Method and apparatus for straightening cylindrical body

Abstract

To provide a method and a device for straightening a cylindrical body by which a highly accurate cylindrical body can be obtained by highly accurately and easily estimating the apex position of the bend of the cylindrical body and performing straightening by aiming at the apex position of the bend.SOLUTION: In the straightening method for straightening the bend of the cylindrical body by applying a load to the peripheral surface of the cylindrical body having the bend by using a load jig, the deflection amount of the cylindrical body is measured at two points, and the bend apex position of the cylindrical body is estimated by using the value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method and apparatus for straightening a curved cylindrical body.

[0002] For example, the present invention relates to a method and apparatus for correcting cylindrical bodies used as cores of elastic rollers, such as charging rollers, developing rollers, toner supply rollers, transfer rollers, fixing rollers, and transport rollers used in electrophotographic devices, in which the core is covered with an elastic layer. [Background technology]

[0003] Correcting a curve in a cylindrical body is performed by applying a load (correction load) to the curved portion of the cylinder in the opposite direction to the direction of the curve and forcing the cylinder into position. In this case, it is necessary to determine the position at which the load is applied. Conventionally, the amount of correction is determined to eliminate the curve at the position where the amount of runout is maximum when the cylinder to be corrected is rotated while supported at both ends, or at the position where the curve is maximum measured at certain intervals along the length of the cylinder. Patent Document 1 discloses a method of correcting a cylinder by measuring multiple points along the length of the cylinder and correcting the cylinder to improve its shape accuracy.

[0004] Elastic rollers for electrophotographic devices, which use a cylindrical core, require high precision in terms of shape accuracy, such as runout relative to the central axis. If the shape accuracy of an elastic roller used in contact with a photosensitive drum or the like is low, uneven contact can cause image defects. For example, when an elastic roller is used as a charging roller, the nip area when the elastic roller is contacted with a photosensitive drum with a predetermined pressure can become uneven in the longitudinal direction, causing uneven charging and resulting in image defects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4419224 Summary of the Invention [Problem to be solved by the invention]

[0006] In the method described in Patent Document 1, the point where the amount of runout in the longitudinal direction of the cylinder is greatest is measured among predetermined measurement points, and correction is performed at the point where the amount of runout is greatest. Therefore, if the measurement point is far from the apex of the curve of the cylinder, the load is applied at a point significantly offset from the apex. The apex of the curve of a cylinder refers to the point where the curvature of the centerline of the cylinder is greatest, and the apex position of the curve refers to the intersection of a vertical line passing through the apex of the curve and the circumferential surface when the cylinder is placed with the apex of the curve facing upward. As a result, correction can sometimes be insufficient.

[0007] The present disclosure provides a method and device for correcting a cylindrical body that can easily estimate the apex position of the bend in a cylindrical body with high accuracy and correct the apex position of the bend, thereby obtaining a highly accurate cylindrical body. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, there is provided a method for correcting a curved cylindrical body by applying a load to the peripheral surface of the cylindrical body using a loading jig, the method comprising the following steps (α) to (δ):

[0009] (α) a straight line connecting the center of gravity A of one end surface of the cylindrical body and the center of gravity B of the other end surface is defined as the X axis; When the X axis is horizontal, the axis perpendicular to the X axis and in the direction of gravity is the Y axis, An XY plane is set between the X axis and the Y axis, The coordinates of the center of gravity A of the surface on the XY plane are (0, 0), and the coordinates of the center of gravity B of the surface are (L, 0), measuring the amount of runout at a position Q1 where the X coordinate on the XY plane is x1 (where x1 satisfies the following formula (1)) and at a position Q2 where x2 (where x2 satisfies the following formula (2)) while rotating the cylindrical body; 0 <x1<L / 2 (1) L / 2 <x2<L (2) (β) determining the maximum values ​​of the deflection of the cylindrical body measured at the positions Q1 and Q2 as y1 and y2 (where y1 and y2 are positive values), respectively, and obtaining points P1 (x1, y1) and P2 (x2, y2) on the XY plane; (γ) drawing a straight line L1 connecting the center of gravity A of the surface and the point P1, and a straight line L2 connecting the center of gravity B of the surface and the point P2 on the XY plane; (δ) a step of determining an intersection C1 between the straight lines L1 and L2 on the XY plane, moving the loading jig to the X coordinate position of the intersection C1, and applying a load to the cylinder from that position in a direction that reduces the deflection of the cylinder, thereby correcting the bending of the cylinder.

