Abstract:
Provided is an attaching device that can convey a component, such as a nut, to a portion to be welded without using an air cylinder. 
     The present invention provides an attaching device ( 100 ) that attaches a nut ( 240 ) to a bracket ( 230 ). The attaching device ( 100 ) has a component feeding part ( 10 ) that stores the nut therein, a welding part ( 40 ) that welds the nut to the bracket by using electrodes ( 41, 42 ), a conveying part ( 20 ) that conveys the nut stored in the component feeding part to a position where the nut is to be attached to the bracket, and a feeding head ( 30 ) that temporarily positioned between the electrodes ( 41, 42 ) and that places the nut conveyed from the conveying part on the lower electrode of the pair of electrodes.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an attaching device. 
       BACKGROUND ART 
       [0002]    Many brackets for connecting suspension links, stabilizer bars or harnesses and the like are attached to a sub-frame of a suspension, and connection by fastening using fastening parts such as bolts and nuts is made. After the nuts are welded to the sub-frame in advance at each connection part, only bolts are installed with a wrench, and use of such a method achieves excellent work efficiency. In the case where the nut is welded to the sub-frame, a so-called projection nut having a projection on the nut seating surface is employed, and measures of attaching the nut to a bracket seating surface of the sub-frame by projection welding are often used. 
         [0003]    In general, a conventional apparatus used for welding the nut to a counterpart component with projection includes a feeder for feeding a nut, a component feeding part, an upper electrode, and a lower electrode (refer to Patent Literature 1). 
       CITATION LIST 
     Patent literature 
     Patent Literature 1: JP 4038403 B1 
     SUMMARY OF INVENTION 
     Technical Problem 
       [0004]    In the component feeding device of Patent Literature 1, an air cylinder is provided at the tip of a hose that feeds a nut from a feeder, and nuts are stored in front of an air cylinder, and nuts are singly transported to the electrode for welding by stroke movement of a rod constituting the air cylinder. However, since the rod of the air cylinder linearly moves by stroke, the device becomes bulky by the rod. When considering installing the component feeding device at a factory overseas from the viewpoint of cost reduction and the like, it is sometimes difficult to ensure a relatively large space for the factory according to lodgments. For this reason, it is probable that compactness of the component feeding device is required. 
         [0005]    Then, the present invention is made in order to solve the above problem, and an object of the present invention is to provide an attaching device which accomplishes space saving. 
       Solution to Problem 
       [0006]    In order to achieve the above object, an attaching device for attaching a nut to a counterpart component according to the present invention includes a storage part storing a plurality of the nuts, a welding part welding the nut to the counterpart component by a pair of electrodes, a conveying part having a flexible long member for conveying the nut stored in the storage part singly to the welding part, and a placement part provided at an outlet of the long member on a side of the welding part, and temporarily getting close between the pair of electrodes of the welding part to place the nut. The nut is placed on a lower electrode of the pair of electrodes after passing through the placement part singly from the conveying part. 
       Advantageous Effect of Invention 
       [0007]    According to the attaching device of the present invention, the conveying part conveys the nuts singly to the welding part, and the nuts pass through the placement part singly to be placed at the lower electrode of the pair of electrodes. Therefore, it is possible to dispense with a conventional configuration of an air cylinder for storing and delivering nuts and a rod attached thereto, thereby accomplishing space saving. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0008]      FIG. 1  is a perspective view of an attaching device according to a first embodiment of the present invention. 
           [0009]      FIG. 2  is a perspective view of the attaching device showing a state different from that in  FIG. 1 . 
           [0010]      FIG. 3  is a side view of the attaching device. 
           [0011]      FIG. 4  is a plan view of the attaching device. 
           [0012]      FIG. 5  is a side view of a placement part of the attaching device. 
           [0013]      FIG. 6  is a plan view of the placement part. 
           [0014]      FIG. 7(A)  is a perspective view of a sub-frame of a suspension,  FIG. 7(B)  is a view showing a state where a welding nut is joined to a component, and  FIG. 7(C)  is a perspective view of a welding nut. 
           [0015]      FIG. 8  is a perspective view of an attaching device according to a second embodiment of the present invention. 
           [0016]      FIG. 9  is a front view of the attaching device. 
           [0017]      FIG. 10  is an enlarged plan view of a placement part in the attaching device. 
