JP4295664B2 - Hot cylindrical workpiece shape measuring apparatus and hot forging method for cylindrical body using the same - Google Patents

Description

  The present invention relates to a shape measuring device for a hot cylindrical workpiece and a method for hot forging a cylindrical body using the same.

  In the hot forging operation, a hot forged steel product for hot forging heated to a high temperature (generally 900 ° C. or higher) is pressed with a press to obtain a hot forged product having a desired shape. . When manufacturing a hot forged cylindrical product, the hot cylindrical workpiece is positioned below the press in a horizontal posture and rotatably supported. Then, a pressurizing process to the hot cylindrical workpiece by the press machine and a process of rotating the hot cylindrical workpiece by a predetermined angle after pressurization (that is, after raising the press die of the press machine) Hot forging is performed by repeating until the outer diameter and inner diameter of the intermediate cylindrical workpiece reach predetermined values. The hot cylindrical workpiece is supported in a horizontal posture by a cylindrical cored bar that passes through the hollow part of the workpiece, and is rotated by a certain angle by rotating the cored bar with a chain or the like.

  For this reason, during hot forging work, it is important to perform hot forging while measuring values such as the outer diameter and inner diameter of the hot cylindrical workpiece and judging whether the values are appropriate. Further, since the temperature of the hot cylindrical workpiece heated to a high temperature decreases with time, a hot forging operation as quick as possible is required. Conventionally, measurement of the outer diameter of a hot cylindrical workpiece has been performed by an operator approaching the hot cylindrical workpiece and measuring it by contacting a path (mechanical dimension measuring instrument). However, with this method, the work was extremely hot, and the variation in measured values by the workers was large.

  On the other hand, the shape of the object to be measured is conventionally measured using an imaging device (solid camera such as an ITV camera or CCD camera) that outputs an image signal for a high-temperature object to be subjected to hot forging or the like. A measuring apparatus or a measuring method for measuring in a non-contact manner has been proposed.

  For example, Japanese Patent Application Laid-Open No. 8-304037 (Patent Document 1) includes a single image pickup device, which is supported on a horizontal posture by a rotating mechanism and is thrown onto the outer peripheral surface of a trunk portion of a forged shaft that is rotated at a predetermined angle. Each time the image of the illuminated slit light irradiation part is rotated by a certain angle, the image is taken and captured by the imaging device, and the partial cross-sectional shape for each rotation angle of the forged shaft is obtained from the captured image, and the overlapping portions of these partial cross-sectional shapes Forging shaft measuring devices have been proposed in which the forging shafts are connected so as to best match to obtain the entire cross-sectional shape of the forging shaft, and the outer diameter size, misalignment, and roundness of the forging shaft are measured.

Japanese Patent Laid-Open No. 1-239406 (Patent Document 2) discloses that the outer circumference of a hollow cylindrical object is rotated by two imaging devices each time a high-temperature hollow cylindrical object supported in a horizontal posture is rotated by a predetermined angle. The partial cross-sectional shapes of the hollow cylindrical objects are obtained by imaging a part of the surface so that they overlap each other, and the partial cross-sectional shapes of the hollow cylindrical objects whose imaging regions partially overlap as the hollow cylindrical objects rotate are synthesized. Thus, there has been proposed a shape measuring method that obtains the entire cross-sectional shape over the entire circumference when the hollow cylindrical object rotates once.
JP-A-8-304037 ([0005] to [0013], FIG. 1) JP-A-1-239406 (page 3-6, FIG. 1)

  However, in these conventional technologies described above, by using the imaging device, it is possible to obtain the outer shape information such as the outer diameter of the high-temperature object to be measured in a non-contact manner, but the inner shape information such as the inner diameter is not obtained. Can't get. For this reason, when hot forging a cylindrical body, it is necessary to measure not only the outer diameter dimension but also the inner diameter dimension, and it is necessary to proceed with the hot forging based on those measured values. None of these were suitable for measuring the shape of a hot cylindrical workpiece for hot forging.

  Also, in hot forging, dimensional information showing the shape of the hot work over its entire circumference is important for setting the amount of press reduction and work rotation angle performed as the forging progresses and for determining the forging end time. Become. In any of the above-described conventional technologies, in order to measure the outer diameter, it is necessary to rotate the hot work once by repeating a constant angle rotation while measuring with the press machine stopped. In addition, when the temperature of the hot workpiece decreases due to natural cooling and it takes time to perform measurement a number of times, there is a possibility that the temperature of the hot workpiece may fall below the limit temperature at which forging can be performed.

  Therefore, the problem of the present invention is that it is possible to measure not only the outer diameter dimension but also the inner diameter dimension in a non-contact manner for a high-temperature hot cylindrical workpiece that is subjected to hot forging or the like and rotated at a constant angle. , Hot cylindrical workpiece shape measuring device capable of obtaining outer diameter and inner diameter showing the shape of the entire circumference of the hot cylindrical workpiece by rotating the workpiece half a round instead of one rotation, and a cylindrical body using the same It is to provide a hot forging method.

  In order to solve the above problems, the present invention takes the following technical means.

