Method and device for inspecting engravings in tire mold

• US 10,451,408 B2
• Filed: 03/31/2015
• Issued: 10/22/2019
• Est. Priority Date: 04/07/2014
• Status: Active Grant

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Tanaka, Tatsunori, Tada, Hirotaro, Motomiya, Shonosuke
• Primary Examiner(s): Rush, Eric
• Application Number:
  US15/302,946
• Publication Number:
  US 20170030709A1
• Time in Patent Office: 1,666 Days
• Field of Search: 382100, 382106, 382108, 382141, 382152, 382154, 382282, 382286, 382291, 382294-296, 702 33, 702 35, 702 36, 702 40, 702 81- 84, 356 2, 356 3, 356 301, 356 303, 356 31, 356 401, 3562371, 3562372, 3562373, 3562374, 3562375, 356394, 356601, 356603, 356606, 7311507, 73146, 700143
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01N 21/8851 Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002
• CPC Class Codes: G01N 21/95 characterised by the material or shape of the object to be examined G01N21/89 - G01N21/91, G01N21/94 take precedence
• CPC Class Codes: G01N 21/9515 Objects of complex shape, e.g. examined with use of a surface follower device measuring contours and curvatures G01B11/24
• CPC Class Codes: G01N 21/95607 using a comparative method
• CPC Class Codes: G01N 2201/12 Circuits of general importance; Signal processing
• CPC Class Codes: G06T 2207/10028 Range image; Depth image; 3D point clouds
• CPC Class Codes: G06T 2207/30116 Casting
• CPC Class Codes: G06T 7/0008 checking presence/absence
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06T 7/337 involving reference images or patches

Abstract

A method for inspecting engravings in a tire mold includes inputting in advance into a data processing device two-dimensional image master data of an engraving formed on a surface of a side plate in a plan view using basic data set as a reference, the image master data having a radial component and a radial position of the engraving corrected on the basis of a locus length in a radial direction of the surface of the side plate; generating two-dimensional image actual measurement data, the image actual measurement data having a radial component and a radial position of three-dimensional data acquired via actual measurement corrected on the basis of a radial locus length of a surface of a side plate on which actual measurement was performed; and determining whether or not an image shape and an image position of the image actual measurement data is within a tolerable range.

Claims

1. A method, comprising:

inspecting engravings in a tire mold to determine suitability of an engraving formed on a surface of an annular side plate, which is a component of the tire mold, wherein the engravings are inspected by;

inputting into a data processing device two-dimensional image master data of the engraving formed on the surface of the annular side plate in a plan view pregenerated using a basic data set as a reference, the image master data having a radial component and a radial position of the engraving corrected on the basis of a locus length in a radial direction of the surface of the annular side plate, wherein the two-dimensional image master data represents only two dimensions of the engraving;

acquiring three-dimensional data of the engraving by actual measurement of the annular side plate as manufactured;

generating two-dimensional image actual measurement data, the image actual measurement data having a radial component and a radial position of the three-dimensional data corrected on the basis of a radial locus length of the surface of the annular side plate on which actual measurement was performed; and

determining whether or not an image shape and an image position of the image actual measurement data is within a tolerable range with respect to an image shape and an image position of the image master data via comparison processing of image contours of the image master data and the image actual measurement data by the data processing device;

wherein

data of an engraving to be a reference in the image master data is input into the data processing device as reference engraving data, and upon the comparison processing of the image contours of the image master data and the image actual measurement data, reference engraving corresponding data in the image actual measurement data corresponding to the reference engraving data is automatically extracted by the data processing device, the method further comprising the steps of;

performing preliminary alignment of images of the image master data and the image actual measurement data by alignment processing of images of the reference engraving data and the reference engraving corresponding data; and

performing final alignment processing of the images of the image master data and the image actual measurement data after the preliminary alignment of the images of the image master data and the image actual measurement data.

2. A device for inspecting engravings in a tire mold capable of determining suitability of an engraving formed on a surface of an annular side plate, which is a component of the tire mold, the device comprising:

a data processing device configured to receive two-dimensional image master data of the engraving formed on the surface of the annular side plate in a plan view using basic data set as a reference, wherein the two-dimensional image master data represents only two dimensions of the engraving, the image master data having a radial component and a radial position of the engraving corrected on the basis of a locus length in a radial direction of the surface of the annular side plate, wherein the data processing device is further configured to receive data of a reference engraving to be a reference in the image master data as reference engraving data; and

a measuring unit configured to acquire three-dimensional data of the engraving by actual measurement of the annular side plate as manufacture;

wherein

two-dimensional image actual measurement data is generated by the data processing device, the image actual measurement data having a radial component and a radial position of the three-dimensional data corrected on the basis of a radial locus length of the surface of the annular side plate on which actual measurement was performed;

whether or not an image shape and an image position of the image actual measurement data is within a tolerable range with respect to an image shape and an image position of the image master data is determined via comparison processing of image contours of the image master data and the image actual measurement data by the data processing device; and

the data processing device is further configured to;

automatically extract reference engraving corresponding data in the image actual measurement data corresponding to the reference engraving data;

perform preliminary alignment of images of the image master data and the image actual measurement data by alignment processing of images of the reference engraving data and the reference engraving corresponding data; and

performing final alignment processing of the images of the image master data and the image actual measurement data after the preliminary alignment of the images of the image master data and the image actual measurement data.

3. The device for inspecting engravings in a tire mold according to claim 2, wherein the measuring unit includes an irradiating device configured to irradiate the surface of the annular side plate with a laser, and a camera device configured to acquire the three-dimensional data by capturing an image of the engraving irradiated by the laser.

4. The device for inspecting engravings in a tire mold according to claim 3, further comprising a rotation mechanism configured to actuate rotational movement of the annular side plate and the camera device relative to one another about an annular center point of the annular side plate.