           [0018]      FIGS. 11(A) to 11(C)  are perspective views showing, in the attaching device, how a nut is disposed on the lower electrode. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0019]    Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The technical scope disclosed in the claims, and the definitions of terms, are not limited to the disclosure hereinbelow. In some cases, the proportions of dimensions in the drawings differ from actual proportions, having been exaggerated for convenience in description. 
         [0020]      FIG. 1  is a perspective view of an attaching device according to a first embodiment of the present invention.  FIG. 2  is a perspective view of the attaching device showing a state different from that in  FIG. 1 .  FIGS. 3 and 4  are a side view and a plan view of the attaching device respectively.  FIG. 5  is a side view of a placement part of the attaching device.  FIG. 6  is a plan view of the placement part.  FIG. 7(A)  is a perspective view of a sub-frame of a suspension.  FIG. 7(B)  is a view showing a state where a welding nut is joined to a component.  FIG. 7(C)  is a perspective view of a welding nut. 
         [0021]    (Example in Which a Component to be Attached is Used) 
         [0022]    The attaching device  100  according to this embodiment is provided when a nut  240  is joined to a bracket  230  for connecting components such as a suspension link in a sub-frame  200  of a suspension as shown in  FIG. 7(A) , for example. Generally, the sub-frame  200  of the suspension includes a side member  210 , a cross member  220 , a bracket  230 , a nut  240 , and a collar  250 . The bracket  230  is joined to the cross member  220 . The nut  240 , which is called a welding nut, is attached to the bracket  230  by welding. 
         [0023]    (Attaching Device) 
         [0024]    Next, the attaching device according to this embodiment will be described. The attaching device  100  includes a component feeding part  10  (corresponding to a storage part), a conveying part  20 , a feeding head  30  (corresponding to a placement part), a welding part  40 , and an operation part  50 . 
         [0025]    The component feeding part  10  includes a vibration part  11 , a nut feeding port (not shown), a helical passage  12 , and a delivery portion  13 . The component feeding part  10  has a columnar outer shape, and the vibration part  11  is constituted by a motor or the like that generates vibration at the lower portion of the component feeding part  10 . The nut feeding port is provided at the lower part of the component feeding part  10 , and the helical passage  12  is formed to extend spirally upward from the nut feeding port. The helical passage  12  includes a slightly inclined helical passage toward the center when viewed in plan, and further includes a projection on the inner peripheral edge portion of the helical passage  12 . As a result, among the welding nuts, a welding nut whose protrusion is not placed in the downward direction in the helical passage is sifted from the helical passage  12 , so that the direction of protrusions of the welding nuts can be aligned. 
         [0026]    The delivery portion  13  is located at an upper terminal of the helical passage  12 , and is connected to the conveying part  20 . The nut  240  thrown from the nut feeding port is vibrated by the vibration part  11 , thereby moves helically from the lower side to the upper side of the helical passage  12 , and is delivered to the delivery portion  13 . 
         [0027]    The conveying part  20  includes an air pressure supply part  21 , an air supply path  22 , a nut conveying path  23  (corresponding to a long member), and a detection part. Although the air pressure supply part  21  is constituted by a compressor in the present embodiment, the air pressure supply part  21  need not be a compressor as long as air pressure for conveying the nut  240  can be supplied. The air supply path  22  is provided slightly downstream of the delivery portion  13  in the nut conveying path  23  and supplies compressed air from the air pressure supply part  21  to the nut  240  which is delivered from the component feeding part  10 . As a result, the nut  240  is delivered to the welding part  40 . In addition, in the present embodiment, the detection part includes a sensor at the delivery portion  13 , whereby the nut  240  is singly sent from the delivery portion  13 . 
         [0028]    The nut conveying path  23  is a long member formed in a substantially rectangular and hollow cross section. The end of the nut conveying path  23  is located at the delivery portion  13  which is located at an upper end of the helical passage  12 . The nut conveying path  23  supplies compressed air from the air pressure supply part  21  to the nut  240 , which moves from the vibration part  11 , via the air supply path  22 . The air supply path  22  and the nut conveying path  23  are constituted by hoses, and their material is made of a flexible resin material or the like, but the material is not limited to a flexible resin. While the nut conveying path  23  has a curved portion, the nut conveying path  23  is configured to extend generally in a horizontal direction intersecting the vertical direction in which the electrodes  41  and  42  are aligned. 