The invention of claim 1 is a shape measuring device for a hot hot cylindrical workpiece that is supported in a horizontal position and is rotatable and rotated at a predetermined angle, and is equipped with an infrared transmission filter, and the hot An imaging device that captures an annular frontal shape of a cylindrical workpiece, a moving mechanism that reciprocates the imaging device by a predetermined distance in the left-right direction so as to generate a parallax with respect to the hot cylindrical workpiece, and an imaging command to the imaging device An image capturing unit that captures an annular front view shape of the hot cylindrical workpiece each time it is rotated by a predetermined angle and obtains and stores the left and right images thereof, For each of the left image and the right image, a feature point detection window is set, and the outer diameter edge point, the inner diameter edge point, and the inner side of the hot cylindrical workpiece are feature points in the circular front view shape. A diameter of the hot cylindrical workpiece based on a stereo method from a feature point detection unit that detects an edge point, the feature point in the left image, and the feature point in the right image corresponding to the feature point A diameter dimension calculation unit for obtaining an outer diameter dimension, an inner diameter dimension, and a rear inner diameter as dimension measurement values, and storing the diameter dimension measurement value obtained for each fixed angle rotation of the hot cylindrical workpiece for half rotation of the workpiece. A hot cylindrical workpiece shape measuring apparatus, comprising: an overall shape calculating unit that obtains diameter dimension information indicating the shape of the hot cylindrical workpiece over the entire circumference.

The invention of claim 2 is a high-temperature hot cylindrical workpiece shape measuring device that is supported in a horizontal posture and is rotatable and rotated at a predetermined angle, and is equipped with an infrared transmission filter, and A first imaging device that captures an annular frontal shape of the intermediate cylindrical workpiece, and a position a predetermined distance away from the first imaging device on the right side of the first imaging device so as to generate a parallax with respect to the hot cylindrical workpiece. The second imaging device that is disposed and is equipped with an infrared transmission filter to capture an annular front view shape of the hot cylindrical workpiece, the first imaging device, and the second imaging device simultaneously. An imaging command is given, and an annular front view shape of the hot cylindrical work is rotated every predetermined angle, and a left image by the first imaging device and a right image by the second imaging device are obtained. An image capturing unit for obtaining and storing the left A feature point detection window is set for each of the image and the right image, and the outer diameter edge point, the inner diameter edge point, and the inner diameter edge point are feature points in the annular front view shape of the hot cylindrical workpiece. The feature point detection unit for detecting the diameter of the hot cylindrical workpiece based on a stereo method from the feature point in the left image and the feature point in the right image corresponding to the feature point The outer diameter dimension, the inner diameter dimension and the inner diameter dimension of the outer diameter dimension as a value , and the diameter dimension measurement value obtained for each fixed angle rotation of the hot cylindrical workpiece is stored for half a workpiece rotation, An apparatus for measuring a shape of a hot cylindrical workpiece, comprising: an overall shape calculating unit that obtains diameter dimension information indicating a shape of the hot cylindrical workpiece over the entire circumference.

The invention according to claim 3 is a cylindrical product by repeatedly applying a pressurizing step by a press machine and a step of rotating at a predetermined angle after pressurizing to a hot hot cylindrical workpiece supported in a horizontal posture and rotatably. When performing hot forging to obtain a hot cylindrical work piece, the hot cylindrical work piece shape measuring device according to claim 1 or 2 is used to measure the diameter of the hot cylindrical work piece. A hot forging method of a cylindrical body characterized by performing forging .

The shape measuring device for a hot cylindrical workpiece according to the invention of claim 1 moves the one image pickup device for each hot cylindrical workpiece rotated by a certain angle to form an annular shape of the hot cylindrical workpiece. The shape of the front view formed is imaged from different positions on the left and right sides, and the outer edge point, the inner edge point, and the inner diameter edge point are detected as corresponding feature points in the obtained left and right images, respectively. Based on the stereo method, the outer diameter dimension, the inner diameter dimension, and the inner diameter dimension on the back side are obtained from the corresponding feature points based on the stereo method. In this way, the annular front view shape of the hot cylindrical workpiece was imaged, and the diameter dimension of the hot cylindrical workpiece was measured based on the stereo method. It is possible to measure not only the inner diameter and the inner diameter of the back side , but also the hot cylindrical workpiece rotates over a whole circumference of the hot cylindrical workpiece by rotating at a constant angle and rotating half a circle instead of one rotation. Diameter dimension information indicating the shape can be obtained.

A hot cylindrical workpiece shape measuring apparatus according to a second aspect of the present invention forms an annular shape of a hot cylindrical workpiece by using two imaging devices for each hot cylindrical workpiece rotated by a certain angle. Stereoscopic imaging of the frontal view shape, and detecting the outer diameter edge point, the inner diameter edge point, and the inner diameter edge point as corresponding feature points in the left image by the first imaging device and the right image by the second imaging device, respectively From these corresponding feature points, the outer diameter dimension, the inner diameter dimension, and the inner diameter dimension on the back side are obtained as measured diameter values of the hot cylindrical workpiece based on the stereo method. Therefore, it is possible to measure not only the outer diameter dimension but also the inner diameter dimension and the inner diameter dimension on the inner side of the hot cylindrical workpiece at a high temperature, and the hot cylindrical workpiece is rotated by a half rotation instead of one rotation. It is possible to obtain diameter dimension information indicating the shape of the entire workpiece. In addition to these effects, stereo imaging can be performed by two imaging devices without moving the imaging device, so that real-time measurement can be performed. As a result, when applied to shape measurement during hot forging, it is possible to perform measurement in real time without moving time of the imaging device, and to perform imaging for measurement of hot cylindrical workpieces, There is no need to delay the start of the pressurizing step of the hot cylindrical workpiece or the step of rotating the hot cylindrical workpiece by a certain angle.

