Apparatus for processing terminal ends of tubes
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus for automatically inserting a plug into an end portion of a metal tube and processing the end portion into a pointed configuration, prior to a drawing of the tube using a die and the plug. 
     2. Prior Art 
     When a hollow tube is drawn by the use of a die and a plug, the plug is inserted into the tube to a location adjacent to an axial end face thereof, an end portion of the tube is pointed by a pointing device , and the pointed end portion is gripped by a chuck of a drawing apparatus and is caused to pass through the die hole so that an outer diameter of the tube is regulated by the die hole and a wall thickness of the tube is regulated by the plug. 
     Heretofore, the insertion of the plug into the tube before pointing the end portion thereof has been performed manually. Specifically, an operator slightly dimples, by a hammer, a portion of the tube remote from the axial end face thereof by a predetermined distance to form a first positioning section on the tube, inserts an oil supply nozzle into the tube to supply oil thereinto, manually inserts a plug from the axial end face of the tube to the first positioning section, thereafter, again slightly dimples by the hammer a portion of the tube intermediate the axial end face of the tube and the inserted plug to form a second positioning section on the tube for preventing the inserted plug from coming out of the tube, thereafter, inserts the end portion of the tube into the pointing device to point the end portion of the tube so as to provide a pointed end portion. In the prior art, such plug inserting operation has been entirely performed manually by an operator, except for the pointing operation by the pointing device, and it has been a great strain on the operator. 
     OBJECT AND SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a tube end processing apparatus which is capable of automatically performing an inserting operation of a plug into an end portion of a tube and pointing the end portion, without any trouble for an operator. 
     According to the present invention, there is provided an automatic tube end processing apparatus comprising: a base disposed below a moving path along which a tube is to be moved; a pointing device mounted on the base so as to be movable toward and away from the moving path and having an insertion opening facing forwardly with respect to a moving direction of the tube; first clamping means mounted on the base in front of the pointing device along the moving path, for supporting and clamping the tube; a tube press for dimpling the tube, the tube press being disposed between the first clamping means and the pointing device so as to be movable along the moving path; second clamping means disposed between the tube press and the pointing device for clamping an end portion of the tube; plug feeding means disposed between the tube press and the pointing device for feeding a plug from a position out of the moving path to a position on the moving path; plug inserting means including an inserting nozzle movable in parallel to the moving direction of the tube for inserting the plug into the tube, the plug inserting means being disposed in the vicinity of the pointing device so as to enable the inserting nozzle to be moved toward and away from the moving path; and lubricant supply means communicating with the inserting nozzle for supplying lubricant into the tube through the inserting nozzle. 
     The automatic tube end processing apparatus in accordance with the present invention operates in such a manner that the first clamping means is actuated to support and clamp the tube, the tube press is actuated to dimple a portion of the tube to form thereon a positioning section, the plug positioned at the axial end face of the tube by the plug feeding means is inserted into the tube by the plug feeding means is inserted into the tube by the inserting nozzle of the plug inserting means, lubricant is supplied into the tube through the inserting nozzle, the tube press is again actuated to dimple a portion of the tube offset from the inserted plug toward the axial end face of the tube to form thereon a second positioning section for preventing the inserted plug from coming out of the tube, and the pointing device is actuated to draw or neck the end portion of the tube to complete a tube pointing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view showing an automatic tube end processing apparatus in accordance with an embodiment of the present invention; 
     FIG. 2 is a front elevational view of the processing apparatus shown in FIG. 1; 
     FIG. 3 is a plan view of an automatic tube end processing apparatus in accordance with another embodiment of the present invention; 
     FIG. 4 is a front elevational view showing the processing apparatus shown in FIG. 3; and 
     FIG. 5 is a side elevational view showing the processing apparatus shown in FIG. 3. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2 which illustrate an automatic tube end processing apparatus, generally designated by the reference character A, in accordance with an embodiment of the present invention, the automatic tube end processing apparatus A comprises, as principal components, a base generally designated by the reference numeral 1 disposed below a moving path C along which a tube B shown by phantom lines is to be moved from the right to the left in FIGS. 1 and 2; a pointing device generally designated by the reference numeral 2 mounted on the base 1 at a trailing side thereof with reference to the moving direction of the tube B; a first clamping device 3 mounted on the base 1 in front of the pointing device 2 along the moving path C; a tube press generally designated by the reference numeral 4, a second clamping device generally designated by the reference numeral 5 and a plug feeding device generally designated by the reference numeral 6 which are disposed between the first clamping device 3 and the pointing device 2; a plug inserting device 7; and a lubricant supply device 8. 