         [0029]    The feeding head  30  is provided at an end portion of the nut conveying path  23  which is opposite to the delivery portion  13 . The feeding head  30  directs the nut  240  delivered from the delivery portion  13  of the nut conveying path  23  toward the welding part  40 . As shown in  FIGS. 5 and 6 , the feeding head  30  includes a driving part  31 , a movable base  32  (corresponding to a moving part), fixing parts  33 ,  34 , and  35 , regulation parts  36  and  37  (corresponding to a direction changing part), and bolts  38   a ,  38   b ,  38   c ,  38   d , and  38   e.    
         [0030]    The driving part  31  as well as the bracket  39  is fixed to the side surface of a housing of the welding part  40  by bolts, and is configured as an electric cylinder. However, the driving part  31  is not limited to the electric cylinder. The movable base  32  is translatably connected to the driving part  31 , and the nut conveying path  23  is fixed to the movable base  32  by the fixing parts  33 ,  34 , and  35  and the bolts  38   a ,  38   b ,  38   c , and  38   d . Since the movable base  32  and the nut conveying path  23  are movably attached to the driving part  31 , the nut conveying path  23  as well as the movable base  32  is configured to be translatable, and can move between a position away from the welding part  40 , as shown in  FIG. 1 , and a position between the electrodes  41  and  42  of the welding part  40  as shown in  FIG. 2 . The movable base  32  is translatably configured to move in a substantially horizontal direction which intersects the vertical direction in which the electrodes  41  and  42  are aligned. 
         [0031]    The fixing parts  33  and  34  are formed by plate-like members attached to the movable base  32  and disposed on the side of the nut conveying path  23  and extending in a substantially vertical direction. The fixing part  35  is a plate-like member sandwiched by the fixing part  33  and the fixing part  34 , and fastened to the fixing parts  33  and  34  by the bolts  38   a  and  38   b . The fixing part  35  together with the movable base  32  sandwiches and fixes the nut conveying path  23  in the vertical direction. 
         [0032]    The regulation part  36  is a plate-like member that is attached to the fixing part  35  and the regulation part  37  and regulates the moving direction of the nut  240  sent from the nut conveying path  23 . The outlet of the nut conveying path  23  is located in the vicinity of the regulation part  36 . The regulation part  36  is attached to the fixing part  35  by bolts  38   c  and  38   d , and is attached to the regulation part  37  by the bolt  38   e . As shown in  FIG. 5 , the regulation part  36  is attached to the fixing part  35  and. the regulation part  37  so as to be inclined with respect to the vertical direction. The degree of inclination of the regulation part  36  is adjusted by the degree of tightening of the bolt  38   e  with respect to the regulation part  37 . 
         [0033]    The regulation part  37  together with the regulation part  36  delivers downward the nut  240  sent from the conveying part  20 . The regulation part  37  is a plate-like member configured such that the outer shape of its lower side in  FIG. 6  is substantially the same shape as that of the regulation part  36  in the plane view, and further the passage of the nut  240  is cut out in a recess shape. Although the end of the regulation part  37  is connected to the movable base  32  by welding, the end of the regulation part  37  may be configured to be attached to the movable base  32  by bolts. 
         [0034]    The welding part  40  has an upper electrode  41  and a lower electrode  42 . The lower electrode  42  is provided with a pin for positioning the welding nut  240 . During welding, the welding nut  240  is positioned at the pin of the lower electrode  42 , and the upper electrode  41  and the lower electrode  42  are energized, whereby the welding nut  240  and a member such as the bracket  230  are joined. The electrodes  41  and  42  are arranged along with each other in a substantially vertical direction. The operation part  50  is provided to control operations of the component feeding part  10 , the conveying part  20 , the feeding head  30 , the welding part  40 , and the like, and performs various operations by button operations. Since the configuration of the operation part  50  is the same as the conventional configuration, the description will be omitted. 
         [0035]    (Attachment of Nut) 
         [0036]    Attachment of the nut  240  by the attaching device  100  is performed as follows. First, when the vibration part  11  generates vibrations in a state where the nut  240  is supplied to the component feeding part  10 , the nut  240  placed in the helical passage  12  moves upward through the helical passage  12  to reach the delivery portion  13 . The nut  240  that has reached the delivery portion  13  receives compressed air supplied from the air supply path  22  and is singly sent inside the nut conveying path  23  toward the welding part  40 . 
         [0037]    On the other hand, the feeding head  30  temporarily gets close between the electrode  41  and the electrode  42  before the nut  240  is delivered from the delivery portion  13  as shown in  FIG. 2 . As shown in  FIG. 5 , the nut  240  sent from the nut conveying path  23  changes its traveling direction from the substantially horizontal direction dl to the substantially vertical direction d 2  by the regulation parts  36  and  37 , and falls and is placed on the lower electrode  42 . 
