JP6405961B2 - Roll hemming method and roll hemming apparatus - Google Patents

Description

  The present invention relates to a roll hemming method and a roll hemming apparatus that are frequently used for edge bending of a panel end, and in particular, a roll suitable for performing edge bending on an arched end such as a wheel arch of an automobile. The present invention relates to a hemming processing method and a roll hemming processing apparatus.

  A machining head described in Patent Document 1 has been proposed as a machining head for the purpose of hemming a body panel of an automobile. The hemming processing head described in Patent Document 1 is based on the premise that the processing head itself is connected to and supported by a robot arm, and a plurality of pairs of rollers each consisting of a combination of a pressing roller and a counter roller. And each roller pair cooperates to bend the hemming flange at a specific angle along the bend line. Then, a plurality of sets of roller pairs are selectively used selectively, for example, in four stages, and the hemming flange portion is gradually bent so that the panel to be processed is hemmed.

JP 2005-501740 gazette

  However, in the hemming head described in Patent Document 1, in any roller pair, the relative positional relationship between the pressing roller and the opposing roller is consistently unchanged from the beginning to the end of bending of the hemming flange portion. The bending load (bending pressure) exerted on the hemming flange portion cannot be changed during the processing. For this reason, for example, at the end corresponding to the bending start position and the bending end position, a sudden change in bending load is inevitably caused, and the outer surface of the base panel, such as distortion or unevenness, becomes defective. Is likely to occur.

  In addition, as described above, the relative positional relationship between the pressing roller and the opposing roller is consistently unchanged from the beginning of bending to the end of bending of the hemming flange, which means that the hemming flange is always bent with a constant bending load. In addition, the bending state according to the shape and shape of the hemming flange portion of the panel to be processed cannot be ensured, and it is difficult to ensure the outer surface quality according to the panel shape.

  For example, in the wheel arch part of the rear fender part in the body side panel of an automobile, the hemming flange part, which is the hemming part, becomes the shape of a so-called stretched flange part. In order to ensure surface quality, at the terminal portion corresponding to the bending start position and bending end position of the wheel arch, the bending degree of hemming is gradually changed, or preliminary bending (pre-hemming) and main bending ( It is considered effective to change the roller movement trajectory in this hemming). Nevertheless, the conventional technique represented by Patent Document 1 cannot meet such a demand, and still leaves room for improvement.

  The present invention has been made paying attention to such problems, and in the processing by the pre-bending roller and the main bending roller individually supported by the processing head, the bending timing and position of each roller can be changed. The present invention provides a roll hemming processing method and a roll hemming processing apparatus that enable quality adjustment according to defects in the outer surface quality.

  The roll hemming processing method of the present invention uses a processing head in which each of the edge bending roller and the backup roller is individually supported by the same support, and keeps the relative distance between the edge bending roller and the backup roller on the die. A roll hemming method for edge bending of a positioned panel, wherein the die is formed such that the width dimension sandwiched between the edge bending roller and the backup roller is a constant width dimension in the processing progress direction. In addition, a gradually changing portion in which the constant width dimension is the maximum width dimension and the width dimension gradually changes is formed in a part of the processing progress direction.

  Then, the edge of the panel positioned on the die is sandwiched between the preliminary bending roller as the edge bending roller supported by the processing head and the backup roller together with the die, and the processing head is moved along the die. Between the main bending roller as the edge bending roller supported by the processing head and the backup roller, and the preliminary bending portion of the panel on the die. And a main bending step of subjecting the end of the panel to main bending by moving the processing head along the die.

  Then, the edge bending is performed in a state where the rotation center position of the pre-bending roller with respect to the support and the rotation center position of the main bending roller with respect to the support are offset from each other in the processing progress direction. It is said.

  Therefore, according to the present invention, when the machining head passes at least a position corresponding to the gradual change portion of the die, the amount of offset between the rotation center positions of the preliminary bending roller and the main bending roller is used for preliminary bending. The movement trajectory slightly changes between the pre-bending roller and the main bending roller for the main bending.

  According to the present invention, along with the change of the movement trajectory between the pre-bending roller and the main bending roller, the bending timing and the position can be changed between the pre-bending roller and the main bending roller, and according to the outer surface quality defect. Therefore, the flexibility for adjusting the quality is increased, which can contribute to the improvement of the outer surface quality at the hemming site.