[0010] Furthermore, according to one aspect of the present disclosure, there is provided a straightening device for applying a load to the peripheral surface of a curved cylindrical body to straighten the curve of the cylindrical body, the straightening device for the cylindrical body having a mechanism and control function for carrying out the following steps (A) to (D).

[0011] (A) A straight line connecting the center of gravity A of one end surface of the cylindrical body and the center of gravity B of the other end surface is defined as the X axis, When the X axis is horizontal, the axis perpendicular to the X axis and in the direction of gravity is the Y axis, An XY plane is set between the X axis and the Y axis, The coordinates of the center of gravity A of the surface on the XY plane are (0, 0), and the coordinates of the center of gravity B of the surface are (L, 0), measuring the amount of runout at a position Q1 where the X coordinate on the XY plane is x1 (where x1 satisfies the following formula (1)) and at a position Q2 where x2 (where x2 satisfies the following formula (2)) while rotating the cylindrical body; 0 <x1<L / 2 (1) L / 2 <x2<L (2) (B) The maximum values ​​of the deflection of the cylindrical body measured at the positions Q1 and Q2 are defined as y1 and y2 (where y1 and y2 are positive values), respectively; Obtaining a point P1(x1, y1) and a point P2(x2, y2) on the XY plane; (C) drawing a straight line L1 connecting the center of gravity A of the surface and point P1, and a straight line L2 connecting the center of gravity B of the surface and point P2 on the XY plane; (D) A step of determining an intersection C1 between the straight lines L1 and L2 on the XY plane, moving the loading jig to the X coordinate of the intersection C1, and applying a load to the cylinder from that position in a direction that reduces the deflection of the cylinder, thereby correcting the bending of the cylinder. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide a method and device for correcting a cylindrical body, which can determine the position and amount of correction for correcting a bend in a cylindrical body by easily and accurately estimating the apex position of the bend in the cylindrical body and correcting the bend by targeting the apex position of the bend (correction position), thereby obtaining a highly accurate cylindrical body with a minimum number of corrections. [Brief explanation of the drawings]

[0013] [Figure 1] An explanatory diagram showing a schematic diagram of a device used for straightening a cylindrical body [Figure 2] Illustration of cylinder coordinate settings [Figure 3] Illustration of how to measure the runout of a cylindrical object [Figure 4] A schematic diagram showing how to estimate the vertex of a cylinder [Figure 5] An explanatory diagram showing a schematic diagram of a method for straightening a cylindrical body [Figure 6] An explanatory diagram showing an example of a correction jig [Figure 7] An example of a cylinder [Figure 8] FIG. 1 is a diagram illustrating the first embodiment. [Figure 9] FIG. 2 is a diagram illustrating the second embodiment. [Figure 10] FIG. 3 is a diagram illustrating Example 3. [Figure 11] FIG. 4 is a diagram illustrating the fourth embodiment. [Figure 12] FIG. 5 is a diagram illustrating the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] When a cylindrical body is used as the core of an elastic roller, the shape precision of the cylindrical body, which is the core, is important for improving the shape precision of the elastic roller. After investigating the reasons for this, the following was discovered. For example, when molding an elastic roller using a crosshead extruder, the rubber material flows along the cylindrical body to form the elastic roller. However, if the shape precision of the cylindrical body is poor, an elastic rubber layer will be formed along the cylindrical body, which will cause the shape precision of the elastic roller to deteriorate.

[0015] Therefore, the inventors focused on improving the shape accuracy of the cylindrical body used as the core in order to improve the shape accuracy of the elastic roller. That is, they discovered that in order to improve the shape accuracy of the cylindrical body, a cylindrical body having a desired shape can be obtained by correcting it by applying a load to the circumferential surface of the cylindrical body.

[0016] The present inventors have investigated methods for correcting a cylindrical body.

[0017] In the technology of the present disclosure, the cylindrical body to be corrected has a bend. Most cylindrical bodies are manufactured by stretching a coiled wire and cutting it to a certain length. Therefore, the cylindrical body has a shape history (=bend) of an approximately arc. By performing a correction method in which a load is applied targeting the apex position of the bend, excellent shape accuracy can be obtained.