         [0038]    When the nut  240  is placed on the lower electrode  42 , the feeding head  30  is moved away from the welding part  40  by the driving part  31  as shown in  FIG. 1 . In this state, the upper electrode  41  gets close to the lower electrode  42 , and welding is performed, and the welding nut  240  is welded to a member such as the bracket  230 . 
         [0039]    (Function and Effect) 
         [0040]    Next, effects of the present embodiment will be described. In a conventional device for attaching a component such as a welding nut to a bracket, nuts sent by air from a device that generates vibration are temporarily stored, and are singly transported to electrodes where welding is performed by stroke movement of a rod constituting an air cylinder. However, the rod of the air cylinder has a large external shape. When considering setting up a factory overseas from the viewpoint of cost reduction and the like, it is sometimes impossible to ensure a relatively large space for the factory. For this reason, it is probable that downsizing for the attaching device is required. 
         [0041]    For this requirement, the attaching device  100  according to the present embodiment includes a component feeding part  10 , a welding part  40 , a conveying part  20 , and a placement part  30 , and the conveying part  20  delivers nuts  240  singly to welding part  40  so that the nut  240  passes through the feeding head  30  and is placed on the electrode  42 . 
         [0042]    Therefore, it is not necessary to transport the nut to the electrode by the rod of the air cylinder after temporarily storing the nut in front of the air cylinder like conventional manner, and since it is not necessary to provide the rod for transporting the stored nut, the attaching device  100  canaccomplish space saving. In addition, since the device is configured to transport nuts singly instead of transporting nuts after storing the nuts in a conventional manner, it is possible to eliminate jamming of the nuts, which may occurs when storing and conveying the nuts. 
         [0043]    Further, in the first embodiment, the configuration corresponding to the placement part is constituted by the movable base  32  as well as the nut conveying path  23  which can move to and away from the electrodes  41  and  42  in a direction intersecting the vertical direction in which the electrodes  41  and  42  are aligned. Thus, it is possible to eliminate the use of an air cylinder for temporarily storing the nuts  240  and transporting them to the electrode  42 . 
         [0044]    In addition, the feeding head  30  is configured to have regulation parts  36  and  37  as a direction changing part for directing the moving direction of the nut  240  sent by air pressure from the nut conveying path  23  extending in a substantially horizontal direction to the electrode  42 . Accordingly, it is possible to guide the nut  240  conveyed from the nut conveying path  23  to the vicinity of the electrode  42 , and reduce the situation where the nut  240  is not properly set on the electrode  42 . Thus, nut joining can be efficiently and quickly achieved. 
         [0045]    Further, the feeding head  30  is configured to linearly move between the electrode  41  and the electrode  42  before welding is performed by the electrodes  41  and  42  corresponding to the welding part  40 . Therefore, the position at which the nut  240  is released can be located closer to the electrode  42 , and accordingly the air pressure necessary for placing the nut  240  on the electrode  42  can be reduced. 
         [0046]    In addition, a component manufactured according to the first embodiment can be configured as the bracket  230  that can be joined to the cross member  220  that constitutes the sub-frame  200  of the suspension, as shown in  FIG. 7(B)  as an example. 
       Embodiment 2 
       [0047]      FIGS. 8 to 10  are a perspective view and a front view showing an attaching device according to the second embodiment of the present invention, and an enlarged plan view showing a placement part of the attaching device. FIGS.  11 (A) to  11 (C) are perspective views showing how the nut is placed on the lower electrode in the attaching device. 
         [0048]    The attaching device  100   a  in the second embodiment includes a component feeding part  10 , a conveying part  20 , a placement part  60 , a welding part  40 , and an operation part  50 . The same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted. 
         [0049]    The placement part  60  includes a rotation driving part  61 , a rotation shaft  62 , holding parts  63  and  64  (corresponding to a rotation holding part), a support base  65 , fixing parts  66 ,  67  and  68 , and bolts  69 ,  71 ,  72 , and  73 . The rotation driving part  61  is fixed to a housing of the attaching device  100   a  with the bracket  75  by bolts, and incorporates structures such as gears and actuators for rotating the rotation shaft  62 , the holding parts  63  and  64 , and the like. 