     The base 1 comprised a rectangular base frame 1a and a table 1b fixedly connected to a side of the base frame 1a which is located forwardly with reference to the moving path C. A pair of spaced guide rails 1c extending perpendicularly to the moving path C are fixedly mounted on the base frame 1a. 
     The pointing device 2 comprises a casing and a publicly known drawing or pointing unit disposed within the casing. The casing includes a front wall having formed therein a central insertion opening through which an end portion of the tube B is inserted into the casing to point the end portion of the tube B. The pointing device 2 is fixedly mounted on a pair of mounts 2a with the insertion opening facing forwardly with respect to the moving direction of the tube B. The mounts 2a are slidably mounted on support rods 2b extending in parallel to the moving path C. Each of the support rods 2b has axial opposite ends thereof on which guide wheels 2c are rotatably mounted, respectively. The guide wheels 2c are in rotatable engagement with the guide rails 1c so as to be movable therealong. Thus, the pointing device 2 is supported on the base 1 so as to be horizontally movable in parallel to the moving path C and perpendicularly thereto. The pointing device 2 is supported on the guide rails 1c such that the insertion opening of the pointing device 2 is located at the same level as the moving path C. 
     The first clamping device 3 is a publicly known one which includes a chuck for automatically grip or clamp the tube B at any location along the moving path C. The first clamping device 3 is fixedly mounted on an upper surface of the table 1b. A pair of rods 3a have their respective one ends fixedly supported by the first clamping device 3 and horizontally extend in parallel to the moving path C toward the pointing device 2 with the moving path C being centrally located between the pair of rods 3a. 
     The tube press 4 is disposed between the first clamping device 3 and the pointing device 2 and comprises a press mount 4a slidably mounted on the guide rods 3a so as to be movable therealong, and a pair of piston and cylinder assemblies 4b fixedly mounted on the press mount 4a with the moving path C being located between the pair of piston and cylinder assemblies 4b. Each of the piston and cylinder assemblies 4b includes a piston rod extending horizontally and perpendicularly to the moving path C. A press head 4c is fixedly connected to an axial free end of each of the respective piston rods of the piston and cylinder assemblies 4b so that the press heads 4c face to each other. The piston and cylinder assemblies 4b are adapted to be actuated to move their respective piston rods so as to enable the press heads 4a to be moved toward and away from the moving path C, i.e., between a position within the moving path C and a position remote therefrom. 
     The second clamping device 5 is disposed between the tube press 4 and the pointing device 2 and comprises a clamp mount 5a slidably mounted on the guide rods 3a so as to be movable therealong, and a pair of piston and cylinder assemblies 5b fixedly mounted on the clamp mount 5a with the moving path C being located between the pair of piston and cylinder assemblies 5b. Each of the piston and cylinder assemblies 5b includes a piston rod extending horizontally and perpendicularly to the moving path C. A support head 5c is fixedly connected to an axial free end of each of the respective piston rods of the piston and cylinder assemblies 5b so that the support heads 5c face to each other. The piston and cylinder assemblies 5b are adapted to be actuated to move their respective piston rods so as to enable the support heads 5c toward and away from the moving path C. 
     The plug feeding device 6 is disposed between the second clamping device 5 and the pointing device 2 and comprises a magazine case receiving therein a plurality of plugs 10 in the form of a projectile arranged in a single row, and a loading unit 6b associated with the case 6a for taking one of the plugs 10 out of the case 6a and locating the taken-out plug 10 in a position on the moving path C as occasion demands. The case 6a has a front wall facing to the moving path C and having-formed therein an opening through which the loading unit 6b can take one of the plugs 10 out of the case 6a. 
