JP2009154174A - Fixture and method of fixing nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixture and a method of fixing a nut, capable of preventing a change in characteristics of setting an annular leaf valve configuring a piston unit when assembling the piston unit to be inserted into a cylinder configuring, e.g. a hydraulic shock absorber. <P>SOLUTION: A punch 11 integrally held in a holder member 12 movable forward and backward in an axial direction of a rod has a tip portion 11a to be press-fitted into a hole formed on the axial core portion of the distal end screw portion of the rod, wherein the external diameters of two portions face to each other with the axial core line sandwiched are larger than the internal diameter of the hole, the holder member 12 has elastic spring members 13 having an end carried by a case 14, and the end of each of the spring members 13 faces the end surface of the nut via the case 14. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut fixing jig and a nut fixing method, and more particularly to a nut fixing jig and a nut suitable for preventing loosening of a piston nut, for example, when assembling a piston portion in a cylinder body constituting a hydraulic shock absorber. Concerning the fixing method.

  There have been various proposals for fixing nuts in the cylinder body constituting the hydraulic shock absorber, for example, for securing the nut of the piston nut when assembling the piston portion. In this case, there is disclosed a method for fixing the nut in the piston portion so as not to change the setting characteristics of the annular leaf valve used for generating a damping force.

  That is, the place disclosed in Patent Document 1 is a caulking tool, and the caulking tool is press-fitted into a hole of a hole in a shaft core portion of the end thread portion of the piston rod. It has a punch.

  The punch is made of a cylindrical body having an outer diameter larger than the inner diameter of the hole and having a two-taper tapered surface at the tip, and notches two surfaces facing each other with the shaft core line in between at the tip. Yes.

  Therefore, according to the proposal disclosed in this Patent Document 1, the axial force to the punch acts so as to increase the inner diameter of the hole at two locations where the axial core is sandwiched, and the tip thread portion of the piston rod The piston nut that is screwed into the valve body is not pressed toward the piston body that is the valve seat member.

Therefore, an extra external force, that is, an external force along the axial direction of the piston rod does not act on the piston nut, so that the fixing force in the annular leaf valve fixed to the piston body is not changed, and as a result, the annular leaf valve The characteristics at are maintained as originally set.
JP 2007-253195 A (refer to abstract, paragraphs 0014 to 0017 and FIGS. 1 to 3 in the specification)

  However, in the proposal disclosed in the above-mentioned Patent Document 1, there is basically no problem in that the characteristics of the annular leaf valve can be maintained as originally set, but the caulking tool is used. In doing so, it may be pointed out that there is a minor bug.

  That is, according to the proposal disclosed in Patent Document 1 described above, the tip portion of the punch press-fitted into the hole bites into the inner periphery of the tip thread portion that forms the hole. When the process is finished and the leading end of the punch is extracted from the hole, there is a concern that it cannot be easily extracted.

  In order to extract the tip of the punch from the hole, for example, when the punch is swung, not only is it necessary to swivel, but the inner diameter of the hole into which the tip of the punch is press-fitted is more than necessary. The diameter is expanded.

  When the inner diameter of the hole is increased more than necessary in order to remove the tip of the punch, an external force is applied to the piston nut screwed to the tip threaded portion, and the piston nut becomes the piston body. There are concerns about changes in the setting characteristics of the annular leaf valve to be fixed to.

  The present invention has been made in view of such a current situation, and an object of the present invention is, for example, when assembling a piston portion of an accommodation in a cylinder body constituting a hydraulic shock absorber. It is possible to provide a nut fixing jig and a nut fixing method that are optimal for expecting an improvement in versatility of the hydraulic shock absorber without changing the setting characteristics of the annular leaf valve that constitutes .