[0018] The inventors have therefore investigated a method for finding the apex position of a curved portion of a cylinder. While it is possible to find the exact apex position by dividing the cylinder into segments in the longitudinal direction and measuring the shape, this method is not practical because it requires a long measurement time. Furthermore, installing multiple measuring devices to measure the cylinder in detail increases the cost of the measuring devices, and the large amount of measurement data generated requires time for data processing, making this method not practical.

[0019] Therefore, the inventors have conducted extensive research and found a method for easily and accurately estimating the apex position of a curved portion of a cylindrical body.

[0020] The cylindrical body correction device, correction method, and inspection method will be described in detail below.

[0021] <Cylinder> Examples of materials for the cylindrical body 1 include metals such as iron, copper, stainless steel, aluminum, and nickel, as well as alloys thereof. Furthermore, the surfaces of these materials may be plated or otherwise treated to provide scratch resistance. Furthermore, the cylindrical body 1 is not particularly limited as long as it is a curved cylindrical body, such as one manufactured by stretching a coiled wire and cutting it to a certain length, or one manufactured by cutting.

[0022] <Orthodontic device> Next, we will explain the straightening device for the cylindrical body 1. Figure 1 is a diagram illustrating the overall outline of the straightening device.

[0023] The illustration shows a rotatable gripping unit 2 that supports both ends of the cylindrical body 1, a rotational drive source 3-1 for rotating the gripping unit 2, and a rotational transmission mechanism 3-2 for transmitting the rotation to the gripping unit 2. Also shown is a rotation mechanism 3 including a link mechanism 3-3 for synchronously rotating the rotational transmission mechanism 3-2, and a measuring device 4 for measuring the runout of the cylindrical body 1. Furthermore, the illustration includes a loading jig 5 that applies a load to the cylindrical body 1 to correct it, an X-axis robot 6 that moves the loading jig 5 in the longitudinal direction of the cylindrical body 1, and a Z-axis robot 7 that moves the loading jig in the direction of gravity of the cylindrical body 1. Although not shown, the illustration also includes a computing device that records and calculates the measured values, a transfer robot that transports the cylindrical body 1, and other components. The rotation mechanism 3 may also be provided with one driving source for each gripping unit 2, and the driving sources may be synchronously controlled.

[0024] When the cylinder 1 is placed on the gripping unit 2, as shown in Figure 2, the line connecting the center of gravity A of one end face of the cylinder 1 and the center of gravity B of the other end face is defined as the X-axis, and when the X-axis is horizontal, the axis perpendicular to the X-axis and in the direction of gravity is defined as the Y-axis. Furthermore, an XY plane is defined between the X-axis and the Y-axis. The coordinate of the center of gravity A of one end face of the cylinder 1 is defined as the origin O (0,0), and the coordinate of the center of gravity B of the other end face is defined as L (L,0). Note that the position of the gripping unit 2 may be changed as appropriate, in which case the position of the cylinder 1 on the gripping unit 2 may be defined as the origin O and the end L of the cylinder.

[0025] Hereinafter, each step in the straightening method using the straightening device will be described in detail.

[0026] <Method for measuring runout of a cylindrical object> A method for measuring the runout of a cylindrical body 1 will now be described. As shown in Figure 3(a), a laser measuring device is used as the measuring device 4 for measuring runout, and the cylindrical body 1 is placed between the light projecting unit 4-1 and the light receiving unit 4-2. Next, the holding unit 2 is rotated to passively rotate the cylindrical body 1, while the light projecting unit 4-1 irradiates it with laser light. The irradiated laser light is blocked by the cylindrical body 1 before reaching the light receiving unit 4-2, allowing the runout to be measured. The measurement points for the measuring device 4 are preset longitudinal positions of the cylindrical body 1 (measurement point 1 and measurement point 2). Note that measurements can be taken by moving a single measuring device 4, or by installing multiple measuring devices 4 and measuring simultaneously, but measurements should be taken at two or more points on either side of the longitudinal center of the cylindrical body 1.

[0027] A more preferable setting position is one where the actual apex position of the bend of the cylinder 1 is between measurement point 1 and measurement point 2, and where the measurement point is not too far from the actual apex position of the bend of the cylinder 1. To achieve this, the cylinder 1 may be measured in advance to determine the actual apex position of the bend and its frequency of occurrence, and then measurement point 1 and measurement point 2 may be set at appropriate positions.

[0028] The position of the curved apex of the cylindrical body 1 is preferably in the range of 0.25×L or more and 0.75×L or less, where L is the coordinate of the center of gravity B of the end face.

