JP2006255788A - Clinch type hemming device using servo motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clinch type hemming device capable of bearing the bending moment on a screw shaft as much as possible while a servo motor is operated to operate a link unit. <P>SOLUTION: In the hemming device capable of folding an outer circumferential edge flange of an external panel by fixing a hemming link unit with driving means mounted thereon to a lower die, and operating each driving means, each driving means comprises a servo motor 4, an electric controller, a ball screw 6, a screw housing 13, a base plate 9, and a drive link 11 to operate the hemming link unit 100. An LM-guide 8 is mounted on the base plate 9, and a guide block 12 is fixed to one side face of a screw nut 7. Thus, the screw nut 7 is guided along the LM-guide 6. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a clinch type hemming device for sequentially operating a preliminary hemming tool and a main hemming tool with a single servo motor.

  The hemming operation means that the outer peripheral edge of the inner panel is surrounded by the outer peripheral edge of the outer panel in order to connect the inner panel and the outer panel, such as a car door, a tailgate, a trunk lid, and a hood. In addition, it refers to the work of bending and joining the outer peripheral edge of the outer panel. Such a hemming operation includes a configuration in which a workpiece is placed on a fixed lower mold, and a hemming tool device appropriately disposed along the periphery of the lower mold is operated while raising and lowering the upper mold. Things are common. Such a hemming device is generally referred to as a press-type hemming device.

  Patent Document 1 discloses a clinch-type hemming device in which a pre-hemming tool and a main hemming tool are simultaneously driven by one main driving unit. In this case, preliminary hemming and main hemming work are sequentially performed by the operation of the hydraulic cylinder. It is also disclosed that a screw and a servo motor can be applied as an alternative to the hydraulic cylinder.

  Further, in Patent Document 2, in order to solve the conventional problem of performing a hemming operation on a workpiece placed on a fixed lower die by lowering the upper die, It is constructed so that it can be raised and lowered by a plurality of hydraulic cylinders on the main base, and this hydraulic cylinder performs preliminary hemming with the lower mold while rotating a certain section around the support shaft. The gist is disclosed.

  Such a press-type hemming device must be equipped with a large press to move the upper die up and down, and it is required to secure sufficient production equipment space. Has raised the problem of being uneconomical.

  In response to such demands, clinch-type hemming devices that do not require a large press are applied to production sites where press-type hemming devices are not appropriate. The clinch type hemming device is commonly called a table top method, and does not include an upper die and a press equipment for raising and lowering the upper die, and each drive source (ie, hydraulic cylinder). ) Is fixed to the lower mold, and the respective driving sources are operated to bend the outer peripheral flange of the outer panel. FIGS. 1a to 1c are operation conceptual diagrams for explaining a hemming operation process by a general clinch type hemming apparatus.

  However, such a clinch type hemming device adopts a hydraulic cylinder as a driving means, and thus causes various problems. That is, as shown in FIG. 2, two or three hemming link units are often fastened to one tool (or also referred to as a blade) in order to maintain an appropriate pressure required for the hemming operation. Of course, each hemming link unit must have a hydraulic cylinder. However, when the workpiece to be hemmed is not flat but has an inclined surface (as a typical example, the trunk lid of a passenger vehicle), the workpiece processing position (height and distance) from the center of rotation of the hemming tool is Since it is not constant, even if the hemming tool operates as a whole, the angular speed of the hemming tool changes at each machining position at the moment when hemming is started, so precise hemming cannot be performed and wrinkles occur at the bent part. Or many problems occur, such as a change in bending position. Each hydraulic cylinder is equipped with a flow control valve, and the flow control valve of each hydraulic cylinder is controlled according to the hemming position (height and distance) of the workpiece to adjust the left and right operating speeds of the hemming tool. However, since the perfect synchronization cannot be achieved and the hemming tool operates in a state where it receives an eccentric load, the durability is significantly reduced.

