JP2009202193A - Method of joining two members - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely perform plastic flow joining without damaging a bar-like member and without shortening service life of a tool even when one of two members is the bar-like member. <P>SOLUTION: In a method of joining by which one end part of a piston rod 3 is fit into the fitting hole 7 of a solenoid case 4 which is the component of the piston, local plastic flow is caused on the solenoid case 4 by pushing in the peripheral part of the fitting hole 7 with a punch which is moved along the piston rod 3 and the material is made to flow into annular grooves 6 which are preformed on the peripheral surface of the piston rod 3, a clinch ring 8 which includes a cross-sectional shape equivalent to a projection and is composed of a material the thickness of which is higher than that of the solenoid case 4, is separately prepared instead of the push-in part of the punch to the solenoid case 4, and the plastic flow is caused by pushing in the clinch ring 8 into the solenoid case 4 with the punch. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a two-member joining method for joining two members using plastic flow (metal flow).

  Conventionally, as a method of joining two members using plastic flow, for example, there is one described in Patent Document 1. This is applied to the coupling between the valve guide and the yoke constituting the electromagnetic fuel injection valve, one end of the valve guide which is one member is fitted into the fitting hole of the yoke which is the counterpart member, The periphery of the fitting hole of the yoke is pushed by a die (tool) to cause local plastic flow in the yoke material, and the material flows into a groove formed in advance on the peripheral surface of the valve guide. I have to.

  By the way, in order to reliably perform the plastic flow coupling described above, the fitting gap between the tool and one member is set to be small so that the material that has caused plastic flow due to the pressing of the tool does not escape to an extra place. There is a need. However, when this type of plastic flow connection is applied to, for example, a connection between a piston rod and a piston of a fluid pressure shock absorber (hydraulic shock absorber), the one member is a long piston rod (rod-like member). Therefore, when the distance of the tool moved along the rod-shaped member is remarkably increased and the fitting gap between the two is set to be small, there is a risk of scratching the surface of the rod-shaped member. And when the damage | wound extends to the whole piston rod, when it assembles | assembles as a fluid pressure buffer, a fluid leak may generate | occur | produce as a cause of the damage | wound directly or indirectly. Further, since the processing load is concentrated on the indented portion of the tool, there is a risk that the indented portion is broken, and shortening of the tool life is inevitable.

Japanese Patent Laid-Open No. 61-201878

  The present invention has been made in view of the technical background described above, and the problem is that even if one of the two members is a rod-shaped member, the rod-shaped member is not damaged and the tool life is increased. It is an object of the present invention to provide a two-member joining method capable of stably performing plastic flow joining without shrinking.

  In order to solve the above-mentioned problems, the present invention is configured to fit one end of a rod-shaped member into a fitting hole of a mating member, and press the peripheral portion of the mating hole of the mating member with a tool so as to localize the mating member. In a two-member joining method in which a plastic flow is caused and the material flows into a groove formed in advance on the peripheral surface of the rod-shaped member, the pushing portion of the tool against the mating member is harder than the mating member Instead of a push ring made of a material, the push ring is pushed into a mating member by the tool to cause plastic flow.

  According to the two-member joining method of the present invention, a separate push ring is pushed into the mating member to cause plastic flow, so that the tool only serves to push the push ring, and as a result, the tool and the rod-like member. Can be set large, and the problem of damage to the rod-shaped member due to the tool can be solved. In addition, since there is no indented portion at the tip of the tool that may break, the life of the tool is extended.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows a hydraulic shock absorber component (fluid pressure shock absorber component) obtained by a two-member joining method according to one embodiment of the present invention. The hydraulic shock absorber component 1 is composed of a piston rod (bar-shaped member) 3 and a solenoid case (counter member) 4 constituting a pilot type damping force adjusting hydraulic shock absorber 2 described later shown in FIG. The coupling portion 5 includes a plurality of (here, two) annular grooves 6 provided at one end of the piston rod 3 and an inner surface of a fitting hole 7 provided at the bottom of a solenoid case (hereinafter simply referred to as a case) 4. Is set between. The coupling portion 5 has a structure in which the material of the case 4 is filled in the annular groove 6 of the piston rod 3 by plastic flow. The coupling portion 4 also includes a pushing ring (clinch ring) 8 that is pushed into the opening end of the fitting hole 7. The pushing ring 8 is pushed in order to cause local plastic flow in the material of the case 4 and is made of a material that is harder than the case 4. In the present embodiment, the push ring 8 is pushed until the back surface thereof is flush with the end face of the case 4. The flat end face of the case 4 including the push ring 8 has an extended end of the piston rod 3. The stop rubber 9 to be regulated is arranged in a surface contact state.