     The plug inserting device 7 comprises a vertical guide frame 7a fixedly mounted on the pointing device 2, a piston and cylinder assembly 7b mounted on the guide frame 7a so as to be vertically movable therealong, and an inserting nozzle 7c fixedly connected to a piston rod of the piston and cylinder assembly 7b. The piston and cylinder assembly 7b is movable up and down along the guide frame 7a and is also movable horizontally together with the pointing device so as to enable the inserting nozzle 7c to be moved between a position in alignment with the moving path C and a position out of alignment therewith. The piston and cylinder assembly 7b has incorporated thereinto the lubricant supply device 8 for supplying lubricant oil into the inserting nozzle 7c. 
     The tube B is guided by guide rollers 11 and 12 and is delivered along the moving path C by a pair of pinch rolls 13 and 13 from the right to the left in FIGS. 1 and 2. 
     A sequential control unit 15 shown in FIG. 1 is electrically connected to limit switches (not shown) associated with the above described various components of the automatic tube pointing apparatus A, and is adapted to receive respective signals from the limit switches to automatically control the respective actuations of the various components. 
     The automatic tube end processing apparatus A having the described construction operates to insert the plug 10 into the end portion of the tube B and to point the end portion in a manner described hereunder. 
     When the tube B is delivered along the moving path C from a previous working station, the first clamping device 3 is in an inoperative position so that the chuck of the first clamping device 3 occupies a position away from the moving path C. Similarly, the press heads 4c of the tube press 4, the support heads 5c of the second clamping device 5 and the loading unit 6b of the plug feeding device 6 occupy their respective positions away from the moving path C. The pointing device 2 and the plug inserting device 7 occupy their respective positions shown by phantom lines in FIG. 1 away from the moving path C. Thus, the tube B can pass along the moving path C, and is delivered by the pinch rolls 13 and 13 from the right to the left in FIGS. 1 and 2 along the moving path C on the automatic tube pointing apparatus A. When the trailing axial end of the tube B is moved to a position between the second clamping device 5 and the plug feeding device 6, the rotation of the pinch rolls 13 and 13 are suspended to halt the movement of the tube B and, subsequently, the plug inserting operation and the pointing operation are performed. 
     As the movement of the tube B is halted, the first clamping device 3 is actuated to cause the chuck thereof to clamp and support the tube B, and the second clamping device 5 is actuated to cause the support heads 5c to be pressed against the trailing axial end portion of the tube B, to thereby support or hold the trailing axial end portion. Simultaneously, the plug inserting device 7 is slightly moved horizontally and is moved downwardly to locate the inserting nozzle 7c in a position in alignment with the moving path C so as to cause the inserting nozzle 7c to face to the trailing axial end face of the tube B. 
     Subsequently, the tube press 4 is actuated to cause the press heads 4c and 4c to be moved toward the tube B on the moving path C so as to be pressed against the opposite side faces of the tube B, to thereby slightly dimple the opposite sides of the tube B to form a first positioning section thereon, and the tube press 4 is again actuated to cause the press heads 4c to be moved away from the tube B. Then, the plug inserting device 7 is actuated to cause the inserting nozzle 7c to be horizontally moved forwardly to the left in FIG. 1 and 2 into the tube B from the axial end face thereof, and the lubricant supply device 8 is then actuated to supply oil into the tube B through the inserting nozzle 7c. 
     After the completion of the oil supply, the plug inserting device 7 is again actuated to cause the inserting nozzle 7c to be moved rearwardly. Subsequently, the plug feeding device 6 is actuated to cause the loading unit 6b to take one of the plugs 10 out of the case 6a and to bring the plug 10 to the position facing to the axial end face of the tube B. The plug inserting device 7 is once again actuated to move forwardly the inserting nozzle 7c to cause the same to urge the plug 10 into the end portion of the tube B until the plug 10 reaches the first positioning section on the tube B and, thereafter, to again move rearwardly the inserting nozzle 7c out of the tube B. The plug inserting device 7 is then moved upwardly and is returned to its home position. 
