JP2012122604A - Front fork - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assemble an axle side tube and an axle bracket in a front fork simply and with high rigidity.
In a front fork, an engaged portion 81 is provided at a lower end portion of an axle side tube 12, and a retainer 90 sandwiched between the lower end portion of the axle side tube 12 and a bottom surface of a concave portion 15 of the axle bracket 14 is provided. The engaging portion 91 that meshes with the engaged portion 81 of the axle side tube 12 is provided, and the retainer 90 is rotated by a fastening tool that is inserted into the axle bracket 14 from the outside, and the engaging portion 91 of the retainer 90 and the axle side tube 12 are rotated. Through the engagement with the engaged portion 81, the male screw portion 71 provided on the outer periphery of the lower end portion of the axle-side tube 12 is screwed to the screw portion 72 to be provided on the inner periphery of the concave portion 15 of the axle bracket 14, By bringing the front end surface A of the lower end portion of the axle side tube 12 into contact with the bottom surface B side of the recess 15 of the axle bracket 14, the lower end portion of the axle side tube 12 becomes the axle bracket. Fastened to the recess 15 of the G14.
[Selection] Figure 2

Description

  The present invention relates to a front fork.

  In an inverted front fork such as a motorcycle, an axle tube is slidably inserted into a vehicle body side tube, a suspension spring is interposed between the vehicle body side tube and the axle tube, and the lower end of the axle tube is the axle. It is inserted and fixed in the recess of the bracket.

  FIG. 7 shows a front fork described in Patent Document 1, in which a male thread portion provided on the outer periphery of the lower end portion of the axle-side tube 1 is screwed to the screw portion so as to be provided on the inner periphery of the concave portion of the axle bracket 2. Let Then, by bringing the front end surface of the lower end portion of the axle side tube 1 into contact with the bottom surface of the recess of the axle bracket 2 (or the spring seat 3 on the bottom surface), the male thread portion of the axle side tube 1 and the axle bracket 2 are connected. The threaded portion is fastened, a surface pressure is generated at the contact portion of both the threaded surfaces, and the axle side tube 1 and the axle bracket 2 are fixed.

  FIG. 8 shows a front fork described in Patent Document 2, and a bolt 5, which is externally engaged with the axle bracket 2, is screwed onto a bottom holder 4 that is axially connected to the lower end of the axle-side tube 1. Then, the axle side tube 1 is pulled toward the axle bracket 2. Then, the front end surface of the lower end portion of the axle side tube 1 is brought into contact with the bottom surface of the recess of the axle bracket 2 to fix the axle side tube 1 and the axle bracket 2.

Reality 8-8361 Patent 4198579

  Generally, in a front fork, when the axle tube 1 or the axle bracket 2 is replaced due to damage to the axle tube 1 or the axle bracket 2, or when the suspension spring 6 inside the axle tube 1 is replaced, the axle tube is replaced. 1 and axle bracket 2 need to be disassembled and reassembled.

  However, in the front fork described in Patent Document 1, the male thread portion of the axle-side tube 1 and the female thread portion of the axle bracket 2 are fastened by a wide contact portion of both screw surfaces, and the axle-side tube 1 and the axle bracket are connected. 2 can improve the assembly rigidity. However, since the axle-side tube 1 and the axle bracket 2 are screw-fastened, a large-size gripping each of the axle-side tube 1 and the axle bracket 2 for disassembly and reassembly of the axle-side tube 1 and the axle bracket 2. Special tools are required. In particular, the outer surface of the axle-side tube 1 that is in sliding contact with the oil seal provided at the opening of the vehicle-body-side tube is not allowed to be scratched, and a dedicated tool for gripping the axle-side tube 1 without being scratched is required. Cost.

  In the front fork described in Patent Document 1, a piston rod attached to the upper end of the vehicle body side tube is slidably inserted into the axle side tube 1 from a partition member provided at the upper end portion of the axle side tube 1. The piston at the tip of the piston rod is provided with a damping force generator. A suspension spring 6 is interposed between the lower end surface of the piston and the upper end surface of the bottom holder provided at the lower end portion of the axle side tube 1 inside the axle side tube 1. At this time, when replacing and maintaining the built-in components of the axle-side tube 1 such as the suspension spring 6 and the damping force generator, the axle bracket 2 that is screwed to the lower end portion of the axle-side tube 1 with high rigidity is easily removed. Therefore, these built-in parts cannot be replaced and maintained from the axle side. Therefore, it is necessary to fasten the partition member provided at the upper end of the axle-side tube 1 with screws so as to be removable, and to replace and maintain these built-in components from the vehicle body side, resulting in an increase in cost.

  On the other hand, in the front fork described in Patent Document 2, the axle-side tube 1 and the axle bracket 2 can be easily disassembled and reassembled by detaching the bolt 5 from the bottom holder 4 with a general tool. However, the axle side tube 1 and the axle bracket 2 are fastened only by a narrow contact surface where the tip surface of the lower end portion of the axle side tube 1 abuts against the bottom surface of the recess of the axle bracket 2. And the assembly rigidity of the axle bracket 2 is low.

  An object of the present invention is to assemble an axle-side tube and an axle bracket in a front fork simply and with high rigidity.