  In order to achieve the above-mentioned object, the nut fixing jig according to the present invention is basically configured so that the tip portion is moved to the axial core portion of the tip thread portion of the rod body when moving forward along the axial direction of the rod body. A punch that is press-fitted into the formed hole, and a holder member that holds the punch together and advances and retracts in the axial direction of the rod body by an external force. The inner diameter of the hole is increased when the punch is pressed into the hole. In a nut fixing jig that can prevent loosening of a nut that is diameter-diametered and screwed to a tip threaded portion, two points that are opposed to each other with an axial center line sandwiched at a tip portion where a punch is press-fitted into the hole. The outer diameter is larger than the inner diameter of the hole, and the holder member has a spring member that can be expanded and contracted while the tip is supported on the case. The tip of the spring member faces the end surface of the nut through the case. The to.

  The nut fixing method according to the present invention is basically configured by fixing the annular leaf valve to the valve seat member that is screwed to the tip thread portion of the rod body and is held by the tip fitting portion of the rod body. In the nut fixing method in which the nut to be held is prevented from loosening by the inner diameter of this hole being expanded by press-fitting the tip of the punch into the hole formed in the shaft core part of the above-described tip screw part. A spring member interposed in a holder member that integrally holds the punch while the outer diameter of the two locations facing each other across the shaft core line is made larger than the inner diameter of the hole at the tip portion press-fitted into the hole. When the punch is pressed into the hole in the tip, the tip is brought into contact with the end surface of the nut to contract, and the punch receives a reaction force from the spring member when being pulled out from the hole in the tip.

  Therefore, in this invention, the punch in which the tip portion is press-fitted into the hole formed in the shaft core portion of the tip thread portion in the rod body moves forward without the eccentricity of the holder member. The inner diameter of the hole is partially enlarged at two opposing positions, and a loosening stop in a screwed nut is embodied as set on the tip thread portion.

  At this time, since the inner diameter of the hole in the tip thread portion of the rod body is only expanded, the fixing force in the nut that is screwed into the tip thread portion of the rod body and fixes the annular leaf valve to the valve seat member is changed. Therefore, the setting characteristics of the annular leaf valve fixed to the valve seat member by screwing of the nut are not changed.

  And in this invention, the holder member has a spring member that expands and contracts with the nut when the punch is advanced and retracted, and a case that supports the tip of the spring member when the tip of the punch is press-fitted into the hole. Is abutted against the end face of the nut, the reaction force of the spring member is received when the punch is retracted, and the punch is easily pulled out from the hole.

  Hereinafter, the present invention will be described based on the illustrated embodiment. For convenience, the nut fixing method according to the present invention will also be described while describing the nut fixing jig according to the present invention.

  The nut fixing jig 10 according to the present invention shown in FIG. 1 is, as an example, a piston part P shown in FIG. 3, that is, although not shown, slidably accommodated in a cylinder body constituting a hydraulic shock absorber. It is used when assembling the piston part P to be used.

  First, the piston portion P will be described briefly. As shown in FIG. 3, the piston portion P has a piston body 1 that is a valve seat member. The piston body 1 is inserted into the cylinder body. It is held by the tip fitting portion 2a which is a reduced diameter portion of the piston rod 2 which is a rod body.

  The nut fixing jig 10 according to the present invention includes a distal end screw continuous with the distal end fitting portion 2a through which the annular leaf valve 3 adjacent to the piston body 1 is interposed while penetrating the shaft core portion of the piston body 1. The loosening prevention of the piston nut 4 which is a nut screwed to the strip part 2b is practiced.

  That is, specifically, the piston nut 4 has a tip thread portion 2b in the piston rod 2 in a state where the inner peripheral side fixing portion 3a of the annular leaf valve 3 is fixed to the inner peripheral side boss portion 1a of the piston body 1. Screwed on.

  And the internal diameter of the hole 2c formed in the axial center part of the front-end | tip thread part 2b in this piston rod 2 is expanded by utilization of the fixing jig 10 of this invention, and the loosening prevention of the piston nut 4 is practiced.

  Incidentally, in many cases, the piston body 1 has an inner peripheral side boss portion 1a formed in an annular shape, and an inner peripheral side fixing portion 3a formed in an annular shape in the annular leaf valve 3 is seated on the inner peripheral side boss portion 1a. Let

  The piston body 1 has a through hole 1b opened in the shaft core portion, that is, inside the inner peripheral boss portion 1a, and the above-described tip fitting of the piston rod 2 is fitted into the through hole 1b. The part 2a is penetrated.

