Patent Publication Number: US-2017361407-A1

Title: Multi-axis nut runner apparatus and method of operating the multi-axis nut runner apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is claims the benefit of priority to Korean Patent Application No. 10-2016-0076529, filed on Jun. 20, 2016 with the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a multi-axis nut runner apparatus and a method of operating the multi-axis nut runner apparatus, and more particularly, to a multi-axis nut runner apparatus capable of changing a fastening position depending on objects having various sizes, and a method of operating the multi-axis nut runner apparatus. 
     BACKGROUND 
     A key point of a vehicle manufacturing factory is to assemble parts of a vehicle or a function unit moved along a line, and to tighten bolts and nuts to complete the vehicle. Since examples of work, or work content, include a bolt fastening work requiring a torque, a fitting work, an attaching work, piping, wiring, and connecting works, and the like, the work is performed depending on abilities and determination of an assembler. 
     In addition, as a fastening tool used for a part assembly by screwing parts such as a bolt or a nut, a screw, and the like, a screw driver may be used for a piece of work. Also, an impact wrench, a nut runner, and the like are used for bolt and nut work, and an electric servo-type nut runner is used for a portion requiring stable tightening torque. 
     Such a nut runner has a problem in that it requires an apparatus configuration capable of accommodating different engine heights between models. Further, since an apparatus configuration capable of accommodating different bolt fastening pitches between the models is required, and shapes and arrangements of equipment are different depending on a fastening position and a model difference, the nut runner needs to be remodeled at the time of adding a new model, which causes a problem that it is difficult to sufficiently secure, or conduct, a test operation. 
     SUMMARY 
     The present disclosure has been made to solve the above-mentioned problems occurring in the prior art while advantages achieved by the prior art are maintained intact. 
     An aspect of the present disclosure provides a flexible multi-axis nut runner apparatus which does not require altering facilities in spite of standardization of the facilities according to a change of engine sizes, and a difference of part shapes between models, and a method of operating the multi-axis nut runner apparatus. 
     However, objects of the present disclosure are not limited to the objects described above, and other objects that are not described above may be clearly understood by those skilled in the art from the following description. 
     According to an exemplary embodiment of the present disclosure, a multi-axis nut runner apparatus includes: a base frame; a mounting frame mounted on the base frame to be vertically movable; a pallet having an object disposed thereon and transferred along a transfer rail; and a variable device installed on the mounting frame and partitioned into a plurality of regions depending on a size of the object to thereby be fastened. 
     The variable device may include a plurality of runners so as to be fastened to the object in the plurality of partitioned regions. 
     The plurality of runners may include a first runner, a second runner, a third runner, and a fourth runner that each partition a portion of the plurality of regions to thereby be fastened thereto. 
     The plurality of runners may include: a first cylinder moved in a direction crossing a movement direction of the object; a second cylinder mounted on the first cylinder and moved in a direction crossing the first cylinder; and a third cylinder mounted on the second cylinder and fastened to the object. 
     The first cylinder may be installed with a linear rail allowing the second cylinder to be moved in the direction crossing the first cylinder. 
     The first cylinder may include a ball screw to axially move the first cylinder. 
     The multi-axis nut runner apparatus may further include a flexible column mounted on the mounting frame so as to maintain a predetermined interval between the variable device and the object. 
     The flexible column may include a fixing pin provided to secure a position of the object. 
     The flexible column may have a support frame formed to fix the fixing pin, and include an electric cylinder vertically moving the support frame. 
     Specific matters of other exemplary embodiments will be included in a detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings. 
         FIG. 1  is a perspective view illustrating a multi-axis nut runner apparatus according to embodiments of the present disclosure. 
         FIG. 2  is a view illustrating a variable device of  FIG. 1 . 
         FIG. 3  is a cross-sectional view taken along plane A-A of  FIG. 2 . 
         FIGS. 4 and 5A and 5B  are views illustrating a multi-axis nut runner apparatus and a fixing pin according to embodiments of the present disclosure. 
         FIGS. 6A to 6H  are perspective views illustrating an operation of a multi-axis nut runner apparatus according to embodiments of the present disclosure. 
         FIG. 7  is a plan view illustrating objects having different sizes stacked on a pallet according to embodiments of the present disclosure. 
         FIG. 8  is a flowchart illustrating a method of operating a multi-axis nut runner apparatus according to embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Advantages and features of the present disclosure and methods to achieve them will become apparent from exemplary embodiments described below in detail with reference to the accompanying drawings. However, the present disclosure is not limited to exemplary embodiments disclosed below, but will be implemented in various different forms. The exemplary embodiments of the present disclosure make a disclosure of the present disclosure thorough and are provided so that those skilled in the art can easily understand the scope of the present disclosure. Therefore, the present disclosure will be defined by the scope of the appended claims. Like reference numerals throughout the description denote like elements. 