  The pilot type damping force adjusting hydraulic shock absorber 2 shown in FIG. 5 is extracted from Japanese Patent Application Laid-Open No. 2006-292092. In the figure, reference numeral 10 denotes a bottomed cylindrical cylinder, and the inside of the cylinder 10 is defined by a free piston 11 into a gas chamber 12 on the bottom side and an oil chamber 13 on the open end side. A piston 14 is slidably disposed in the oil chamber 13. The piston 14 includes a piston body 14a, a piston bolt 14b connected to the piston body 14a, and the case (solenoid case) 4 connected to the piston bolt 14b. One end of the piston rod 3 is coupled to the case 4, and the other end is slidably and liquid-tightly inserted through the guide means 15 attached to the opening end of the cylinder 10. Has been extended. The piston 12 includes an expansion side main valve 16, a contraction side main valve 17, a damping force adjustment valve 18 that can adjust the internal pressure of the back pressure chamber of each main valve 16, 17, and a solenoid actuator that drives the damping force adjustment valve 18. 19 etc. are built in. The solenoid actuator 19 is accommodated in the case 4, and a lead wire W for supplying electric power to the solenoid actuator 19 extends in the hollow piston rod 3.

  In the pilot type damping force adjusting hydraulic shock absorber 2 described above, by driving the damping force adjusting valve 18 by the solenoid actuator 19, the internal pressures of the back pressure chambers of the main valves 16 and 17 on the expansion side and the contraction side change, As a result, the valve opening pressures of the main valves 16 and 17 are controlled, and the damping force characteristics can be adjusted over a wide range. For the detailed configuration and operation of the hydraulic shock absorber 2, refer to the above-mentioned JP-A-2006-292092.

  Hereinafter, a method of connecting the piston rod 3 and the case 4 constituting the pilot type damping force adjusting hydraulic shock absorber 2 will be specifically described with reference to FIGS.

  FIG. 2 shows a coupling device for carrying out the present coupling method. In the figure, 20 is a punch (tool) having a cylindrical shape, and 21 is a holder fitted on the punch 20. The holder 21 is fixed to the front surface of the movable body 22 that moves forward and backward in the direction of the arrow FF ′ by driving means (not shown), and in this state, the rear end of the punch 20 is movable. It comes into contact with the front surface of the body 22. A rod insertion hole 22a that allows the piston rod 3 to be inserted is formed in the movable body 22, and the punch 20 and the holder 21 are positioned so as to be concentric with the rod insertion hole 22a. The inner diameter of the punch 20 and the diameter of the rod insertion hole 22a are set to a size that allows the piston rod 3 to be loosely inserted, whereby the punch 20 and the movable body 22 can move along the piston rod 3 without resistance. It is like that. Further, the length of the punch 20 is shorter than the holder 21 by a predetermined length S, and the front end of the holder 21 is more than the punch 20 in a state where the rear end of the punch 20 is in contact with the front surface of the movable body 22. Also protrudes by a predetermined length S.

  Reference numeral 25 denotes a columnar support block that supports the bottomed cylindrical case 4 that is a coupling partner (a mating member) of the piston rod 3. The support block 25 is fixed to the front surface of the stationary platen 26 arranged on the front side in the forward direction F of the movable body 22 by using bolts 27 and is concentric with the punch 20 and the holder 21 on the movable body 22 side. Is positioned. The diameter of the support block 25 is set to a size that can be loosely fitted to the case 4, whereby the case 4 is fitted to the support block 25 with its inner bottom in contact with the tip of the support block 25. It comes to be supported. Further, an elastic ring 28 as an automatic alignment mechanism is mounted on the outer peripheral surface of the support block 25, and the case 4 is fitted and supported by the support block 25 so as to be slightly floatable in the radial direction by the elastic ring 28. It has become so.

  Here, the inner diameter of the holder 21 on the movable body 22 side is set to be equal to or slightly larger than the outer diameter of the bottom of the case 4 provided with the fitting hole 7 (FIG. 1). Therefore, when the holder 21 moves forward integrally with the movable body 22, the case 4 fitted and supported by the support block 25 is fitted into the holder 21 while floating slightly in the radial direction, and the outer diameter thereof is restrained by the holder 21. . On the other hand, the punch 20 functions to press the back surface of the push ring 8 in accordance with the advance of the movable body 22 and push the push ring 8 into the inner peripheral portion of the fitting hole 7 of the case 4.

