JP5215946B2 - Roller hemming apparatus and roller hemming method - Google Patents

Description

  The present invention relates to a roller hemming device and a roller hemming method. More specifically, the present invention relates to a roller hemming apparatus and a roller hemming method for hemming a workpiece on which a flange is formed.

Conventionally, panels such as a door panel, a side panel, and a bonnet of an automobile are configured by integrating an outer outer panel and an inner inner panel.
The process of integrating the panels includes, for example, a marriage process in which an inner panel is superimposed on an outer panel having a flange formed upward, and a hemming process in which the flange of the outer panel is bent inward by a roller hemming device. It consists of.

This roller hemming device includes a main body, a roller rotatably supported by the main body, and a moving mechanism that is provided on the main body and moves the roller in the rotation axis direction (see Patent Document 1).
In this roller hemming device, the position of the roller in the rotational axis direction is adjusted in advance according to the characteristics of the outer panel. Then, by moving the roller hemming device along the edge of the outer panel, the flange of the outer panel is pressed by the roller and bent inward.

JP 2008-023587 A

  By the way, the outer panel used in the above hemming process may have some variation in material and flange length for each lot. In this case, since the deformation resistance of the flange is not constant, there is a problem that the spring back amount of the flange after the hemming process is not constant, and the angle of the flange after the hemming process varies.

  An object of the present invention is to provide a roller hemming device and a roller hemming method that can make the flange shape of a workpiece after hemming constant.

  A roller hemming device (for example, a roller hemming device 10 described later) of the present invention is a roller hemming device for hemming a workpiece (for example, an outer panel 20 described later) on which a flange (for example, a flange 22 described later) is formed. A cylindrical roller (for example, a later-described hemming roller 12) rotatably supported by a body (for example, a later-described body 11), and a first position for adjusting a position in a direction orthogonal to the rotation axis direction of the roller An adjustment mechanism (for example, a pressure mechanism 13 described later), a second position adjustment mechanism (for example, an extrusion mechanism 14 described later) for adjusting the position of the roller in the rotation axis direction, the first position adjustment mechanism, and the second position adjustment mechanism Control means (for example, a controller 50 described later) for controlling the position adjusting mechanism, and the control means controls the first position adjusting mechanism to The roller is brought into contact with a position separated from the bending point of the die by a predetermined distance, and a load acting in the axial direction of the roller is detected as a driving load (for example, torque described later). And calculating the difference with the master load, and controlling the second position adjusting mechanism according to the difference to adjust the position of the roller in the rotation axis direction.

  The roller hemming method of the present invention is a roller hemming method for hemming a workpiece on which a flange is formed. The roller hemming method includes a cylindrical roller rotatably supported by a main body, and a direction perpendicular to the rotation axis direction of the roller. Using a roller hemming device comprising a first position adjusting mechanism for adjusting the position and a second position adjusting mechanism for adjusting the position of the roller in the rotation axis direction, a load acting on the roller in the axial direction is driven. Detecting step for detecting the difference between the detected driving load and a predetermined master load, and controlling the second position adjusting mechanism according to the difference to determine the rotational axis direction of the roller. And a position adjusting step for adjusting the position of.

According to the present invention, the hemming process is performed as follows. That is, the roller hemming device is moved along the flange while the roller of the roller hemming device is in contact with the workpiece flange. Then, the flange is pressed by the roller and bent.
Here, the first position adjusting mechanism is controlled so that the corner of the tapered surface of the roller is brought into contact with a position away from the bending point of the flange by a predetermined distance.
Further, a load acting in the axial direction of the roller is detected as a drive load, and a difference between the detected drive load and a predetermined master load is calculated. Then, the second position adjusting mechanism is controlled according to this difference to adjust the position of the roller in the rotation axis direction.

The deformation resistance of the workpiece can be detected as a driving load acting in the axial direction of the roller. Therefore, as described above, by adjusting the position of the roller in the rotation axis direction according to the driving load by the second position adjusting mechanism, the pressing force against the roller flange can be changed according to the deformation resistance of the workpiece. it can. Therefore, even if there is some variation in workpiece material and flange length from lot to lot, the machining conditions for hemming can be changed as appropriate, and the flange shape of the workpiece after hemming can be made constant.
Further, since the distance between the pressing point of the roller from the bending point of the flange is adjusted by controlling the second position adjusting mechanism, it is possible to prevent the workpiece from buckling.

  In this case, when the driving load is larger than the master load, it is preferable that the roller is positioned in a direction in which the flange is greatly bent in the position adjusting step.