The perspective view which shows the frame | skeleton structure of the vehicle body of a motor vehicle. It is a figure which shows an example of the process site | part by the roll hemming processing apparatus which concerns on this invention, and is an expanded sectional view along the aa line of FIG. Process explanatory drawing which shows the coupling | bonding procedure in the hemming coupling | bond part shown in FIG. Plane explanatory drawing which shows schematic structure of the roll hemming processing apparatus which concerns on this invention. It is a figure which shows the hemming processing head at the time of pre-hemming roller mounting | wearing, and is a cross-sectional schematic explanatory drawing along the bb line of FIG. It is a figure which shows the hemming process head at the time of hemming roller mounting | wearing, and is a cross-sectional schematic explanatory drawing along the bb line of FIG. (A) is explanatory drawing which shows the detail of the prehemming roller of FIG. 5, (B) is explanatory drawing which shows the detail of the hemming roller of FIG. Explanatory drawing of the hemming die shown in FIG. FIG. 7 is an enlarged explanatory view showing a locus during processing of the pre-hemming roller and the hemming roller shown in FIGS. (A), (B) is explanatory drawing which shows the modification of the prehemming roller shown to (A) of FIG. The perspective view which shows the detail which actualized further the hemming processing head shown in FIG. The perspective view which shows another example of a hemming process head as the 2nd Embodiment of this invention. FIG. 13 is a front view of the hemming head shown in FIG. 12. FIG. 13 is a plan view of the hemming head shown in FIG. 12. Explanatory drawing which shows the conventional process form corresponding to FIG.

  1 to 10 are views showing a more specific first embodiment for carrying out the roll hemming processing apparatus according to the present invention. In particular, FIG. 1 shows a skeleton structure of an automobile body, and FIG. 2 shows a wheel of FIG. The expanded sectional view along the aa line of the arch part 2 is shown. FIG. 3 shows a joining procedure at the hemming joint, FIG. 3A shows a pre-hemming machining mode as a pre-bending, and FIG. 3B shows a hemming machining mode as a main bending. Respectively. FIG. 4 shows a schematic plan view of an apparatus for performing roll hemming at the wheel arch portion 2.

  As shown in FIG. 1, in the rear fender portion of the body side panel 1 that forms the vehicle body of the automobile, a wheel arch portion 2 is formed outside the wheel house portion that receives the wheels (tires). As shown in FIG. 2, the wheel arch portion 2 is formed by superimposing the arch portions of the body side outer panel 1a and the wheel house outer panel 3, and then the hemming flange of the terminal of the arch portion on the body side outer panel 1a side. The portion 4 is folded back to the wheel house outer panel 3 side and hemmed and joined, and both are substantially clinched.

  In this case, as shown in FIG. 3A, hemming processing as edge bending with respect to the hemming flange portion 4 is performed by using the hemming flange portion 4 formed upright in advance at the end of the arch portion on the body side outer panel 1a side. For example, pre-bending (pre-hemming) as an edge bend that is bent to about 45 ° by the pre-bending roller R1, and the hemming flange portion 4 after the pre-bending as shown in FIG. The process is divided into two steps of main bending (main hemming) as edge bending to be folded back to the house outer panel 3 until polymerization is performed. At that time, the hemming flange portion 4 is in the form of an elongated flange portion that receives a tensile force in the longitudinal direction during both the preliminary bending and the main bending.

  In addition, the hemming process in the wheel arch part 2 is performed in the state of the body side panel 1 alone before the body side panel 1 is combined with the floor main. Further, depending on the specifications of the vehicle body, hemming flange portions that overlap each other are formed at the ends of the arch portions of both the body side outer panel 1a and the wheel house outer panel 3, and both the hemming flange portions are folded back together. Sometimes.

  In the roll hemming processing apparatus, as shown in FIG. 4, a hemming die 6 corresponding to a lower mold is fixedly arranged on a horizontal pedestal 5, and this hemming die 6 has a curvature of the wheel arch portion 2 shown in FIG. It is formed as the thing of the circular arc shape curved so that it may correspond. As shown in FIGS. 5 and 6, which will be described later, the hemming die 6 has a substantially angled cross section composed of an upper wall portion 6a and a vertical wall portion 6b. The hemming die 6 is shown in FIG. 2 on the upper wall portion 6a. The portion corresponding to the wheel arch portion of the body side outer panel 1a and the wheel house outer panel 3 is positioned and placed with the body side outer panel 1a facing down. In addition, both the panels 1a and 3 are pressed against the hemming die 6 by a pad or a clamper corresponding to an upper mold (not shown) and restrained by pressure, and thereby positioned on the hemming die 6.

  As shown in FIG. 4, a hemming head 7 is provided in the vicinity of the hemming die 6. As will be described later, this hemming processing head 7 is directly in charge of roll hemming in cooperation with the hemming die 6, that is, the edge bending processing of both the preliminary bending and the main bending, and is a long arm. The arm 8 is slidably supported at the tip of the member 8 and is slidably supported by a slider 9 as a moving body. Further, a ball screw 11 is constituted by a nut member (not shown) provided on the slider 9 and a screw shaft 10 screwed to the nut member. The screw shaft 10 is rotatably supported by a support bracket 12 erected from the base 5. Has been supported.