  The piston body 1 has an extension side channel 1c and a pressure side channel 1d opened along the axial direction of the cylinder body, and the downstream end that is the upper end in the drawing of the extension side channel 1c is described above. The expansion side damping valve composed of the annular leaf valve 3 is closed so that the outer peripheral side bending portion 3b can be opened and closed, and the downstream end serving as the lower end in the drawing of the pressure side channel 1d is the outer periphery of the compression side damping valve composed of the annular leaf valve 5 as well. The side bending part 5a side closes so that opening and closing is possible.

  Incidentally, the extension side damping valve is formed by stacking a plurality of annular leaf valves 3 having different diameters so that the piston body 1 slides in the cylinder body in the so-called extension side. Under the state that 3a is fixed to the inner peripheral boss 1a of the piston body 2 in a pressure contact state, the outer peripheral bending portion 3b bends to generate a predetermined extension side damping force.

  An annular leaf valve 5 serving as a compression side damping valve is disposed on the opposite side of the annular leaf valve 3 with the piston body 1 interposed therebetween. The effect of the present invention is fixed to the piston body 1. The effect that the setting characteristics in the annular leaf valve 3 are not changed extends to the annular leaf valve 5 constituting the compression side damping valve.

  In the piston nut 4, the tightening force is set in advance, and the inner peripheral side fixing portion 3 a in the annular leaf valve 3 is fixed to the inner peripheral side fixing portion 1 a of the piston body 1 based on the tightening force. Tightening work to make it happen is practiced.

  As described above, the piston rod 2 allows the tip fitting portion 2a to pass through the through hole 1b opened in the shaft core portion of the piston body 1, that is, in the piston rod 2, the tip fitting portion 2a is The above-described piston body 1 is interposed on the outer periphery, and the above-described annular leaf valves 3 and 5 are arranged so as to sandwich the piston body 1 from so-called both sides.

  Further, in this piston rod 2, a portion which becomes the upper end portion in the drawing continuous with the front end fitting portion 2a through which the piston body 1 is interposed is defined as a front end thread portion 2b, and this front end thread portion 2b. And a piston nut 4 to be described later is screwed.

  By the way, in the piston rod 2, the tip fitting portion 2a and the tip screw portion 2b are not shown, but they do not become so-called shaft portions 2d that are slidably contacted with the bearings when protruding and retracting at the opening end of the cylinder body. At this time, a stepped portion 2e is formed between the shaft portion 2d and the tip fitting portion 2a, and the stepped portion 2e is connected to the inside of the piston body 1 via the valve stopper 6 and the annular leaf valve 5. The circumferential boss 1a is brought into contact, that is, locked.

  And when this piston rod 2 forms the above-mentioned tip fitting part 2a and tip thread part 2b, or performs other processing, it is centered around the axis line as a center of rotation. In addition, the above-described hole 2c is formed in the shaft core portion of the tip thread portion 2b, and this hole 2c remains as an empty portion.

  Therefore, in the present invention, a caulking process for expanding the inner diameter of the hole 2c is performed by press-fitting the tip 11a of the punch 11 in the fixing jig 10 into the hole 2c (see FIG. 4).

  Hereinafter, the fixing jig 10 will be described briefly. First, the fixing jig 10 has a punch 11 as shown in FIG. 1 and actually practiced caulking. The holder member 12 is integrally held so as to be movable back and forth in the axial direction of the piston rod 2, and the holder member 12 further includes a spring member 13 that expands and contracts with the piston nut 4 when the punch 11 moves back and forth. .

  The punch 11 has two outer diameters opposed to each other across the shaft core line in the tip end portion 11a press-fitted into the hole 2c larger than the inner diameter of the hole 2c. The inner diameter of the hole 2c is expanded at a portion where the two portions are adjacent to each other by press-fitting into 2c.

  As a result, the deformation when expanding the inner diameter extends to the outer periphery of the tip thread portion 2b, and at this time, the slack of the piston nut 4 between the inner periphery of the piston nut 4 and the inner periphery of the tip thread portion 2b. Therefore, the piston nut 4 is prevented from loosening.

