JP2013123760A - Positional shift detection device of cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positional shift detection device of a cable capable of easily recognizing the positional shift of the cable.SOLUTION: The positional shift detection device 1 of the cable for detecting the positional shift of a cable D laid on an arm robot RB includes a bracket 3 fixed to the arm A1 of the arm robot RB to hold the cable D, and a mechanical sensor 4 for detecting the axial positional shift of the cable D with respect to the bracket 3.

Description

  The present invention relates to a cable misalignment detection device that detects a misalignment of a cable disposed in an arm robot.

  Conventionally, an arm robot has been used in various scenes of a manufacturing process such as a painting process, a welding process, and a conveyance process. For example, a welding robot described in Patent Document 1 includes a plurality of arms, an indirect portion that connects the arms, a welding torch attached to the tip of the arm, and a longitudinal direction of the arm from the welding torch. And an arranged cable. The cable is a flow path for supplying electricity, welding wire, coolant, shield gas, and the like to the welding torch.

  Since the arm of the welding robot performs complicated movements such as rotation, twisting, turning, and tilting, there is a possibility that “cable entrainment” occurs in which the cable is entrained in the arm. Cable entrainment may cause disconnection of the cable, breakage of each connector, etc., and may require a long time to recover. Therefore, conventionally, the cable is prevented from being caught by installing a bracket for holding the cable and minimizing the movement of the cable with respect to the arm.

JP 2011-67893 A

  However, even if the cable is held by the bracket, the cable may be displaced axially with respect to the bracket due to cable sag due to aging, dropping of the bracket, or interference with other robots. There was a problem that occurred. In order to prevent the cable from being caught, the cable is inspected. However, depending on the number of welding robots and the number of brackets, there is a problem that the inspection work becomes complicated. In addition, even if a cable position shift occurs while the welding robot is operating, it is difficult to grasp it.

  The present invention was created to solve such problems, and an object of the present invention is to provide a cable misalignment detection device that can easily grasp the misalignment of the cable.

  In order to solve the above-mentioned problems, the present invention provides a cable misalignment detecting device for detecting a misalignment of a cable disposed in an arm robot, the bracket being fixed to the arm of the arm robot and holding the cable And a mechanical sensor that detects a positional deviation of the cable in the axial direction with respect to the bracket, and a notification unit that notifies a detection result of the mechanical sensor.

  According to this configuration, since the mechanical sensor is provided on the bracket, it is possible to easily grasp the positional deviation of the cable in the axial direction. Thereby, generation | occurrence | production of a cable can be prevented. In addition, since the positional deviation of the cable can be reliably grasped, the cable inspection work can be reduced. Further, according to the configuration of the present invention, it is possible to grasp the deviation of the cable during the operation of the arm robot.

  Further, a step portion is formed on the outer periphery of the cable, and the mechanical sensor includes a step portion or a contact portion that contacts the cable, and the mechanical sensor is moved by the movement of the step portion. It is preferable that the displacement of the cable in the axial direction is detected when the contact portion is displaced. The arm robot is preferably a welding robot.

  When a proximity current sensor is used as a sensor when a large current is flowing through a cable such as a welding robot, a strong magnetic field is generated around the cable and the sensor may malfunction. However, according to the configuration of the present invention, a mechanical sensor including the stepped portion or the contact portion that contacts the cable is used, and the stepped portion is provided on the outer periphery of the cable, thereby mechanically shifting the position of the cable. Can be detected. Thereby, it is possible to avoid malfunction when a large current flows through a cable such as a welding robot.

  Moreover, when the said cable is comprised by the some line, it is preferable that the said level | step-difference part is a binding band which bundles the said some line. According to this configuration, the cable tie can be used as a stepped portion, and the number of parts can be reduced.

  According to the cable misalignment detection device of the present invention, it is possible to easily grasp the cable misalignment.

It is the side view which showed the whole arm robot which concerns on this embodiment, and the position shift detection apparatus of a cable. It is a perspective view which shows the position shift detection apparatus of the cable which concerns on this embodiment. (A) is a principal part expansion perspective view which shows the position shift detection apparatus of a cable, (b) is sectional drawing of (a). It is a sectional side view which shows the effect | action which concerns on this embodiment, Comprising: (a) is normal, (b) shows the time of abnormality. It is a sectional side view which shows the effect | action which concerns on a modification, Comprising: (a) is normal time, (b) shows the time of abnormality.

  Embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the cable misalignment detection device 1 is a device that is attached to the arm A1 of the arm robot RB. The arm robot RB is a welding robot in this embodiment, but may be a robot for other purposes such as a painting robot or a transfer robot. First, the configuration of the arm robot RB will be described.

  As shown in FIG. 1, the arm robot RB includes a plurality of arms A1, A2, A3, a plurality of indirect portions B connecting adjacent arms A1 to A3, and a welding torch portion attached to the tip of the arm A3. C and cable D. The cable D is a plurality of lines (flow paths) such as a welding wire line that supplies a welding wire to the welding torch part C, an electric line that supplies electricity, a cooling line that supplies coolant, and a gas line that supplies shielding gas. It is configured.

  The plurality of lines are integrated by winding with a vinyl tape over the longitudinal direction. In each figure, the cable D is schematically drawn in a cylindrical shape. As shown in FIG. 1, a plurality of binding bands E are attached to the outer periphery of the cable D at intervals. By providing the binding band E, a plurality of lines are more reliably integrated.

  As shown in FIG. 3A, the cable tie E is formed so as to protrude outward from the outer peripheral surface of the cable D. Thereby, a step is generated between the outer peripheral surface of the binding band E and the outer peripheral surface of the cable D. The binding band E uses a resin band member in the present embodiment, but may be made of other materials as long as a plurality of lines can be bundled. The binding band E is a member corresponding to the “step portion” in the claims. In the present embodiment, the cable D is configured by a plurality of lines, but may be configured by a single line.

  Next, the cable misalignment detection apparatus 1 will be described in detail. As shown in FIG. 2, the cable misalignment detection device 1 according to the present embodiment mainly includes a movable connecting jig 2, a bracket 3, and a mechanical sensor 4.

  The movable connecting jig 2 includes a fixed portion 2a, a guide hole 2b, and a movable portion 2c. The movable connection jig 2 is a member that can permit the movement of the cable D around the arm A1 while holding the cable D. The fixing part 2a is a part fixed to the arm A1. The fixing part 2a is fixed via a bolt. The guide hole 2b is formed in the lower part of the fixed part 2a. The guide hole 2b is a hole that penetrates in an arc shape in plan view along the outer periphery of the arm A1. The movable part 2c is configured to slide smoothly in the guide hole 2b. A bracket 3 is fixed to the side surface of the movable portion 2c.

  As shown in FIG. 2, the bracket 3 includes a pair of fixing portions 3a, a pair of side plate portions 3b erected on the respective fixing portions 3a, and a top plate portion 3c that connects the side plate portions 3b. ing. The fixed portion 3a is fixed to the movable portion 2c of the movable connecting jig 2 with a bolt. The cable D is surrounded by the side surface of the movable portion 2c, the side plate portions 3b and 3b, and the top plate portion 3c. The bracket 3 is a member that holds the cable D so as not to separate from the arm A1 and prevents the cable D from shifting in the axial direction with respect to the bracket 3.

  As shown in FIG. 3B, the mechanical sensor 4 is a sensor provided with a contact portion 4a. The mechanical sensor 4 is attached to the top plate portion 3 c of the bracket 3 so as to penetrate therethrough. The mechanical sensor 4 is electrically connected to a notifying unit (not shown). The contact portion 4a is biased in a direction away from the top plate portion 3c. The tip of the contact portion 4a is a spherical surface.

  The mechanical sensor 4 is configured so that, when normal (when the position of the cable D is not shifted), the contact portion 4a abuts against the outer surface of the binding band E, so that an ON signal is transmitted to the notification portion. Yes. On the other hand, when an abnormality occurs (when the position of the cable D is shifted), an OFF signal is transmitted to the notification unit when the contact portion 4a comes into contact with the outer surface of the cable D. The notification unit is configured to notify, for example, visually or audibly that the position of the cable D has shifted when receiving the OFF signal. The mechanical sensor means a device that detects an object to be detected by contact.

  Next, the function and effect of the cable misalignment detection device 1 according to this embodiment will be described. As shown in FIG. 4A, the contact portion 4a of the mechanical sensor 4 is in contact with the outer surface of the binding band E at the normal time.