         [0050]    As shown in  FIG. 9 , the rotation shaft  62  is rotatably attached to the upper part of the rotation driving part  61 , and the holding parts  63  and  64  are attached to the upper part of the rotation shaft  62 . As a result, the holding parts  63  and  64  move in the rotation direction as the rotation shaft  62  rotates. The holding parts  63  and  64  have shafts which are rotatable separately from the rotation shaft  62 . The holding parts  63  and  64  each have recesses  63   a  and  64   a , and the nut  240  from the nut conveying path  23  can be placed on the recesses  63   a  and  64   a.    
         [0051]    The holding parts  63  and  64  are configured so that the holding part  63  and the holding part  64  can move away from each other in the rotation direction by rotating around the respective shafts. As a result, as shown in  FIG. 11(A) , the holding parts  63  and  64  place the nut  240  sent from the nut conveying path  23  in the recesses  63   a  and  64   a  and, as shown in  FIG. 11(B) , the holding parts  63  and  64  are temporarily positioned between the electrode  41  and the electrode  42  by the rotation shaft  62 . Then, as shown in  FIG. 11(C) , as the holding part  63  and the holding part  64  move away from each other in the rotation direction around the respective rotation shafts, the nut  240  placed on the recesses  63   a  and  64   a  is released and placed on the electrode  42 . 
         [0052]    The support base  65  supports the nut conveying path  23 , and the support base  65  is fixed with the bracket  76  by bolts. The fixing part  66 , the fixing part  67 , the fixing part  68  have the same structure as the fixing part  33 , the fixing part  34 , and the fixing part  35  in the first embodiment respectively, and thus description thereof is omitted. Since the bolts  69 ,  71 ,  72 , and  73  have the same configuration as the bolts  38   a ,  38   b ,  38   c , and  38   d  of the first embodiment, the description is omitted. The outlet  23   a  of the nut conveying path  23  is located in the vicinity of the holding parts  63  and  64  of the fixing part  68  in the second embodiment. 
         [0053]    Regarding the attachment of the nut by the attaching device  100   a  of the second embodiment, the feeding of the nut  240  by the conveying part  20  from the component feeding part  10  is performed in the same manner as that in the first embodiment. The nut  240  fed by the air pressure from the conveying part  20  is placed on the recesses  63   a  and  64   a  of the holding parts  63  and  64  on the welding part  40  side of the nut conveying path  23 . As with the above description, the rotation shaft  62  rotates so that the holding parts  63  and  64  are positioned between the electrode  41  and the electrode  42 , and the holding part  63  and the holding part  64  move away from each other so that the nut  240  is placed on the electrode  42 . As with the first embodiment, the holding parts  63  and  64  are retracted from the welding part  40 , and the nut  240  is welded to a member such as the bracket  230  by the electrodes  41  and  42 . 
         [0054]    According to the second embodiment, the placement part  60  is provided with the rotation shaft  62 , and is configured to move to the outlet  23   a  of the nut conveying path  23  and move between the pair of electrodes  41  and  42  by rotation around the rotation shaft  62 . Thus, it is not necessary to lengthen the nut conveying path  23  such that the nut conveying path  23  can move closer to a position between the electrodes  41  and  42  from a state where long nut conveying path  23  is evacuated from the electrodes  41  and  42 . This configuration contributes to space saving. 
         [0055]    Further, the placement part  60  has a pair of holding parts  63  and  64  which hold the nut  240  until the nut is transported to the lower electrode  42 , and the pair of holding parts  63  and  64  rotates around the rotation shaft  62 , and moves closer to each other at the outlet  23   a  of the nut conveying path  23  so as to hold the nut  240  coming out of the outlet  23   a , and then moves away from each other around the rotation shaft  62  at a position between the pair of electrodes  41  and  42  such that the nut  240  is placed on the lower electrode  42 . Thus, this configuration can prevent the size of the nut conveying path  23  from becoming larger and contribute to space saving as with the above description. 
         [0056]    The present invention is not limited to the above embodiments, and various modifications are possible within the scope of the claims. 
         [0057]    In the above description, the embodiment is described in which a fluid for conveying the nut is air. However the present invention is not limited thereto, and the fluid may be constituted by other fluid such as nitrogen. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           10  Component feeding part (storage part) 
           100 ,  100   a  Attaching device 
           20  Conveying part 
           23  Nut conveying path (long member) 
           30  Feeding head (placement part) 
           32  Movable base (moving part) 
           36 ,  37  Regulation part (direction changing part) 
           40  Welding part 
           60  Placement part 
           63 , 64  Holding part (rotation holding part) 
           200  Sub-frame of suspension 
           210  Cross member 
           220  Side member 
           230  Bracket 
           240  Welding nut