JP4596767B2 - Method of preventing workpiece collision with workpiece holding device - Google Patents

Description

    The present invention relates to a workpiece holding device that holds a workpiece at the time of welding by automatic welding or manual welding with a welding robot or an automatic welding device, and in particular, a three-axis lift that can freely change the posture of the workpiece in three axis directions. It relates to the expression positioner.

In recent years, as a work holding device that can efficiently perform welding work with a welding robot or the like, a lifting surface plate is supported by the device main body so that it can be moved up and down, and the tilting surface plate can be swung in a vertical plane with respect to the lifting surface plate. The arm is extended horizontally from this tilting face plate, the work support is rotatably arranged at the tip of this arm, and the work position of the welded work placed and fixed on the work support can be freely changed A three-axis lift positioner that can do this is provided.
Japanese Patent Laid-Open No. 2003-117682

  However, in such a three-axis lift type positioner, the work placed and fixed on the upper surface of the work support base is moved up and down in the vertical direction, rotated and tilted around the horizontal axis, or rotated around the center axis of the work support base. The work posture is changed to facilitate welding work with automatic welding equipment such as a welding robot, but the work placed and fixed on the work support base will protrude greatly from the work support base. There is. If the posture changing operation of the workpiece is performed in such a case, the workpiece interferes (collises) with the tilting face plate, the leg portion, or the floor surface of the workpiece holding device. When the workpiece collides with the part of the workpiece holding device or the floor surface in this way, the workpiece is not only damaged, but it is also conceivable that the workpiece holding device itself is damaged or a broken piece of the member hits the operator. .

  For this reason, conventionally, an operator visually checks the safety and operates a pendant inching switch or the like to rotate, tilt, or lift the work support base. There is a problem that is large.

  The present invention has been made paying attention to such points, and provides a method of preventing a workpiece placed thereon from interfering with surrounding objects when a workpiece support base is operated with a simple configuration. The purpose is to do.

In order to achieve the above-described object, the present invention provides an external dimension of a work placed and fixed on a work support base, and an amount of eccentricity from the center of rotation of the work support base in the front, rear, left, and right sides of the work placed Is input to the control unit, and when the workpiece holding device is activated based on the input numerical value and the workpiece rotates, tilts, or moves up and down, it collides with the tilting face plate, leg, or floor surface of the workpiece holding device. This calculated value indicates whether the workpiece interferes with the tilting face plate, legs, or floor surface from the amount of movement and eccentricity of each axis when the posture change value is calculated in advance by the control device and the workpiece holding device is actually operated. Based on the control device, when the movement amount of each axis accompanying the movement of the workpiece approaches the calculated value, a signal is issued from the control device , and the workpiece support device is completely stopped based on the signal It is characterized by.

In the present invention configured as described above, the external dimensions of the work placed on the work support base and the eccentric amount from the center of rotation of the work support base on the front, back, left, right, and top surfaces of the work are input, Based on the input numerical value, when the work holding device is operated, the posture change value until it collides with the tilting face plate, leg part or floor surface of the work holding device is calculated in advance by the control device, and the work holding device is actually operated. At this time, the control unit determines whether the workpiece interferes with the tilting face plate, legs, or floor surface from the amount of movement and eccentricity of each axis, and the amount of movement of each axis that accompanies the movement of the workpiece. Since the control device emits a signal when the value approaches the calculated value and the operation of the work holding device is completely stopped, the work does not collide with surrounding objects during operation, and the operator Work burden is reduced.

FIG. 1 shows an embodiment of an apparatus for carrying out the present invention, and FIG. 1 is a schematic side view of a three-axis lifting positioner that supports a workpiece for welding.
In this three-axis positioner, a device body (3) is composed of a leg portion (1) arranged along the floor surface and a column portion (2) erected from the leg portion (1). The lifting / lowering arm (4) is arranged along the column part (2) so as to be movable up and down, and a work support (5) is rotatably mounted on the tip of the lifting / lowering arm (4).

  Inside the column part (2) of the apparatus main body (3), an elevating drive mechanism for the elevating arm (4) using a ball screw mechanism is arranged. The elevating drive mechanism includes an electric motor (5) and a speed reducer. It is rotationally driven by the raising / lowering drive source comprised by (6).

