JP2012117601A - Insertion tool and method for manufacturing shock absorber using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insertion tool allowing an annular seal member to be inserted satisfactorily into a rod body with a step and a method for manufacturing shock absorber using the same.SOLUTION: The insertion tool 10 is used when the annular seal member is inserted into the rod body 15 with the step 37 by being passed through the step 37, and includes a core part 47 coming in contact with one end of the rod body 15 and a cover 48 for covering an outer peripheral side of the core part 47 and extending beyond the step 37.

Description

  The present invention relates to an insertion jig used when an annular seal member is inserted into a rod-shaped body, and a shock absorber manufacturing method using the insertion jig.

  For example, when attaching a piston ring to a piston, there is one using a taper-shaped slide jig (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 62-231725

  By the way, when the annular seal member is inserted into the rod-shaped body, if the rod-shaped body has a stepped portion, the annular seal member may be damaged at such a stepped portion.

  Accordingly, an object of the present invention is to provide an insertion jig capable of satisfactorily inserting an annular seal member into a rod-shaped body having a stepped portion, and a shock absorber manufacturing method using the insertion jig.

  In order to achieve the above object, the present invention provides an insertion jig used when inserting an annular seal member through a stepped portion into a rod-shaped body having a stepped portion, and has a maximum outer diameter of the rod-shaped body. A core part made of a rigid body having an outer diameter less than the outer diameter of the body, contacting with one end of the rod-shaped body, covering the outer periphery of the core part and having a length exceeding the stepped part, and formed by heat shrink using a heat shrinkable tube And a cover portion formed.

  According to the present invention, it is possible to satisfactorily insert the annular seal member into the rod-shaped body having the stepped portion.

It is sectional drawing of the insertion jig which concerns on one Embodiment of this invention. It is sectional drawing of the shock absorber assembled by using the insertion jig which concerns on one Embodiment of this invention. It is sectional drawing which shows the use condition of the insertion jig which concerns on one Embodiment of this invention.

  An insertion jig according to an embodiment of the present invention and a shock absorber manufacturing method using the insertion jig will be described below with reference to the drawings.

  The insertion jig 10 according to this embodiment shown in FIG. 1 is used when assembling the shock absorber 11 shown in FIG. The shock absorber 11 is for a suspension device of an automobile, for example. The shock absorber 11 has a bottomed cylindrical cylinder 12. A piston 13 is slidably fitted into the cylinder 12, and the piston 12 causes the cylinder 12 to have a cylinder upper chamber 12A and a cylinder. It is divided into two chambers, lower chamber 12B. One end of a piston rod 15, which is a rod-like body, is connected to the piston 13 by a nut 16, and the other end of the piston rod 15 is an annular rod guide (annular member) mounted on the opening side of the cylinder 12. ) 17 and an oil seal (annular seal member) 18 which is an annular seal member and is extended to the outside.

  Between the piston 13 and the rod guide 17 of the piston rod 15, in order from the piston 13 side, an annular retainer 20, an annular spring receiver 21, an overall coil spring 22, an annular spring receiver 23 and an annular rubber shock absorber (annular member) 24 are provided through the piston rod 15 on the inside. Here, the retainer 20 is fixed to the piston rod 15, and one end side of the coil spring 22 is locked to the piston rod 15 via a spring receiver 21. On the other hand, the spring receiver 23 and the buffer body 24 are slidable with respect to the piston rod 15 by expansion and contraction of the coil spring 22. A free piston 25 for defining a cylinder lower chamber 12 </ b> B is slidably provided between the cylinder 12 and the piston 13 on the bottom side of the piston 13. Oil liquid (fluid) is sealed in the cylinder upper chamber 12A and the cylinder lower chamber 12B in the cylinder 12.

  The piston 13 receives the flow of the oil in the extension passage 26 (a) and the passage 26 (a) through which the oil passes when the piston 13 moves to the extension side where the piston rod 15 extends out of the cylinder 12. An expansion-side damping force generation mechanism 27 (a) that generates a damping force by controlling, and a contraction-side passage 26 through which oil passes when the piston 13 moves to the contraction side where the piston rod 15 enters the cylinder 12. (B) and a contraction-side damping force generating mechanism 27 (b) for controlling the flow of the oil liquid in the passage 26 (b) and generating a damping force are provided.

  In the piston rod 15, an internal male screw 30 to which the nut 16 is screwed, a piston 13, and damping force generating mechanisms 27 (a) and 27 (b) are arranged in order from the inner end on the side inserted into the cylinder 12. The arrangement shaft portion 31, the intermediate shaft portion 32 having a larger diameter than the arrangement shaft portion 31 and having a constant diameter, the fixed shaft portion 33 having a smaller diameter than the intermediate shaft portion 32, and the spring receiver 21 being fixed, A large-diameter shaft portion 34, a small-diameter shaft portion 35 having a smaller diameter than the large-diameter shaft portion 34 and a constant diameter, and an external male screw 36 for attachment to the vehicle body side are formed.