  In the invention according to claim 1, the axle side tube is slidably inserted into the vehicle body side tube, a suspension spring is interposed between the vehicle body side tube and the axle side tube, and the lower end portion of the axle side tube is the axle bracket. A front fork that is inserted and fixed in a recess has a retainer integrated around the center axis of the axle tube at the lower end of the axle tube, and the retainer is attached to the axle bracket by an externally inserted fastening tool. Rotate and screw the male screw provided on the outer periphery of the lower end of the axle tube that rotates integrally with the retainer into the inner periphery of the recess of the axle bracket, and screw it into the lower end of the axle tube. By bringing the front end surface into contact with the bottom side of the recess of the axle bracket, the lower end of the axle side tube is fastened to the recess of the axle bracket. It is intended.

  The invention according to claim 2 is the invention according to claim 1, wherein the retainer is further sandwiched between the lower end portion of the axle side tube and the bottom surface of the recess of the axle bracket, and is provided at the lower end portion of the axle side tube. A certain engaged portion is provided with an engaging portion that meshes with the axle side tube about the central axis thereof, and the retainer and the axle side tube are integrated with each other through the engagement between the engaging portion and the engaged portion. It is made to rotate.

  According to a third aspect of the present invention, in the second aspect of the invention, a notched groove-like engaged portion is provided on the tip surface of the lower end portion of the axle-side tube, and a protrusion-like engaging portion is provided on the outer periphery of the retainer. Is provided.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, when the lower end portion of the axle side tube is fastened to the concave portion of the axle bracket, the elastic is provided between the retainer and the bottom surface of the concave portion of the axle bracket. The body is clamped.

  According to a fifth aspect of the invention, in the first aspect of the invention, the retainer is screwed to and integrated with the inner periphery of the lower end portion of the axle side tube.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, further, a winding direction of a screw thread for screwing the retainer and the axle side tube, and a winding of a screw thread for screwing the axle side tube and the axle bracket. The direction is reversed.

  According to a seventh aspect of the invention, in the invention according to the fifth or sixth aspect, the retainer further includes a collar portion that abuts against an end surface of a lower end portion of the axle-side tube and sits on a bottom surface of a concave portion of the axle bracket. It was made to become.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the fastening tool is inserted from an operation hole opened in the axle bracket and engaged with an engagement hole provided in the retainer. The retainer is rotated through the gap.

  The invention according to a ninth aspect is the invention according to any one of the first to eighth aspects, wherein when the lower end portion of the axle side tube is fastened to the recess of the axle bracket, the tip end surface of the lower end portion of the axle side tube is A washer is interposed between the bottom surface of the concave portion of the axle bracket.

(Claim 1)
(a) A retainer integrated around the central axis of the axle tube is provided at the lower end of the axle tube. When the axle tube and the axle bracket are assembled, the retainer is rotated by a fastening tool inserted from the outside into the axle bracket, and the male screw provided on the outer periphery of the lower end of the axle tube that rotates integrally with the retainer. Since the end is provided on the inner periphery of the recessed portion of the axle bracket, the front end surface of the lower end portion of the axle side tube is brought into contact with the bottom surface side of the recessed portion of the axle bracket (the washer on the bottom surface or the bottom surface). Thus, the lower end portion of the axle side tube is fastened to the recess of the axle bracket. Surface pressure is generated at a wide contact portion between both the male thread portion of the axle side tube and the female thread portion of the axle bracket, and the axle side tube and the axle bracket can be fixed with high rigidity.

  (b) If the retainer is rotated in reverse by the fastening tool, the contact pressure between the male threaded part of the axle side tube and the female threaded part of the axle bracket will be temporarily stopped, and the axle side tube The axle bracket can be easily disassembled by screwing it manually.

  Further, after the axle side tube and the axle bracket are temporarily fixed by hand tightening or the like, the axle side tube can be easily reassembled to the axle bracket by rotating the retainer with a fastening tool.

  (c) In order to fix the axle side tube to the axle bracket, it is not necessary to grip at least the outer surface of the axle side tube to be inserted into the vehicle body side tube. Quality can be assured without scratching the outer surface of the axle-side tube that is in sliding contact with the seal. For this reason, the production line of the upright front fork in which the vehicle body side tube is slidably inserted into the axle side tube can be shared.

  (d) Since the axle bracket can be easily disassembled and removed from the lower end of the axle side tube, built-in parts of the axle side tube such as a suspension spring and a damping force generator can be replaced and maintained from the axle side. Thereby, the partition member provided in the upper end part of the axle side tube and into which the piston rod is inserted can be caulked and fixed to the upper end part of the axle side tube, and the cost can be reduced.

(Claim 2)
(e) The retainer is sandwiched between the lower end portion of the axle side tube and the bottom surface of the recess of the axle bracket, and is engaged with the engaged portion provided at the lower end portion of the axle side tube around the center axis of the axle side tube. An engaging portion is provided. Therefore, when the retainer is rotated by a fastener inserted from the outside into the axle bracket, the retainer and the axle side tube rotate integrally through the engagement between the engaging portion and the engaged portion. become.

(Claim 3)
(f) A notched groove-like engaged portion is provided on the distal end surface of the lower end portion of the axle side tube, and a protrusion-like engaging portion is provided on the outer periphery of the retainer described in (e). The engaged portion and the engaging portion can be simply configured.

(Claim 4)
(g) When the lower end portion of the axle side tube is fastened to the recess of the axle bracket, an elastic body is sandwiched between the retainer (e) described above and the bottom surface of the recess of the axle bracket. After assembling the axle side tube and axle bracket using the retainer, it is possible to prevent the retainer from rattling.