  In addition, the installation space of the hydraulic pump for hydraulic supply, the hydraulic supply line for hydraulic oil supply of the hydraulic cylinder not only inconvenience the operator's activities, but also due to the hydraulic pump operating noise and hydraulic impact force Many inconveniences occur, such as noise caused by hard noise and contamination of the working environment due to oil leakage.

Of course, as described above, Patent Document 1 has already disclosed a technique of operating a hemming link unit by using a screw and a servo motor instead of a hydraulic cylinder. However, as another problem that has been raised in the conventional hydraulic driving system or servo motor driving type hemming device, the rod (Rod) or screw (Screw) for operating the link unit is broken. It is recognized as a serious problem. The reason for this is that, as shown in FIG. 3, when the pressure is applied at the end of the stroke, the frictional force is maximized at the hinge point of the cylinder, and the cylinder body can freely rotate in the direction of loading of the cylinder rod (or screw shaft). Therefore, a large force momentarily acts on the end of the rod (or screw shaft) in the vertical direction of the shaft, and a bending moment acts on the rod (screw shaft). is there.
US Pat. No. 5,457,981 Korean Registered Utility Model No. 20-0344041

  The present invention has been made to solve the above-described problems, and adopts a conventional clinch type hemming that uses a hydraulic cylinder as a driving source by adopting a servo motor and a screw as a driving source of the hemming link mechanism. The object is to solve the problems of the device.

  In particular, an object of the present invention is to provide a clinch type hemming device having a structure capable of maximally overcoming a bending moment applied to a screw shaft when a servo motor is operated to operate a link unit.

  In order to achieve such an object, the hemming device according to the present invention has a linear guide for minimizing a bending moment that is applied to the screw shaft and guiding an accurate linear motion while the servo motor is operated. It is installed on the base plate. More specifically, the present invention relates to a hemming system in which a hemming link unit equipped with each driving means is fixed to a lower mold, and each driving means is operated to bend the outer peripheral flange of the outer panel. In the apparatus, the drive means includes a servo motor 4; an electrical controller that controls a rotation speed and a rotation amount of the servo motor; and is connected to a rotation shaft of the servo motor, and converts the rotational force of the motor into a transfer motion. A ball screw 6; a screw housing 13 that supports both ends of the ball screw; a base plate 9 that fixes the screw housing 13 and is connected to a bracket 10 by a hinge P1; and a hinge connection to a screw nut 7 of the ball screw Operated hemming link unit 100 LM-guide 8 is attached to the base plate 9 in the same direction as the ball screw 6, and a guide block 12 is fixed to one side surface of the screw nut 7. A clinch type hemming device using a servo motor, wherein the screw nut 7 is guided along a guide 6.

  As described above, the hemming device of the present invention using a servo motor can control the hemming link unit by the rotation speed and rotation amount of the motor by an electrical signal, not by controlling the hydraulic pressure. The invention has the advantage that hemming quality can be improved easily because not only the perfect synchronization of the equipment can be achieved and the durability of the equipment can be increased, but also the pressure can be adjusted freely. is there.

  Another advantage is not only the improvement of the working environment (cleanliness and noise) caused by the use of hydraulic pressure, but also the supply of electricity only during operation, saving energy compared to the hydraulic type in which continuous operation without load is inevitable. There are great advantages that can be made.

  Hereinafter, preferred embodiments of a hemming device according to the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIGS. 4a and 4b, the hemming device according to the present invention is connected to an electric controller for controlling the rotation speed and rotation amount of the servo motor 4 and a rotation shaft of the servo motor, and transfers the rotation force of the motor. The LM-guide 8 is provided on a base plate 9 which is composed of a ball screw 6 to be converted into motion and a drive link 11 which is hinged to the screw nut 7 of the ball screw and operates the hemming link unit 100. A guide block 12 is attached to one side of the screw nut 7 so that the screw nut 7 is guided along the LM-guide.