  According to this invention, when the driving load is larger than the master load, the roller is positioned in the direction in which the flange bends greatly. That is, when the deformation resistance of the workpiece is large, the pressing force on the roller flange is increased by adjusting the position of the roller in the rotation axis direction. Therefore, the flange shape of the workpiece after hemming can be reliably made constant.

According to the present invention, the pressing force on the roller flange can be changed according to the deformation resistance of the workpiece by adjusting the position of the roller in the rotation axis direction according to the driving load by the second position adjusting mechanism. . Therefore, even if there is some variation in workpiece material and flange length from lot to lot, the machining conditions for hemming can be changed as appropriate, and the flange shape of the workpiece after hemming can be made constant.
Further, since the distance between the pressing point of the roller from the bending point of the flange is adjusted by controlling the second position adjusting mechanism, it is possible to prevent the workpiece from buckling.

1 is an overall perspective view of a roller hemming system to which a roller hemming device according to an embodiment of the present invention is applied. It is an expansion perspective view of the processing table of the roller hemming system concerning the embodiment. It is a perspective view of the roller hemming device concerning the embodiment. It is a figure which shows the structure of the control means of the roller hemming apparatus which concerns on the said embodiment. It is a flowchart of the operation | movement which adjusts the position of the rotating shaft direction of the hemming roller of the roller hemming apparatus which concerns on the said embodiment. It is a figure which shows the operation | movement which contact | abuts the hemming roller of the roller hemming apparatus which concerns on the said embodiment to the flange of a workpiece | work. It is another figure which shows the operation | movement which contact | abuts the hemming roller of the roller hemming apparatus which concerns on the said embodiment to the flange of a workpiece | work. It is another figure which shows the operation | movement which contact | abuts the hemming roller of the roller hemming apparatus which concerns on the said embodiment to the flange of a workpiece | work.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an overall perspective view of a roller hemming system 1 to which a roller hemming device 10 according to an embodiment of the present invention is applied.

The roller hemming system 1 includes a processing table 30 on which an outer panel 20 as a workpiece is placed, a robot 40 installed in the vicinity of the processing table 30, and a controller 50 that controls the robot 40.
The outer panel 20 is formed by bending a single panel, and includes a flat plate-like base portion 21 and a flange 22 formed on the periphery of the base portion 21.

FIG. 2 is an enlarged perspective view of the processing table 30.
The processing table 30 includes a support base 31 provided on the floor surface, and a mold 32 supported by the support base 31.
The peripheral portion of the upper surface of the mold 32 is higher than the central portion, and thereby a step surface 321 is formed along the peripheral portion. The outer panel 20 described above is disposed such that the flange 22 abuts on the stepped surface 321.
A groove 322 is formed on the lower surface of the mold 32 along the peripheral edge. Therefore, the groove 322 is parallel to the extending direction of the flange 22 of the outer panel 20.

  The robot 40 includes a base 41 fixed to the floor surface, and a robot arm 42 that is provided on the base and adjusts the position and posture of the roller hemming device 10 in the three-dimensional space.

FIG. 3 is a perspective view of the roller hemming device 10.
The roller hemming device 10 is attached to the tip flange 42a of the robot arm 42. The roller hemming device 10 includes a main body 11, a hemming roller 12 as a cylindrical roller rotatably supported by the main body 11, and a position in a direction perpendicular to the rotation axis direction of the hemming roller 12 provided in the main body 11. A pressurizing mechanism 13 as a first position adjusting mechanism for adjusting the position, and an extruding mechanism 14 as a second position adjusting mechanism provided in the main body 11 for adjusting the position of the hemming roller 12 in the rotation axis direction.

  The main body 11 includes an outer box 15 in which a long hole 15a is formed, a hemming roller support 16 that protrudes from the hole 15a of the outer box 15 and rotatably supports the hemming roller 12, and the hemming roller support. The extrusion mechanism 14 that adjusts the position of the portion 16, the disk-shaped guide roller 17 provided opposite to the hemming roller 12, and a guide that protrudes from the hole 15 a of the outer box 15 and supports the guide roller 17 rotatably. A roller support 18.

  The guide roller support portion 18 includes a support portion main body 18a that rotatably supports the guide roller 17, and a support portion that has a rotation axis in a direction that protrudes from the hole portion 15a of the outer box 15 and is orthogonal to the rotation axis of the hemming roller 12. And an arm 18b that rotatably supports the main body 18a. Thereby, the rotation axis of the guide roller 17 is parallel to the rotation axis of the hemming roller 12 or is inclined with respect to the rotation axis of the hemming roller 12.