In the method for hot forging a cylindrical body according to the invention of claim 3 , each time the rotation of the hot cylindrical workpiece is rotated half a turn by repeating the rotation at a constant angle, the diameter dimension information indicating the shape over the entire circumference of the hot cylindrical workpiece is obtained. I can know. Therefore, it is possible to set the press reduction amount and work rotation angle by the operator of the press machine and to determine the forging end time based on these diameter dimension information, so that hot forged cylindrical products with good dimensional accuracy can be obtained. Can be obtained.

In addition, in the hot forging method of a cylindrical body using the hot cylindrical workpiece shape measuring device according to claim 1, in addition to the above-mentioned effects, one imaging device is moved for several seconds for measurement. Therefore, it is only necessary to delay the start of the process of rotating the hot cylindrical workpiece by a fixed angle or pressurizing the hot cylindrical workpiece by the press machine after imaging the hot cylindrical workpiece, Hot forging can be performed with high productivity. In addition, in the hot forging method of a cylindrical body using the hot cylindrical workpiece shape measuring device according to claim 2, in addition to the above-mentioned effects, real-time measurement can be performed by stereo imaging with two imaging devices. Therefore, the process for hot forging for shape measurement is not delayed, and hot forging can be performed with higher productivity.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view for explaining hot forging of a cylindrical body to which the present invention is applied, in which (a) is a side view and (b) is a front view. 2 is a view for explaining hot forging of a cylindrical body to which the present invention is applied, as in FIG.

  As shown in FIG. 1, a cored bar 22 is passed through a hot cylindrical workpiece 21 made of steel heated to a high temperature (generally 900 ° C. or higher), and placed on a cored bar support base (base) 23 in this state. Thus, the hot cylindrical workpiece 21 is supported in a horizontal posture and rotatably, and is positioned below the press machine 24 that pressurizes the hot cylindrical workpiece 21 from the outer peripheral surface side of the workpiece. The cored bar 22 can be rotated by a workpiece rotating chain 25, and when the workpiece rotating chain 25 is driven, the hot cylindrical workpiece 21 is also rotated. In the hot forging of a cylindrical product, a step of pressing the hot cylindrical workpiece 21 by a pressing die of a press machine 24, a step of driving the workpiece rotating chain 25 and rotating the hot cylindrical workpiece 21 by a certain angle, Is repeated for hot forging to obtain a cylindrical product having a target outer diameter, inner diameter, and roundness (see FIG. 2).

  FIG. 3 is a diagram showing the overall configuration of the hot cylindrical workpiece shape measuring apparatus according to the first embodiment of the present invention.

  As shown in FIG. 3, a spatial coordinate system XYZ is set, and the hot cylindrical workpiece 21 is supported so that its axis is in the Z-axis direction (front-rear axis direction). 7 is arranged toward one end side of the hot cylindrical workpiece 21, and an infrared transmission filter 7 a is attached, and the imaging device 7 is used as an imaging device for imaging the annular front view shape of the hot cylindrical workpiece 21. It is a CCD camera. A moving mechanism 8 moves the CCD camera 7 by a certain distance L in the X-axis direction (left-right axis direction) so that parallax with respect to the hot cylindrical workpiece 21 occurs. The CCD camera 7 obtains the left image VL obtained by imaging the annular front view shape of the hot cylindrical workpiece 21 at the first imaging position, and then immediately by the moving mechanism 8 provided on the gantry, the first imaging position. Is moved by a certain distance L in the X-axis direction so as to be located on the right side (the back side in the drawing in FIG. 3), and a right image obtained by imaging the annular front view shape of the hot cylindrical workpiece 21 at the second imaging position. After obtaining VR, the moving mechanism 8 immediately returns to the first imaging position.

Although not shown, the moving mechanism 8 includes a ball screw that is rotationally driven by a pulse motor, a slide plate that is coupled to a ball screw nut that meshes with the ball screw, and guides the slide plate in the X-axis direction. It consists of a guide to do. The CCD camera 7 is attached to the slide plate of the moving mechanism 8.

  Reference numeral 2 denotes an image capturing unit, 3 denotes a feature point detection unit, 4 denotes a diameter size calculation unit, 5 denotes an overall shape calculation unit, and 6 denotes a display unit. The image capturing unit 2, the feature point detecting unit 3, the diameter size calculating unit 4, the overall shape calculating unit 5 and the display unit 6, which will be described later, constitute an image measuring unit 1, and the image measuring unit 1 is configured by a personal computer. It is configured.

  FIG. 4 is a schematic diagram for explaining an image of an annular front view shape of a hot cylindrical workpiece by a CCD camera equipped with the infrared transmission filter in FIG.

  As described above, the infrared transmission filter 7 a is attached to the lens of the CCD camera 7. Thereby, visible light entering the lens can be cut as much as possible, and a large amount of infrared light from the hot cylindrical work 21 can be taken in. Therefore, the brightness of the background as an image is suppressed and the hot cylindrical work 21 is reduced. An image with more pronounced brightness can be obtained. As schematically shown in FIG. 4, the background is dark and the hot hot cylindrical workpiece 21 is bright. In this case, since the CCD camera 7 is arranged near one end portion side of the hot cylindrical workpiece 21, normally, not only the peripheral end surface portion (peripheral portion) 21a of the hot cylindrical workpiece 21 but also the inner periphery. The surface portion 21b is also imaged. The temperature of the inner peripheral surface portion 21b is unlikely to decrease due to radiant heat from the opposite wall surfaces. As a result, the inner peripheral surface portion 21b has a higher temperature than the peripheral end surface portion 21a, and even in the obtained image of the hot cylindrical workpiece 21, the inner peripheral surface portion 21b has a brightness level of the peripheral end surface as shown in FIG. It becomes higher than the part 21a. In addition, as shown in FIG. 4, not only the inner peripheral image forming a circular shape on the front side (CCD camera 7 side) but also the inner peripheral edge forming a circular shape on the rear side (opposite side of the CCD camera 7). The image of can also be captured.