  A step portion 37 is formed between the large-diameter shaft portion 34 and the small-diameter shaft portion 35, and a locking ring 38 is locked to the step portion 37. The external male screw (step part) 36 has a maximum outer diameter equal to or smaller than the outer diameter of the small-diameter shaft part 35, and has a spiral step shape so that the small diameter part and the large diameter part alternately occur in the axial direction. .

  Here, the oil seal 18 seals the space between the piston rod 15 and the cylinder 12, and has a cylindrical shape made of rubber so as to protrude in the axial direction on the inner peripheral side of the metal annular member 40. An inner peripheral side seal portion 41 is integrally provided, and an outer peripheral side seal portion 42 made of rubber is also provided integrally on the outer peripheral side of the annular member 40. On the outer side in the axial direction of the inner peripheral side seal portion 41, a ring-shaped spring 43 that urges the inner peripheral side seal portion 41 radially inward is engaged. The inner diameter of the inner peripheral side seal portion 41 in the natural state is equal to or smaller than the large-diameter shaft portion 34 of the piston rod 15, specifically, smaller than the large-diameter shaft portion 34. Seal. Further, the rod guide 17 is provided with a collar 44 made of synthetic resin on the inner peripheral surface on which the large-diameter shaft portion 34 of the piston rod 15 is inserted on the inner peripheral side.

  As shown in FIG. 1, the insertion jig 10 according to the present embodiment is made of a metal, specifically a stainless steel core 47 and a synthetic resin provided so as to cover the outer periphery of the core 47. The cover portion 48 is included.

  The core portion 47 is composed of a rigid body whose maximum outer diameter is equal to or smaller than the outer diameter of the rod-shaped body, and in order from one end in the axial direction, a disk-shaped flange portion 49, a small-diameter shaft portion 50 having a smaller diameter than the flange portion 49, A tapered diameter shaft portion 51 having a larger diameter as a whole than the small diameter shaft portion 50 and having a larger diameter as the distance from the small diameter shaft portion 50 increases, and a large diameter shaft having a constant diameter that connects the large diameter side of the taper shaft portion 51 and the outer peripheral surface. A portion 52, a locking shaft portion 53 having a smaller diameter than the large diameter shaft portion 52, and a contact large diameter shaft portion 54 having the same diameter as the large diameter shaft portion 52 are formed. The core portion 47 has an air vent hole 56 that opens to an end surface of the taper shaft portion 51 opposite to the contact large diameter shaft portion 54 and an end surface of the contact large diameter shaft portion 54 opposite to the taper shaft portion 51. Is formed penetrating in the axial direction. Here, the outer diameter of the flange portion 49 is set to be equal to or smaller than the minimum diameter of the tapered shaft portion 51.

The cover portion 48 is integrally formed with a FEP (tetrafluoroethylene / hexafluoropropylene copolymer) heat shrinkable tube, and is in close contact with the outer peripheral side of the tapered shaft portion 51 of the core portion 47 in order from one end in the axial direction. A tapered cylindrical portion 58 that covers this, a small-diameter cylindrical portion 59 having a constant diameter that is in close contact with and covers the outer peripheral side of the large-diameter shaft portion 52 of the core portion 47, and a smaller-diameter locking than the small-diameter cylindrical portion 59 A cylindrical portion 60, a small diameter cylindrical portion 61 having the same diameter as the small diameter cylindrical portion 59, and a large diameter cylindrical portion 62 having a slightly larger diameter than the small diameter cylindrical portion 61 are formed. The locking cylindrical portion 60 enters between the large-diameter shaft portion 52 and the contact large-diameter shaft portion 54 so as to contact the locking shaft portion 53 over the entire circumference with respect to the core portion 47. Thereby, the axial shift | offset | difference of the cover part 48 and the core part 47 is controlled, and these are integrated. The cover 48 has a thickness of about 0.3 mm.
In addition, as a cover part, the FEP heat contraction tube obtained the desired result as a result of experiment. However, it is also possible to use a heat-shrinkable tube made of a fluororesin such as another PFA or PTFE heat-shrinkable tube having self-lubricating properties.

