JP4723611B2 - Hydraulic shock absorber - Google Patents

Description

  The present invention relates to a hydraulic shock absorber for a vehicle.

  As a hydraulic shock absorber for a vehicle, as described in Patent Document 1, an inner tube on the axle side is slidably inserted into an outer tube on the vehicle body side, and a partition member is provided on the inner periphery of the inner tube. A hydraulic oil chamber is defined in the lower part of the member, an oil reservoir chamber is defined in the upper part, and a piston rod attached to the outer tube side is inserted into the hydraulic oil chamber through the partition member, and the tip of the piston rod Provided with a piston that slides in the hydraulic oil chamber, and a suspension spring is interposed between the upper spring receiver on the piston rod side and the lower spring receiver on the bottom side of the inner tube in the hydraulic oil chamber of the inner tube. There is something.

  In the hydraulic shock absorber of Patent Document 1, a plunger is slidably fitted to the bottom side of the inner tube, a lower spring support for a suspension spring is placed on the upper part of the plunger, and a hydraulic oil pressurizing chamber is placed on the lower part of the plunger. And the spring load of the suspension spring can be adjusted from the outside by pressurizing the pressurizing chamber by a pump piston that is moved by an external operation.

The hydraulic shock absorber disclosed in Patent Document 2 supports the spring load of the suspension spring with a plunger, and includes a slope member facing the plunger, and presses a ball interposed between the plunger and the slope of the slope member with an adjustment bolt. The spring load of the suspension spring can be adjusted from the outside.
2-150439 Shokai 60-139591

  In the hydraulic shock absorber disclosed in Patent Document 1, it is necessary to slidably incorporate a plunger and a pump piston on the bottom side of the inner tube, resulting in difficulty in parts workability and assembly, and high cost.

  In addition, the load of the suspension spring is supported by the hydraulic oil in the pressurizing chamber, which entails difficulty in sealing the high hydraulic pressure in the pressurizing chamber and increases the cost.

  The hydraulic shock absorber disclosed in Patent Document 2 has a structure in which a ball pressed by an adjusting bolt is pushed from a lateral direction with respect to a slope of a slope member, and the ball is pushed up on the slope. This may impair the durability of the slope member. The diameter of the ball is limited in its installation space, and the adjustment range of the spring load cannot be increased.

  In the hydraulic shock absorber, the spring load of the suspension spring is preferably adjusted even when the axle is not removed from the hydraulic shock absorber.

  An object of the present invention is to lift and lower a lower spring receiver from outside without removing an axle in a hydraulic shock absorber that adjusts the spring load of a suspension spring by raising and lowering a lower spring receiver provided on the bottom side of an inner tube. The purpose is to simplify the structure and to ensure a sufficient spring load adjustment width and durability.

According to the first aspect of the present invention, the inner tube on the axle side is slidably inserted into the outer tube on the vehicle body side, an axle bracket is screwed to the lower end portion of the inner tube, and a partition member is formed on the inner periphery of the inner tube. A hydraulic oil chamber in the lower part of the partition member, an oil reservoir chamber in the upper part, and a piston support member attached to the outer tube side is inserted into the hydraulic oil chamber through the partition member, A piston that slides in the hydraulic oil chamber is provided at the tip of the piston support member, and is suspended between an upper spring receiver on the piston support member side and a lower spring receiver on the axle bracket side in the hydraulic oil chamber of the inner tube. In a hydraulic shock absorber provided with a spring, the lower spring retainer is prevented from rotating with respect to the axle bracket, inserted into the axle bracket, and an adjuster facing the outside at a position where the axle mounting hole of the axle bracket is removed. And a spring load adjusting device for adjusting the spring load of the suspension spring by raising and lowering the lower spring receiver by rotation of the adjustment bolt, and is incorporated around the lower end protrusion of the lower spring receiver, and A washer that is locked to the bulging portion provided at the tip of the lower end protrusion and is prevented from falling off is loaded on the stepped portion of the axle bracket, and the tip of the inner tube that is screwed to the axle bracket is attached to the washer. the support, detent groove provided in the lower end projections of receiving the lower spring at sandwiching the intermediate portion of the adjusting bolt of the spring load adjusting apparatus, which receives the spring is in so that the detent to the axle bracket It is.

According to a second aspect of the present invention, in the first aspect of the present invention, the washer is prevented by the O-ring loaded in the annular groove of the axle bracket from falling off at the stage of assembling the inner tube and the axle bracket. It is a thing.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the spring load adjusting device further includes a washer abutting against a step surface on one end side of the adjustment bolt, and a slider is inserted into the other end side of the adjustment bolt. The slider can be linearly moved in the direction intersecting the central axis of the inner tube by the rotational force of the adjusting bolt, and the lower slope of the lower spring receiver is placed on the upper slope of the slider, and the lower part of the lower spring receiver The vertical surface is brought into contact with the end surface of the washer .