(Claim 5)
(h) The retainer is screwed (J) and integrated with the inner periphery of the lower end of the axle side tube. Therefore, when the retainer is rotated by a fastening tool inserted from the outside into the axle bracket, the retainer rotates integrally through the above-described screw coupling J.

(Claim 6)
(i) The winding direction of the screw thread that joins (J) the retainer and the axle side tube of the above (h) and the winding direction of the screw thread that joins (K) the axle side tube and the axle bracket are reversed. In the direction. Therefore, when the retainer is rotated by the fastening tool inserted from the outside into the axle bracket, the retainer rotates integrally through the above-described screw coupling J, and the retainer rotates integrally with the retainer. The outer peripheral male threaded portion is surely screwed into the inner peripheral female threaded portion of the axle bracket via the screw coupling K described above.

(Claim 7)
(j) The retainer of (h) described above includes a collar portion that contacts the end surface of the lower end portion of the axle-side tube and sits on the bottom surface of the recess of the axle bracket. As a result, the tip end surface of the lower end portion of the axle-side tube comes into contact with the bottom surface of the recess of the axle bracket via the flange portion of the retainer integrated with the axle-side tube, and the lower end portion of the axle-side tube is Fastened to the recess of the bracket.

(Claim 8)
(k) The fastening tool is inserted from an operation hole opened in the axle bracket, and the retainer is rotated through engagement with an engagement hole provided in the retainer. The structure for rotating the retainer by the fastening tool can be easily configured.

(Claim 9)
(l) When the lower end portion of the axle side tube is fastened to the recess of the axle bracket, a washer is interposed between the tip surface of the lower end portion of the axle side tube and the bottom surface of the recess of the axle bracket. When the axle side tube is made of a hard material such as iron and the axle bracket is made of a soft material such as an aluminum alloy, the axle bracket can be protected.

FIG. 1 is a cross-sectional view showing the entire front fork of the first embodiment. FIG. 2 is a lower cross-sectional view of FIG. 3 is a cross-sectional view of the middle part of FIG. FIG. 4 is a top sectional view of FIG. FIG. 5 is a sectional view showing a damping force generator. 6 is an exploded perspective view of the main part of FIG. FIG. 7 is a sectional view showing a conventional example. FIG. 8 is a sectional view showing a conventional example. FIG. 9 is a cross-sectional view showing the front fork of the second embodiment. FIG. 10 is an enlarged cross-sectional view of the main part of FIG. FIG. 11 is an exploded perspective view of the front fork.

Example 1 (FIGS. 1 to 6)
The front fork (hydraulic shock absorber) 10 is fixed to the outer periphery of the upper end opening of the axle side tube 12 and the bush 11A fixed to the inner periphery of the lower end opening of the vehicle body side tube 11 as shown in FIGS. This is an inverted type in which the axle side tube 12 is slidably inserted into the vehicle body side tube 11 through the bush 12A. An oil seal 11B and a dust seal 11C are stored below the bush 11A in the lower end opening of the vehicle body side tube 11. A fork bolt 13 is screwed into the upper end opening of the vehicle body side tube 11 in a sealed state. The lower end portion of the axle-side tube 12 is inserted and fixed in an annular long concave portion 15 of the axle bracket 14 as described later.

  The front fork 10 defines an annular oil chamber 20 surrounded by the inner periphery of the vehicle body side tube 11, the outer periphery of the axle side tube 12, and the two bushes 11A and 12A.

  The front fork 10 inserts a cylindrical body 31 into the inner periphery on the upper end side of the axle side tube 12, and fastens and fixes the cylindrical body 31 by the upper end caulking portion 12 </ b> C of the axle side tube 12. A collar 32 with an upper annular plate (provided with an upper annular plate 33) and a lower annular plate 34 are sequentially inserted into the inner periphery of the lower end of the cylindrical body 31, and these are crimped and held by the lower end crimping portion 31A of the cylindrical body 31. The cylindrical body 31, the upper annular plate collar 32, and the lower annular plate 34 constitute a partition member 30 provided on the inner periphery of the axle-side tube 12, partition the oil chamber 21 below the partition member 30, and The oil reservoir chamber 22 is partitioned. In the oil reservoir chamber 22, the lower region is an oil chamber 22A, and the upper region is an air chamber 22B.

  In the front fork 10, the upper end surface of the piston rod 40 is applied to the inner surface on the central axis of the fork bolt 13 provided at the upper end portion of the vehicle body side tube 11, and the bolt 40 </ b> A inserted from the outside into the through hole of the fork bolt 13 is provided. The piston rod 40 is screwed to the hollow female thread portion of the piston rod 40 and pulled, and the piston rod 40 is attached to the fork bolt 13.

  The front fork 10 slidably inserts a piston rod 40 attached to the fork bolt 13 of the vehicle body side tube 11 from the partition member 30 into the axle side tube 12. A piston 41 that is in sliding contact with the inner periphery of the axle side tube 12 is provided at the tip of the piston rod 40 inserted into the axle side tube 12. A bolt 42 that is screwed onto the front end surface of the piston rod 40 is inserted into the center hole portion of the piston 41, and the piston 41 is fixed to the front end portion of the piston rod 40. A piston ring 41 </ b> A is provided on the outer periphery of the piston 41. The piston 41 of the piston rod 40 divides the oil chamber 21 inside the axle side tube 12 into a piston rod side oil chamber 21A in which the piston rod 40 is accommodated and a piston side oil chamber 21B in which the piston rod 40 is not accommodated.