  Each part of the image measuring unit 1 will be described below.

  The image pickup unit 2 gives an image pickup command to the CCD camera 7 and a move command to the moving mechanism 8 to pick up an annular front view shape of the hot cylindrical workpiece 21 every time it is rotated by a certain angle, and to the left The image VL and the right image VR are obtained and stored. The image capturing unit 2 includes an image input board that stores the images VL and VR, a moving mechanism control unit that gives a command to the pulse motor driver of the moving mechanism 8, and the like.

FIG. 5 is an explanatory diagram of the outer diameter edge detection window. FIG. 5A is an explanatory diagram of the outer diameter edge detection windows WP _L1 and WQ _L1 set in the left image VL, and FIG. 5B is the right image VR. It is explanatory drawing of the set outer diameter edge detection window WP _R1 and WQ _R1 . FIG. 6 is an explanatory diagram of an inner diameter edge detection window, in which (a) is an explanatory diagram of inner diameter edge detection windows WP _L2 and WQ _L2 set in the left image VL, and (b) is set in the right image VR. and is an explanatory view of the inner diameter edge detection window WP _R2, WQ _R2. FIG. 7 is an explanatory diagram of the inner diameter edge detection window on the back side, in which (a) is an explanatory diagram of the inner diameter edge detection windows WP _L3 and WQ _L3 set in the left image VL, and (b) is the right image. It is explanatory drawing of the back inner diameter edge detection window WP _R3 and WQ _R3 set to VR.

The feature point detection unit 3 sets a feature point detection window for each of the left image VL and the right image VR captured by the CCD camera 7, and the feature points in the circular front view shape of the hot cylindrical workpiece 21. Is detected. That is, as shown in FIG. 5A, outer diameter edge detection windows WP _L1 and WQ _L1 are set as feature point detection windows in the left image VL. In the left image VL, the window WP _L1 is for detecting an outer diameter left edge point (outer diameter left outermost point) P _L1 , and the window WQ _L1 is an outer diameter right edge point (outer diameter right outermost point). Point) This is for detecting Q _L1 . Similarly, as shown in FIG. 5B, outer edge detection windows WP _R1 and WQ _R1 are set as feature point detection windows in the right image VR. In the right image VR, the window WP _R1 is for detecting the outer diameter left edge point P _R1 , and the window WQ _R1 is for detecting the outer diameter right edge point Q _R1 .

Further, as shown in FIG. 6A, inner edge detection windows WP _L2 and WQ _L2 are set as feature point detection windows in the left image VL. In the left image VL, the window WP _L2 is for detecting an inner diameter left edge point (inner diameter left outermost point) P _L2 , and the window WQ _L2 is an inner diameter right edge point (inner diameter right outermost point) Q _L2 It is for detecting. Similarly, as shown in FIG. 6B, inner diameter edge detection windows WP _R2 and WQ _R2 are set as feature point detection windows in the right image VR. In the right image VR, the window WP _R2 is for detecting the inner diameter left edge point P _R2 , and the window WQ _R2 is for detecting the inner diameter right edge point Q _R2 .

Further, as shown in FIG. 7A, the inner diameter edge detection windows WP _L3 and WQ _L3 are set as feature point detection windows in the left image VL. In the left image VL, the window WP _L3 is for detecting a back inner diameter left edge point (back inner diameter left outermost point) P _L3 , and the window WQ _L3 is a rear inner diameter right edge point (back side). This is to detect Q _{L3 (the} innermost right innermost point). Similarly, as shown in FIG. 7B, the inner diameter edge detection windows WP _R3 and WQ _R3 are set as feature point detection windows in the right image VR. In the right image VR, the window WP _R3 is for detecting the back inner diameter left edge point P _R3 , and the window WQ _R3 is for detecting the back inner diameter right edge point Q _R3 .

FIG. 8 is a diagram for explaining the detection of the outer diameter left edge point P _L1 in the outer diameter edge detection window WP _L1 set in the left image VL.

In the feature point detection unit 3, first, the outer diameter edge detection windows WP _L1 and WQ _L1 are set for the left image VL, and the outer diameter as a feature point in the annular front view shape of the hot cylindrical workpiece 21 is set. The left edge point P _L1 and the outer diameter right edge point Q _L1 are detected. This feature point detection will be described next. This feature point detection is performed by a programmed personal computer.

In the outer diameter edge detection windows WP _L1 and WQ _L1 , the background is dark and the peripheral end surface portion 21a of the hot cylindrical workpiece 21 is bright. That is, for the outer径左edge point P _L1 in the window WP _L1, dark its left outer peripheral edge as a boundary, since the right is bright, the image processing procedure of (4) from the following (1), an outer diameter The left edge point P _L1 is detected.

(1) A horizontal Sobel filter for detecting the brightness in the horizontal direction is applied to the image data in the outer diameter edge detection window WP _L1 to generate a differential image as shown in FIG. Table 1 shows the coefficients (weighting values) of the horizontal Sobel filter.