  When connecting the piston rod 3 and the case 4, as described with reference to FIG. 1, a plurality of (here, two) annular grooves 6 are formed in advance at the tip of the piston rod 3. A body pushing ring 8 is prepared. As is well shown in FIG. 3, the annular groove 6 has a triangular cross-sectional shape having an apex angle α. The plurality of annular grooves 6 are formed so as to be connected from a portion adjacent to the indentation depth D of the indentation ring 8 with respect to the case 4, and the entire groove width (inlet width) E is substantially equal to each annular groove. 6 entrance width is added. Note that the depth d of the annular groove 6 is set to a size necessary for ensuring a desired coupling strength.

  On the other hand, the pushing ring 8 has an inner diameter that can be fitted to the piston rod 3 with a slight clearance, as shown in FIG. The pushing ring 8 has a truncated conical surface in which the back surface on the side pressed by the punch 20 forms a vertical surface perpendicular to the axis, and the front surface on the side pushed into the case 4 gradually falls toward the inner diameter side. It has an irregular cross section that forms That is, a predetermined wedge angle θ is given to the front surface side of the pushing ring 8 by the truncated conical surface, and when the pushing ring 8 is pushed into the case 4 by the wedge angle θ, it enters the annular groove 6. The plastic flow of the case material is promoted. The cross-sectional size of the pushing ring 8 determined by the pushing depth D, the wedge angle θ, and the width B of the pushing ring 8 is large enough to cause a plastic flow amount sufficient to fill the annular groove 6 with the material. It becomes.

  In order to couple the piston rod 3 and the case 4, the movable body 22 is retracted in advance with respect to the stationary platen 26 so that the punch 20 and the holder 21 are largely separated from the support block 25. Then, in this state, the case 4 is fitted and set to the support block 25, and at the same time, the piston rod 3 is inserted into the punch 20 through the rod insertion hole 22 a of the movable body 22, and the tip portion is protruded from the punch 20. Next, the pushing ring 8 is fitted and inserted into the tip of the piston rod 3, and this is positioned at the back side of the annular groove 6 as shown in the upper side of FIG.

  Thereafter, the front end of the piston rod 3 is fitted into the fitting hole 7 of the case 4 on the support block 25 until it bottoms, and in this state, the punch 20 and the holder 21 are advanced together with the movable body 22. By this advancement, as shown in the upper side of FIG. 4, first, the holder 21 is fitted to the bottom of the case 4, and the outer diameter of the case 4 is restrained by the holder 21. At this time, the case 4 is aligned by the elastic ring 28, and the case 4 is smoothly fitted into the holder 21.

  Even after the outer diameter of the case 4 is restricted by the holder 21, the movable body 22 continues to advance. Subsequently, the punch 20 presses the back surface of the push ring 8, and the push ring 8 is inserted into the fitting hole 7 of the case 4. Push it into the periphery. By this pushing, the material in the periphery of the fitting hole 7 of the case 4 locally causes plastic flow and flows into the annular groove 6 of the piston rod 3, whereby the piston rod 3 and the case 4 are plastically flow-coupled. The At this time, since the pushing ring 8 is fitted to the piston rod 3 with a slight clearance and the outer diameter of the case 4 is constrained by the holder 21, the material in the periphery of the case 4 is smoothly formed in the annular groove 6. It flows into the inside, and both are reliably plastically flow-coupled. Particularly in the present embodiment, since the wedge angle θ is formed on the front surface of the pushing ring 8, the material that has caused plastic flow is surely directed to the annular groove 6, and the both are more securely plastically bonded. On the other hand, since the punch 20 is loosely inserted into the piston rod 3, the piston rod 3 is not damaged even if it moves along the long piston rod 3 for a long distance. Further, since the pushing ring 8 is fitted into the tip of the piston rod 3, the entire piston rod 3 is not damaged.