  Further, for example, a rotation shaft of a motor 13 is connected to one end of the screw shaft 10 as a rotation drive source. Thus, if the screw shaft 10 is driven forward or reverse, the slider 9 slides in the axial direction of the screw shaft 10 accordingly. Therefore, the ball screw 11 composed of the screw shaft 10 and a nut member (not shown) screwed to the screw shaft 10 forms a feed imparting means using the motor 13 as a rotational drive source.

  Here, as the motor 13, in addition to an electric motor, a hydraulic motor or a pneumatic motor can be used, and an impact wrench or a nut runner can be used instead of the motor 13. Further, when roll hemming is performed manually by an operator, a handle for manual operation is fitted to the end of the screw shaft 10, and the screw shaft 10 is rotated by a rotation operation by the handle. It is also possible.

  In order to explain the feed drive system having the ball screw 11 as a main element in more detail, if the hemming die 6 has the same curvature as the curvature of the wheel arch part 2 (see FIG. 1) to be processed, A screw shaft 10 is arranged substantially in parallel with an arc string of a predetermined curvature drawn by the hemming die 6. A nut member screwed to the screw shaft 10 is provided on the slider 9, and a long arm member 8 orthogonal to the screw shaft 10 in a plan view is slidable on the slider 9, that is, the hemming die 6. The bearing is supported so as to be movable forward and backward. In the example of FIG. 4, the arm member 8 is oriented in the normal direction at the longitudinal center of the hemming die 6.

  As shown in FIG. 5, a hemming head 7 is supported at the tip of the arm member 8 via a ball joint 14 so as to be swingable. Here, FIG. 5 is a schematic sectional view taken along the line bb of FIG. 4 as a structure of the hemming head 7 to which the pre-hemming roller 18 for pre-bending is mounted, and FIG. 6 is the hemming of FIG. The same schematic cross-sectional explanatory views when the processing head 7 is replaced with a hemming roller 23 for main bending are shown.

  As shown in FIGS. 5 and 6, the hemming head 7 includes a main body portion 16 as a support body including a guide yoke portion 17 having a substantially deformed channel shape, a holder portion 15 fixedly supported by the main body portion 16, a holder For example, a pre-hemming roller 18 as a pre-bending roller which is also an edge bending roller or a hemming roller 23 as a main bending roller which is also an edge bending roller is rotatably mounted on the portion 15. The prismatic adapter 19 or 24 is used as a main element. And, as will be described later, when the hemming flange portion 4 is preliminarily bent, a prehemming roller 18 is attached to the holder portion 15 shown in FIG. The hemming roller 23 is attached to the holder portion 15 shown in FIG. The details of the pre-hemming roller 18 and the hemming roller 23 will be described later.

  One end of the main body portion 16 in the hemming head 7 serves as a joint portion with the arm member 8 via the ball joint 14 described above, and a substantially deformed channel-shaped guide yoke portion 17 is provided in the vertical direction of the hemming die 6. This is received in a form straddling the wall 6b, and the vertical wall 6b of the hemming die 6 is held from three directions.

  As described above, the pre-hemming roller 18 (FIG. 5) or the hemming roller 23 (FIG. 6) is supported on the holder portion 15 via the prismatic adapter 19 or 24 as an edge bending roller. ing. The pre-hemming roller 18 is rotatably supported by the adapter 19, and the hemming roller 23 is rotatably supported by the adapter 24. Further, a backup roller 20 is rotatably supported at a position of the guide yoke portion 17 facing the pre-hemming roller 18 or the hemming roller 23 in the vertical direction across the vertical wall portion 6b of the hemming die 6. As shown in FIG. 8, the backup roller 20 is disposed as a pair of front and rear in the longitudinal direction of the hemming die 6 (the moving direction of the hemming head 7), and the lower end surface of the vertical wall portion 6 b in the hemming die 6. Will roll as a guide surface. The pre-hemming roller 18, the hemming roller 23, and the backup roller 20 are set so that their rotation centers are parallel to each other.