  The lifting plate (7) is moved up and down along the rising side surface of the column portion (2) by the operation of the lifting drive mechanism. The elevating arm (4) is fixed to a tilting surface plate (8) that is mounted on the elevating surface plate (7) so as to be rotatable about a horizontal axis. The rotation driving motor (9) of the tilting face plate (8) is provided on the side surface of the column (2), and the rotation driving motor (10) of the work support (5) is provided in the lifting arm (4). It is arranged.

  The raising / lowering drive motor (5), the tilting face plate drive motor (9), and the work support base drive motor (10) are each configured to be rotationally controlled by the control device (11). Reference numeral (W) in the drawing denotes a work (workpiece to be welded) placed and fixed on the work support base (5).

In the three-axis elevating positioner having the above-described configuration, when the work (W) is placed and fixed on the work support base (5), the operator tilts the work support base (5) with the external dimensions of the work. In addition, the amount of eccentricity from the center of rotation is input to the control device (11). Based on the input numerical value, the control device (11) holds the workpiece when the workpiece holding device is operated and the workpiece is rotated / tilted / lifted to change the workpiece (W) to an appropriate working posture. The posture change value until the workpiece (W) collides with the tilting face plate (8), the leg (1) or the floor surface of the apparatus is calculated by the control device.

  Based on this calculated value, when the operator operates the pendant type inching switch (12) to operate the work support (5) to change the posture of the work (W), The control device (11) determines whether or not the workpiece (W) interferes with the tilting face plate, the leg portion or the floor surface of the workpiece holding device from the movement amount of the workpiece and the eccentric amount. The control device (11) emits a signal and immediately stops the main body of the device immediately before it interferes with the holding device portion and the floor surface.

In the above-described operation, the operation when the workpiece is placed on the workpiece holding device has been described. However, when the workpiece interferes with a portion of the workpiece holding device or the floor surface during welding work, , And the entire apparatus can be stopped .

In this way, the external dimensions of the work (W) placed on the work support (5) and the amount of eccentricity from the operation center at the time of installation are input to the control device, and the posture change value until the collision is calculated in advance. If the apparatus is stopped by issuing a signal when the actual movement amount on each axis approaches the calculated value, work safety including the operator is effectively ensured.

  The method of preventing a workpiece collision with a three-axis positioner according to the present invention is used for a workpiece holding device that holds a workpiece during automatic welding with a welding robot or an automatic welding device or during manual welding, or a workpiece holding device with a machine tool. be able to.

It is a schematic side view of the triaxial positioner which shows one Embodiment of the apparatus to which this invention is applied.

  DESCRIPTION OF SYMBOLS 1 ... Leg part, 2 ... Column part, 3 ... Apparatus main body, 4 ... Elevating arm, 5 ... Work support stand, 7 ... Elevating face plate, 8 ... Tilt face plate, 11 ... Control apparatus, W ... Workpiece.

Claims (1)

The elevating face plate (7) is supported by the column portion (2) of the apparatus body (3) so as to be able to move up and down, and the tilting face plate (8) is positioned so as to be capable of pivoting with respect to the elevating face plate (7). 8) In a workpiece holding device in which a lifting arm (4) is extended from the arm (4) and a workpiece support (5) is rotatably arranged at the tip of the arm (4).
External dimensions of the work (W) placed and fixed on the work support (5) and the amount of eccentricity from the center of rotation of the work support (5) in the front, rear, left, and right sides of the work (W) Is input to the control device (11), and when the workpiece holding device is operated based on the input numerical value and the workpiece (W) is rotated, tilted or lifted, the tilting face plate (8) and legs of the workpiece holding device are The posture change value until it collides with the part (1) or the floor surface is calculated in advance by the control device (11), and when the work holding device is actually operated by manual operation, the workpiece ( The controller (11) determines whether or not W) interferes with the tilting face plate (8), the leg (1), or the floor surface, based on this calculation value, and each axis as the workpiece (W) moves. It issues a signal from the control device when the amount of movement approaches the calculated value (11), workpiece holding instrumentation which constitutes the workpiece holding device so as to totally stopped based on the signal Work collision prevention method in.

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