JP2016068127A - Jointing method, and joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress vibrations which occur at the time of frictional pressure-welding members to each other.SOLUTION: A jointing method of a piston rod 30 for jointing a rod body 10 (a first member) and a rod head 20 (a second member) comprises: a bending step of forming a bent portion 13 by bending the tip of a hollow cylindrical part 12 formed in the rod body 10 to a radially inner side; and a jointing step of jointing the joint face 13A to be formed in the bent portion 13 and the joint face 22 of the rod head 20 by frictional pressure-welding.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a joining method and a joined body for joining members together by friction welding.

  A method of manufacturing a piston rod by joining a pipe-shaped member and an end member by friction-welding the end surfaces of each other is known.

  Patent Document 1 discloses a friction welding component in which a cylindrical portion of a first member and a cylindrical portion of a second member are joined by friction welding.

JP 2008-55486 A

  However, in such a conventional friction welding component, when the first member and the second member are friction-welded, vibration is generated by the impact of the cylindrical portion of the first member and the cylindrical portion of the second member hitting each other. There arises a problem that the two are not smoothly joined by this vibration.

  The present invention has been made in view of the above-described problems, and an object thereof is to suppress vibrations that occur when members are friction-welded to each other.

  The present invention is a joining method in which a first member and a second member are joined by friction welding, and a bent portion is formed by bending a distal end portion of a hollow cylindrical portion formed in the first member radially inward. It comprises a bending step, and a joining step for joining the joining surface formed in the bent part and the joining surface of the second member by friction welding.

  Further, the present invention is a joined body in which the first member and the second member are joined by friction welding, and the first member has a bent portion in which a distal end portion of a hollow cylindrical portion is bent radially inward. The second member includes a joining surface joined by friction welding to a joining surface formed in the bent portion.

  In the present invention, the bent portion is formed by bending the distal end portion of the hollow cylindrical portion formed in the first member radially inward, and the joining surface of the first member formed in the bent portion is changed from the cylindrical portion to the diameter. Extends inward. Thereby, when the joining surface of the first member and the joining surface of the second member are friction-welded, the contact portion where the joining surface of the first member abuts on the joining surface of the second member is near the central axis of the cylindrical portion I come to. For this reason, the vibration produced by the impact which arises in a contact part is suppressed, and joining by friction welding is performed smoothly.

It is a top view which shows the piston rod which concerns on 1st Embodiment of this invention, and shows it with a partial cross section. It is a top view which shows a rod head and the rod main body before a process, and shows in a partial cross section. It is a top view which shows the rod main body in a bending process, and shows in a partial cross section. It is a top view which shows the rod main body in a cutting process, and shows a partial cross section. It is a top view which shows the rod main body and rod head in a joining process, and shows in a partial cross section. It is a top view which shows the rod main body in the cutting process which concerns on 2nd Embodiment of this invention, and shows it with a partial cross section. It is a top view which shows the rod main body and rod head in a joining process, and shows in a partial cross section. It is a top view which shows the rod main body and rod head in a joining process, and shows in a partial cross section. It is a top view which shows the rod head in the bending process which concerns on 3rd Embodiment of this invention, and shows it with a partial cross section. It is a top view which shows the rod head in a cutting process, and shows in a partial cross section. It is a top view which shows the rod main body in a bending process, and shows in a partial cross section. It is a top view which shows the rod main body in a cutting process, and shows a partial cross section. It is a top view which shows the rod main body and rod head in a joining process, and shows in a partial cross section.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a plan view showing a piston rod 30 in the present embodiment. In addition, for simplification of description, the rod main body 10 is illustrated with a part omitted. The piston rod 30 of the present embodiment is inserted into a cylinder body (not shown) of a fluid pressure cylinder used as an actuator so as to freely advance and retract. In the drawing, O is a central axis extending to the center of the piston rod 30.