  Incidentally, when plastic flow bonding is performed without using the pushing ring 8, as shown in FIG. 6, a punch 30 provided with a pushing projection (pushing portion) 31 instead of the pushing ring 8 at the tip is used, and The tip of the punch 30 must be fitted to the piston rod 3 which is a rod-shaped member with a slight clearance. In this case, since the punch 30 moves for a long distance with the piston rod 3 tightly fitted, there is a risk that the piston rod 3 may be damaged. Further, since a large processing load is applied to the pushing protrusion 31 at the tip of the punch 30, there is a risk that the pushing protrusion 31 is broken, and the tool life is shortened. The pushing ring 8 used in the present invention replaces the pushing projection 31 of the punch 30. Therefore, the tip of the punch 20 used in the present invention is finished in a flat shape.

  Further, when the pushing ring 8 is not used, the trace of the pushing projection 31 of the punch 30 described above remains as a concave hole on the end surface of the case 4 which is the counterpart member. For this reason, as shown in FIG. 7, the stop rubber 9 'is required to have a modified cross-section matched to the concave hole, and in this case, the manufacture of the stop rubber 9' becomes troublesome and its manufacturing cost Rises. However, according to the coupling method of the present invention, the stop rubber 9 is left in surface contact with the flat surface of the case 4 including the push ring 8 by leaving the push ring 8 pushed into the case 4 as described above. Therefore, the manufacturing cost is reduced correspondingly.

  In the above embodiment, two annular grooves 6 are provided in the piston rod 3, and the number of the annular grooves 6 is arbitrary, and may be one or three or more. The annular groove 6 may be replaced with a groove that is intermittent in the circumferential direction.

  Here, in the said embodiment, the example applied to the coupling | bonding of the piston rod 3 and the case 4 of the pilot type damping force adjustment type hydraulic shock absorber 2 provided with the back pressure chamber on both the expansion side and the contraction side was shown. However, the type of the pilot type damping force adjusting hydraulic shock absorber is arbitrary, and it is needless to say that the pilot type damping force adjusting type hydraulic shock absorber having a back pressure chamber only on the extension side may be used.

  The application range of the present invention is also arbitrary, and can be applied to the connection between a piston rod and a piston of a general-purpose hydraulic shock absorber or cylinder device, and can be used to connect various rod-shaped members to a mating member.

It is sectional drawing which shows the hydraulic shock absorber components obtained by the joining method of 2 members which is one Embodiment of this invention. It is sectional drawing which shows the implementation condition of the coupling | bonding apparatus and the coupling | bonding method for performing coupling | bonding of these 2 members. It is sectional drawing which expands and shows the principal part of FIG. The implementation state of the method of joining the two members is shown, with the upper side showing the initial stage of implementation and the lower side showing the final stage of implementation. It is sectional drawing which shows the whole structure of the pilot type damping force adjustment type hydraulic shock absorber including the hydraulic shock absorber components obtained by the method of the present invention. It is sectional drawing which shows the implementation condition at the time of applying the conventional general plastic flow coupling | bonding to manufacture of a hydraulic shock absorber component. It is sectional drawing which shows the shape of the stop rubber required when the conventional general plastic fluid coupling | bonding is applied to manufacture of a hydraulic shock absorber component.

Explanation of symbols

1 Hydraulic shock absorber parts 2 Pilot type damping force adjustable hydraulic shock absorber 3 Piston rod (bar-shaped member)
4 Solenoid case (mating member)
6 Annular groove 7 Fitting hole 8 Push ring 9 Stop rubber 20 Punch 21 Holder 25 Support block

Claims (4)

  One end of the rod-shaped member is fitted into the mating hole of the mating member, and the peripheral portion of the mating hole of the mating member is pushed in by a tool to cause local plastic flow in the mating member, and the material is the rod-shaped In the joining method of two members to flow into a groove formed in advance on the peripheral surface of the member, the pushing portion of the tool against the mating member is replaced with a pushing ring made of a material harder than the mating member, and the pushing A two-member joining method, wherein a ring is pushed into a mating member by the tool to cause plastic flow.   2. The method of connecting two members according to claim 1, wherein after the pushing ring is pushed into the mating member, the pushing ring is left as it is in the mating member.   The two-member coupling method according to claim 1 or 2, wherein the rod-shaped member is a piston rod of a fluid pressure shock absorber, and the counterpart member is a piston of the fluid pressure shock absorber.   2. The rod-shaped member is a piston rod of a pilot type damping force adjusting fluid pressure buffer, and the mating member is a solenoid case of the pilot type damping force adjusting fluid pressure buffer. Alternatively, the two-member joining method according to 2.

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