(2) The differential image is scanned in the horizontal direction to search for the maximum value, and a peak point sequence is generated as shown in FIG. (3) A peak point approximate curve is obtained by approximating this peak point sequence with a quintic function (Y = aX ⁵ + bX ⁴ + cX ³ + dX ² + eX + f). In this case, the coordinate system XY shown in FIG. 8 is unrelated to the XY plane of the coordinate system in FIG. (4) Then, the leftmost end of the obtained peak point approximate curve is set as the outer diameter left edge point P _L1 .

Next, the outer径右edge point Q _L1 in the window WQ _L1, bright left as a boundary the outer peripheral edge of the window WQ _L1, because the right is dark, the image processing procedure of the following (1) (4) The outer right edge point Q _L1 is detected.

(1) A differential image is generated by applying a horizontal Sobel filter that detects the contrast in the horizontal direction to the image data in the outer diameter edge detection window WQ _L1 . (2) The differential image is scanned in the horizontal direction to perform a minimum value search, and a downwardly convex peak point sequence is generated. (3) A peak point approximate curve is obtained by approximating this peak point sequence with a quintic function (Y = aX ⁵ + bX ⁴ + cX ³ + dX ² + eX + f). (4) Then, the rightmost end of the obtained peak point approximate curve is set as an outer diameter right edge point Q _L1 .

As described above, depending on whether the “dark → bright” edge (boundary) is detected by the edge detection windows WP _L1 and WQ _L1 , or conversely, the “bright → dark” edge is detected, the differential image by the Sobel filter is obtained. The difference is whether the minimum value search or the maximum value search is performed. Table 2 shows “dark → light” edge detection and “bright → dark” edge detection in each edge detection window (see FIGS. 5 to 7) of the outer diameter, the inner diameter, and the inner diameter on the back side.

In this way, the outer diameter left edge point P _L1 and the outer diameter right edge point Q _L1 are detected for the left image VL. Similarly, the right image VR corresponds to the outer diameter left edge point P _R1 as the point corresponding to the outer diameter left edge point P _L1 in the left image VL and the outer diameter right edge point Q _L1 in the left image VL. detecting an outer径右edge point Q _R1 as a point.

Similarly, the feature point detection process is performed to detect the inner diameter left edge point P _L2 and the inner diameter right edge point Q _{L2 in} the left image VL, and the inner diameter left edge point P _R2 and the right image in the right image VR. detecting the inner diameter right edge point Q _R2 in VR (see FIG. 6). Similarly, a feature point detection process is performed to detect a back side inner diameter left edge point P _L3 in the left image VL and a back side inner diameter right edge point Q _L3 in the left image VL, and in the right image VR. The back side inner diameter left edge point P _R3 and the back side inner diameter right edge point Q _R3 in the right image VR are detected (see FIG. 7).

The diameter size calculation unit 4 is a hot cylindrical shape based on the stereo method from the outer diameter edge points P _L1 and Q _L1 in the left image VL and the outer diameter edge points P _R1 and Q _R1 in the right image VR. The outer diameter dimension D1 of the workpiece 21 is obtained. Further, the diameter dimension calculation unit 4 is a hot cylindrical shape based on the stereo method from the inner diameter edge points P _L2 and Q _L2 in the left image VL and the inner diameter edge points P _R2 and Q _R2 in the right image VR. Based on the stereo method, the inner diameter dimension of the workpiece 21 is obtained, and the inner diameter edge points P _L3 and Q _L3 on the back image VL in the left image VL and the inner diameter edge points P _R3 and Q _R3 on the right image VR are obtained. The inner diameter of the back side of the hot cylindrical workpiece 21 is obtained. The calculation method of the outer diameter dimension D1, the inner diameter dimension D2 and the inner diameter dimension D3 of the hot cylindrical workpiece 21 is the same procedure, and therefore, the determination method of the outer diameter dimension D1 will be described below. . The diameter calculation is performed by a programmed personal computer.

  FIG. 9 is a diagram for explaining how to obtain the outer diameter of the hot cylindrical workpiece.

In order to calculate the outer diameter dimension D1 of the hot cylindrical workpiece 21, first, the outer diameter left edge point (outer diameter left outermost point) P (X _p , Z _p ) in the space coordinates XZ is calculated. To do. In FIG. 8, now, when the outer diameter left edge point P is observed in the left and right images, L (mm): moving distance of the CCD camera 7, f (mm): camera focal length, α (rad): left image Deviation amount of camera optical axis when imaging VL, β (rad): Deviation amount of camera optical axis when imaging right image VR, x _L (mm): CCD (camera when imaging left image VL) The position of the point P on the imaging element) surface, x _R (mm): the position of the point P on the CCD surface when the right image VR is imaged.

As described above, the outer left edge point P is now observed as x _L on the CCD surface of the CCD camera 7 at the first imaging position, and x _R on the CCD surface of the CCD camera 7 at the second imaging position. Is observed, the outer diameter left edge point P is represented by Expression (1) in the left camera coordinate system. In Expression (1), x _L is a value corresponding to the aforementioned outer diameter left edge point P _L1 in the left image VL, and s is a scaling parameter. As shown in FIG. 9, the left camera coordinate system is a coordinate system in which the left camera optical axis direction is set to Z ′ _L , parallel to the CCD surface, and the direction passing through the center of the left camera lens is set to X ′ _L. is there.

Similarly, the outer diameter left edge point P is expressed by Expression (2) in the right camera coordinate system. In Expression (2), x _R is a value corresponding to the aforementioned outer diameter left edge point P _R1 in the right image VR, and t is a scaling parameter. As shown in FIG. 8, the right camera coordinate system is a coordinate system in which the right camera optical axis direction is set to Z ′ _R , parallel to the CCD surface, and the direction passing through the center of the right camera lens is set to X ′ _R. is there.