  The piston rod 30 is a joined body in which a rod body 10 provided as a first member and a rod head 20 provided as a second member are joined together. The rod body 10 and the rod head 20 are made of metal. As will be described later, the rod body 10 is formed of a thick pipe material, and a hollow cylindrical portion 12 extends at one end. The rod body 10 is formed with a bending portion 13 (drawing portion) bent radially inward by spinning (drawing) the distal end portion of the cylindrical portion 12, and is formed on a joint surface 13 </ b> A formed on the bending portion 13. The joint surface 22 of the rod head 20 is joined by friction welding. The “radial direction” means a radial direction around the central axis O of the rod body 10.

  The rod body 10 includes a small-diameter portion 16 to which a piston (not shown) that slides in the cylinder body is coupled, and a large-diameter portion 17 having a larger diameter than the small-diameter portion 16. The annular piston is fitted on the outer periphery of the small-diameter portion 16, is locked to the step portion 18 at the boundary between the small-diameter portion 16 and the large-diameter portion 17, and is fastened to the screw portion 19 of the small-diameter portion 16 ( (Not shown).

  FIG. 2 is a plan view showing the rod body 10 before spinning. A cylindrical tube portion 12 extends on the opposite side to the small diameter portion 16 of the rod body 10 in the axial direction, and a hollow portion 11 is formed inside the tube portion 12. The hollow portion 11 is open to the end surface 12A of the cylindrical portion 12.

  The solid rod head 20 includes an annular clevis 25 connected to a load, and a solid body portion 26 having the same diameter as the large diameter portion 17 of the rod body 10. The clevis 25 is connected to the other party via a pin (not shown) inserted therein. The body portion 26 includes a planar joining surface 22 (end surface) on the opposite side to the clevis 25 in the axial direction, and the joining surface 22 is joined to a joining surface 13 </ b> A formed on the bending portion 13 of the rod body 10.

  Next, a joining method for joining the rod main body 10 (first member) and the rod head 20 (second member) will be described with reference to FIGS. 3A to 3C.

  First, as shown in FIG. 3A, a bending process (squeezing process) is performed in which the tip of the cylindrical portion 12 of the rod body 10 is spun. In the spinning process, the rod main body 10 is rotationally driven by a chuck spindle (not shown), and a die 8 (on the tip of the cylindrical portion 12 of the rod main body 10 that rotates about the central axis O as indicated by an arrow in the figure). By pressing the roller), the distal end portion of the cylindrical portion 12 is plastically deformed and bent inward in the radial direction, and a bent portion 13 extending from the cylindrical portion 12 inward in the radial direction is formed. When the thickness of the cylindrical portion 12 is large, the cylindrical portion 12 may be heated using a high-frequency heating device (not shown) during the spinning process.

  As shown in FIG. 3A, the bent portion 13 extends radially inward from the cylindrical portion 12 and comes into contact with the central axis O, thereby closing the opening of the hollow portion 11.

  The bent portion 13 is bent into an arc shape in cross section, so that a central hollow portion 14 that is recessed in a concave shape is formed outside the central portion of the bent portion 13. The central depression 14 is a tapered hole centered on the central axis O, and the opening diameter thereof gradually decreases in the direction of the central axis O.

  Between the inner periphery of the cylindrical portion 12 and the bent portion 13, an inner peripheral recess portion 15 that is recessed in an annular shape is formed. The cross-sectional shape of the inner peripheral recess 15 is formed in a substantially U-shaped arc shape.

  Next, as shown to FIG. 3B, the cutting process which cuts and removes a part of bending part 13 is performed. In the cutting process, the rod body 10 is rotationally driven by a chuck spindle (not shown), and a part of the bending portion 13 of the rod body 10 that rotates about the central axis O as shown by an arrow in the figure is cut by the cutting tool 9. To cut.

  In the cutting process, the bending surface 13 is formed with a joining surface 13A by cutting. The joining surface 13A is formed in a planar shape so that the central depression 14 opened to the joining surface 13A is eliminated.