  The front fork 10 communicates the annular oil chamber 20 to the piston rod side oil chamber 21 </ b> A through an oil hole 20 </ b> A provided in the axle side tube 12.

  The front fork 10 faces the piston side oil chamber 21 </ b> B of the bottom holder 44 provided at the lower end surface facing the piston side oil chamber 21 </ b> B of the piston 41 and the lower end portion of the axle side tube 12 inside the axle side tube 12. A suspension spring 43 is interposed between the upper end surfaces. The front fork 10 absorbs the impact force received from the road surface when the vehicle is traveling by the expansion and contraction of the suspension spring 43.

  The bottom holder 44 is loaded in a sealed state on the inner diameter of the lower end portion of the axle-side tube 12 via an O-ring 45. The bottom holder 44 has a small-diameter stepped portion provided on the outer periphery on the lower end side engaged from above with a retaining ring 46 engaged with an annular groove having an inner diameter at the lower end portion of the axle-side tube 12. It is connected to the lower end in the axial direction. The upper end surface of the bottom holder 44 becomes a spring seat surface of the suspension spring 43.

  The front fork 10 includes a damping force generator 50 on a piston 41. As shown in FIG. 5, the damping force generating device 50 includes a piston 41 including a pressure expansion common channel 51 that allows the piston rod side oil chamber 21 </ b> A and the piston side oil chamber 21 </ b> B to communicate with each other. Then, a disc valve 52 with an orifice (orifice 52A) for opening and closing the pressure expansion common flow channel 51 is attached to an end surface (valve seat surface) facing the piston rod side oil chamber 21A in the piston 41. Is backed up by a valve spring 53 and a valve stopper 54. That is, when the piston 41 is fixed to the front end surface of the piston rod 40 by the bolt 42, the disc valve 52, the valve spring 53, and the valve stopper 54 are sandwiched between the front end surface of the piston rod 40 and the upper end surface of the piston 41. Retained.

  In the extension stroke, the damping force generator 50 pumps the high pressure oil in the piston rod side oil chamber 21A to the piston side oil chamber 21B through the orifice 52A of the disc valve 52 and the pressure expansion common flow path 51, and the orifice 52A. The extension side damping force due to the flow path resistance is generated. In the pressure side stroke, the high pressure oil in the piston side oil chamber 21B acts on the disc valve 52 from the pressure expansion common flow path 51, and the disc valve 52 is lifted from the upper end surface of the piston 41 and is pumped to the piston rod side oil chamber 21A. A compression side damping force is generated due to the flow path resistance of the gap formed between the disc valve 52 and the upper end surface of the piston 41.

  The front fork 10 has a stopper rubber 47 that is in contact with the lower surface of the fork bolt 13 arranged around the outer periphery of the upper end of the piston rod 40, and a stopper plate 48 that is backed up by a retaining ring 48 </ b> A engaged with the outer periphery of the upper end of the piston rod 40. Press against the lower surface of the rubber 47. When the front fork 10 is most compressed, the upper end crimped portion 12C of the axle-side tube 12 abuts against the stopper rubber 47 via the stopper plate 48 to restrict the most compressed stroke.

  The front fork 10 carries a rebound spring 49 disposed around the outer periphery of the lower end of the piston rod 40 on the upper surface of the valve stopper 54. When the front fork 10 is fully extended, the partition member 30 abuts on the rebound spring 49 to restrict the maximum extension stroke.

  However, in the front fork 10, as shown in FIG. 3, the sectional area S1 of the annular oil chamber 20 formed by the annular gap between the vehicle body side tube 11 and the axle side tube 12 is set to the sectional area (outer diameter) of the piston rod 40. (Area surrounded by) S2 or more.

  Further, the partition member 30 is provided with a partition check valve 60. The bulkhead check valve 60 (A), in the extension stroke, removes excess oil in the oil chamber 21 due to the difference ΔS between the cross-sectional area S1 of the annular oil chamber 20 and the cross-sectional area S2 of the piston rod 40. A minute gap channel for discharging from the side oil chamber 21A to the oil reservoir chamber 22 is formed around the piston rod 40, and (B) in the pressure side stroke, the difference between the sectional area S1 of the annular oil chamber 20 and the sectional area S2 of the piston rod 40 A flow path for supplying the oil shortage due to ΔS from the oil reservoir 22 to the oil chamber 21 is formed.

  As shown in FIG. 3, the partition check valve 60 is accommodated between the upper annular plate 33 and the lower annular plate 34 of the partition member 30, and is shorter than the interval between the upper annular plate 33 and the lower annular plate 34. The outer diameter of the piston rod 40 is smaller than the inner diameter of the piston rod 40, and the cylinder is vertically displaced via a minute gap channel. A lateral groove 61 is formed on the lower end surface. The partition check valve 60 is interposed between the lower annular plate 34 and a valve spring 62 made of a compression coil spring, and is biased toward the upper annular plate 33. During the compression side stroke, the piston rod 40 moves into the axle side tube 12 and moves downward, abuts against the lower annular plate 34, and forms a gap between the upper annular plate 33 and the oil reservoir chamber. 22 oil can be supplied from the lateral groove 61 to the piston rod side oil chamber 21A via the outer periphery thereof.