     Hereinafter, the present disclosure will be described with reference to the accompanying drawings for describing a multi-axis nut runner apparatus according to exemplary embodiments of the present disclosure. 
       FIG. 1  is a perspective view illustrating a multi-axis nut runner apparatus according to embodiments of the present disclosure,  FIG. 2  is a view illustrating a variable device of  FIG. 1 ,  FIG. 3  is a cross-sectional view taken along plane A-A of  FIG. 2 ,  FIGS. 4 and 5A and 5B  are views illustrating a multi-axis nut runner apparatus and a fixing pin according to embodiments of the present disclosure,  FIGS. 6A to 6H  are perspective views illustrating an operation of a multi-axis nut runner apparatus according to embodiments of the present disclosure,  FIG. 7  is a plan view illustrating objects having different sizes stacked on a pallet according to embodiments of the present disclosure, and  FIG. 8  is a flowchart illustrating a method of operating a multi-axis nut runner apparatus according to embodiments of the present disclosure. 
     A multi-axis nut runner apparatus of a vehicle may be modified by those skilled in the art, and the present exemplary embodiment corresponds to a case of a multi-axis nut runner apparatus. 
       FIG. 1  is a perspective view illustrating a multi-axis nut runner apparatus according to embodiments of the present disclosure,  FIG. 2  is a view illustrating a variable device of  FIG. 1 ,  FIG. 3  is a cross-sectional view taken along plane A-A of  FIG. 2 , and  FIGS. 4 and 5A and 5B  are views illustrating a multi-axis nut runner apparatus and a fixing pin according to embodiments of the present disclosure. 
     The multi-axis nut runner apparatus according to the present disclosure will be described with reference to  FIGS. 1 to 5A and 5B . The multi-axis nut runner apparatus according to the present disclosure may include a base frame  20 , a mounting frame  32  mounted on the base frame  20  to be vertically movable, a pallet  15  having an object disposed thereon and transferred along a transfer rail  5 , and a variable device  40  installed on the mounting frame  32  and partitioned into a plurality of regions depending on a size of the object to be fastened. 
     The pallet  15  may have the object  10  disposed thereon, and may be transferred along the transfer rail  5 . While the pallet  15  is moved along the transfer rail  5 , the object  10  is disposed to coincide with a flexible column  30 . 
     The flexible column  30  vertically descends and maintains a predetermined interval with the object  10 . Here, the flexible column  30  is mounted on the mounting frame  32  mounted on the base frame  20  of the multi-axis nut runner apparatus  1 . The mounting frame  32  may include a vertical control cylinder  34  that vertically moves the mounting frame from the base frame  20 . 
     The flexible column  30  may include a support frame  36  mounted on the mounting frame  32 . The support frame  36  may include a fixing pin  39  so as to maintain the predetermined interval with the object  10 . The fixing pin  39  is formed on a support plate  30   a  formed to be perpendicular to the support frame  36 , and is mounted on the support plate  30   a . In addition, the support frame  36  has an electric cylinder  38  mounted thereon, so that the support plate  30   a  is moved in a vertical direction (a Z-axis direction). 
     Therefore, the mounting frame  32  of the flexible column  30  vertically descends by an operation of the vertical control cylinder  34  and the support plate  30   a  thereof is moved by an operation of the electric cylinder  38  at the same time, such that the fixing pin  39  is in contact with the pallet  15 . In this case, the variable device  40  is in contact with the fixing pin  39  along the movement of the mounting frame  32 . Therefore, even in the case in which the variable device  40  ascends for a fastening of a nut and a variation of a pitch, it is possible to maintain a degree of position with the pallet  15 . 
     The variable device  40  may be installed on the mounting frame  32  and partitions the object  10  into a plurality of regions a, b, c and d as shown in  FIG. 7  to thereby be fastened. The variable device  40  is fixed to a fixing plate  40   a  and is mounted on the mounting plate. 
     The variable device  40  may include a plurality of runners  42 ,  44 ,  46  and  48  so as to be each fastened to the object in the plurality of regions a, b, c and d. The plurality of runners may include a first runner  42 , a second runner  44 , a third runner  46  and a fourth runner  48  that each partition a portion of the plurality of regions a, b, c and d to thereby be fastened thereto. 
     Here, since the first runner  42 , the second runner  44 , the third runner  46  and the fourth runner  48  may have the same configuration, the first runner  42 , which is one of the plurality of runners, will be described below by way of example. 