[0029] Next, we will explain how to measure the runout amount. The runout amount measurement value is the distance to the top end of the cylinder 1, with the top end of the laser beam as the zero reference, or the distance to the bottom end of the cylinder 1, with the bottom end of the laser beam as the zero reference. When the measurement values ​​obtained when the cylinder 1 is rotated once are recorded using a calculator or the like, measurement value 1 becomes a trigonometric function with the horizontal axis representing the rotation phase and the vertical axis representing the measurement value, as shown in Figure 3(b). The runout amount is defined as the "maximum value - minimum value" of the obtained measurement values. Regarding the measured runout amount, the runout amount at measurement point 1 is defined as y1, and the runout amount at measurement point 2 is defined as y2. Furthermore, the rotation phase showing the measurement value with the smallest absolute value from the zero reference is defined as the MAX phase.

[0030] Measurement point 1 is a position Q1 where the X coordinate on the XY plane is x1 (where x1 satisfies the following formula (1)). Measurement point 2 is a position Q2 where the X coordinate on the XY plane is x2 (where x2 satisfies the following formula (2)). 0 <x1<L / 2 (1) L / 2 <x2<L (2)

[0031] It is more preferable that x1 satisfies the following formula (3) and x2 satisfies the following formula (4). L / 10 <x1<3L / 10 (3) 7L / 10 <x2<9L / 10 (4)

[0032] The measured values ​​obtained by the laser measuring instrument may be subjected to noise removal processing such as moving average.

[0033] It is more preferable that x1 and x2 satisfy the following formula (5). 0.8×x1≦(L-x2)≦1.2×x1 (5)

[0034] <How to estimate the curve apex of a cylinder> The method for estimating the apex of the bend in a cylinder will now be explained. As shown in Figure 4(a), the deflection amount y1 measured at measurement point 1 is set as point P1(x1, y1), and the deflection amount y2 measured at measurement point 2 is set as point P2(x2, y2), and each is plotted on the XY plane.

[0035] Next, as shown in Figure 4(b), find the line L1 connecting the center of gravity A (origin O) and P1, and the line L2 connecting the center of gravity B and P2. At this time, the equations for each line can be found using the following formulas.

[0036]

number

[0037] Then, as shown in Figure 4(c), the intersection point C1(X, Y) can be found from the obtained straight lines L1 and L2. Note that these calculations can be performed using a computing device.

[0038] Here, it has been experimentally proven that there is little error between the X coordinate of C1 and the longitudinal position of the actual bend apex position of the cylinder 1, but there may be a large error between the Y coordinate of C1 and the actual deflection amount of the bend apex position of the cylinder 1.

[0039] In this case, a method for improving the accuracy of the Y coordinate of the estimated vertex position may be introduced. For example, a device for measuring the load, such as a load cell (not shown), may be installed on the loading jig 5. The loading jig 5 may then be moved to the intersection coordinate X, and the loading jig 5 may be moved toward the cylindrical body 1. The coordinate Y' detected by the load cell or the like when the loading jig 5 makes contact with the cylindrical body 1 may be taken as the estimated vertex coordinate M'(X,Y'). Alternatively, the measuring device 4 may be moved to the intersection coordinate X to measure the amount of runout. Furthermore, the measuring device 4 may be installed in advance near the midpoint between measurement point 1 and measurement point 2, which may be used as measurement point 3, and the estimated vertex coordinate may be estimated using the values ​​at each measurement point.

[0040] <Correction method> Next, a method for correcting the bending of the cylindrical body 1 will be described.

[0041] First, as shown in Figure 5(a), rotate the cylinder 1 so that the MAX phase obtained when measuring the runout of the cylinder 1 is on the upper side in the direction of gravity. At this time, the MAX phase 1 obtained at measurement point 1 and the MAX phase 2 obtained at measurement point 2 may not match. Normally, this is a slight change, and if it is thought that it will not affect the correction, it is possible to set either one or the other, or to set the phase to the average value of the two. Alternatively, it is also possible to set measurement point 3 between measurement point 1 and measurement point 2, and make the MAX phase 3 obtained at measurement point 3 on the upper side in the direction of gravity. Any method that maximizes the effect during correction can be selected as appropriate.

[0042] Next, as shown in FIG. 5(b), the loading jig 5 is moved by the X-axis robot 6 toward the X-coordinate of the intersection point C1 obtained above.