The front fork 10 operates as follows.
(Pressure side stroke)
The vehicle body side tube 11 enters the axle side tube 12, and the oil in the piston side oil chamber 21B contracted by the piston 41 moving together with the vehicle body side tube 11 becomes high pressure, and the disc valve 52 is opened as described above to open the piston. As a result of being pumped to the rod side oil chamber 21A, a compression side damping force is generated as described above.

  In this pressure side stroke, oil to be replenished to the annular oil chamber 20 due to the difference ΔS between the sectional area S1 of the annular oil chamber 20 and the sectional area S2 of the piston rod 40 is supplied from the oil reservoir chamber 22 to the partition wall check valve. 60, the piston rod side oil chamber 21A is replenished.

(Extension process)
The vehicle body side tube 11 retreats from the axle side tube 12, and the oil in the piston rod side oil chamber 21 </ b> A contracted by the piston 41 moving together with the vehicle body side tube 11 becomes high pressure, and passes through the orifice 52 </ b> A of the disc valve 52. As a result of being pumped to the side oil chamber 21B, the extension side damping force is generated as described above.

  In this extension side stroke, the amount of oil to be discharged from the annular oil chamber 20 due to the difference ΔS between the sectional area S1 of the annular oil chamber 20 and the sectional area S2 of the piston rod 40 from the piston rod side oil chamber 21A. The oil is discharged to the oil reservoir 22 via the partition check valve 60.

  However, in the front fork 10, in order to assemble the vehicle body side tube 11 and the axle side tube 12 simply and with high rigidity, the lower end portion of the axle side tube 12 is placed in the recess 15 of the axle bracket 14 in the following (1), (2 ) And fixed as shown in FIGS. 2 and 6.

  Here, the axle tube 12 is provided with a threaded portion 71 on the outer periphery of the lower end. The axle bracket 14 includes a long recess 15 having a considerable depth into which a corresponding length range of the lower end portion of the axle-side tube 12 is inserted, and a female screw portion 72 is provided on the inner periphery of the recess 15. The axle bracket 14 has an operation hole 14A for a fastening tool (not shown) provided on the central axis of the recess 15 from the outside to the bottom surface. The operation hole 14A is sealed with a cap 14B.

  As shown in FIG. 2, the axle bracket 14 has a lateral hole 14C that intersects a part of the inner periphery of the recess 15, and a part of the outer periphery of the stopper bolt 16 that is inserted into the lateral hole 14C is on the axle side. The axle 12 is engaged with a part of an annular groove 12D provided on the outer periphery of the tube 12 to prevent the axle-side tube 12 from coming off the axle bracket 14. The male thread portion 71 of the axle side tube 12 is provided closer to the front end surface A than the annular groove 12D, and the female thread portion 72 of the axle bracket 14 is provided closer to the bottom surface B than the lateral hole 14C.

  Then, an engaged portion 81 is provided at the lower end portion of the axle side tube 12. Further, a disc-shaped retainer 90 is provided between the tip end surface A of the lower end portion of the axle-side tube 12 and the bottom surface B of the recess 15 of the axle bracket 14, and the engaged portion 81 of the axle-side tube 12 is attached to the engaged portion 81. The retainer 90 is provided with an engaging portion 91 that meshes around the central axis of the axle-side tube 12. In the present embodiment, square cut groove-like engaged portions 81 are provided at a plurality of locations (for example, four locations) in the circumferential direction of the distal end surface A of the lower end portion of the axle tube 12. Engaging portions 91 in the form of square protrusions are provided at a plurality of circumferential locations (for example, four locations) on the outer periphery of the retainer 90. The retainer 90 includes an engagement hole 92 that can be engaged with a fastening tool inserted from the operation hole 14A of the axle bracket 14, for example, a hexagon wrench, at the center thereof.

  (1) Since the male thread portion 71 provided on the outer periphery of the lower end portion of the axle-side tube 12 is provided on the inner periphery of the concave portion 15 of the axle bracket 14, the screw portion 72 is screwed by hand tightening or the like and temporarily fixed.

  At this time, the disc spring washer 100 is placed on the bottom surface B of the recess 15 in the recess 15 of the axle bracket 14, the retainer 90 is placed on the disc spring washer 100, and the engaging portion 91 of the retainer 90 is connected to the axle side tube. The twelve engaged parts 81 are engaged. The bottom surface of the bottom holder 44 loaded in the inner diameter of the lower end portion of the axle side tube 12 and engaged with the retaining ring 46 in the axial direction of the axle side tube 12 from above is an engaged portion 81 of the axle side tube 12. The retainer 90 does not interfere with the retainer 90 through a gap between the retainer 90 and the upper surface of the retainer 90 that is engaged with the shaft 12 and abuts the engaged portion 81 in the axial direction of the axle-side tube 12. The retainer 90 and the disc spring washer 100 have a slightly smaller outer diameter than the inner diameter of the recess 15 of the axle bracket 14 and are loosely inserted into the inner periphery of the recess 15.

  (2) In a state where the outer surface of the axle bracket 14 is held by the gripping tool and is prevented from rotating, the retainer 90 is rotated by a hexagon wrench (fastening tool) inserted from the outside into the axle bracket 14 (the hexagon wrench is attached to the axle bracket 14). The retainer 90 is inserted into the recess 15 through the provided operation hole 14A and is engaged with the engagement hole 92 provided in the retainer 90), and the engagement portion 91 of the retainer 90 and the axle side tube The axle-side tube 12 is rotated through meshing with the 12 engaged portions 81, and a male thread portion 71 provided on the outer periphery of the lower end portion of the axle-side tube 12 is provided on the inner periphery of the recess 15 of the axle bracket 14. Therefore, the threaded portion 72 is engaged. By causing the front end surface A of the lower end portion of the axle side tube 12 to abut against the bottom surface B side of the recess 15 of the axle bracket 14 (the Belleville spring washer 100 on the bottom surface B), the lower end portion of the axle side tube 12 becomes the axle. Fastened to the recess 15 of the bracket 14.