  Then, the hemming portion of the panel 1a is sandwiched between the pre-hemming roller 18 or hemming roller 23 as the edge bending roller and the backup roller 20 together with the hemming die 6, so that the roll hemming processing (edge bending) is performed to the pre. Since the pre-bending (pre-hemming) by the ming roller 18 or the main bending (main hem) by the hemming roller 23 is performed, the relative distance between the pre-hemming roller 18 or the hemming roller 23 and the backup roller 20, That is, the distance between the rotation centers of the pre-hemming roller 18 or the hemming roller 23 and the backup roller 20 is set in advance according to the bending degree (preliminary bending degree or main bending degree) of the hemming portion at the completion of the processing. 5 and 6, the panel 3 of FIG. 2 is not shown.

  The pre-hemming roller 18 shown in FIG. 5 has a truncated cone shape for pre-bending (pre-heming) as shown in detail in FIG. 5 is rotatably supported by a small-diameter shaft portion 19a offset by a predetermined amount Of and is detachably supported by the holder portion 15 of FIG. 5 using the adapter 19 as a support portion. Then, the offset amount Of is the moving direction of the hemming head 7 in FIG. 5 (the processing progress direction and the direction perpendicular to the paper surface of FIG. 5), and the smaller-diameter shaft portion 19 a is moved by the hemming head 7 than the adapter 19. The adapter 19 is supported by the holder portion 15 so as to be on the rear side in the direction.

  On the other hand, as shown in detail in FIG. 7B, the hemming roller 23 shown in FIG. 6 has a simple circular cylindrical shape for the main bending (main hemming), and the prismatic adapter 24 is formed. 6 is rotatably supported by a small-diameter shaft portion 24a located on the same axis line, and is detachably supported by the holder portion 15 of FIG. 6 using the adapter 24 as a support portion.

  Although the pre-hemming roller 18 and the hemming roller 23 are not attached to the holder portion 15 at the same time, the holder portion 15 and the backup roller 20 that are used in common during the preliminary bending and the main bending are used as a reference. Then, as shown in FIG. 9 to be described later, the hemming roller 23 at the time of the final bending is positioned at the front side in the moving direction of the hemming head 7 by the offset amount Of than the pre-hemming roller 18 at the time of preliminary bending. Will be set to.

  In addition, a plurality of guide rollers 21 and 22 serving as guide members that sandwich the vertical wall portion 6b of the hemming die 6 from both sides in the thickness direction (both sides in the rotation center direction of the backup roller 20) are rotatable on the guide yoke portion 17. Is provided. Here, a pair of front and rear guide rollers 21 are disposed along the longitudinal direction of the hemming die 6 on the back side of the vertical wall portion 6b, and a pair of guide rollers 22 vertically paired on the front side of the vertical wall portion 6b are hemming dies. 6 are arranged at two places in the front-rear direction along the longitudinal direction. Thus, the hemming head 7 that supports the pre-hemming roller 18 or the hemming roller 23 is restrained in the vertical direction by the backup roller 20 with respect to the hemming die 6, and a plurality of guide rollers 21. , 22 restrains the position in the left-right direction in FIGS. Instead of the guide rollers 21 and 22 as the guide members, other rolling elements such as needles and balls, or fixed sliding members having a small friction coefficient may be used.

  Thus, since the backup roller 20 and the plurality of guide rollers 21 and 22 on the hemming head 7 side substantially hold the vertical wall portion 6b of the hemming die 6, the screw shaft of the ball screw 11 in FIG. If a linear feed is applied along the axial direction of the shaft 10, for example, a straight feed is applied from the left end portion to the right end portion of the screw shaft 10 in FIG. 4, the hemming head 7 autonomously swings and swings. However, the hemming die 6 moves in the longitudinal direction following the curvature of the hemming die 6. As the hemming head 7 moves, the pre-hemming roller 18 or the hemming roller 23 rolls along the hemming flange portion 4 on the panel 1a side, and cooperates with the hemming die 6 to move to the panel 1a side. The hemming flange 4 is subjected to preliminary bending or main bending as edge bending.

  Here, FIG. 8 shows a development view near one end of the hemming die 6. The hemming die 6 occupies most of the longitudinal direction by the general portion L1 having a constant width dimension of the vertical wall portion 6b, but the width dimension of the vertical wall portion 6b is equal to that of the general portion L1 on the terminal side of the general portion L1. It is between the narrow part L3 smaller than the width dimension, the general part L1 and the narrow part L3, and the width dimension of the vertical wall part 6b gradually increases from the narrow part L3 side toward the general part L1 side. A gradually changing portion L2 that converges with a width dimension on the portion L1 side is provided. That is, in the gradual change part L2, the lower end surface of the vertical wall part 6b used as the guide surface for the backup roller 20 is formed as the inclined surface 6c which becomes a downward slope from the narrow part L3 side toward the general part L1 side. ing. Note that the symbol Q indicates the locus of the center position of the hemming roller 23, for example.