[0043] Thereafter, as shown in Fig. 5(c), the Z-axis robot 7 moves the loading jig 5 toward the cylindrical body 1 to press the cylindrical body 1 and correct the cylindrical body 1 so as to reduce the amount of runout of the cylindrical body 1. Thereafter, as shown in Fig. 5(d), the Z-axis robot 7 moves the loading jig 5 away from the cylindrical body 1.

[0044] At this time, the correction using the loading jig 5 is performed under load control, and a specified load is applied to press the cylinder 1. At this time, it is preferable to record the amount of deformation (correction amount) of the cylinder 1 caused by applying a load to the cylinder 1, and record this in a table showing the relationship between the load and the correction amount. It is desirable to determine the load required for correction by referring to a table prepared in advance for the measured runout amount of the cylinder 1. Alternatively, the control method may be position control, and as with load control, a table is prepared in advance that shows the relationship between the movement distance of the loading jig 5 and the amount of deformation (correction amount) of the cylinder 1. Then, it is preferable to determine the movement distance of the loading jig 5 from the measured runout amount of the cylinder 1.

[0045] At this time, it is preferable not to apply too much load to the cylindrical body 1. This is because if the correction amount exceeds a certain value, the phenomenon of work hardening will occur, in which the hardness of the cylindrical body 1 increases, and it is expected that this will shorten the life of the loading jig 5. Furthermore, if correction is performed until the direction of runout of the cylindrical body 1 after correction is reversed from the direction of runout before correction, the degree of work hardening will increase. Therefore, depending on how the cylindrical body 1 is used, there is a concern that deformation may occur, so it is preferable to adjust the correction amount so that the direction of runout is not reversed, and to apply a load corresponding to that correction amount.

[0046] In addition, the control software may be configured to not perform correction if the runout measured at the longitudinal position of the cylindrical body 1 (measurement point 1 and measurement point 2) before correction is smaller than a predetermined standard value.

[0047] <Correction jig> An example of the shape of the loading jig 5 is shown in Fig. 6. There are no particular restrictions on the shape or material as long as it can correct the cylindrical body 1, but shapes and materials that do not easily damage the surface of the cylindrical body 1 are preferred.

[0048] <Cylinder runout amount after correction> After the cylindrical body 1 has been straightened, the amount of runout after the straightening may be measured using the method described above. If the result does not satisfy the desired shape, the straightening can be repeated using the same method.

[0049] <Elastic roller> The cylindrical body 1 may be used as the core of an elastic roller by covering the outer periphery of the core with an elastic layer such as rubber. As for the manufacturing device and method for the elastic roller, the elastic roller can be manufactured using known manufacturing devices and methods such as a crosshead extrusion device and a mold molding device.

[0050] The elastic layer may be either a solid body or a foam body, and examples of the binder resin that is the material of the elastic layer include rubbers and thermoplastic elastomers, including natural rubber, butadiene rubber, styrene butadiene rubber (SBR), nitrile rubber, ethylene propylene rubber (EPDM), chloroprene rubber (CR), nitrile butadiene rubber (NBR), epichlorohydrin rubber, butyl rubber, silicone rubber, urethane rubber, fluororubber, and chlorine rubber. The binder resin may also contain particles such as carbon black.

[0051] The obtained elastic roller can be used as a charging roller, a developing roller, a toner supply roller, a transfer roller, a fixing roller, a transport roller, etc. in an electrophotographic device. If necessary, a coating layer may be provided on the elastic layer to form an elastic roller having multiple layers. [Example]

[0052] The technology of the present disclosure will be described in more detail below using examples, but is not limited thereto.

[0053] In this example, 700 curved cylinders were prepared by cutting the same coiled wire to a fixed length as the cylinders 1. These cylinders had a total length L of 250 mm and an outer diameter of φ5 mm.

[0054] First, the apex position of the curve of the cylinder 1 in its initial state before straightening was determined using a separately prepared measuring device. As shown in Fig. 7, the apex position was determined by dividing the line segment AB connecting the center of gravity A and center of gravity B of the cylinder 1 into 10 equal parts at nine points E1 to E9, cutting the cylinder 1 with nine planes that included any one of the points E1 to E9 and were parallel to the Y axis, and dividing the line segment AB into 10 equal parts. The coordinates of the center of gravity B of the surface were set to (250,0). The cylinder 1 used in this example had a curve apex position located near the longitudinal center of the cylinder 1, between 75 mm and 175 mm (3L / 10 and 7L / 10).