The X _L and Z _L in the left camera coordinate system, the outer diameter left edge point P (X _p , Z _p ) in the space coordinate XZ, and the X _R and Z _R in the right camera coordinate system The outer diameter left edge point P (X _p , Z _p ) at the spatial coordinates XZ is related by the conversion formula of Formula (3).

  When formula (3) is expanded, formula (4) is obtained. If the terms in parentheses in this equation (4) are placed as in equation (5), equation (4) becomes equation (6).

Then, when the simultaneous equations (6) of the unknowns s and t are solved, s and t are obtained by the equation (7). Therefore, from Expressions (1) and (7), the values of X _L and Z _L are expressed by Expression (8), respectively.

Therefore, the outer diameter left edge point P (X _p , Z _p ) at the space coordinates XZ can be calculated by the equation (9).

Similarly, the outer diameter right edge point (outer diameter right outermost point) Q (X _q , Z _q ) in the space coordinates XZ is x ′ _L (mm): CCD surface when the left image VL is imaged. The position of the point Q above, x ′ _R (mm): If the position of the point Q on the CCD surface when the right image VR is imaged, it can be calculated by equation (10). The x ′ _L is a value corresponding to the aforementioned outer diameter right edge point Q _L1 in the left image VL, and the x ′ _R is the same as the aforementioned outer diameter right edge point Q _R1 in the right image VR. Corresponding value.

  Therefore, the outer diameter D1 of the hot cylindrical workpiece 21 can be calculated by the equation (11).

  As described above, in this embodiment, pressurization is performed by the press machine 24, the hot cylindrical workpiece 21 is imaged in a state where the press die of the press machine 24 is raised, and a hot cylindrical shape is formed by the workpiece rotation chain 25. The workpiece 21 is repeatedly rotated by a certain angle, and the diameter dimension calculation unit 4 has the outer diameter dimension D1, the inner diameter dimension D2, and the inner diameter dimension D3 for the hot cylindrical workpiece 21 each time the workpiece 21 is rotated by a certain angle. It is measured.

  Then, the overall shape calculation unit 5 stores the measured values of the outer diameter D1, the inner diameter D2, and the inner diameter D3 of the outer diameter obtained every rotation of the hot cylindrical workpiece 21 by half rotation of the workpiece. Thus, dimensional information indicating the shape of the hot cylindrical workpiece 21 over the entire circumference is obtained. This total shape calculation is performed by a programmed personal computer.

  FIG. 10 is an explanatory diagram of diameter dimension information over the entire circumference of the hot cylindrical workpiece.

  Every time the hot cylindrical workpiece 21 is rotated by a certain angle, the angle amount is taken in. If the hot cylindrical workpiece 21 rotating at a certain angle at a time rotates 180 degrees, the shape of the hot cylindrical workpiece 21 over the entire circumference can be known. In the example shown in FIG. 10, the hot cylindrical workpiece 21 is rotated 180 degrees at a constant angle of N times, and the i-th outer diameter dimension: D1i, inner diameter dimension: D2i, and rear inner diameter dimension: D3i Then, the average outer diameter D1mean, the average inner diameter D2mean, and the average inner diameter D3mean of the hot cylindrical workpiece 21 are obtained by the following equations (12), (13), and (14), respectively. Further, the roundness of the outer diameter can be known from the maximum value D1max and the minimum value D1min in the outer diameter dimensions D1i, i = 1 to N. Similarly, the roundness of the inner diameter of the hot cylindrical workpiece 21 can be known from the maximum value D2max and the minimum value D2min in the inner diameter dimensions D2i, i = 1 to N, and the roundness of the inner diameter on the back side. The degree can be known from the maximum value D3max and the minimum value D3min in the inner diameter dimension D3i, i = 1 to N. In FIG. 10, in order to make the drawing easier to see, a dimensional difference is intentionally given to the inner diameter dimension and the inner diameter dimension on the back side.

  The display unit 6 displays diameter dimension information over the entire circumference of the hot cylindrical workpiece 21 obtained by the overall shape calculation unit 5, and is configured by a CRT display, for example. In this CRT display, the graph shown in FIG. 10 for the hot cylindrical workpiece 21, the average outer diameter D1mean, the average inner diameter D2mean, the average inner diameter D3mean, and the outer diameter, inner diameter, and inner diameter of the inner diameter are shown. Each roundness (defined by the maximum and minimum values) is displayed.

  As described above, the shape measuring apparatus according to the first embodiment moves the single CCD camera 7 with respect to the hot cylindrical workpiece 21 every time it is rotated by a certain angle, and the annular shape of the hot cylindrical workpiece 21. The front view shape is imaged from different positions on the left and right, and corresponding feature points (outer diameter edge point, inner diameter edge point, inner diameter edge point on the inner side) in the obtained left image VL and right image VR are respectively detected. From these corresponding feature points, the outer diameter dimension D1, the inner diameter dimension D2, and the inner diameter dimension D3, which are measured diameter values of the hot cylindrical workpiece 21, are obtained based on the stereo method. In this way, the annular front view shape of the hot cylindrical workpiece 21 is imaged and the diameter of the hot cylindrical workpiece is measured based on the stereo method. It is possible to measure not only the diameter dimension D1 but also the inner diameter dimensions D2 and D3, and the hot cylindrical workpiece 21 repeats the rotation at a constant angle and rotates half a circle instead of one rotation. Diameter dimension information (D1i, D2i, D3i, i = 1 to N, D1mean, D2mean, D3mean and the roundness of the outer diameter, inner diameter, and inner diameter on the back side) indicating the shape over the entire circumference can be obtained.