  From this, in the punch 11, it is only necessary to make the outer diameters of the two positions facing each other across the shaft core line larger than the inner diameter of the hole 2c in the tip portion 11a press-fitted into the hole 2c. As long as the above condition is satisfied, the cross-sectional shape of the tip end portion 11a, particularly the tip end portion 11a, can be arbitrarily set.

  By the way, as shown in the figure, the tip corner portion of the tip portion 11a made of a cylindrical body having an outer diameter larger than the inner diameter of the hole 2c is rounded, while the tip portion 11a is opposed to each other across the axis line. The surface is notched (see FIG. 2), and two locations are formed in which the outer diameter is larger than the inner diameter of the hole 2c.

  From the above, although not shown, the outer diameter of the cylindrical body forming the tip portion 11a is made the same as or smaller than the inner diameter of the hole 2c, while the inner diameter of the hole 2c is opposed to two locations across the shaft core wire. It is also possible to provide the above-described expansion of the inner diameter by providing a longitudinal rib having a larger outer diameter and press-fitting the longitudinal rib into the hole 2c.

  In the punch 11 described above, since the tip of the tip 11a is rounded, it is possible to obtain smoothness when the tip 11a is press-fitted into the hole 2c. In the punch disclosed in the above, the press-fitting of the tip end portion 11a into the hole 2c can be facilitated as compared with the case where the tip is formed of a two-step tapered surface.

  Further, facilitating the press-fitting of the front end portion 11a of the punch 11 into the hole 2c leads to easier removal of the front end portion 11a of the punch 11 from the hole 2c. This is an advantage of the present invention compared to the disclosed punch.

  As described above, in this fixing jig 10, the punch 11 is the axis of the tip thread portion 2 b of the piston rod 2 that allows the piston nut 4 to be screwed to fix the annular leaf valve 3 to the piston body 1. The tip end portion 11a is press-fitted into the hole 2c formed in the portion, and caulking is performed to increase the inner diameter of the hole 2c, thereby preventing the piston nut 4 from loosening.

  In addition, when the front-end | tip part 11a of the punch 11 is press-fitted in the hole 2c and the internal diameter of the hole 2c is expanded, the expanded diameter may be practiced as follows instead of the above.

  That is, when the front end portion 11a of the punch 11 is press-fitted into the hole 2c, the front end portion 11a is not press-fitted as deeply as shown in FIG. 4, and from the rear end of the piston nut 4 in the front end thread portion 2b forming the hole 2c. Only the inner diameter of the protruding tip 2f (see FIG. 3) may be expanded.

  As described above, when only the inner diameter of the front end portion 2f protruding from the rear end of the piston nut 4 in the front end thread portion 2b forming the hole 2c is expanded, the front end portion 11a of the punch 11 is placed in the hole 2c. When press-fitting, it is necessary not to apply an extra external force to the piston nut 4, and therefore it is necessary to be concerned that the setting characteristics of the annular leaf valves 3 and 5 that the piston nut 4 is fixed to the piston body 1 may be changed by mistake. It is advantageous in that there is no even.

  As long as the tip 11a of the punch 11 is press-fitted into the hole 2c to increase the inner diameter of the hole 2c as predetermined, the penetration length of the tip 11a into the hole 2c is free. For example, the distal end of the distal end portion 11a may be in contact with the inner bottom of the hole 2c, that is, the bottom end may be attached.

  Incidentally, in the punch 11, the base portion 11b for connecting the tip portion 11a to the punch 11 is detachably screwed to the shaft portion of the main body portion 12a of the holder member 12. It is connected under the arrangement of appropriate stationary means so as not to rotate with respect to 12a.

  Further, the punch 11 has a stopper portion 11c adjacent to the end surface of the holder member so that when the punch 11 is mounted on the holder member 12, the protruding length from the holder member 12 is the same. Yes.

  On the other hand, the holder member 12 has a case portion 12b formed in a cylindrical shape concentric with the main body portion 12a from the main body portion 12a, and has a spring member 13 inside the case portion 12b.