[0055] These 700 cylinders 1 were divided into seven groups of 100 cylinders each. The vertex positions were distributed approximately evenly within each group. Each group of 100 cylinders 1 will be used in the examples and comparative examples described below.

[0056] [Example 1] A measuring device 4 was installed at measurement point 1 and measurement point 2 shown in Table 1. Figure 8 shows a schematic diagram of Example 1. The amount of runout of the cylindrical body 1 was measured at each measurement point, and the intersection C1 (X, Y) was estimated using the method described above. The amount of runout at coordinate X was measured. Then, the X-axis robot 6 moved the loading jig 5 toward coordinate X, which was the estimated vertex. In addition, the rotation mechanism 3 rotated the cylindrical body 1 so that the MAX phase was upward in the direction of gravity.

[0057] Next, using a table of loads and correction amounts prepared in advance, the load at which the runout value of the X coordinate coincided with the correction amount value was calculated. The Z-axis robot 7 moved the loading jig 5, and a load was applied to the cylindrical body 1 to perform correction. After that, the runout amount after one straightening was measured.

[0058] This process was repeated for 100 cylinders. The average runout amount after straightening and the amount of change (before straightening - after straightening) are shown in Table 1. Table 1 also shows the average value for 100 cylinders of the deviation between the apex position of the bend before straightening and the position of the weighted point. If the measurement points are set in appropriate positions as shown in Figure 8, the apex position can be estimated with high accuracy.

[0059] [Example 2] FIG. 9 shows a schematic diagram of Example 2. Measuring instruments were installed at measurement points 1 and 2 shown in Table 1. Other than that, the same procedure was carried out as in Example 1. This procedure was repeated for 100 cylindrical bodies, and the average value of the runout amount after straightening and the amount of change (before straightening - after straightening) are shown in Table 1. Table 1 also shows the average value of the deviation between the apex position of the bend before straightening and the position of the weight point for 100 bodies.

[0060] As shown in FIG. 9, the deviation between the estimated apex position and the actual apex position of the curve of the cylindrical body is larger than in the first embodiment.

[0061] [Example 3] FIG. 10 shows a schematic diagram of Example 3. Measuring instruments were installed at measurement points 1 and 2 shown in Table 1. Other than that, the same procedure was carried out as in Example 1. This procedure was repeated for 100 cylindrical bodies, and the average value of the runout amount after straightening and the amount of change (before straightening - after straightening) are shown in Table 1. Table 1 also shows the average value of the deviation between the apex position of the bend before straightening and the position of the weight point for 100 bodies.

[0062] As shown in FIG. 10, there are cases where a measurement point is set inside the apex of the curve of a cylindrical body.

[0063] [Example 4] FIG. 11 shows a schematic diagram of Example 4. Measuring instruments were installed at measurement points 1 and 2 shown in Table 1. Other than that, the same procedure was carried out as in Example 1. This procedure was repeated for 100 cylindrical bodies, and the average value of the runout amount after straightening and the amount of change (before straightening - after straightening) are shown in Table 1. Table 1 also shows the average value of the deviation between the apex position of the bend before straightening and the position of the weight point for 100 bodies.

[0064] [Example 5] FIG. 12 shows a schematic diagram of Example 5. Measuring instruments were installed at measurement points 1 and 2 shown in Table 1. Other than that, the same procedure as in Example 1 was carried out. This procedure was repeated for 100 cylindrical bodies, and the average value of the runout amount after straightening and the amount of change (before straightening - after straightening) are shown in Table 1. Table 1 also shows the average value of the deviation between the apex position of the bend before straightening and the position of the weight point for 100 bodies.

[0065] [Comparative Example 1] The amount of runout was measured at the center position in the longitudinal direction of the cylindrical body 1. After that, the X-axis robot 6 moved the loading jig 5 toward the coordinate X, which was the estimated vertex. In addition, the rotation mechanism 3 rotated the cylindrical body 1 so that the MAX phase was on the upper side in the direction of gravity.

[0066] Next, using a table of loads and correction amounts prepared in advance, the load at which the runout value at the center position coincided with the value of the correction amount was calculated. The Z-axis robot 7 moved the loading jig 5 to the center position in the longitudinal direction of the cylindrical body 1, and a load was applied to the cylindrical body 1 to perform correction. After that, the runout amount after one straightening was measured.