  Next, as shown in FIG. 3C, a joining process is performed in which the joining surface 13A of the rod body 10 and the joining surface 22 of the rod head 20 are joined by friction welding. In the joining step, the rod body 10 is rotationally driven by a chuck spindle (not shown), and the joining surface 13A of the rod body 10 that rotates about the central axis O as shown by the arrow in the figure is used as the joining surface 22 of the rod head 20. The base materials that are melted by the generated frictional heat are bonded to each other.

  When friction welding is started, the contact portion where the joint surface 13A of the rod body 10 and the joint surface 22 of the rod head 20 first contact each other is on the central axis O on which the rod body 10 and the rod head 20 rotate relative to each other. Since it exists or is close to the center axis O, vibrations caused by an impact generated in the contact portion are suppressed, and the rod body 10 and the rod head 20 are smoothly joined.

  At the time of friction welding, the base material of the joint surface 13A of the rod body 10 and the joint surface 22 of the rod head 20 is discharged outward from the joint portion of the rod body 10 and the rod head 20 by plastic flow. At this time, since the joining surface 13A formed in the bent portion 13 extends radially inward of the cylindrical portion 12, the base material is not discharged to the inner peripheral side of the cylindrical portion 12 by plastic flow, and the cylindrical portion 12 It is discharged only on the outer peripheral side. Thereby, as shown in FIG. 1, in the rod body 10, the base material discharged to the outer peripheral side of the cylindrical portion 12 remains as a bead (burr), but no bead remains on the inner peripheral side of the cylindrical portion 12. In the cutting process performed after the joining process, the beads 13B and 22B left on the outer peripheral side of the cylindrical portion 12 are deleted by cutting.

  As shown in FIG. 3C, since the central recess 14 does not open on the joint surface 13A of the rod body 10 in the joining step, the joint of the joint surface 13A of the rod body 10 and the rod head 20 joined together as shown in FIG. There is no gap between the surface 22.

  Thus, the piston rod 30 (joined body) is joined by friction welding to the rod body 10 (first member) having the bending portion 13 extending radially inward from the cylindrical portion 12 and the joining surface 13A formed on the bending portion 13. It is formed by joining the rod head 20 (second member) having the joined surface 22.

  According to the above 1st Embodiment, there exists an effect shown below.

  The piston rod 30 is joined by bending the distal end portion of the hollow cylindrical portion 12 formed in the rod body 10 inward in the radial direction to form the bent portion 13, and the rod body 10 formed in the bent portion 13. The joining surface 13A extends radially inward from the cylindrical portion 12. Thereby, when the joint surface 13A of the rod body 10 and the joint surface 22 of the rod head 20 are friction-welded, the contact portion where the joint surface 13A of the rod body 10 contacts the joint surface 22 of the rod head 20 is a cylindrical portion. It comes near the 12 central axis O. For this reason, the vibration produced by the impact which arises in a contact part is suppressed, and joining by friction welding is performed smoothly.

  The piston rod 30 formed as a joined body of the rod main body 10 and the rod head 20 in this way can suppress the vibration generated when the rod main body 10 and the rod head 20 are friction-welded, thereby improving the joining position accuracy of both. As a result, quality can be improved and productivity can be improved by shortening the time required for joining.

  In addition, since the rod body 10 and the rod head 20 are smoothly joined, vibration applied to the equipment that performs friction welding can be reduced, and the durability of the equipment can be enhanced.

  Further, since the rod body 10 includes an inner peripheral recess 15 that is annularly recessed between the inner periphery of the cylindrical portion 12 and the bent portion 13, the flow of a line of force against the load acting in the axial direction of the piston rod 30 is reduced. It can be changed by the circumferential recess 15 to reduce the stress generated on the inner periphery of the cylindrical portion 12 at the time of friction welding, and the deterioration of the durability of the piston rod 30 can be suppressed.

  Furthermore, since the cross-sectional shape of the inner peripheral recess portion 15 is a substantially U-shaped arc shape, a change in the cross-sectional shape of the inner peripheral recess portion 15 of the cylindrical portion 12 is reduced to suppress local concentration of stress. Therefore, it is possible to suppress a decrease in the durability of the piston rod 30.