  As shown in FIG. 4B, when the cable D is displaced in the axial direction against the holding force of the bracket 3, the binding band E is separated from the contact portion 4a, and the contact portion 4a is displaced downward. . As a result, an OFF signal is transmitted from the mechanical sensor 4 to the notification unit to notify that the position of the cable D has shifted. The operator can correct the slack of the cable D by stopping the arm robot RB and returning the cable D to the original position.

  That is, according to the above-described cable misalignment detection device 1, by grasping the axial misalignment of the cable D with respect to the bracket 3, it is possible to prevent the arm robot RB from operating while the cable D is slack. Can do. Thereby, generation | occurrence | production of a cable can be prevented.

  Also, according to the cable position deviation detection device 1, it is possible to grasp the position deviation of the cable D while the arm robot RB is in operation. Moreover, since the positional deviation of the cable D can be reliably grasped, the inspection work of the cable D can be reduced.

  Further, in the present embodiment, since the positional deviation is mechanically detected using the mechanical sensor 4, malfunction of the sensor when a large current flows through the cable D such as a welding robot can be avoided.

  Further, in the present embodiment, by using the binding band E as the “stepped portion”, each line of the cable D can be integrated and can be used as the detected portion of the mechanical sensor 4, thereby reducing the number of parts. be able to.

  Although the embodiments of the present invention have been described above, design changes can be made as appropriate without departing from the spirit of the present invention. For example, FIG. 5 is a side sectional view showing the operation according to the modified example, where (a) shows a normal time and (b) shows an abnormal time.

  The modification differs from the above-described embodiment in that the cable D is provided with two binding bands E, E. In the mechanical sensor 4 in the modification, when the contact portion 4a is in contact with the outer peripheral surface of the cable D, an ON signal is transmitted to the notification portion, and the contact portion 4a resists urging. When the position is displaced upward, an OFF signal is transmitted to the notification unit.

  In the modification, as shown in FIG. 5A, the contact portion 4 a is in contact with the outer peripheral surface of the cable D at the normal time. The contact portion 4a is arranged between the binding bands E and E.

  As shown in FIG. 5B, when the cable D is displaced in the axial direction against the holding force of the bracket 3, the contact portion 4a rides on the binding band E, and the contact portion 4a is displaced upward. As a result, an OFF signal is transmitted from the mechanical sensor 4 to the notification unit to notify that the position of the cable D has shifted. By providing the binding band E on both sides of the contact portion 4a, it is possible to cope with the deviation of both sides of the cable D in the axial direction.

  In the present embodiment, the “stepped portion” provided in the cable D is configured by the binding band E in the present embodiment, but is not limited thereto. For example, apart from the binding band E, a protruding portion that protrudes outward may be provided on the outer peripheral surface of the cable D, and the protruding portion may correspond to the contact portion 4 a of the mechanical sensor 4. That is, the “stepped portion” is displaced in the direction in which the contact portion 4a of the mechanical sensor 4 approaches or separates from the cable D by projecting outward from the outer peripheral surface of the cable D or by recessing it inward. A step may be provided on the outer peripheral surface of the cable D. The “step portion” may be provided over the entire circumference of the cable D or may be provided intermittently.

  In addition, the bracket 3 is fixed via the movable connecting jig 2 in this embodiment, but the movable connecting jig 2 may be omitted and fixed directly to the arm A1. A plurality of cable deviation detection devices 1 may be installed in the arm robot RB.

DESCRIPTION OF SYMBOLS 1 Cable deviation detection apparatus 2 Movable connection jig 3 Bracket 4 Mechanical sensor 4a Contact part A1 Arm D Cable E Binding band (step part)
RB arm robot

Claims (4)

A cable position deviation detecting device for detecting a position deviation of a cable arranged in an arm robot,
A bracket fixed to the arm of the arm robot and holding the cable;
A mechanical sensor for detecting an axial displacement of the cable with respect to the bracket;
A cable misalignment detection device, comprising: a notification unit configured to notify a detection result of the mechanical sensor. A step is formed on the outer periphery of the cable,
The mechanical sensor includes a contact portion that contacts the stepped portion or the cable,
The cable according to claim 1, wherein the mechanical sensor is configured to detect an axial displacement of the cable when the contact portion is displaced by the movement of the stepped portion. Misalignment detection device. In the case where the cable is composed of a plurality of lines,
The cable position deviation detection device according to claim 2, wherein the stepped portion is a binding band that bundles a plurality of the lines.   The cable position deviation detection device according to any one of claims 1 to 3, wherein the arm robot is a welding robot.

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