  Screw housings 13 are provided at both ends of the ball screw, and the screw housings are fixed to the base plate 9. The base plate is coupled to the lower mold bracket 10 and the hinge P1, and is installed so as to freely rotate with respect to the hinge point when the servo motor is operated.

  The LM-guide 8 must be located on the opposite side of the screw nut 7 to which the drive link 11 is coupled in order to prevent interference when the screw nut 7 is moved. A gear box 5 is provided between the servo motor 4 and the ball screw 6 to amplify the rotational force of the servo motor, thereby obtaining a large force necessary for the hemming operation.

  The operation process of the present invention configured as described above will be briefly described as follows.

  Depending on the machining position (height and distance) of the workpiece to be hemmed, the operation start time and speed of each servo motor of the hemming link unit are set in advance and input to the controller.

  If the servo motor is rotated by the controller, the rotational force of the motor generates a large rotational torque through the gear box and transmits the rotational force to the ball screw. The rotation of the ball screw causes the screw nut to follow the ball screw and the LM-guide. Start a linear motion upward.

  The drive link is rotated around the hinge point by linear movement of the screw nut, and after this, the main hemming tool and the spare hemming tool enter by the amount of rotation of the drive link of the hemming link unit and perform the preliminary hemming work. The main hemming tool that has moved backward and rotated downward pressurizes the workpiece to complete the hemming operation. Since the operation trajectory of the preliminary hemming tool and the operation trajectory of the main hemming tool are not related to the core content of the present invention, detailed description thereof will be omitted.

  Of course, the hemming device using the servo motor according to the present invention can obtain various approach angles by changing the position and shape of the spare parallel link, as in the conventional hydraulic hemming device.

  As mentioned above, the hemming device using the servo motor according to the present invention has been described based on the specific shape and structure based on the attached drawings, but the present invention can be variously modified and changed by those skilled in the art. Variations and modifications should be construed as belonging to the protection scope of the present invention.

  The present invention can be applied to a clinch type hemming device for sequentially operating a preliminary hemming tool and a main hemming tool with one servo motor.

It is a conceptual diagram of the conventional common clinch type hemming apparatus. It is a conceptual diagram of the conventional common clinch type hemming apparatus. It is a conceptual diagram of the conventional common clinch type hemming apparatus. It is a perspective view for demonstrating the concept of a general clinch type hemming apparatus. It is a conceptual diagram explaining generation | occurrence | production of the bending moment in the conventional clinch type hemming device of a hydraulic cylinder drive system. It is a schematic block diagram of the hemming device by this invention. It is a schematic block diagram of the hemming device by this invention.

Explanation of symbols

1 Workpiece 2 Preliminary hemming tool 3 Main hemming tool 4 Servo motor 5 Gear box 6 Ball screw 7 Screw nut 8 LM-guide 9 Base plate 10 Bracket 11 Drive link 12 Guide block 13 Screw housing 100 Hemming link unit

Claims (1)

In the hemming device of the type which bends the outer peripheral flange of the outer panel by fixing the hemming link unit equipped with each driving means to the lower mold and operating each driving means.
The drive means includes: a servo motor 4; an electric controller that controls the rotation speed and amount of rotation of the servo motor; and a ball screw 6 that is connected to a rotation shaft of the servo motor and converts the rotation force of the motor into a transfer motion. A screw housing 13 that supports both ends of the ball screw; a base plate 9 that fixes the screw housing 13 and is coupled to the bracket 10 by a hinge P1; and a hemming that is hinged to the screw nut 7 of the ball screw. A drive link 11 for operating the link unit 100;
An LM-guide 8 is attached to the base plate 9 in the same direction as the ball screw 6,
A servo motor is used, wherein a guide block 12 is fixed to one side of the screw nut 7 so that the screw nut 7 is guided along the LM-guide 6. Clinch type hemming device.

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