  When the lower end portion of the axle side tube 12 is fastened to the recess 15 of the axle bracket 14, the washer is provided between the front end surface A of the lower end portion of the axle side tube 12 and the bottom surface B of the recess 15 of the axle bracket 14. Then, the part near the outer periphery of the disc spring washer 100 is interposed.

  Further, when the lower end portion of the axle side tube 12 is fastened to the recess 15 of the axle bracket 14, an elastic body, in the present embodiment, a disc spring washer, is provided between the lower surface of the retainer 90 and the bottom surface B of the recess 15 of the axle bracket 14. A portion closer to the inner periphery of 100 is pinched.

According to the present embodiment, the following operational effects can be obtained.
(a) In the assembled state of the axle side tube 12 and the axle bracket 14, the retainer 90 is rotated by a fastening tool inserted from the outside into the axle bracket 14, so that the engaging portion 91 of the retainer 90 and the axle side tube 12 are engaged. Through engagement with the portion 81, the male screw portion 71 provided on the outer periphery of the lower end portion of the axle-side tube 12 is screwed to the screw portion 72 to be provided on the inner periphery of the concave portion 15 of the axle bracket 14, and the axle-side tube 12. The lower end portion of the axle-side tube 12 is brought into contact with the bottom surface B of the recess 15 of the axle bracket 14 (or the washer (belleville spring washer 100) on the bottom surface B). Fastened to the recess 15. A surface pressure is generated at a wide contact portion between both screw surfaces of the male thread portion 71 of the axle-side tube 12 and the female thread portion 72 of the axle bracket 14, and the axle-side tube 12 and the axle bracket 14 can be fixed with high rigidity.

  (b) When the retainer 90 is reversely rotated with a fastening tool, the surface pressure of the contact portion between both the male screw portion 71 of the axle side tube 12 and the female screw portion 72 of the axle bracket 14 is temporarily fixed. The axle side tube 12 and the axle bracket 14 can be easily screwed and disassembled by hand rotation or the like.

  Further, after the axle-side tube 12 and the axle bracket 14 are temporarily fixed by hand tightening or the like, the axle-side tube 12 can be easily reassembled to the axle bracket 14 by rotating the retainer 90 with a fastening tool.

  (c) Since it is not necessary to hold the outer surface of the axle side tube 12 in order to fix the axle side tube 12 to the axle bracket 14, the axle side tube that is in sliding contact with the oil seal 11B provided in the opening of the body side tube Quality assurance is possible without scratching the outer surface of the twelve. For this reason, the production line of the upright front fork 10 in which the vehicle body side tube is slidably inserted into the axle side tube 12 can be shared.

  (d) Since the axle bracket 14 can be easily disassembled and removed from the lower end portion of the axle side tube 12, built-in components of the axle side tube 12 such as the suspension spring 43 and the damping force generator 50 can be replaced and maintained from the axle side. Thereby, the partition member 30 provided at the upper end portion of the axle-side tube 12 and into which the piston rod 40 is inserted can be caulked and fixed to the upper end portion of the axle-side tube 12, thereby reducing the cost.

  In this embodiment, the bottom holder 44 and the suspension spring 43 can be attached to and detached from the lower end opening of the axle side tube 12 with the outside while the axle bracket 14 is removed from the lower end portion of the axle side tube 12, and the fork bolt The piston rod 40 and the piston 41 (damping force generating device 50) separated from the 13 bolts 40A can be attached to and detached from the lower end opening of the axle side tube 12.

  (e) A notched groove-like engaged portion 81 is provided on the distal end surface A of the lower end portion of the axle-side tube 12, and a protruding engagement portion 91 is provided on the outer periphery of the retainer 90. The engaged portion 81 and the engaging portion 91 can be simply configured.

  (f) The fastening tool is inserted from the operation hole 14A opened in the axle bracket 14, and the retainer 90 is rotated through engagement with the engagement hole 92 provided in the retainer 90. The rotating operation structure of the retainer 90 by the fastening tool can be easily configured.

  (g) When the lower end portion of the axle side tube 12 is fastened to the recess 15 of the axle bracket 14, the washer is provided between the front end surface A of the lower end portion of the axle side tube 12 and the bottom surface B of the recess 15 of the axle bracket 14. (Belleville spring washer 100) is interposed. When the axle-side tube 12 is made of a hard material such as iron and the axle bracket 14 is made of a soft material such as an aluminum alloy, the axle bracket 14 can be protected.

  (h) When the lower end portion of the axle side tube 12 is fastened to the recess 15 of the axle bracket 14, an elastic body (belleville spring washer 100) is sandwiched between the retainer 90 and the bottom surface B of the recess 15 of the axle bracket 14. Pressed. After assembling the axle side tube 12 and the axle bracket 14 using the retainer 90, the retainer 90 can be prevented from rattling.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention. For example, when the lower end portion of the axle-side tube 12 is fastened to the recess 15 of the axle bracket 14, the axle-side tube 12 is interposed between the front end surface A of the lower end portion of the axle-side tube 12 and the bottom surface B of the recess 15 of the axle bracket 14. The washer and the elastic body sandwiched between the lower surface of the retainer 90 and the bottom surface B of the recess 15 of the axle bracket 14 may be made of different members.