  Such a structure is the same for the other end side opposite to the one end of the hemming die 6, and this structure is because the hemming portion includes a so-called outer plate surface of the vehicle body, as will be described later. In addition, it is employed to prevent the occurrence of secondary defects such as distortion and unevenness on the outer surface of the panel due to hemming.

  Therefore, according to the present embodiment, as described above, for example, if linear feed is applied from the left end portion of the screw shaft 10 of FIG. 4 toward the right end portion side, the hemming processing head 7 is autonomous. The head moves in the longitudinal direction of the hemming die 6 while following the curvature of the hemming die 6 while swinging.

  For example, in the case of the hemming head 7 to which the hemming roller 23 is attached as shown in FIG. 6, the hemming roller 23 rolls along the hemming flange portion 4 on the panel 1a side as the hemming head 7 moves. In cooperation with the hemming die 6, the main bending (main hemming) is performed on the hemming flange portion 4 on the panel 1 a side. Since the hemming head 7 moves in accordance with the curvature of the hemming die 6, it is sufficient to apply a thrust force that can move the hemming head 7 as a linear feed by the ball screw 11. As the linear feed by the ball screw 11, a very small feed force is sufficient.

  In this case, as shown in FIG. 8, the relative distance between the hemming roller 23 and the pair of backup rollers 20 is constant, whereas the hemming die 6 has an end portion on the front side of the general portion L1. A narrow portion L3 having a small width dimension of the vertical wall portion 6b and a gradually changing portion L2 in which the width dimension of the vertical wall portion 6b gradually changes from the narrow portion L3 side toward the general portion L1 side are provided. .

  Therefore, even when the hemming die 6 is sandwiched between the hemming roller 23 and the backup roller 20 together with the panel 1a, the hemming roller 23 is narrow even if the hemming head 7 moves in the longitudinal direction of the hemming die 6. Until the passage through the portion L3, the hemming roller 23 slightly contacts the edge of the hemming flange portion 4 on the panel 1a side. This is because until the hemming roller 23 finishes passing through the narrow portion L3, the hemming roller 23 does not exert sufficient pressure (bending load) on the hemming flange portion 4, and the main bending (main hemming) is performed. It means not applied.

  Thereafter, when the hemming roller 23 reaches the gradual change portion L2 as the hemming head 7 further moves, the lower end surface of the gradual change portion L2 becomes the inclined surface 6c. The hemming die 6 is gradually pulled down. Therefore, the pressure applied by the hemming roller 23 to the hemming flange 4 on the panel 1a side gradually increases, and the main bending (main hemming) is performed in such a manner that the bending degree gradually changes while the hemming flange 4 is incomplete. Start to be. That is, the gradually changing portion 4 a is also formed in the hemming flange portion 4.

  Further, when the hemming head 7 reaches the general portion L1 of the hemming die 6, the width dimension of the vertical wall portion 6b becomes constant in the general portion L1, so that the hemming flange portion 4 on the panel 1a side is set in advance. The main bending (main hemming) is performed evenly in the longitudinal direction under a certain degree of bending. Such a state is the same on the other end side of the hemming die 6, and in the wheel arch portion 2 of the panel 1a subjected to the main bending (main hemming), a narrow portion is provided at both ends in the longitudinal direction. The pre-hemming unprocessed portion corresponding to L3 and the gradually changing portion 4a which is an incomplete pre-hemming processed portion corresponding to the gradually changing portion L2 remain attached.

  When the entire wheel arch part 2 subjected to the main bending (main hemming) is viewed, the unprocessed part of the hemming corresponding to the narrow part L3 as described above and the unprocessed part between the processing start end and the general part L1. Since the gradual change portion 4a, which is a complete hemming portion, is interposed, a sudden change in pressing force for the main bending (main hemming) between the processing start end and the general portion L11 is mitigated. Alternatively, it is possible to prevent the occurrence of secondary problems such as distortion and unevenness on the outer surface of the panel 1a.

  In the wheel arch portion 2, the presence of the unprocessed hemming portion and the gradual change portion 4a as described above is functionally allowed, and a gap between the panels 1a and 3 provided thereby is input to the painting process of the vehicle body. In the sealing process up to, for example, it is filled with a sealant or the like.

  Further, as shown in FIGS. 5 and 8, the pre-hemming is performed by using the hemming head 7 equipped with the pre-hemming roller 18 of FIG. 5 instead of the hemming roller 23 of FIG. The only difference is whether the outer peripheral surface of each of the rollers 18 and 23 is a cylindrical surface or a conical surface, and the behavior during processing shown in FIG. 8 is basically the same. Then, preliminary bending (pre-hemming) is first performed using the hemming head 7 of FIG. 5 to which the pre-hemming roller 18 is mounted. When the preliminary bending is completed, the pre-hemming roller 18 is moved from the hemming head 7. While the adapter 19 is removed together, a hemming roller 23 supported by the adapter 24 is newly attached, and the main bending (main hemming) is performed using the hemming processing head 7 of FIG. Will be applied.