The front end surface 121 of the hemming roller 12 is chamfered to form two tapered surfaces as a first position adjusting mechanism (see FIG. 6). These two taper surfaces are formed on the first taper surface 122 formed on the distal end side of the hemming roller 12 and on the base end side of the first taper surface, and the inclination angle with respect to the rotation axis is larger than that of the first taper surface. A small second taper surface 123.
The rotating shaft of the hemming roller 12 extends in a direction projecting and retracting from the hole 15 a of the outer box 15.

  The push-out mechanism 14 includes a servo motor 141, a ball screw connected to the rotation shaft of the servo motor, a nut portion (not shown) fixed to the hemming roller support portion 16 and screwed to the ball screw, and the servo motor 141. A load detection sensor 142 that detects torque as an acting drive load and a position detection sensor 143 that detects the position of the hemming roller 12 in the axial direction are provided.

  The push-out mechanism 14 drives the servo motor 141 to rotate the ball screw, thereby moving the hemming roller support 16 in a direction that protrudes and retracts with respect to the outer box 15. That is, the hemming roller support portion 16 is moved along the rotation axis direction of the hemming roller 12.

The pressure mechanism 13 adjusts the distance between the hemming roller 12 and the guide roller 17 by moving at least one of the hemming roller support 16 and the guide roller support 18.
The guide roller 17 can be fitted in a groove 322 provided in the above-described mold 32 at the periphery.

FIG. 4 is a diagram illustrating a configuration of the controller 50.
The controller 50 includes a CPU (Central Processing Unit) that performs processing of each function, a table that stores data, a memory that stores a program that executes each function, and the like, and controls the robot arm 42 of the robot 40. The roller hemming device 10 is controlled.

  The controller 50 includes an arm control unit 51 that controls the robot arm 42 of the robot 40, a pressure control unit 52 that controls the pressure mechanism 13, and a command value of the position of the hemming roller 12 in the rotational axis direction as a position command value. A position command value data table 53 to be stored, an extrusion control unit 54 for controlling the servo motor 141 of the extrusion mechanism 14 based on the position command values stored in the position command value data table 53, and a torque reference value as a master load are stored. The master load data table 55, the difference load calculation unit 56 for calculating the difference between the torque detected by the load detection sensor 142 and the torque reference value stored in the master load data table 55, and the difference calculated by the difference load calculation unit 56 Is calculated by a position command value calculation unit 57 that calculates a position command value according to A new torque reference value is calculated according to the difference calculated by the position command value changing unit 58 for storing the position command value in the position command value data table 53 and the difference load calculating unit 56 and stored in the master load data table 55. A master load changing unit 59.

  The extrusion controller 54 reads the position command value stored in the position command value data table 53, and the position detection sensor 143 causes the hemming roller 12 to be positioned at a predetermined position corresponding to the read position command value. The current supplied to the servo motor 141 is controlled while monitoring the position of.

  The differential load calculation unit 56 reads the torque reference value stored in the master load data table 55 and subtracts the read torque reference value from the torque detected by the load detection sensor 142 to calculate the torque difference.

The position command value calculation unit 57 increases the position command value of the hemming roller 12 in the rotation axis direction when the difference calculated by the differential load calculation unit 56 is positive.
That is, when the torque detected by the load detection sensor 142 is larger than the torque reference value, it is determined that the deformation resistance of the outer panel 20 is high, the position command value is increased, and the position of the hemming roller 12 is further protruded from the outer box 15. .

  When the torque detected by the load detection sensor 142 is larger than the torque reference value, that is, when the difference calculated by the differential load calculation unit 56 is positive, the master load changing unit 59 newly sets the torque detected by the load detection sensor 142. The new torque reference value is stored in the master load data table 55.

FIG. 5 is a flowchart of an operation for adjusting the position of the hemming roller 12 in the rotation axis direction.
In step S1, the extrusion control unit 54 reads the position command value stored in the position command value data table 53, and the extrusion mechanism 14 is set so that the hemming roller 12 is positioned at a predetermined position corresponding to the read position command value. The current supplied to the provided servo motor 141 is controlled to move the hemming roller 12 toward a predetermined position in the rotation axis direction.

In step S2, the extrusion controller 54 determines whether or not the position of the hemming roller 12 detected by the position detection sensor 143 has reached a predetermined position.
If this determination is YES, the process proceeds to step S4, and if it is NO, the process proceeds to step S3.

