JP2010160023A - Method and device for detecting circumferential surface distortion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for highly accurately detecting distortion of a circumferential surface in an object in a short time. <P>SOLUTION: The device for detecting distortion of a circumferential surface in an object includes: a drive device 1 for rotating the object around the center axial line in the circumferential surface; an illumination device 2 for optically illuminating the circumferential surface; a measuring device 3 for measuring the intensity of light reflected from the circumferential surface; and a control device 4 for determining the reflected light intensity obtained by the measuring device while correlating the intensity with the rotation position of the object. This invention also includes a detection method using the detection device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a strain detection method and a strain detection apparatus for a circumferential surface of an object having a circumferential surface.

  For example, if a cylindrical roller or a tapered roller for a bearing has a slight distortion on the outer diameter surface with respect to a perfect circle, it becomes a vibration factor of the bearing, which is not preferable. In addition, in many cases, an object having a circumferential surface such as a cylindrical surface or a conical surface is required to have processing accuracy of the circumferential surface, and accordingly, detection of distortion with respect to a perfect circle is required. Many.

  Conventionally, a contact-type detection device has been mainly used for such strain detection (for example, Patent Document 1). However, the contact-type detection device rotates the inspection object with a contact such as a stylus in contact with the inspection object, and detects the distortion of the outer peripheral shape of the inspection object based on the displacement of the contact. To do. Therefore, in order to accurately align the contact and the object to be inspected, it is necessary to perform tilting of the object to be inspected and centering (centering) in advance to set the detection device. It took a lot of time. As a result, depending on the processing line, there is a problem in that it cannot be detected within the processing cycle time of the object, and 100% in-line inspection becomes impossible.

Japanese Patent No. 3738844

  An object of the present invention is to solve such problems of the prior art and to provide a method and apparatus capable of detecting distortion of a circumferential surface of an object having a circumferential surface with high accuracy in a short time. .

  In order to achieve the above object, the present invention provides a method for detecting a strain on a circumferential surface of an object, wherein light is applied to the circumferential surface while rotating the object about a central axis of the circumferential surface. An object of the present invention is to provide a strain detection method for detecting a strain on the circumferential surface by irradiating and measuring a change in reflected light intensity depending on a rotational position of the object.

  In order to achieve the above object, the present invention is also a device for detecting a distortion of a circumferential surface of an object, the driving device rotating the object about a central axis of the circumferential surface, and the circumferential surface An irradiation device for irradiating light, a measuring device for measuring the intensity of reflected light from the circumferential surface, and a control device for determining the reflected light intensity obtained by the measuring device in association with the rotational position of the object The present invention provides a strain detection device characterized by comprising the above.

  In addition, said distortion means the shift | offset | difference from the perfect circle in circumferential shape.

  The strain detection method according to the present invention employs the above-described configuration, so that the object to be inspected is rotated around the central axis on the circumferential surface, and the circumferential surface is irradiated with light, depending on the rotational position of the object. By measuring the change in reflected light intensity, it is possible to detect the distortion of the outer peripheral shape from the measurement result. Therefore, it is not necessary to bring a contact or the like into contact with the object to be inspected, and even if the setting accuracy of tilting or centering (centering) of the object to be inspected is somewhat low, the reflected light is reflected by the object under inspection. Measurements can be made using light. As a result, the time required for setting the inspection object can be shortened. Further, the measurement of the reflected light intensity can easily follow the fast rotation of the inspection object. Accordingly, it is possible to detect the distortion of the inspection object in a short time and with high accuracy.

  Further, the strain detection apparatus according to the present invention sets the object to be inspected to the driving device based on the above configuration, performs the light irradiation and the reflected light intensity measurement by the irradiation device and the measurement device, and the reflected light intensity is measured by the control device. Distortion can be detected by making a determination in association with the rotational position of the object. Therefore, in this case as well, the contact between the contact and the inspection object is not required, the time required for setting the inspection object can be shortened, and the reflected light intensity can be easily measured even when the inspection object is rapidly rotated. Accordingly, it is possible to detect the distortion of the inspection object in a short time and with high accuracy.