  Further, since the bent portion 13 of the rod body 10 extends radially inward to close the hollow portion 11, the base material of the rod body 10 and the rod head 20 is discharged to the inner peripheral side of the cylindrical portion 12 by plastic flow during friction welding. And will not remain as a bead. Thereby, it is avoided that the stress concentration resulting from a bead arises in the inner periphery of the cylinder part 12. FIG.

  Furthermore, as for the piston rod 30, since the rod main body 10 is formed of a thick-pipe material, it is possible to achieve both sufficient securing of the rigidity of the rod main body 10 and reduction in weight.

  Further, the bending portion 13 is cut in the cutting process to form the joining surface 13A into a flat shape, and the central depression 14 opened to the outside of the bending portion 13 is eliminated, thereby joining by friction welding in the joining step. There is no gap between the bent portion 13 and the rod head 20. Thereby, when the nondestructive inspection of a product is performed, it is avoided that the space | gap produced between the rod main body 10 and the rod head 20 is detected as a flaw in the inside of the piston rod 30, and inspection accuracy is improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. 4A to 4C. Below, it demonstrates centering on a different point from the said 1st Embodiment, the same code | symbol is attached | subjected to the structure same as the piston rod 30 of the said 1st Embodiment, and description is abbreviate | omitted.

  In the cutting process according to the first embodiment, the joining surface 13A of the rod body 10 is formed into a flat shape by cutting, and the central depression 14 that opens to the joining surface 13A is eliminated. On the other hand, in the cutting process according to the second embodiment, the joint surface 13D of the rod body 10 is cut into a taper shape to project the central portion, and the central recess portion 14 that opens to the joint surface 13D remains.

  As shown to FIG. 4A, in a cutting process, as shown by the arrow in a figure, a part of bending part 13 rotated centering on the center axis | shaft O is cut and removed by the cutting tool 9. FIG. The joint surface 13D of the rod main body 10 is formed in a taper shape so that the central portion protrudes by cutting, and a central depression 14 that opens to the joint surface 13D is left at the central portion of the joint surface 13D.

  Next, as shown in FIG. 4B and FIG. 4C, in the joining step, the joining surface 13D of the rod body 10 and the joining surface 22 of the rod head 20 that rotate relative to each other about the central axis O as shown by the arrows in the figure. Join by friction welding.

  At the start of the friction welding, as shown in FIG. 4B, the central portion of the joint surface 13 </ b> D protruding from the rod body 10 in a tapered shape and the joint surface 22 of the rod head 20 first come into contact with each other. Thereby, since the contact part of the rod main body 10 and the rod head 20 comes to a position close to the central axis O, the occurrence of vibration due to the impact generated in the contact part is suppressed, and the joint between the rod main body 10 and the rod head 20 is prevented. It is done smoothly.

  At the time of friction welding, the base material of the joint surface 13D of the rod body 10 and the joint surface 22 of the rod head 20 is discharged to the outside by plastic flow, and as shown in FIG. The central depression 14 that has been opened is eliminated. For this reason, there is no gap between the joint surface 13D of the rod body 10 to be joined and the joint surface 22 of the rod head 20.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. 5A to 5E. Below, it demonstrates centering on a different point from the said 1st Embodiment, the same code | symbol is attached | subjected to the structure same as the piston rod 30 of the said 1st Embodiment, and description is abbreviate | omitted.

  The piston rod 30 according to the first embodiment is formed by joining a hollow rod body 10 and a solid rod head 20. In contrast, the piston rod 130 according to the third embodiment is formed by joining the hollow rod body 10 and the hollow rod head 120 as shown in FIG. 5E.

  The hollow rod head 120 includes an annular clevis 125 connected to a load, and a cylindrical body 126.

  First, as shown in FIG. 5A, a bending process is performed in which the tip of the body 126 of the rod head 120 is spun. In the spinning process, the rod head 120 is rotationally driven by a chuck spindle (not shown), and the die 8 is attached to the tip of the body 126 of the rod head 120 that rotates about the central axis O as indicated by an arrow in the figure. By pressing, the distal end portion of the body portion 126 is plastically deformed and bent radially inward to form a bent portion 123 extending radially inward. The bent portion 123 is bent into an arc shape in cross section, so that a central recess 124 that is recessed in a concave shape is formed outside the central portion of the bent portion 123.