[0067] This process was repeated for 100 cylinders, and the average runout amount after straightening and the amount of change (before straightening - after straightening) are shown in Table 1. Table 1 also shows the average value for 100 cylinders of the deviation between the apex position of the bend before straightening and the position of the weight point.

[0068] In this case, if the apex is located in the center of the cylinder, the straightening can be performed correctly, but in reality, there is variation in the position of the apex of the bend, so in many cases a position other than the apex of the bend is straightened.

[0069] Comparative Example 2 Measurement points 1 and 2 were the same as in Example 1, but measurement point 3 was also installed at the longitudinal center (125 mm) of the cylinder. The load at which the maximum runout value among the three points matched the value of the correction amount was calculated. The correction tool was moved to the position where the runout amount obtained from the three points was the maximum, and a load was applied to perform correction. The runout amount after one straightening was then measured. This was repeated for 100 cylinders, and the average runout amount after straightening and the change (before straightening - after straightening) are shown in Table 1. Table 1 also shows the average deviation of 100 cylinders between the apex position of the bend before straightening and the position of the load point.

[0070] In this case, correction is only performed at one of the three measurement points, so similar to Comparative Example 1, correction is often performed at a position other than the apex of the bend.

[0071] [Table 1]

[0072] The present disclosure relates to the following configurations.

[0073] (Configuration 1) A method for correcting a curved cylindrical body by applying a load to the peripheral surface of the cylindrical body using a loading jig, comprising: (α) a straight line connecting the center of gravity A of one end surface of the cylindrical body and the center of gravity B of the other end surface is defined as the X axis; When the X axis is horizontal, the axis perpendicular to the X axis and in the direction of gravity is the Y axis, An XY plane is set between the X axis and the Y axis, The coordinates of the center of gravity A of the surface on the XY plane are (0, 0), and the coordinates of the center of gravity B of the surface are (L, 0), measuring the amount of runout at a position Q1 where the X coordinate on the XY plane is x1 (where x1 satisfies the following formula (1)) and at a position Q2 where x2 (where x2 satisfies the following formula (2)) while rotating the cylindrical body; 0 <x1<L / 2 (1) L / 2 <x2<L (2) (β) determining the maximum values ​​of the deflection of the cylindrical body measured at the positions Q1 and Q2 as y1 and y2 (where y1 and y2 are positive values), respectively, and obtaining points P1 (x1, y1) and P2 (x2, y2) on the XY plane; (γ) drawing a straight line L1 connecting the center of gravity A of the surface and the point P1, and a straight line L2 connecting the center of gravity B of the surface and the point P2 on the XY plane; (δ) determining an intersection C1 between the straight lines L1 and L2 on the XY plane, moving the loading jig to the X coordinate position of the intersection C1, and applying a load to the cylinder from that position in a direction that reduces the deflection of the cylinder, thereby correcting the bending of the cylinder; A method for straightening a cylindrical body, comprising:

[0074] (Configuration 2) The method for straightening a cylindrical body according to Configuration 1, wherein x1 satisfies the following formula (3), and x2 satisfies the following formula (4). L / 10 <x1<3L / 10 (3) 7L / 10 <x2<9L / 10 (4)

[0075] (Configuration 3) The x1 and x2 satisfy the following formula (5): 3. The method for correcting a cylindrical body according to claim 1 or 2. 0.8×x1≦(L-x2)≦1.2×x1 (5)

[0076] (Configuration 4) A straightening device for straightening a curved cylindrical body by applying a load to the peripheral surface of the cylindrical body using a loading jig, (A) A straight line connecting the center of gravity A of one end surface of the cylindrical body and the center of gravity B of the other end surface is defined as the X axis, When the X axis is horizontal, the axis perpendicular to the X axis and in the direction of gravity is the Y axis, An XY plane is set between the X axis and the Y axis, The coordinates of the center of gravity A of the surface on the XY plane are (0, 0), and the coordinates of the center of gravity B of the surface are (L, 0), measuring the amount of runout at a position Q1 where the X coordinate on the XY plane is x1 (where x1 satisfies the following formula (1)) and at a position Q2 where x2 (where x2 satisfies the following formula (2)) while rotating the cylindrical body; 0 <x1<L / 2 (1) L / 2 <x2<L (2) (B) The maximum values ​​of the deflection of the cylindrical body measured at the positions Q1 and Q2 are defined as y1 and y2 (where y1 and y2 are positive values), respectively; Obtaining a point P1(x1, y1) and a point P2(x2, y2) on the XY plane; (C) drawing a straight line L1 connecting the center of gravity A of the surface and point P1, and a straight line L2 connecting the center of gravity B of the surface and point P2 on the XY plane; (D) determining an intersection C1 between the straight lines L1 and L2 on the XY plane, moving the loading jig to the X coordinate of the intersection C1, and applying a load to the cylinder from that position in a direction that reduces the deflection of the cylinder, thereby correcting the bending of the cylinder; A cylindrical body straightening device comprising: [Explanation of symbols]