  Therefore, in the hot forging of the cylindrical body, every time the hot cylindrical workpiece 21 is rotated by half a rotation by rotating at a constant angle, the dimensional information indicating the shape of the hot cylindrical workpiece 21 over the entire circumference is known. Can do. Therefore, it is possible to set the press reduction amount and work rotation angle by the operator of the press machine and to determine the forging end time based on these diameter dimension information, so that hot forged cylindrical products with good dimensional accuracy can be obtained. Can be obtained.

  The first embodiment has an advantage that only one expensive CCD camera 7 is required as compared with the second embodiment described later.

  FIG. 11 is a diagram showing an overall configuration of a shape measuring apparatus for a hot cylindrical workpiece according to the second embodiment of the present invention. The first embodiment is the same as the first embodiment except that the single CCD camera 7 is not moved, but the two CCD cameras 9 and 10 are used to perform stereo imaging of the circular front view shape of the hot cylindrical workpiece 21. Since it is the same as the configuration, the same reference numerals are given to the common parts of both embodiments, the description thereof is omitted, and different points will be described.

  In FIG. 11, 9 is arranged toward one end side of the hot cylindrical workpiece 21, is attached with an infrared transmission filter 9 a, and captures the annular front view shape of the hot cylindrical workpiece 21. This is a first CCD camera (first imaging device). Further, 10 is arranged at a position a predetermined distance away from the first CCD camera 9 on the right side (the back side in the drawing in FIG. 11) so that a parallax with respect to the hot cylindrical workpiece 21 is generated, and the infrared transmission filter 10a. Is a second CCD camera (second imaging device) that captures an annular front view shape of the hot cylindrical workpiece 21.

  Reference numeral 2 'denotes an image capturing unit. The image pickup unit 2 ′ simultaneously gives an image pickup command to the CCD cameras 9 and 10, and takes a stereo image of the annular front view shape of the hot cylindrical work 21 every time the CCD camera 9 and 10 are rotated by a certain angle, thereby the first CCD camera 9. The left image VL and the right image VR obtained by the second CCD camera 10 are obtained and stored. The configuration of each unit other than the image capturing unit 2 ′ in the image measurement unit 1 is the same as the configuration of the first embodiment.

  The shape measuring apparatus according to the second embodiment uses the two CCD cameras 9 and 10 for the hot cylindrical workpiece 21 each time it is rotated by a certain angle, and the annular front view shape of the hot cylindrical workpiece 21. Stereo image, and corresponding feature points (outer diameter edge point, inner diameter edge point, inner diameter edge point on the inner side) in the left image by the first CCD camera 9 and the right image by the second CCD camera 10 are detected. The outer diameter dimension D1, the inner diameter dimension D2, and the inner diameter dimension D3 which are measured diameter values of the hot cylindrical workpiece 21 are obtained from the corresponding feature points based on the stereo method. Therefore, not only the outer diameter D1 but also the inner diameters D2 and D3 can be measured for the high-temperature hot cylindrical workpiece 21, and the hot cylindrical workpiece 21 is heated not only by one rotation but by a half rotation. Obtain diameter dimension information (D1i, D2i, D3i, i = 1 to N, D1mean, D2mean, D3mean and the roundness of each of the outer diameter, inner diameter, and inner diameter on the inner side) indicating the shape of the cylindrical workpiece 21 over the entire circumference. Can do.

  In addition, since stereo imaging can be performed without moving the CCD camera, real-time measurement can be performed. Thereby, in order to perform imaging for measurement of the hot cylindrical workpiece 21, the press process of the hot cylindrical workpiece 21 by the press machine 24, or the start of the step of rotating the hot cylindrical workpiece 21 by a certain angle is started. You don't have to delay.

  Therefore, in the hot forging of the cylindrical body, every time the hot cylindrical workpiece 21 is rotated by half a rotation by rotating at a constant angle, the dimensional information indicating the shape of the hot cylindrical workpiece 21 over the entire circumference is known. Can do. Therefore, it is possible to set the press reduction amount and work rotation angle by the operator of the press machine and to determine the forging end time based on these diameter dimension information, so that hot forged cylindrical products with good dimensional accuracy can be obtained. Can be obtained. Furthermore, since real-time measurement can be performed by stereo imaging by the two CCD cameras 9 and 10, the hot forging can be performed with higher productivity without delaying the process for hot forging for shape measurement. Can do.

  In the first and second embodiments, the imaging device (CCD camera) captures an annular front view shape from one end side of the hot cylindrical workpiece 21. The present invention is not limited, and in the present invention, the ring-shaped front view shape from both end portions of the hot cylindrical workpiece 21 may be imaged by the imaging device. By doing so, the more accurate overall shape of the hot cylindrical workpiece 21 can be known.