  Next, as shown to FIG. 5B, the cutting process which cuts and removes a part of bending part 13 is performed. In the cutting process, the rod head 120 is rotationally driven by a chuck spindle (not shown), and a part of the bending portion 123 of the rod head 120 rotating around the central axis O as shown by an arrow in the figure is cut by the cutting tool 9. To cut.

  In the cutting process, a bonding surface 123A is formed in the bending portion 123 by cutting. The joining surface 123A is formed in a planar shape so that the central depression 124 that opens to the joining surface 123A is eliminated.

  Next, as shown in FIG. 5C, a bending process is performed in which the tip of the cylindrical portion 12 of the rod main body 10 is spun. Thereby, the bending part 13 extended in the radial inside from the cylinder part 12 is formed.

  Next, as shown to FIG. 5D, the cutting process which cuts and removes a part of bending part 13 is performed. Thereby, the joining surface 13A is formed in the bending part 13 by cutting.

  Next, as shown in FIG. 5E, a joining step is performed in which the joining surface 13A of the rod body 10 and the joining surface 123A of the rod head 20 are joined by friction welding. In the joining step, the rod body 10 is rotationally driven by a chuck spindle (not shown), and the joining surface 13A of the rod body 10 that rotates about the central axis O as shown by the arrow in the figure is used as the joining surface 123A of the rod head 20. The base materials that are melted by the generated frictional heat are bonded to each other.

  In this manner, the piston rod 130 is formed by bending the end portions of the cylindrical rod body 10 (pipe material) and the cylindrical rod head 20 (pipe material) inward in the radial direction to form the bent portions 13 and 123. 13 and 123 are joined by friction welding.

  The embodiment of the present invention has been described above. However, the above embodiment is merely one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  In the above-described embodiment, the bending process, the cutting process, and the joining process are sequentially performed. However, the cutting process may be omitted, and the joining process may be performed after the bending process. In this case, the joint surface of the rod body 10 becomes the outer surface of the bent portion 13 that is not cut.

  Furthermore, in the said embodiment, although the bending part 13 is bent so that the hollow part 11 may be plugged up in a bending process, it is not restricted to this, and it bends so that the bending part 13 may open the hollow part 11 slightly in a bending process. It is good also as a structure to be made.

  The joining method of the present invention can be used not only for piston rods of fluid pressure cylinders but also for joined bodies used in other machines and equipment.

10 Rod body (first member)
DESCRIPTION OF SYMBOLS 11 Hollow part 12 Cylinder part 13 Bending part 13A, 13D Joining surface 15 Inner peripheral hollow part (dent part)
20, 120 Rod head (second member)
22, 123A Joint surface 30, 130 Piston rod (joint)

Claims (6)

A joining method for joining the first member and the second member by friction welding,
A bending step of bending the distal end portion of the hollow cylindrical portion formed in the first member radially inward to form a bent portion;
A joining step of joining the joining surface formed in the bent portion and the joining surface of the second member by friction welding.   The joining method according to claim 1, further comprising a cutting step of cutting the bent portion bent in the bending step to process the joining surface into a flat shape.   The joining method according to claim 1, further comprising a cutting step of cutting the bent portion bent in the bending step to process the joint surface into a taper shape so that a central portion protrudes. A joined body in which the first member and the second member are joined by friction welding,
The first member includes a bent portion in which a distal end portion of a hollow cylindrical portion is bent radially inward,
Said 2nd member is equipped with the joining surface joined by the friction welding on the joining surface formed in the said bending part, The joined body characterized by the above-mentioned.   5. The joined body according to claim 4, wherein the first member includes a hollow portion that is recessed in an annular shape between an inner periphery of the cylindrical portion and the bent portion. The joined body is a piston rod,
The first member is a rod body;
The joined body according to claim 4, wherein the second member is a rod head.

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