  Here, the minimum diameter of the tapered cylindrical portion 58 is smaller than the minimum inner diameter of the oil seal 18 in the natural state, and is smaller than the inner diameter of the rod guide 17 and the inner diameter of the buffer body 24. Further, the inner diameter of the small diameter cylindrical portion 61 of the cover portion 48 is slightly larger than the outer diameter of the external male screw 36 and the small diameter shaft portion 35 of the piston rod 15 shown in FIG. 1 and smaller than the outer diameter of the large diameter shaft portion 34. ing. In addition, the axial length of the portion of the cover portion 48 that protrudes from the core portion 47 of the small diameter cylindrical portion 61 is slightly shorter than the axial length of the external male screw 36 and the small diameter shaft portion 35 combined. Further, the inner diameter of the large-diameter cylindrical portion 62 of the cover portion 48 is slightly larger than the outer diameter of the large-diameter shaft portion 34 of the piston rod 15, and a portion protruding from the core portion 47 of the small-diameter cylindrical portion 61 and the large-diameter cylindrical portion. The total axial length of 62 is longer than the total axial length of the external male screw 36 and the small-diameter shaft portion 35 by a predetermined length.

  The above-described insertion jig 10 is manufactured as follows, for example. An unillustrated cored bar having an outer peripheral surface having the same shape as the inner peripheral surface of the small-diameter cylindrical part 61 and the large-diameter cylindrical part 62 described above is prepared, and the cored bar and the core part 47 are coaxially arranged to have a constant diameter. Insert into heat shrink tube of predetermined length. Then, the heat-shrinkable tube is heated with warm air or the like to shrink along the outer peripheral surface of the core 47 and the metal core, and then the metal core is pulled out. Thus, the insertion jig in which the cover portion 48 having the tapered cylindrical portion 58, the small diameter cylindrical portion 59, the locking cylindrical portion 60, the small diameter cylindrical portion 61, and the large diameter cylindrical portion 62 is formed of the heat shrinkable tube. 10 is produced. In the cover portion 48, a step portion 64 having a small diameter and a large diameter is formed between the small diameter cylindrical portion 61 and the large diameter cylindrical portion 62. However, the cover portion 48 is made of a heat shrinkable tube made of synthetic resin. The cross-sectional curved shape is formed. A step 65 from the large diameter to the small diameter between the small diameter cylindrical portion 59 and the locking cylindrical portion 60 and a step portion 66 from the small diameter to the large diameter between the locking cylindrical portion 60 and the small diameter cylindrical portion 61. The same applies to.

  The assembly process of the shock absorber 11 described above includes a process of fixing the retainer 20 to the fixed shaft portion 33 with respect to the piston rod 15, a pre-assembled piston 13 and damping force generating mechanisms 27 (a), 27 (b ) With the nut 16 from the side of the internal male screw 30, and the step of inserting the pre-assembled spring receiver 21, coil spring 22 and spring receiver 23 from the external male screw 36 side so as to be placed on the retainer 20. And a step of inserting the buffer body 24, the rod guide 17 and the oil seal 18.

  Then, before the step of inserting the buffer body 24, the rod guide 17 and the oil seal 18 into the piston rod 15 in this order from the side of the external male screw 36, the above-mentioned insertion jig 10 is inserted into the piston with the external male screw 36 facing upward. The rod 15 is placed on the external male screw 36 side from the large-diameter cylindrical portion 62 side. Then, the insertion jig 10 covers the piston rod 15 while removing the air inside through the air vent hole 56, and as shown in FIG. 3, the large diameter of the contact portion 47 of the core portion 47 on one end of the piston rod 15 on the external male screw 36 side. The shaft portion 54 is brought into contact. In this state, in the insertion jig 10, the cover portion 48 covers the external male screw 36 and the small diameter shaft portion 35 in the small diameter cylindrical portion 61, and the large diameter cylindrical portion 62 has a small diameter on the large diameter shaft portion 34 side. A part of the shaft part 35, the step part 37, and a part of the large diameter shaft part 34 are covered. In other words, at this time, the cover part 48 is in a state of extending beyond the external male screw 36 and the step part 37 having a step shape.

  In this state, the step of inserting the buffer body 24, the rod guide 17 and the oil seal 18 shown in FIG. 1 is performed. First, the buffer body 24 is inserted so that the insertion jig 10 passes inside. Then, it moves beyond the insertion jig 10 to a portion exposed from the cover portion 48 of the large-diameter shaft portion 34. As a result, the buffer body 24 allows the external male screw 36 and the stepped portion 37 of the piston rod 15 to pass in the axial direction while interposing the cover portion 48 inside. Therefore, the inner peripheral portion of the rubber shock absorber 24 is protected by the synthetic resin cover portion 48 even if the metal stepped external male screw 36 and the stepped portion 37 are passed inside. It is prevented from being scratched.