     The first runner  42  may include a first cylinder  50  moved in a direction crossing a movement direction of the object, a second cylinder  60  moved in a direction crossing the first cylinder  50  and mounted on the first cylinder  50  and a third cylinder  70  mounted on the second cylinder  60  and fastened to the object. 
     More particularly, the first cylinder  50  may be mounted on the fixing plate  40   a  so as to be moved in an x axis direction, and the second cylinder  60  may be mounted on the first cylinder  50  so as to be moved in a y axis direction. In this case, the first cylinder  50  includes a linear rail R connecting the first cylinder  50  and the second cylinder  60  to each other. In addition, the first cylinder  50  may include a ball screw S to axially move the first cylinder  50 , and is movable in the x axis direction. 
     Here, the movements of the first cylinder  50  and the second cylinder  60  do not interfere with each other by the linear rail R. That is, the first cylinder  50  may be moved in the x axis direction on an axis of the ball screw S, and the second cylinder  60  may be moved in the y axis direction. Meanwhile, the x axis direction is a direction perpendicular to a movement direction of the object  10 , the y axis direction is the same direction as the movement direction of the object  10 , and the z axis direction is a vertical axis direction perpendicular to the x axis direction and the y axis direction. 
     Meanwhile, when the flexible column  30  is vertically moved in the z axis direction, the third cylinder  70  is mounted on the second cylinder  60  so as to be fastened to the object. Therefore, the first cylinder  50  and the second cylinder  60  are each moved in the x axis direction and the y axis direction, and the third cylinder  70  is fastened to the object by operating the first cylinder  50  and the second cylinder  60  to thereby vertically descend the flexible column  30  in the z axis direction at a position of a fastening point. 
     Meanwhile, referring to  FIG. 7 , the object is partitioned into a plurality of regions, that is, four regions, and the first runner  42  is fastened in a first region a, the second runner  44  is fastened in a second region b, the third runner  46  is fastened in a third region c and the fourth runner  48  is fastened in a fourth region d, respectively. 
     An operation of the multi-axis nut runner apparatus according to an exemplary embodiment of the present disclosure having the configuration as described above will be described. 
       FIGS. 6A to 6H  are perspective views illustrating an operation of a multi-axis nut runner apparatus according to embodiments of the present disclosure,  FIG. 7  is a plan view illustrating objects having different sizes and stacked on a pallet, and  FIG. 8  is a flowchart illustrating a method of operating a multi-axis nut runner apparatus according to embodiments of the present disclosure. 
     The multi-axis nut runner apparatus according to the present disclosure will be described with reference to  FIGS. 6A to 8 . The object is stacked on the pallet and the pallet is moved along the transfer rail to be disposed below the variable device (S 10 ). That is, after the object  10  is stacked on the pallet  15 , the pallet  15  is disposed to be moved to the nut runner along the transfer rail. 
     Next, if the object  10  is disposed on the pallet  15 , the flexible column  30  descends toward the object  10  by an operation of the vertical control cylinder  34  (S 20 ). That is, the vertical control cylinder  34  is operated to allow the flexible column  30  to descend in a lower z axis direction in which the object  10  is present. 
     Next, the flexible column  30  may include the fixing pin  39 , such that the fixing pin  39  is in contact with the pallet  15  when the flexible column  30  descends, and the flexible column  30  stops. The descending of the variable device  40  is limited by the fixing pin  39 , thereby leaving a predetermined gap between the object  10  and the variable device  40 . That is, the electric cylinder  38  is operated simultaneously with the vertical control cylinder  34 , such that one side of the fixing pin  39  is in contact with the pallet. In this case, the fixing pin  39  is first in contact with the pallet  15 , thereby making it possible to prevent the flexible column  30  from being excessively moved to the object  10 , and to maintain a constant interval between the variable device  40  and the object  10 . 
     Thereafter, the fixing plate  40   a  is in contact with the other side of the fixing pin  39 . Therefore, the constant interval may be maintained between the variable device  40  and the object  10  by the fixing pin  39 . 
     In addition, when the flexible column  30  stops (S 30 ), and the variable device  40  descends, the plurality of runners  42 ,  44 ,  46  and  48  included in the variable device  40  are fastened to the object (S 40 ). The first cylinder  50  and the second cylinder  60  perform a straight-line motion in each of the x axis direction and the y axis direction so that the variable device  40  is coincided with a first fastening point  10   a  of the object  10 , thereby allowing the third cylinder  70  to be disposed over the first fastening point  10   a . That is, when the object  10  is positioned below the flexible column  30 , and the first cylinder  50  and the second cylinder  60  are moved in the x axis direction and the y axis direction, the third cylinder  70  is positioned over the first fastening point  10   a . Then, the third cylinder  70  vertically descends in the z axis direction to thereby be fastened to the nut. 