  However, as shown in FIG. 7A, the pre-hemming roller 18 has an offset amount Of on the rear side in the processing progress direction as compared with the hemming roller 23 in FIG. If 20 is used as a reference, the pre-hemming roller 18 is processed with a delay by an offset amount Of compared to the hemming roller 23.

  As described above, although the preliminary bending (pre-hemming) by the pre-hemming roller 18 and the main bending (main hemming) by the hemming roller 23 are not performed simultaneously, FIG. The relationship between the pre-hemming roller 18 and the hemming roller 23 is shown in FIG. As can be seen from the figure, since the pre-hemming roller 18 has an offset amount Of on the rear side in the processing progress direction with respect to the hemming roller 23, the pre-hemming roller 18 and the hemming roller 23 have a pair of front and rear backups. The relative distance to the roller 20 will change.

  However, FIG. 9 shows a case where the distance of the gradually changing portion L2 of the hemming die 6 is smaller than the distance W between the contacts of the pair of backup rollers 20 with respect to the hemming die 6 as an example. The comparative example in the largest diameter part with the hemming roller 23 is shown.

  In FIG. 9, the trajectory of the outer peripheral surface of the pre-hemming roller 18 when the pre-hemming roller 18 passes through the gradual change portion L2 of the hemming die 6 and the front and back thereof is denoted by reference numeral M1. A trajectory of the outer peripheral surface of the hemming roller 23 when 23 passes through the gradual change portion L2 of the hemming die 6 and the front and rear thereof is indicated by a symbol M2. As is apparent from the figure, in the pre-hemming roller 18 and the hemming roller 23, the gradually changing portion L2 of the hemming die 6 and the trajectory when passing through the front and rear thereof slightly change. This means that the bending force load position exerted on the hemming flange portion 4 and the bending timing are slightly different between the pre-hemming roller 18 and the hemming roller 23. Therefore, due to a synergistic effect with the setting of the gradual change portion L2 in the hemming die 6, it is accompanied by preliminary bending (pre-hemming) and main bending (main hemming) between the processing start end and the general portion L11. An abrupt change in bending load (pressing force) is alleviated or avoided, and secondary defects such as distortion and unevenness on the outer surface of the panel 1a can be further prevented.

  Here, the magnitude of the offset amount Of of the pre-hemming roller 18 shown in FIGS. 7 and 9 is appropriately set through experiments or trial production in advance. Further, regarding the pre-hemming roller 18, as shown in FIGS. 10A and 10B, in the front-rear direction (arrow a1 direction) and the vertical direction (arrow a2 direction), the shim plate 25a or 25b is used. It is more desirable to finely adjust the position appropriately in order to prevent the occurrence of secondary defects such as distortion and unevenness on the outer surface of the panel 1a. The same applies to the hemming roller 23.

  FIG. 11 shows a detailed view of the hemming head 7 of FIG. 5 in more detail, and the same parts as those in FIG. In the hemming head 7 shown in FIG. 11, a holder portion 15 whose side surface is opened is fixed to a horizontal base portion 16 a in the main body portion 16, and a pre-hemming roller 18 is attached to the holder portion 15. A supported prismatic adapter 19 is detachably mounted. Further, when the pudding hemming roller 18 is viewed from the center of rotation, the guide rollers 21 and 22 are positioned on the front and rear sides of the pudding hemming roller 18, respectively.

  The span, which is the distance between the pair of front and rear guide rollers 21 and 21, is set to the same size as the span of the other front and rear guide rollers 22 and 22, and the pair of backup rollers. The span between 20 and 20 is set slightly smaller than the span between the guide rollers 21 and 21 or between the guide rollers 22 and 22. Furthermore, the shimming plate 25a or 25b described above with reference to FIG. 10 is also used in the hemming head 7 of FIG.

  12 to 14 show another example of the hemming head 7 as the second embodiment of the roll hemming apparatus according to the present invention. However, the same code | symbol is attached | subjected to the part which is common in FIG. 11 demonstrated previously.