It is an enlarged view of the distortion of the circumference of the object used as the object of distortion detection by the method and apparatus of the present invention. It is a figure showing roughly the distortion detecting device concerning one embodiment of the present invention. It is a figure which shows the image of the to-be-inspected object obtained by the apparatus of FIG. It is a figure which shows roughly the distortion detection apparatus which concerns on other embodiment of this invention. It is a figure which shows roughly the distortion detection apparatus which concerns on other embodiment of this invention. It is a figure which shows roughly the distortion detection apparatus which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The same or similar parts in the drawings are denoted by the same reference numerals and description thereof is partially omitted.

  FIG. 1 shows a cross section of a cylindrical roller which is an example of an object to be inspected. In the drawing, the unevenness is enlarged for easy understanding. FIG. 2 shows an apparatus according to an embodiment of the present invention for detecting the distortion of the inspection object. The strain detection apparatus includes a driving device 1 that rotates the inspection object S around the central axis of the cylindrical shape (rotating body shape), an irradiation device 2 that irradiates the outer diameter surface of the inspection object S, and A measurement output device 3 for measuring the intensity of reflected light from the outer diameter surface, and a control device 4 for determining the reflected light intensity obtained by the measuring device in association with the rotational position of the inspection object. Yes.

  In this embodiment, the drive device 1 includes a pair of drive wheels 11 and 12, and rotates the inspection object S placed thereon by rotating in the same direction. . By using a driving wheel with a small rotation of the outer diameter surface and good rotation accuracy, the inspection object S rotates at a fixed position on the driving device, and rotates around the central axis of the cylindrical shape.

  The irradiation device 2 is preferably a point light source or a linear light source extending parallel to the inspection object S so that distortion of the inspection object can be clearly detected. However, a surface light source can be used as long as the distortion of the inspection object can be detected. Irradiation light can be coherent or incoherent light such as visible light, infrared light, or ultraviolet light, depending on the function of the measuring apparatus.

  The measuring device 3 has a function of measuring the intensity of reflected light from the outer diameter surface of the inspection object S irradiated with light by the irradiation device 2, and in this example, a line sensor camera (line CCD camera) is used. Note that an optical device such as a lens or a reflecting mirror or an optical element may be appropriately interposed between the irradiation device 2 and the inspection object S or between the inspection object S and the measurement device 3.

  The control device 4 is connected to the signal line of the measuring device 3 and includes an image processing device. The control device 4 determines a change in the light intensity signal sent from the measuring device 3 in association with the rotational position of the inspection object S. This association can be performed in real time by sending the rotational position information of the inspection object S sent from the driving device 1 and the light intensity signal detected by the optical sensor to the control device 4 in real time. It can also be performed after obtaining a series of reflected light intensity values for the outer periphery of the inspection object. The distortion can be detected by measuring the position where the light intensity signal of the reflected light changes.

  FIG. 3 shows an image obtained when the inspection object S of FIG. 1 is irradiated with light using the apparatus of FIG. 2 in the form of a developed image. W in the figure corresponds to the width of the cylindrical surface of the inspection object S, and C corresponds to the length of the peripheral surface thereof. If the outer diameter surface of the object to be measured S is distorted, the direction of reflection of the irradiated light changes at that location, and the amount of light received by the measuring device 3 changes accordingly. Thus, in the case of an outer diameter surface having distortion at n places as shown in FIG. 3, a striped image whose brightness changes at n places is obtained. Imaging of the inspection object S progressed from the left to the right in FIG. In this embodiment, the position of distortion can be detected by measuring the position showing the light intensity change in the light intensity distribution of FIG. The reflected light intensity can be measured by obtaining a light intensity signal, but can also be measured by measuring the brightness of the reflected light image.