Example 2 (FIGS. 9 and 10)
The front fork 10 of the second embodiment shown in FIGS. 9 and 10 is different from that of the first embodiment in that a retainer 200 that replaces the bottom holder 44 and the retainer 90 is used.

  The retainer 200 is screwed (J) and integrated with the inner periphery of the lower end portion of the axle-side tube 12. In this embodiment, the retainer 200 is integrated with the lower end portion of the axle-side tube 12 (the engaged state of the first embodiment). A flange portion 201 that is in contact with the flat end surface A of the axle bracket 14 and is seated on the bottom surface B of the recess 15 of the axle bracket 14 is provided at the lower end portion.

  The retainer 200 is provided with a threaded portion 211 on the outer periphery of the upper portion of the collar portion 201, and the axle tube 12 is provided with a female threaded portion 212 on the inner periphery of the lower end portion. As in the first embodiment, the axle side tube 12 is provided with a threaded portion 71 on the outer periphery of the lower end portion, and is provided with a female threaded portion 72 on the inner periphery of the recess 15 of the axle bracket 14.

  At this time, the winding direction of the thread of the male threaded portion 211 and the female threaded portion 212 for screw coupling (J) the retainer 200 and the axle side tube 12 and the axle side tube 12 and the axle bracket 14 are threadedly coupled (K). The winding direction of the thread of the external thread part 71 and the internal thread part 72 is reversed. That is, the screw connection J between the external thread part 211 and the internal thread part 212 is a right-hand thread, and the thread connection K between the external thread part 71 and the internal thread part 72 is a left-hand thread.

  Since the retainer 200 also serves as the bottom holder 44 of the first embodiment, the O-ring 202 is loaded on the outer periphery fitted to the inner periphery of the axle-side tube 12 between the collar portion 201 and the male screw portion 211. The upper end surface of the retainer 200 becomes the spring seat surface of the suspension spring 43.

  Therefore, in the front fork 10, in order to assemble the vehicle body side tube 11 and the axle side tube 12 simply and with high rigidity, the lower end portion of the axle side tube 12 is placed in the recess 15 of the axle bracket 14 as shown in (1) to (3) below. Insert and fix as shown in ().

  (1) The outer periphery of the axle-side tube 12 that is to be inserted into the recess 15 of the axle bracket 14 (the outer periphery other than the portion that is to be inserted into the vehicle-body-side tube 11) is gripped by a gripper to prevent rotation. Then, the male threaded portion 211 of the retainer 200 is firmly screwed (J) to the inner peripheral female threaded portion 212 at the lower end of the axle tube 12. As a result, the collar portion 201 of the retainer 200 is seated against the end surface A of the lower end portion of the axle-side tube 12.

  (2) The lower end portion of the axle side tube 12 to which the retainer 200 is coupled according to the above (1) is inserted into the recess 15 of the axle bracket 14, and the male thread portion 71 of the axle side tube 12 is inserted into the female thread portion 72 of the axle bracket 14. Screw in hand and tighten temporarily. At this time, the collar portion 201 of the retainer 200 is lightly seated on the bottom surface B of the recess 15 of the axle bracket 14.

  (3) In a state where the outer surface of the axle bracket 14 is gripped by the gripping tool and prevented from rotating, the retainer 200 is rotated by a hexagon wrench (fastening tool) inserted from the outside into the axle bracket 14 (the hexagon wrench is attached to the axle bracket 14). The retainer 200 is rotated through engagement with an engagement hole 203 provided in the retainer 200 and inserted into the recess 15 from the provided operation hole 14A), and the axle side rotating integrally with the retainer 200 The male screw portion 71 provided on the inner periphery of the lower end portion of the tube 12 is engaged with the screw portion 72 so as to be provided on the inner periphery of the concave portion 15 of the axle bracket 14. The front end surface A of the lower end portion of the axle side tube 12 comes into contact with the bottom surface B of the recess 15 of the axle bracket 14 via the collar portion 201 of the retainer 200, and the lower end portion of the axle side tube 12 is the axle bracket 14. The recess 15 is fastened.

According to the present embodiment, the following operational effects can be obtained.
(a) A retainer 200 that is integrated around the central axis of the axle side tube 12 is provided at the lower end of the axle side tube 12. When the axle side tube 12 and the axle bracket 14 are assembled, the retainer 200 is rotated by a fastening tool inserted into the axle bracket 14 from the outside, and the lower end portion of the axle side tube 12 that rotates together with the retainer 200 is rotated. Since the external thread portion 71 provided on the outer periphery is provided on the inner periphery of the recess 15 of the axle bracket 14, it is screwed into the screw portion 72, and the tip end surface A of the lower end portion of the axle-side tube 12 is connected to the bottom surface B of the recess 15 of the axle bracket 14. The lower end portion of the axle-side tube 12 is fastened to the recess 15 of the axle bracket 14 by being brought into contact with this side (the bottom surface B or the washer on the bottom surface B). A surface pressure is generated at a wide contact portion between both screw surfaces of the male thread portion 71 of the axle-side tube 12 and the female thread portion 72 of the axle bracket 14, and the axle-side tube 12 and the axle bracket 14 can be fixed with high rigidity.