It is a figure for demonstrating the hot forging of the cylindrical body to which this invention is applied, Comprising: (a) is a side view, (b) is a front view. It is a figure for demonstrating the hot forging of the cylindrical body to which this invention is applied like FIG. 1 is a diagram illustrating an overall configuration of a shape measuring apparatus for a hot cylindrical workpiece according to a first embodiment of the present invention. It is a schematic diagram for demonstrating the image of the annular | circular front view shape of a hot cylindrical workpiece | work by the CCD camera with which the infrared transmission filter in FIG. 3 was mounted | worn. It is explanatory drawing of an outer diameter edge detection window, The (a) is explanatory drawing of outer diameter edge detection window WP _L1 and WQ _L1 set to the left image VL, The (b) is set to the right image VR. It is explanatory drawing of outer diameter edge detection window WP _R1 and WQ _R1 . It is explanatory drawing of an internal diameter edge detection window, The (a) is explanatory drawing of internal diameter edge detection window WP _L2 and WQ _L2 set to the left image VL, The (b) is an internal diameter edge set to the right image VR. It is explanatory drawing of detection window WP _R2 and WQ _R2 . It is explanatory drawing of a back side internal diameter edge detection window, The (a) is explanatory drawing of the back side internal diameter edge detection windows WP _L3 and WQ _L3 set to the left image VL, The (b) is set to the right image VR. It is explanatory drawing of the made back inner diameter edge detection window WP _R3 and WQ _R3 . It is a figure for demonstrating the detection of the outer diameter left edge point P _L1 in the outer diameter edge detection window WP _L1 set to the left image VL. It is a figure for demonstrating how to obtain | require the outer diameter dimension of a hot cylindrical workpiece. It is explanatory drawing of the diameter dimension information over the perimeter of a hot cylindrical workpiece. It is a figure which shows the whole structure of the shape measuring apparatus of the hot cylindrical workpiece by 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image measurement part 2, 2 '... Image pick-up part 3 ... Feature point detection part 4 ... Diameter dimension calculation part 5 ... Whole shape calculation part 6 ... Display part 7 ... CCD camera 7a ... Infrared transmission filter 9 ... 1st CCD camera 9a ... Infrared transmission filter 10 ... Second CCD camera 10a ... Infrared transmission filter 8 ... Moving mechanism 21 ... Hot cylindrical workpiece 22 ... Core metal 23 ... Core metal support 24 ... Press machine 25 ... Work rotation Chain VL ... Left image VR ... Right image

Claims (3)

A shape measurement device for a hot, hot cylindrical workpiece that is supported in a horizontal position and is rotatable and rotated at a predetermined angle,
An imaging device that is equipped with an infrared transmission filter and that captures an annular front view shape of the hot cylindrical workpiece;
A moving mechanism for reciprocating the imaging device by a predetermined distance in the left-right direction so as to generate a parallax with respect to the hot cylindrical workpiece;
An imaging command is given to the imaging device and a movement command is given to the moving mechanism to capture the circular front view shape of the hot cylindrical workpiece every time it is rotated by a certain angle, and obtain and store the left and right images thereof An image capturing unit to
For each of the left image and the right image, a feature point detection window is set, and an outer diameter edge point, an inner diameter edge point, and a rear inner diameter are feature points in an annular front view shape of the hot cylindrical workpiece. A feature point detector for detecting edge points;
From the feature point in the left image and the feature point in the right image corresponding to the feature point, an outer diameter dimension, an inner diameter dimension, and a diameter dimension measurement value of the hot cylindrical workpiece based on a stereo method. A diameter dimension calculation unit for obtaining the inner diameter dimension on the back side ;
The overall shape calculation for storing the diameter dimension measurement value obtained for each rotation of the hot cylindrical workpiece at a predetermined angle for the half rotation of the workpiece so as to obtain the diameter dimension information indicating the shape of the entire circumference of the hot cylindrical workpiece. And
A shape measuring apparatus for a hot cylindrical workpiece characterized by comprising: A shape measurement device for a hot, hot cylindrical workpiece that is supported in a horizontal position and is rotatable and rotated at a predetermined angle,
A first imaging device that is mounted with an infrared transmission filter and images the shape of the annular front view of the hot cylindrical workpiece;
A circle of the hot cylindrical workpiece is disposed at a position a predetermined distance away from the first imaging device so that a parallax with respect to the hot cylindrical workpiece is generated, and an infrared transmission filter is attached. A second imaging device for imaging an annular frontal view shape;
An imaging command is simultaneously given to the first imaging device and the second imaging device, and an annular front view shape of the hot cylindrical workpiece is stereo-photographed every time it is rotated by a certain angle, and the first imaging device is provided. An image capturing unit that obtains and stores a left image from the imaging device and a right image from the second imaging device;
For each of the left image and the right image, a feature point detection window is set, and an outer diameter edge point, an inner diameter edge point, and a rear inner diameter are feature points in an annular front view shape of the hot cylindrical workpiece. A feature point detector for detecting edge points;
From the feature point in the left image and the feature point in the right image corresponding to the feature point, an outer diameter dimension, an inner diameter dimension, and a diameter dimension measurement value of the hot cylindrical workpiece based on a stereo method. A diameter dimension calculation unit for obtaining the inner diameter dimension on the back side ;
The overall shape calculation for storing the diameter dimension measurement value obtained for each rotation of the hot cylindrical workpiece at a predetermined angle for the half rotation of the workpiece so as to obtain the diameter dimension information indicating the shape of the entire circumference of the hot cylindrical workpiece. And
A shape measuring apparatus for a hot cylindrical workpiece characterized by comprising:   Performs hot forging to obtain a cylindrical product by repeatedly applying a pressurizing step with a press machine and a step of rotating a certain angle after pressurizing a hot hot cylindrical workpiece that is horizontally supported and rotatably supported. At the time, the hot forging is performed based on the measured value while measuring the diameter of the hot cylindrical workpiece using the hot cylindrical workpiece shape measuring device according to claim 1 or 2. Hot forging method for cylindrical body.

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