  Further, the radial dimension of the strain can be detected from the reflected light intensity. This utilizes the fact that the change in the radial dimension is reflected in the intensity of the reflected light. For this measurement, for example, an object having the same design dimensions as the object to be inspected and having a known radial strain is set in the detection device, and the light irradiation and the reflected light intensity are measured, and the measured value of the reflected light intensity is measured. Is prepared as a reference value. It is desirable to prepare several objects for obtaining the reference value, one having an outer diameter surface that is as close to a perfect circle as possible with no radial distortion and one having a known strain dimension with a different strain dimension. Thereby, the reflected light intensity (reference value) in the circumferential direction of the outer diameter surface including large and small strain dimensions is obtained. Then, the object to be inspected is set in the detection device in the same manner, the reflected light intensity is measured, and the measured value is compared with the reference value. Due to the difference in reflected light intensity, it is possible to detect a distortion in the radial dimension.

  Furthermore, when an image is obtained using a line sensor camera or an area sensor camera, local defects such as wrinkles and rust on the circumferential surface can be detected by image processing based on changes in reflected light intensity. . Alternatively, it may be found by visual recognition.

  The strain detection performed in this way can be performed in about several seconds including the conveyance time for an inspection object having a diameter of about 20 mm. Therefore, in-line inspection is also possible.

  FIG. 4 shows another example of a detection apparatus for carrying out the distortion detection method according to the present invention. The strain detection apparatus according to this embodiment includes a liquid tank 6, and the drive device 1 and the inspection object S are immersed in oil stored in the liquid tank. The irradiation device 2, the measurement device 3, and the control device 4 are disposed outside the liquid tank 6.

  In the liquid layer 6, at least a portion through which irradiation from the irradiation device 2 and reflected light to be measured by the measurement device 3 pass is translucent. In this embodiment, the liquid layer 6 has an opening 62 formed in the side wall of a metal body 61 having a rectangular parallelepiped shape, and the opening is liquid-tightly covered with a transparent glass plate 63. Oil L is stored in the liquid layer 6, and the driving device 1 and the inspection object S are immersed therein.

  Cutting oil is used for objects such as bearing rollers when machining, and rust preventive oil is used for other objects, and oil adheres to the surface of processing equipment. There are many cases. In that case, the adhered oil changes the reflected light intensity, preventing accurate strain detection. On the other hand, removing the adhering oil is problematic in that it takes time and eliminates the rust prevention effect.

  On the other hand, if the apparatus shown in FIG. 4 is used, since the inspection object S is immersed in the oil stored in the liquid tank 6, the oil adhering to the surface is integrated with the oil in the liquid tank. The influence on the reflected light intensity disappears or is reduced, and accurate distortion detection is not hindered.

  As shown in FIG. 4, either or both of the filtering device 7 and the deaeration device 8 are connected to the liquid tank 6 through a conduit, and the oil in the liquid tank 6 can be circulated through these apparatuses. By removing contaminants in oil by the filtering device 7 and removing bubbles by the deaeration device 8, it becomes possible to maintain highly accurate detection for a longer period of time. The filtering device and the deaeration device can be similarly connected to the liquid tank of the embodiment described below.

  FIG. 5 shows still another example of a detection apparatus for carrying out the distortion detection method according to the present invention. The strain detection apparatus according to this embodiment also includes a liquid tank 6, and the driving device 1, the inspection object S, and the irradiation apparatus 2 are immersed in the oil L in the liquid tank. . The measuring device 3 and the control device 4 are arranged outside the liquid tank 6. In the liquid layer 6, at least a portion through which reflected light to be detected by the measuring device 3 passes is assumed to have translucency. Similarly to the above-described liquid layer 6, the liquid layer 6 also has an opening 62 formed on the side wall of a metal body 61 having a rectangular parallelepiped shape, and the opening is liquid-tightly covered with a transparent glass plate 63.

  Thus, when light irradiation is performed through a translucent member such as glass by immersing not only the driving device 1 and the inspection object S but also the irradiation device 2 in the oil of the liquid tank 6, Efficient light irradiation can be performed by eliminating reflection caused by the translucent member.

  FIG. 6 shows still another example of a detection apparatus for carrying out the distortion detection method according to the present invention. The strain detection apparatus according to this embodiment also includes a liquid tank 6 ′, and the driving apparatus 1, the inspection object S, the irradiation apparatus 2, and the measurement apparatus 3 are immersed in the oil L in the liquid tank. It has become. The control device 4 is disposed outside the liquid tank 6. Since the liquid tank 6 ′ does not need to transmit light to the tank wall, the liquid tank 6 ′ only needs to have a size that can store the oil L and accommodate the member.