  Incidentally, the upper end side of the holder member 12 in the drawing is an input shaft portion 12c, and the input shaft portion 12c is connected to lifting / lowering means having an appropriate configuration (not shown). When there is input from the lifting / lowering means, The holder member 12 is lowered in the drawing.

  By the way, in this fixing jig 10, the spring member 13 of the holder member 12 has the tip 11a pressed into the hole 2c and the punch 11 which has finished a predetermined caulking operation is retracted to retract the tip 11a. It becomes a reaction force source when extracting from the inside of the hole 2c.

  That is, as described above, the front end portion 11a of the punch 11 press-fitted into the hole 2c bites into the inner periphery of the front end thread portion 2b forming the hole 2c, so that the predetermined caulking operation is finished. Thus, when the front end portion 11a of the punch 11 is extracted from the hole 2c, it cannot be extracted easily.

  In order to extract the tip 11a of the punch 11 from the hole, for example, when the punch 11 is swung, the inner diameter of the hole 2c into which the tip 11a of the punch 11 is press-fitted is increased more than necessary, and the piston Speaking of the nut 4, an extra external force is applied, which is not preferable.

  Therefore, as described above, in the present invention, in the punch 11, the tip end portion 11a can be easily pulled out as compared with the conventional example in which the tip end portion 11a is rounded and the tip end is a two-step tapered surface. On the other hand, when the spring member 13 is provided and the tip end portion 11a of the punch 11 is extracted from the hole 2c, the reaction force of the spring member 13 is obtained to facilitate this.

  Therefore, in the illustrated case, in the holder member 12, when the case 14 is interposed on the outer periphery of the case portion 12b so as to be movable up and down, and the tip portion 11a of the punch 11 is press-fitted into the hole 2c, It is assumed that the lower end is in contact with the end face of the piston nut 4 (see FIG. 4).

  Then, when the punch is lowered with the case 14 in contact with the end face of the piston nut 4, that is, when the holder member 12 is lowered, the spring member 13 contracts and reacts as shown in FIG. If the external force that lowers the holder member 12 is eliminated, the spring member 13 exerts a reaction force to help the holder member, that is, the punch 11 to move upward.

  Incidentally, the case 14 is slidably held by the case portion 12b of the holder member 12, but at this time, consideration is given so as not to separate from the case portion 12b by any connecting means.

  By the way, the spring member 13 may be arbitrarily configured as long as it is used as the reaction force source described above. However, in the drawing, the spring member 13 is formed of a coil spring, and a plurality of coil springs are formed in the main body 12a of the holder member 12. Is disposed so as to surround.

  At this time, a plurality of coil springs are arranged so as to be arranged in a circumferential direction in a single cylindrical hollow portion defined between the main body portion 12a and the case portion 12b in the holder member 12. Also good.

  However, from the viewpoint of avoiding mutual interference when each coil spring expands and contracts, a plurality of cylindrical hollow portions that are independent from each other on the same circumference are defined between the main body portion 12a and the case portion 12b. The coil springs are preferably housed in the cylindrical hollow portions defined with respect to each other.

  Thus, when using a plurality of coil springs, a single coil spring is used, that is, compared to a case where the main body portion 12a of the holder member 12 is inserted through the center of a single coil spring. There is an advantage that a general-purpose coil spring can be used, and there is an advantage that the magnitude of the reaction force can be easily adjusted.

  Of course, in the case of focusing on obtaining a reaction force having a remarkable magnitude, although not shown, instead of using a plurality of coil springs as the spring member 13, a disc spring is used. The body portion 12a of the holder member 12 may be inserted through the center portion of the holder member 12.

  When the external force acting on the holder member 12 is a small load, although not shown in the figure, the spring member 13 may be a single coil spring having a large diameter instead of the above-described disc spring. good.

  As described above, in the nut fixing jig according to the present invention, the shape of the tip portion 11a of the punch 11 is taken into consideration, and the reaction force when the tip portion 11a of the punch 11 is extracted from the press-fitted hole 2c. Since it has a source, it is possible not only to smoothly carry out a predetermined caulking operation, but also to smoothly extract the punch 11 from the hole 2c after the operation is completed.