  Next, the rod guide 17 is inserted so that the insertion jig 10 passes inside, and is moved beyond the insertion jig 10 to a portion exposed from the cover portion 48 of the large-diameter shaft portion 34. Therefore, the collar 44 on the inner side of the rod guide 17 is protected by the synthetic resin cover 48 even if the metal stepped external screw 36 and the step 37 are passed in the axial direction. Is prevented from sticking. The collar 44 of the present embodiment is made of metal, and there is shown an example in which there is a gap corresponding to the thickness of the cover portion 48 between the inner periphery of the collar 44 and the large diameter shaft portion 36. If there is no gap between the inner periphery of the collar 44 and the large-diameter shaft portion 36 by the thickness of the cover portion 48, the jig 10 is once removed and the rod guide 17 is inserted. Alternatively, in the case where the collar 44 is formed of a stretchable resin material, the application of the present invention is more effective.

  Next, the oil seal 18 in which grease is applied to the inner side of the inner peripheral side seal portion 41 is inserted so that the insertion jig 10 passes through the inner side of the inner peripheral side seal portion 41, and beyond the insertion jig 10. The large-diameter shaft portion 34 is moved from the cover portion 48 to the exposed portion. At this time, the oil seal 18 has a stepped portion of the piston rod 17 while the inner peripheral side seal portion 41 is pushed by the cover portion 48 to widen the diameter and the cover portion 48 is interposed inside the inner peripheral side seal portion 41. The external male screw 36 and the stepped portion 37 are passed in the axial direction. Accordingly, the inner peripheral portion of the rubber inner peripheral side seal portion 41 is protected by the synthetic resin cover portion 48 even when the metal external male screw 36 and the step portion 37 are passed in the axial direction. It is prevented from being scratched.

  Thereafter, the insertion jig 10 is removed from the piston rod 15. Although not shown, the insertion jig 10 is held by a chuck of an automatic machine at the small-diameter shaft portion 50 and is put on the piston rod 15 by this automatic machine.

  According to the insertion jig 10 according to the present embodiment described above, the external male screw 36 and the stepped portion 37 are passed through the piston rod 15 having the stepped external male screw 36 and the stepped portion 37, so that the shock absorber 24, When the rod guide 17 and the oil seal 18 are inserted, if the core portion 47 is brought into contact with the external male screw 36 side of one end of the piston rod 15, the cover portion 48 covers the outer peripheral side of the core portion 47 and the external male screw 36 and the step. Since the state extends beyond the portion 37, it is possible to insert the buffer body 24, the rod guide 17 and the oil seal 18 satisfactorily without damaging them. Therefore, the durability of the buffer body 24 can be improved, and the slidability and sealing performance of the rod guide 17 and the oil seal 18 with respect to the piston rod 15 and the durability can be improved.

Moreover, since the cover portion 48 is formed of a heat-shrinkable tube made of a synthetic resin having flexibility, it is easy to manufacture, has low material cost, is hard to be damaged, has durability, and reduces running cost. Can do. In addition, the cover portion 48 can be formed thin, and the cover portion 48 does not unnecessarily increase the diameter of the buffer body 24, the rod guide 17, and the oil seal 18, so that the assembling property can be improved. . Further, since the cover portion 48 is formed using a self-lubricating material, the oil seal 18 and the like can be inserted more smoothly than a metal jig, and productivity is improved.
In the above embodiment, stepped portions having different diameters are shown as the stepped portions. However, the present invention is not limited to this, and a groove extending in the circumferential direction is provided in the middle of the rod-shaped body. Some are included in the step of the present invention.

10 Insertion jig 11 Shock absorber 15 Piston rod (rod-like body)
17 Rod guide 18 Oil seal (annular seal member)
24 buffer body 37 step part 50 core part 51 cover part

Claims (5)

An insertion jig used when inserting an annular seal member by passing the step portion into a rod-shaped body having a step portion,
A core portion made of a rigid body having a maximum outer diameter equal to or less than the outer diameter of the rod-shaped body, and a length that covers the outer peripheral side of the core portion and exceeds the stepped portion, An insertion jig comprising a cover portion formed by heat shrinkage.   The insertion jig according to claim 1, wherein the heat shrinkable tube is made of a fluorine-based resin.   The insertion jig according to claim 1, wherein the rod-shaped body is a piston rod of a shock absorber, and the annular seal member is an oil seal of the shock absorber. A method of manufacturing a shock absorber having a piston rod having a stepped portion and an annular oil seal that slides with the piston rod,
A core portion made of a rigid body whose maximum outer diameter is equal to or less than the outer diameter of the rod-shaped body, and a length that covers the outer peripheral side of the core portion and exceeds the stepped portion, A step of covering an end of the piston rod with an insertion jig composed of a cover part formed by heat shrinkage using,
And a step of inserting the annular seal member from the core side.   The shock absorber manufacturing method according to claim 4, further comprising a step of removing air between the insertion jig and the piston rod after the step of placing the insertion jig on one end of the piston rod.

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