[0077] 1. Cylinder 2 Grip part 3-1 Rotation drive source 3-2 Rotation transmission mechanism 3-3 Link mechanism 4. Measuring equipment 4-1 Light projector 4-2 Light receiving section 5 Loading fixture 6 X-axis robot 7 Z-axis robot 8. Cylinder after straightening

Claims

1. A method for correcting a curved cylindrical body by applying a load to the peripheral surface of the cylindrical body using a loading jig, comprising: (α) the straight line connecting the center of gravity A of one end surface of the cylindrical body and the center of gravity B of the other end surface is defined as the X axis; When the X axis is set horizontally, the axis perpendicular to the X axis and in the direction of gravity is set as the Y axis, An XY plane is set between the X axis and the Y axis, The coordinates of the center of gravity A of the surface on the XY plane are (0, 0), and the coordinates of the center of gravity B of the surface are (L, 0), measuring the amount of runout at a position Q1 where the X coordinate in the XY plane is x1 (where x1 satisfies the following formula (1)) and at a position Q2 where x2 (where x2 satisfies the following formula (2)) while rotating the cylindrical body; 0<x1<L / 2 (1) L / 2<x2<L (2) (β) determining the maximum values ​​of the deflection of the cylindrical body measured at the positions Q1 and Q2 as y1 and y2 (where y1 and y2 are positive values), respectively, and obtaining points P1 (x1, y1) and P2 (x2, y2) on the XY plane; (γ) drawing a straight line L1 connecting the center of gravity A of the surface and the point P1, and a straight line L2 connecting the center of gravity B of the surface and the point P2 on the XY plane; (δ) determining an intersection C1 between the straight lines L1 and L2 on the XY plane, moving the loading jig to the X coordinate position of the intersection C1, and applying a load to the cylinder from that position in a direction that reduces the deflection of the cylinder, thereby correcting the bending of the cylinder; A method for straightening a cylindrical body, comprising:

2. The method for correcting a cylindrical body according to claim 1 , wherein the x1 satisfies the following formula (3), and the x2 satisfies the following formula (4): L / 10<x1<3L / 10 (3) 7L / 10<x2<9L / 10 (4)

3. The method for correcting a cylindrical body according to claim 1 or 2, wherein the x1 and the x2 satisfy the following formula (5): 0.8×x1≦(L-x2)≦1.2×x1 (5)

4. A straightening device for straightening a curved cylindrical body by applying a load to the peripheral surface of the cylindrical body using a loading jig, (A) The line connecting the center of gravity A of one end surface of the cylindrical body and the center of gravity B of the other end surface is defined as the X axis, When the X axis is set horizontally, the axis perpendicular to the X axis and in the direction of gravity is set as the Y axis, An XY plane is set between the X axis and the Y axis, The coordinates of the center of gravity A of the surface on the XY plane are (0, 0), and the coordinates of the center of gravity B of the surface are (L, 0), measuring the amount of runout at a position Q1 where the X coordinate in the XY plane is x1 (where x1 satisfies the following formula (1)) and at a position Q2 where x2 (where x2 satisfies the following formula (2)) while rotating the cylindrical body; 0<x1<L / 2 (1) L / 2<x2<L (2) (B) The maximum values ​​of the deflection of the cylindrical body measured at the positions Q1 and Q2 are y1 and y2 (where y1 and y2 are positive values), respectively. obtaining a point P1 (x1, y1) and a point P2 (x2, y2) in the XY plane; (C) drawing a straight line L1 connecting the center of gravity A of the surface and point P1, and a straight line L2 connecting the center of gravity B of the surface and point P2 on the XY plane; (D) determining an intersection C1 between the straight lines L1 and L2 on the XY plane, moving the loading jig to the X coordinate of the intersection C1, and applying a load to the cylinder from that position in a direction that reduces the deflection of the cylinder, thereby correcting the bending of the cylinder; A cylindrical body straightening device comprising:

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