  In the above, the nut fixing jig according to the present invention is used when assembling the piston portion P accommodated in the cylinder body. The nut fixing jig may also be embodied in a base valve portion that is housed in the cylinder body, and the operation and effect in that case are also the same.

  Further, in the above-described case, particularly, in the illustrated case, in the punch 11 before being press-fitted into the hole 2c, the tip end of the tip end portion 11a protrudes from the lower end of the case 14 as shown in FIG. In short, it does not have to protrude from the lower end of the case 14 as long as this is practiced without any obstacle when the tip 11a is press-fitted into the hole 2c.

  And in the place mentioned above, although the punch 11 made the outer-diameter part larger than the internal diameter of the hole 2c in the front-end | tip part 11a, if this invention intends, as long as predetermined | prescribed diameter expansion work can be practiced, The number of points may be increased or decreased.

  However, in the case of one location, labor is required for alignment, and in the case of 3 locations, it takes time to select the optimum caulking force. Would be preferred.

It is a front view showing a nut fixing jig according to an embodiment of the present invention in a partially broken view. It is a side view of the punch in FIG. It is a front view which partially fractures and shows the piston part in which the fixing jig of the nut by this invention is utilized. It is a half-ridge front view which shows the utilization state of the fixing jig of the nut by this invention partially broken.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piston body which is a valve seat member 2 Piston rod which is a rod body 2a Tip fitting portion 2b Tip thread portion 2c Hole 3,5 Annular leaf valve 4 Piston nut which is a nut 10 Fixing jig 11 Punch 11a Tip portion 12 Holder member 13 Spring Member 14 Case

Claims (6)

A punch that press-fits the tip of the rod body into the hole formed in the shaft core of the tip thread portion of the rod body when moving forward along the axial direction of the rod body, and this punch is held together to advance and retract in the axial direction of the rod body by external force And a nut fixing jig that can prevent loosening of the nut screwed into the tip threaded portion by expanding the inner diameter of the hole when the punch is press-fitted into the hole. The outer diameter of the two locations facing each other across the shaft core line is made larger than the inner diameter of the hole at the tip portion where the punch is press-fitted into the hole, and the holder member can be expanded and contracted while holding the tip on the case. A nut fixing jig characterized by having a spring member that is formed and having a tip of the spring member opposed to an end surface of the nut through a case. The rod body is a piston rod that holds the piston body slidably accommodated in the cylinder body at the distal end fitting portion, and the nut is screwed to the distal end thread portion that is continuous with the distal end fitting portion of the piston rod. The nut fixing jig according to claim 1, wherein the nut is a piston nut. The holder member has a plurality of cylindrical hollow portions that are mutually defined on the same circumference, the spring member is composed of a coil spring, and the coil spring is housed in each cylindrical hollow portion. Fixing nut fixing jig. A nut for fixing the annular leaf valve to the valve seat member, which is screwed to the tip thread portion of the rod body and held by the tip fitting portion of the rod body, enters the hole formed in the shaft core portion of the tip thread portion. In the nut fixing method in which the inner diameter of the hole is expanded by press-fitting the tip of the punch, the punch is pressed into the hole and the two ends facing each other across the shaft core line. While the outer diameter of the portion is made larger than the inner diameter of the hole, the spring member interposed in the holder member that holds the punch as a unit is pressed against the end face of the nut when the punch is press-fitted into the hole. A method for fixing a nut, wherein the punch is contracted by contact and is subjected to a reaction force from a spring member when the punch is pulled out from the hole in the tip. The rod body is a piston rod that holds the piston body slidably accommodated in the cylinder body at the distal end fitting portion, and the nut is screwed to the distal end thread portion that is continuous with the distal end fitting portion of the piston rod. The nut fixing method according to claim 4, wherein the nut is a piston nut. The holder member has a plurality of cylindrical hollow portions that are defined on the same circumference, the spring member is formed of a coil spring, and the coil spring is accommodated in each cylindrical hollow portion. The nut fixing method described.

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