     Subsequently, the second clamping device 5 is actuated to move the support heads 5c away from the tube B. The tube press 4 is moved along the moving path C toward the axial end face of the tube B to a position between the inserted plug 10 and the axial end face of the tube B, and is again actuated to dimple the opposite sides of the tube B to form a second positioning section thereon for preventing the inserted plug 10 from coming out of the tube B. 
     Subsequently, the tube press 4 and the second clamping device 5 are moved toward the first clamping device 3 and, simultaneously, the pointing device 2 is moved toward the moving path C to receive the end portion of the tube 3 in the insertion opening and is actuated to apply the pointing operation to the received end portion of the tube B. 
     After the completion of the pointing operation by the pointing device 2, the pointing device 2 is moved away from the tube B and is returned to its home position shown by the phantom lines in FIGS. 1 and 2. 
     Then, the tube B is moved along the moving path C and is delivered to a subsequent working station, and a new tube B is delivered on the automatic tube end processing apparatus A. 
     The sequential control unit 15 is operative in response to the respective signals from the limit switches associated with the various components to automatically control the positioning of the tube B, the respective movements of the pointing device 2 and the plug inserting device 7, and the respective actuations of the first clamping device 3, tube press 4, second clamping device 5, plug feeding device 6, plug inserting device 7 and lubricant supply device 8. 
     With the automatic tube end processing apparatus A in accordance with the present invention, the inserting operation of the plug 10 into the tube B and the pointing operation on the end portion of the tube B can be performed automatically without relying on an operator&#39;s labor. Thus, operator&#39;s working of dimpling the tube by the hammer, the operator&#39;s working of inserting the plug 10 into the tube B and the operator&#39;s working of inserting the end portion of the tube B into the pointing device 2 become unnecessary to prevent a strain from being applied to the operator, to thereby considerably improve the working efficiency. 
     FIGS. 3 to 5 illustrate an automatic tube end processing apparatus generally designated by the reference character A&#39; in accordance with another embodiment of the present invention. The automatic tube end processing apparatus A&#39; comprises a plug inserting device, generally designated by the reference numeral 70, modifying the plug inserting device 7 shown in FIGS. 1 and 2. The remaining components of the apparatus A&#39; are substantially identical with those of the previous apparatus A and are designated by the same reference characters. Such identical or like components of the apparatus A&#39; will not be described in detail for simplification. 
     The plug inserting device 70 comprises a support frame 70a fixedly mounted on a side of the base frame 1a so as to face to a side face of the pointing device 2, a pivotable arm structure 70b pivotally mounted on the support frame 70a, and a piston and cylinder assembly 70c connected to the pivotable arm structure 70b to angularly move the same. A pair of parallel guide cylindrical members 70d are fixedly mounted on the pivotable arm structure 70b. Rods 70f extending in parallel to the moving path C are slidably supported within the guide cylindrical members 70d, respectively, so as to be guided thereby. The rods 70f have their respective axial opposite ends connected by bridging members 70g and 70h, respectively. An inserting nozzle 70e communicating with the lubricant supply device 8 is connected to the bridging member 70g, and a piston and cylinder assembly 70i has a piston rod which is also connected to the bridging member 70g. Thus, when the piston and cylinder assembly 70c is actuated to angularly move the pivotable arm structure 70b, the inserting nozzle 70e connected to the arm structure 70b through the bridging member 70g, rods 70f and guide members 70d is moved between a position in alignment with the moving path C and a position out of alignment therewith. In addition, when the piston and cylinder assembly 70i is actuated, the inserting nozzle 70e connected to the piston rod of the piston and cylinder assembly 70i through the bridging member 70g is moved in parallel to the moving path C. 
     The automatic tube end processing apparatus A&#39; having the described construction operates in a manner substantially the same as that in which the previously described apparatus A operates.