In step S3, the extrusion controller 54 increases the current input to the servo motor 141 provided in the extrusion mechanism 14, and the process returns to step S1.
In step S4, since the hemming roller 12 has reached a predetermined position corresponding to the read position command value, the torque detected by the load detection sensor 142 by the differential load calculation unit 56 and the torque reference value stored in the master load data table 55 The difference is calculated.

  In step S5, the position command value calculator 57 determines whether or not the difference calculated by the differential load calculator 56 is positive. When this determination is YES, the process proceeds to step S6, and when it is NO, the process is terminated.

In step S6, since the difference calculated by the differential load calculation unit 56 is positive, it is determined that the deformation resistance of the outer panel 20 is high, and the position command value calculation unit 57 increases the position command value to change the position command value. The increased position command value is stored in the position command value data table 53 by the unit 58.
In step S7, the torque detected by the load detection sensor 142 is set as a new torque reference value by the master load changing unit 59, the new torque reference value is stored in the master load data table 55, and the process returns to step S1.

Next, the operation of the roller hemming system 1 will be described.
The roller hemming system 1 operates as follows.
In the initial state, the outer panel 20 is disposed on the mold 32 so that the flange 22 contacts the stepped surface 321. An inner panel (not shown) is disposed on the outer panel 20.

  First, the arm control unit 51 of the controller 50 controls the robot arm 42 of the robot 40 to bring the roller hemming device 10 closer to the processing table 30, and the guide roller 17 of the roller hemming device 10 is moved to the groove 322 on the lower surface of the mold 32. To fit.

Next, the pressurization control unit 52 of the controller 50 controls the pressurization mechanism 13 so that the distance between the hemming roller 12 and the guide roller 17 is approached, and the hemming roller 12 is placed on the peripheral portion of the upper surface of the mold 32. Deploy.
Next, the hemming roller 12 is protruded from the outer box 15 by the push-out mechanism 14, and the front end surface 121 of the hemming roller 12 is brought into contact with the flange 22 of the outer panel 20, as shown in FIG.

Next, the hemming roller 12 is further protruded from the outer box 15 by the extrusion mechanism 14, and as shown in FIG. 7, the corners of the front end surface 121 and the first taper surface 122 of the hemming roller 12 are set to the flange of the outer panel 20. The flange 22 is pressed against the flange 22. Contact position of the hemming roller 12 is made of bent point A of the flange 22 with a predetermined distance B ₁ apart position.

  Next, the roller hemming device 10 is moved along the flange 22 by moving the guide roller 17 along the groove 322. Then, the flange 22 is pressed and bent by the hemming roller 12.

During the period in which the roller hemming device 10 is moved along the flange 22, the controller 50 adjusts the position of the hemming roller 12 in the rotation axis direction.
Specifically, according to the above flowchart, it is determined whether the torque of the servo motor 141 is larger than a predetermined reference torque value. If the torque of the servo motor 141 is larger than the predetermined torque reference value, hemming is performed. The position of the roller 12 is further protruded from the outer box 15. In other words, the hemming roller 12 is further protruded from the outer box 15 by the pushing mechanism 14, and the corners of the first taper surface 122 and the second taper surface 123 of the hemming roller 12 are formed on the outer panel 20 as shown in FIG. The flange 22 is pressed against the flange 22.
As a result, the hemming roller 12 is positioned in a direction in which the flange 22 bends greatly. The distance between the contact position and the bending point A of the hemming roller 12 becomes shorter B ₂ than the predetermined distance B _1.

According to this embodiment, there are the following effects.
(1) The deformation resistance of the outer panel 20 can be detected as a load acting in the axial direction of the hemming roller 12. This deformation resistance is proportional to the torque of the servo motor 141. Therefore, by adjusting the position of the hemming roller 12 in the rotation axis direction according to the torque by the extrusion mechanism 14, the pressing force of the hemming roller 12 against the flange 22 can be changed according to the deformation resistance of the outer panel 20.
Therefore, even if there is some variation in the material of the outer panel 20 and the length of the flange 22 for each lot, the shape of the flange 22 of the outer panel 20 after the hemming can be made constant by appropriately changing the processing conditions of the hemming. .
Moreover, since the distance of the pressing point of the hemming roller 12 from the bending point A of the flange 22 is adjusted by controlling the extrusion mechanism 14, the buckling of the outer panel 20 can be prevented.