     Next, after the variable device  40  ascends (S 50 ) to be returned to an original position, the variable device  40  is moved along shafts of the plurality of cylinders included in the plurality of runners  42 ,  44 ,  46  and  48  so as to cross each other (S 60 ). The flexible column  30  again vertically ascends to be returned to an original position. The first cylinder  50  and the second cylinder  60  are moved in the x axis direction and the y axis direction along a second fastening point  10   b  to allow the third cylinder  70  to be coincided with the second fastening point  10   b . In addition, the flexible column  30  descends in the z axis direction, and the third cylinder  70  is fastened to the second fastening point  10   b . In this case, the plurality of runners  42 ,  44 ,  46  and  48  are moved on the shafts of the plurality of cylinders in the regions partitioned so as not to interfere with each other. 
     Thereafter, after the flexible column  30  is fastened to the second fastening point  10   b , the flexible column  30  again vertically ascends ( 100 ) to be returned to the original position. 
     Here, the case in which the objects are fastened depending on sizes of the objects will be described with reference to  FIG. 7 . Although the case in which a plurality of objects are stacked is described for convenience of explanation, only one of the respective objects is fastened to the nut runner apparatus. That is, only one of the plurality of objects is disposed on the pallet, so as to be fastened by the variable device. Meanwhile, fastening points  110   a ,  110   b ,  210   a  and  210   b  of a first object  110  and a second object  210  except for those illustrating the illustration of the present disclosure among the plurality of objects illustrating the objects being fastened to the first cylinder, the second cylinder and the third cylinder by the variable device according to the present disclosure. 
     More particularly, the first object  110  greater than the object  10  according to the present disclosure, and the second object  210  greater than the first object  110  are downwardly stacked in this order. The plurality of objects has a plurality of fastening points formed along a circumference thereof. 
     An upper side of the plurality of objects stacked as in  FIG. 7  is partitioned into the first region a of a right side and the second region b of a left side, and a lower side of the plurality of objects is partitioned into the third region c of the left side and the fourth region d of the right side. 
     Here, referring to  FIGS. 1 and 7 , a plurality of runners are each controlled within the first region a, the second region b, the third region c and the fourth region d. That is, the first runner  42  is operated in the first region a, such that the object is fastened depending on the size thereof. The fastening in the first region a will be described by way of example. When the object  10  is disposed on the pallet  15 , the first runner  42  is moved to be positioned on a vertical line with the first fastening point  10   a  on the shaft. Next, when the flexible column  30  descends, the third cylinder  70  is rotated and is fastened to the nut. 
     Thereafter, when the fastening is completed by the variable device  40 , the flexible column  30  ascends to be returned to an original state, and the variable device  40  is again moved on the shaft to be coincided with the second fastening point  10   b . In this case, since the variable device  40  is moved in the x axis direction and the y axis direction by the first cylinder  50  and the second cylinder  60 , the fastening may be implemented regardless of the sizes of the objects. As a result, facilities do not need to be added or altered depending on models. 
     In addition, when the flexible column  30  again descends, the third cylinder  70  is rotated and is fastened to the nut, and the flexible column  30  is then returned to the original state. 
     Therefore, since the variable device  40  may move the size between the plurality of objects according to a value preset in a controller, the variable device  40  may be fastened to the respective fastening points  110   a ,  110   b ,  210   a  and  210   b  formed in the first object  110  and the second object  210  having different sizes according to a user selection. 
     As described above, according to the present disclosure, the multi-axis nut runner apparatus and the method of operating the multi-axis nut runner apparatus have one or more of the following effects. 
     First, in the multi-axis nut runner apparatus and the method of operating the multi-axis nut runner apparatus according to the present disclosure, since the nut runner apparatus is provided in a multi-axis, an area of the facilities may be reduced, and since the nut runner apparatus does not need to be replaced or altered even for a new model, costs may be reduced. 
     Second, in the multi-axis nut runner apparatus and the method of operating the multi-axis nut runner apparatus according to the present disclosure, flexibility of the facilities fastening the bolt is improved and secured, thereby making it possible to respond to a change of the model and to implement a sharing production of an engine of multiple models, that is, the sharing production of the engine of two to three models or more. 
     However, effects of the present disclosure are not limited to the effects described above, and other effects that are not described above may be clearly understood by those skilled in the art from the claims. 
     In the multi-axis nut runner apparatus and the method of operating the multi-axis nut runner apparatus according to an exemplary embodiment, the configuration and the method of the above-mentioned exemplary embodiments are not restrictively applied. That is, all or some of the respective exemplary embodiments may be selectively combined with each other so that they may be variously modified. 
     Hereinabove, although the present disclosure has been described with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.