  In the hemming head 7 shown in FIGS. 12 to 14, as apparent from comparison with FIG. 11, the pair of front and rear backup rollers 20, 20 are brought close to each other, and the distance (span) between the backup rollers 20, 20 is made. The guide roller 31 that is positioned on the back side of the vertical wall 6b (see FIGS. 5 and 6) of the hemming die 6 is made single, and the hemming die 6 Only a pair of upper and lower guide rollers 32 are positioned on the front side of the vertical wall 6b. Then, as shown in FIG. 13, when the hemming head 7 is viewed from the front, that is, when the pre-hemming roller 18 is viewed from the direction of the rotation center, the vertical axis C perpendicular to the rotation center of the pre-hemming roller 18 Thus, the guide rollers 31 and 32 are aligned.

  In this way, the span between the pair of backup rollers 20 and 20 is minimized, and the guide rollers 31 and 32 are aligned on the vertical axis C in FIG. 13, as shown in FIG. When the hemming head 7 is moved to follow the curvature of the hemming die 6 that is curved in a straight line, the followability is improved, but conversely, the degree of freedom of swinging of the hemming head 7 is too large. As a result, the posture of the hemming head 7 may become unstable.

  Therefore, in the hemming head 7 shown in FIGS. 12 to 14, a part of the guide yoke portion 17 of the main body portion 16 is projected toward the guide roller 31 as shown in FIG. A guide surface 30 is formed, and when the hemming head 7 moves following the hemming die 6, the guide surface 30 is brought into sliding contact with the vertical wall portion 6 b of the hemming die 6.

  Therefore, according to the second embodiment, as described above, the span between the pair of backup rollers 20, 20 is minimized, and the guide rollers 31, 32 are arranged on the vertical axis C in FIG. Even when the flat guide surface 30 is used together, the degree of freedom of swinging of the hemming head 7 is not increased so that the posture of the hemming head 7 does not become unstable. When the hemming head 7 moves following the hemming die 6, the posture of the hemming head 7 is stabilized. As a result, the same effect as the hemming head 7 in the first embodiment is obtained.

  The hemming head 7 shown in FIGS. 11 and 12 to 14 does not have the offset amount Of as shown in FIG. 7A between the adapter 19 and the pre-hemming roller 18. In this case, in the relationship between the hemming roller 23 to be used in place of the pre-hemming roller 18 shown in FIG. If the offset amount Of is opposite to the offset amount Of in FIG. 5A, the intended purpose can be achieved as in the first embodiment.

  Here, for reference, let us compare the conventional general roll hemming method with the roll hemming method in the present embodiment. In the conventional general roll hemming method, for example, as disclosed in JP-A-6-344037 and JP-A-2000-246351, the pressurizing force necessary for hemming, that is, the hemming roller and the backup roller approach each other. Since a constant pressing force in the direction is obtained by an actuator such as a pneumatic cylinder or a hydraulic cylinder, the pressing force required for hemming cannot be actively variably controlled.

  Therefore, for example, as shown in FIG. 15, particularly at the start end of hemming, a large pressure is applied suddenly by the hemming roller 28 using the actuator as a pressure source in the region R without passing through the gradual change section as described above. Therefore, quality defects such as unevenness and distortion may occur on the outer surface of the panel, which is the base material. This tendency is particularly noticeable in the wheel arch portion in which the panel itself is pre-formed into a predetermined three-dimensional shape and the hemming flange portion becomes an elongated flange portion. On the other hand, in the present embodiment, as described above, it is possible to reliably prevent such secondary problems and to achieve the intended purpose without using an actuator such as a pneumatic cylinder or a hydraulic cylinder. Can be achieved.

  In the above embodiment, an example in which the pre-hemming roller 18 and the hemming roller 23 are replaced each time on the assumption that the common hemming processing head 7 is used has been described. May be adopted. In this case, the hemming head 7 to which the pre-hemming roller 18 is attached and the hemming head 7 to which the hemming roller 23 is attached are prepared separately, and both of these hemming heads 7 are selectively used selectively. It will be.

  Furthermore, if it is assumed that the gradually changing portion L2 and the narrow portion L3 having different inclination directions shown in FIG. 8 are used in combination, depending on the modeling of the panel to be processed, these gradually changing portions L2 and The narrow portion L3 can be set not at the end portion of the hemming die 6 but at the central portion in the longitudinal direction as necessary.

  Furthermore, the roll hemming processing apparatus according to the above-described embodiment can cope with edge bending other than the wheel arch part 2 as well as the part having the curvature and also the edge bending of the straight part as necessary. It is possible to respond.