  In this way, not only the driving device 1 and the inspection object S but also the irradiation device 2 and the measuring device 3 are immersed in the oil in the liquid tank 6 ′, so that light is irradiated through a translucent member such as glass. In addition, when the reflected light intensity is measured, reflection caused by the translucent member can be eliminated, and efficient light irradiation and detection can be performed.

  The present invention is not limited to the above embodiment, and various modifications can be made. For example, the object to be inspected can be not only the cylindrical roller described in the embodiment, but also various objects having a surface having a rotating body shape such as a cylinder or a cone. When the surface to be detected has a conical shape, it is desirable to rotate the object about the central axis of the cone and place the irradiation device and the measurement device at a position perpendicular to the generatrix. The same applies to the case where the target shape has a truncated cone shape as a whole.

  In addition to the above-mentioned drive device, the drive device may include a support portion that supports one end portion or both end portions of the inspection object, and the support portion may be rotated. The supporting part may be one that grips one end part or both end parts, or a pin-like one that engages the center part of both end faces.

  The liquid tank may contain other liquid instead of oil. As the liquid, it is desirable to select the same liquid as the liquid adhering to the object to be inspected, or one having the property of integrating the adhering liquid by dissolution or the like.

DESCRIPTION OF SYMBOLS 1 Drive apparatus 2 Irradiation apparatus 3 Measuring apparatus 4 Control apparatus 6, 6 'Liquid layer L Oil S Inspected object

Claims (13)

  A method for detecting a distortion of a circumferential surface of an object, wherein the object is irradiated with light while rotating the object around a central axis on the circumferential surface, and the reflected light intensity of the rotation position of the object is measured. A strain detection method, comprising: detecting a strain on the circumferential surface by measuring a change.   The strain detection method according to claim 1, wherein the measurement of light irradiation and reflected light intensity is performed from outside the liquid tank while the object is immersed and rotated in a liquid stored in the liquid tank.   2. The object according to claim 1, wherein the object is immersed and rotated in a liquid stored in a liquid tank, and light irradiation is performed in the liquid tank, and the reflected light intensity is measured outside the liquid tank. The distortion detection method as described.   The strain detection method according to claim 1, wherein the object is immersed in a liquid stored in a liquid tank and rotated, and light irradiation and reflected light intensity are measured in the liquid tank.   The strain detection method according to any one of claims 1 to 4, wherein a circumferential position of a strain portion on the circumferential surface is detected.   The radial dimension of the strained portion on the circumferential surface of the inspection object is detected by comparing the measurement data obtained for the circumferential surface whose strain state is known and the measurement data of the inspection object. Item 6. The distortion detection method according to any one of Items 1 to 5.   The distortion detection method according to claim 1, wherein local defects such as wrinkles and rust on the circumferential surface are detected by image processing of the reflected light.   A device for detecting distortion of a circumferential surface of an object, the driving device rotating the object about a central axis of the circumferential surface, an irradiation device for irradiating the circumferential surface with light, and from the circumferential surface A strain detection apparatus comprising: a measurement device that measures reflected light intensity; and a control device for determining the reflected light intensity obtained by the measurement device in association with the rotational position of the object.   The strain according to claim 8, further comprising a liquid tank for immersing the driving device and the object in the liquid, wherein the irradiation device, the measurement device, and the control device are arranged outside the liquid tank. Detection device.   A liquid tank for immersing the driving device and the object in the liquid is further provided, the irradiation device is disposed in the liquid tank, and the measuring device and the control device are disposed outside the liquid tank. The strain detection apparatus according to claim 8.   A liquid tank for immersing the drive device and the object in the liquid is further provided, the irradiation device and the measuring device are disposed in the liquid tank, and the control device is disposed outside the liquid tank. The strain detection apparatus according to claim 8.   The strain detection device according to any one of claims 8 to 11, wherein a filtering device for removing contaminants in the liquid is connected to the liquid tank.   The strain detection apparatus according to claim 8, wherein a deaeration device for removing bubbles in the liquid is connected to the liquid tank.