  (2) When the torque detected by the load detection sensor 142 is larger than the torque reference value, the hemming roller 12 is positioned in a direction in which the flange 22 bends greatly. That is, when the deformation resistance of the outer panel 20 is large, the position of the hemming roller 12 in the rotation axis direction is adjusted to increase the pressing force against the flange 22 of the hemming roller 12. Therefore, the shape of the flange 22 of the outer panel 20 after the hemming process can be made constant.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements and the like within a scope that can achieve the object of the present invention are included in the present invention.

  For example, in the present embodiment, the step surface 321 is provided on the mold 32 in order to determine the contact position of the hemming roller 12 with respect to the flange 22, but this is not restrictive. For example, the position of the hemming roller 12 with respect to the flange 22 may be determined by controlling the position of the hemming roller 12 with respect to the direction perpendicular to the rotation axis or by providing a step on the front end surface 121 of the hemming roller 12. Good.

  Further, in this embodiment, when the difference calculated by the differential load calculation unit 56 is positive, the position command value calculation unit 57 always increases the position command value in proportion to the magnitude of the difference. However, it is not limited to this. For example, even if the difference is positive, if the magnitude of the difference exceeds a predetermined range, it is determined that continuation of the hemming process is impossible, an error is notified, and the roller hemming device 10 is driven. The hemming process may be stopped after stopping.

10 Roller hemming device 11 Main body 12 Hemming roller (roller)
13 Pressurization mechanism (first position adjustment mechanism)
14 Extrusion mechanism (second position adjustment mechanism)
20 Outer panel (work)
22 Flange 50 Controller (Control means)

Claims (5)

A roller hemming device for hemming a workpiece on which a flange is formed,
A cylindrical roller rotatably supported by the main body, a first position adjusting mechanism for adjusting the position of the roller in the direction orthogonal to the rotation axis direction, and a second position for adjusting the position of the roller in the rotation axis direction An adjustment mechanism, and a control means for controlling the first position adjustment mechanism and the second position adjustment mechanism,
The control means includes
Controlling the first position adjustment mechanism to bring the roller into contact with a position separated from the bending point of the flange by a predetermined distance;
Wherein the load acting in the axial direction of the roller is detected as the driving load, and calculates a difference between the detected driving load and a predetermined master load, by controlling the second position adjusting mechanism in accordance with the difference, the A roller hemming device characterized by causing a roller to go straight in the direction of a rotation axis . The roller hemming device according to claim 1,
The roller has a distal end surface, a first tapered surface formed on the distal end side, a second tapered surface formed on the proximal end side with respect to the first tapered surface, and having a smaller angle of inclination with respect to the rotation axis than the first tapered surface. A tapered surface;
The control means includes
Controlling the first position adjustment mechanism to bring a corner of the tip surface of the roller and the first taper surface into contact with a position separated from the bending point of the flange by a predetermined distance;
A load acting in the axial direction of the roller is detected as a driving load, a difference between the detected driving load and a predetermined master load is calculated, and when the driving load is larger than the master load, the difference is determined according to the difference. The roller is controlled by controlling a second position adjusting mechanism so that the corners of the first taper surface and the second taper surface of the roller come into contact with a position closer to the predetermined distance from the bending point of the flange. A roller hemming device characterized in that the roller travels straight in the direction of the rotation axis. A roller hemming method for hemming a workpiece on which a flange is formed,
A cylindrical roller rotatably supported by the main body, a first position adjusting mechanism for adjusting the position of the roller in the direction orthogonal to the rotation axis direction, and a second position for adjusting the position of the roller in the rotation axis direction Using a roller hemming device comprising an adjustment mechanism,
A detection step of detecting a load acting in the axial direction of the roller as a driving load;
A difference calculating step for calculating a difference between the detected drive load and a predetermined master load;
And a position adjusting step of controlling the second position adjusting mechanism in accordance with the difference to move the roller straight in the direction of the rotation axis . The roller hemming method according to claim 3 ,
If the drive load is greater than the master load,
In the position adjustment step, the roller hemming method is characterized in that the roller is positioned in a direction in which the flange is largely bent. The roller hemming method according to claim 4 ,
The roller has a distal end surface, a first tapered surface formed on the distal end side, a second tapered surface formed on the proximal end side with respect to the first tapered surface, and having a smaller angle of inclination with respect to the rotation axis than the first tapered surface. A tapered surface;
In the detecting step, the first position adjusting mechanism is controlled so that corners of the tip surface of the roller and the first tapered surface are brought into contact with each other at a predetermined distance from a bending point of the flange. , Detecting a load acting in the axial direction of the roller as a driving load,
In the position adjusting step, a corner portion between the first taper surface and the second taper surface of the roller is brought into contact with a position closer to the predetermined distance from a bending point of the flange. .

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