DESCRIPTION OF SYMBOLS 1 ... Body side panel 1a ... Body side outer panel 2 ... Wheel arch part 6 ... Hemming die 6a ... Inclined surface 7 ... Hemming processing head 8 ... Arm member 9 ... Slider (moving body)
10 ... Screw shaft 11 ... Ball screw (feeding means)
13. Motor (rotation drive means)
15 ... Holder part 16 ... Main part (support)
18: Pre-hemming roller (preliminary bending roller) as an edge bending roller
DESCRIPTION OF SYMBOLS 19 ... Adapter 20 ... Backup roller 21 ... Guide roller (guide member)
22 ... Guide roller (guide member)
23. Hemming roller as a bending roller (main bending roller)
24 ... Adapter 30 ... Guide surface (sliding guide part)
31 ... Guide roller (guide member)
32 ... Guide roller (guide member)
L1 ... General part L2 ... Gradual change part Of ... Offset amount

Claims (13)

Using a processing head in which each of the edge bending roller and the backup roller is individually supported by the same support, the edge of the panel positioned on the die is fixed while keeping the relative distance between the edge bending roller and the backup roller constant. A roll hemming method for bending,
The die is formed so that the width dimension sandwiched between the edge bending roller and the backup roller is a constant width dimension in the processing progress direction, and the constant width dimension is set to a maximum width dimension in a part of the processing progress direction. As the gradual change portion whose width dimension gradually changes is formed,
The edge of the panel positioned on the die is sandwiched between the pre-bending roller as the edge bending roller supported by the processing head and the backup roller, and the processing head is moved along the die. A pre-bending step of pre-bending the end of the panel by allowing
By sandwiching the preliminary bending part of the panel on the die together with the die between the main bending roller as the edge bending roller supported by the processing head and the backup roller, and moving the processing head along the die. A main bending process in which the end of the panel is subjected to a main bending;
Including
Roll hemming characterized in that edge bending is performed in a state in which the rotation center position of the pre-bending roller with respect to the support and the rotation center position of the main bending roller with respect to the support are offset from each other in the processing progress direction. Processing method.   By moving the machining head so as to follow the gradual change part of the die, a prebending gradual change part is formed in a part of the prebend part and a main bending gradual change part is formed in a part of the main bend part. The roll hemming method according to claim 1, wherein the roll hemming method is provided.   The main bending is performed by the main bending roller in a state in which the rotation center position of the main bending roller with respect to the support is offset to the front side in the processing progress direction with respect to the rotation center position of the preliminary bending roller with respect to the support. The roll hemming processing method according to claim 2. The panel is positioned on one surface of the die, and the backup roller rolls on the backup roller guide surface opposite to the one surface.
4. The roll hemming method according to claim 3, wherein the back-up roller guide surface is inclined at the gradual change portion.   5. The roll hemming method according to claim 4, wherein pre-bending and main bending are respectively performed as edge bending to become an extended flange portion on the arch-shaped end portion of the panel positioned on the die.   6. The roll hemming method according to claim 5, wherein the arched end portion of the panel is a wheel arch portion of a side panel of an automobile. In the roll hemming processing apparatus used for the roll hemming processing method according to claim 5 or 6,
The backup roller has a rotation center parallel to the rotation center of the pre-bending roller or the main bending roller, which is an edge bending roller, and a pair of backup rollers are arranged in parallel in the processing advancing direction on the processing head. A roll hemming processing device. In the roll hemming processing apparatus according to claim 7,
The roll hemming processing apparatus according to claim 1, wherein the processing head includes a guide member that sandwiches the die from both sides in the rotation center direction of the backup roller. In the roll hemming processing apparatus according to claim 8,
The guide member is a guide roller,
A roll hemming apparatus characterized in that a guide roller is provided on each side of the die on both sides of a pre-bending roller or a main bending roller which is an edge bending roller. In the roll hemming processing apparatus according to claim 8,
The guide members are guide rollers provided on both sides of the die,
Roll hemming processing, characterized in that, when the pre-bending roller or the main bending roller as the edge bending roller is viewed from the rotation center direction, each guide roller is provided on an axis perpendicular to the rotation center. apparatus. In the roll hemming processing device according to claim 10,
A roll hemming processing apparatus, wherein a sliding guide portion slidable with a die is disposed in the processing head in the proximity of the guide roller in the processing progress direction. In the roll hemming processing device according to any one of claims 7 to 11,
The processing head is supported by the arm member so as to be swingable,
By applying a linear feed to the arm member in a direction parallel to the chord at the arched edge bending portion, the machining head moves in accordance with the curvature of the die while swinging and swinging, thereby performing preliminary bending and main bending. A roll hemming processing device characterized in that each is provided. In the roll hemming processing apparatus according to claim 12,
A moving body that guides and supports the arm member so as to be slidable in a direction orthogonal to the linear feed direction;
Feed applying means for applying the linear feed to the moving body;
With
A roll hemming processing device, wherein the processing head swings and swings in parallel with the advance and retreat movement of the arm member by applying the linear feed to the moving body.

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