, it is also effective to use a lens with little aberration, such as a doublet lens, a triplet lens, or an aspheric lens.

  In the said embodiment, it is comprised so that the irradiation surface of a measuring object may be moved relatively by moving the molding 1 by the stage unit 10, However, This structure can be changed suitably. For example, the irradiation system can be moved by moving the optical system 20 of the shape measuring apparatus 3 with respect to the measurement target.

  In the said embodiment, although the vehicle body panel of the motor vehicle was made into the molded object 1, naturally the shape measuring apparatus 3 of this embodiment is applicable also to molded objects other than the vehicle body panel of an automobile. For example, the molding method is not limited to press molding, and the shape measuring device 3 of the present embodiment can be applied to a molded product whose shape is molded by injection molding or the like.

  In the above embodiment, an example in which the present invention is applied to the Mach-Zehnder system has been described. However, the present invention is not limited to this system, and the present invention can be applied to various interferometers such as a Michelson interferometer. .

1 Molded object (measurement object)
3,203,300 Shape measuring device (interferometer)
10 Stage unit (moving device)
DESCRIPTION OF SYMBOLS 11 Light source 20,320 Optical system 41 Phase shift mirror 50 Camera unit (detector)

Claims (5)

A molding process for molding the material into a predetermined shape;
A measurement process for measuring the shape of the molded product molded in the molding process as a measurement object;
A determination step of determining whether a non-defective product is a defective product based on shape information of the molded product measured in the measurement step, and reference shape information based on a predetermined shape,
Including
The measurement step includes
A light source that generates broadband light;
An optical system that divides the broadband light into measurement light and reference light having different paths, irradiates the measurement object with the measurement light, and reflects the measurement light;
A phase shift mirror that is arranged in the optical path of the reference light and changes an optical path length according to a position in a predetermined direction in the reference light by a reflecting surface formed in a step shape;
A detector that receives reflected light of the measurement light irradiated on the measurement object and reference light whose optical path length is modulated by the phase shift mirror;
With
A method for manufacturing a molded article, wherein the shape of the measurement target is measured using an interferometer in which the measurement light irradiated on the measurement target is parallel light.   The method for manufacturing a molded article according to claim 1, wherein the shape of the measurement object is measured by linearly moving the irradiation surface of the measurement light irradiated on the measurement object in a direction orthogonal to the irradiation direction. A shape measuring method using an interferometer,
A light source that generates broadband light;
An optical system that divides the broadband light into measurement light and reference light having different paths, irradiates the measurement object with the measurement light, and reflects the measurement light;
A phase shift mirror that is arranged in the optical path of the reference light and changes an optical path length according to a position in a predetermined direction in the reference light by a reflecting surface formed in a step shape;
A detector that receives reflected light of the measurement light irradiated on the measurement object and reference light whose optical path length is modulated by the phase shift mirror;
With
A shape measurement method for measuring the shape of a measurement object using an interferometer in which the measurement light applied to the measurement object is parallel light. A light source that generates broadband light;
An optical system that divides the broadband light into measurement light and reference light having different paths, irradiates the measurement object with the measurement light, and reflects the measurement light;
A phase shift mirror that is arranged in the optical path of the reference light and changes an optical path length according to a position in a predetermined direction in the reference light by a reflecting surface formed in a step shape;
A detector that receives reflected light of the measurement light irradiated on the measurement object and reference light whose optical path length is modulated by the phase shift mirror;
With
A shape measuring apparatus in which the measurement light applied to the measurement object is parallel light.   The shape measuring apparatus according to claim 4, further comprising a moving device that linearly moves an irradiation surface of the measurement light irradiated on the measurement target in a direction orthogonal to the irradiation direction.