  (b) The retainer 200 is screwed (J) and integrated with the inner periphery of the lower end of the axle tube 12. Therefore, when the retainer 200 is rotated by a fastening tool inserted from the outside into the axle bracket 14, the retainer 200 rotates integrally through the above-described screw coupling J.

  (c) The direction of winding of the thread for screwing (J) the retainer 200 and the axle side tube 12 of (b) described above, and the winding of the thread for screwing (K) the axle side tube 12 and the axle bracket 14. Set the direction opposite. Therefore, when the retainer 200 is rotated by a fastening tool inserted from the outside into the axle bracket 14, the retainer 200 rotates as a unit via the above-described screw coupling J, and the retainer 200 rotates as a unit. The external thread part 71 of the outer periphery of the axle side tube 12 is surely screwed to the internal thread part 72 of the inner periphery of the axle bracket 14 through the above-described screw coupling K.

  (d) The retainer 200 of (b) described above includes a collar portion 201 that contacts the end surface A of the lower end portion of the axle-side tube 12 and sits on the bottom surface B of the recess 15 of the axle bracket 14. As a result, the tip end surface A of the lower end portion of the axle-side tube 12 comes into contact with the bottom surface B of the recess 15 of the axle bracket 14 via the flange portion 201 of the retainer 200 integrated therewith. The lower end of the side tube 12 is fastened to the recess 15 of the axle bracket 14.

  (e) The fastening tool is inserted from the operation hole 14A opened in the axle bracket 14, and the retainer 200 is rotated through engagement with the engagement hole 203 provided in the retainer 200. The rotating operation structure of the retainer 200 by the fastening tool can be easily configured.

  The retainer may be a pin 301 that is bridged and integrated in the diametrical direction on the inner periphery of the lower end portion of the axle tube 12 (FIG. 11).

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

  In the present invention, the axle side tube is slidably inserted into the body side tube, a suspension spring is interposed between the body side tube and the axle side tube, and the lower end of the axle side tube is inserted into the recess of the axle bracket. The fixed front fork has a retainer integrated around the central axis of the axle tube at the lower end of the axle tube, and the retainer is rotated by a fastening tool inserted from the outside into the axle bracket. The external thread provided on the outer periphery of the lower end of the axle side tube that rotates integrally with the screw is screwed to the threaded portion so as to be provided on the inner periphery of the recess of the axle bracket, and the front end surface of the lower end of the axle side tube is The lower end portion of the axle side tube is fastened to the recess portion of the axle bracket by making contact with the bottom surface side of the recess portion of the bracket. Thereby, in the front fork, the axle side tube and the axle bracket can be assembled easily and with high rigidity.

DESCRIPTION OF SYMBOLS 10 Front fork 11 Car body side tube 12 Axle side tube 14 Axle bracket 14A Operation hole 15 Recess 43 Suspension spring 71 Male thread part 72 Female thread part 81 Engagement part 90 Retainer 91 Engagement part 92 Engagement hole 100 Belleville spring washer ( Washers, elastic bodies)
200 Retainer 201 Brim

Claims (9)

The axle side tube is slidably inserted into the vehicle body side tube, a suspension spring is interposed between the vehicle body side tube and the axle side tube, and the lower end portion of the axle side tube is inserted and fixed in the recess of the axle bracket. In the front fork,
A retainer integrated around the central axis of the axle tube at the lower end of the axle tube;
The retainer is rotated by a fastening tool inserted from the outside into the axle bracket, and the male thread provided on the outer periphery of the lower end of the axle tube that rotates integrally with the retainer is provided on the inner periphery of the recess of the axle bracket. The lower end portion of the axle tube is fastened to the recess of the axle bracket by screwing the end face of the lower end portion of the axle tube to the bottom surface of the recess of the axle bracket. And front fork. The retainer is sandwiched between the lower end portion of the axle side tube and the bottom surface of the recess of the axle bracket, and meshes with the engaged portion provided at the lower end portion of the axle side tube around the center axis of the axle side tube. With an engaging part,
The front fork according to claim 1, wherein the retainer and the axle-side tube rotate as a unit through engagement between the engaging portion and the engaged portion.   The front fork according to claim 2, wherein a notch groove-like engaged portion is provided on a tip end surface of a lower end portion of the axle side tube, and a protrusion-like engaging portion is provided on an outer periphery of the retainer.   The front fork according to claim 2 or 3, wherein an elastic body is sandwiched between the retainer and a bottom surface of the concave portion of the axle bracket when the lower end portion of the axle side tube is fastened to the concave portion of the axle bracket.   The front fork according to claim 1, wherein the retainer is screwed and integrated with an inner periphery of a lower end portion of the axle side tube.   The front fork according to claim 5, wherein a winding direction of a screw thread connecting the retainer and the axle tube is screwed reversely with a winding direction of a screw thread connecting the axle tube and the axle bracket.   The front fork according to claim 5 or 6, wherein the retainer is provided with a flange portion that abuts on an end surface of a lower end portion of the axle side tube and is seated on a bottom surface of a concave portion of the axle bracket.   The front fork according to any one of claims 1 to 7, wherein the fastening tool is inserted from an operation hole opened in an axle bracket and rotates the retainer through engagement with an engagement hole provided in the retainer.   9. A washer is interposed between the tip end surface of the lower end portion of the axle side tube and the bottom surface of the recess portion of the axle bracket when the lower end portion of the axle side tube is fastened to the recess of the axle bracket. The front fork as described in any of the above.

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