  1 is a cross-sectional view showing the entire hydraulic shock absorber, FIG. 2 is a cross-sectional view showing a spring load adjusting device, FIG. 3 is a cross-sectional view showing a damping force adjusting device, FIG. 4 is an enlarged view of the main part of FIG. Shows a nut, (A) is a front view, (B) is a cross-sectional view, FIG. 6 shows a slider, (A) is a front view, (B) is a side view, and (C) is a C- of (A). 7 is a sectional view taken along line C, FIG. 7 shows a lower spring receiver, (A) is a front view, (B) is a sectional view, (C) is a plan view, and FIG. 8 shows a lower end of the lower spring receiver. FIG. 9A is a bottom view, FIG. 9B is a cross-sectional view taken along line BB in FIG. 9A, FIG. 9B shows a modification of the slider, FIG. 9A is a front view, and FIG.

  The front fork (hydraulic shock absorber) 10 is an inverted front fork in which the outer tube 11 is disposed on the vehicle body side and the inner tube 12 is disposed on the wheel side. As shown in FIGS. The inner tube 12 is slidably inserted into the outer tube 11 through a guide bush 11A fixed to the inner periphery of the inner tube 12 and a guide bush 12A fixed to the outer periphery of the upper end opening of the inner tube 12. 11B is an oil seal, and 11C is a dust seal. A cap 13 is screwed in a liquid-tight manner at the upper end opening of the outer tube 11, and vehicle body side mounting members 14 </ b> A and 14 </ b> B are provided on the outer periphery of the outer tube 11. An axle bracket 15 is liquid-tightly inserted and screwed into the lower end opening of the inner tube 12 to form a bottom portion of the inner tube 12, and an axle mounting hole 16 is provided in the axle bracket 15.

  The front fork 10 defines an annular oil chamber 17 defined by the inner periphery of the outer tube 11, the outer periphery of the inner tube 12, and the two guide bushes 11A and 12A.

  The front fork 10 is provided with a partition wall member 19 in a liquid-tight manner, for example, via an O-ring on the inner periphery of the upper end side of the inner tube 12, and defines a hydraulic oil chamber 21 below the rod guide portion 19A of the partition wall member 19, An oil reservoir 22 is defined in the upper part. In the oil reservoir chamber 22, the lower region is an oil chamber 22A, and the upper region is an air chamber 22B.

  The front fork 10 slidably inserts the piston rod 23 attached to the outer tube 11 into the rod guide portion 19 </ b> A of the partition wall member 19. Specifically, the hollow piston rod 23 is screwed to the mounting collar 24 screwed to the lower end portion of the center portion of the cap 13, and this is fixed by the lock nut 24A.

  The front fork 10 fixes a piston 26 slidably in contact with the inner periphery of the inner tube 12 to a piston bolt 25 screwed to the tip of a piston rod 23 inserted into the inner tube 12 from the rod guide portion 19A of the partition wall member 19. The oil chamber 21 is divided into a piston rod side oil chamber 21A in which the piston rod 23 is accommodated and a piston side oil chamber 21B in which the piston rod 23 is not accommodated. The piston 26 is fixed by a nut 27.

  The front fork 10 always communicates the annular oil chamber 17 with the piston rod side oil chamber 21 </ b> A through an oil hole 28 provided in the inner tube 12.

  The front fork 10 abuts the upper spring receiver 31 on the lower end surface of the piston 26 facing the piston-side oil chamber 21B, and arranges the lower spring receiver 32 on the bottom of the inner tube 12 formed by the axle bracket 15, A suspension spring 33 is interposed between 31 and the lower spring receiver 32. The front fork 10 absorbs the impact force received from the road surface when the vehicle travels by the expansion and contraction vibration of the suspension spring 33. At this time, a spring load adjusting device 100 described later raises and lowers the lower spring receiver 32 so that the spring load of the suspension spring 33 can be adjusted.

The front fork 10 includes a damping force generator 40 on the piston 26 (FIG. 3).
The damping force generator 40 includes a compression side channel 41 and an extension side channel 42 (not shown). The pressure side channel 41 is opened and closed by a pressure side disk valve 41A (pressure side damping valve) backed up by a valve stopper 41B. The extension side flow path 42 is opened and closed by an extension side disk valve 42A (extension side damping valve) backed up by a valve stopper 42B. The valve stopper 41B, the valve 41A, the piston 26, the valve 42A, and the valve stopper 42B constitute a valve assembly that is inserted into the piston bolt 25, and are fixed by being sandwiched between nuts 27 that are screwed into the piston bolt 25. Is done.

  The damping force generator 40 is provided with a damping force adjusting device 40A, which will be described in detail later, at the center of the cap 13, and the needle valve 85 of the damping force adjusting device 40A is inserted into the hollow portion of the piston rod 23 and provided on the piston rod 23. The opening degree of the bypass passage 45 is adjusted by the vertical movement of the needle valve 85. The bypass passage 45 bypasses the piston 26 and connects the piston rod side oil chamber 21A and the piston side oil chamber 21B.

  In the compression side stroke, the damping force generator 40 generates a compression side damping force by the passage resistance of the bypass passage 45 whose opening degree is adjusted by the needle valve 85 in the low speed region, and the deformation of the compression side disk valve 41A in the middle and high speed region. Generates a compression damping force. Further, in the extension side stroke, an extension side damping force is generated by the passage resistance of the bypass passage 45 whose opening degree is adjusted by the needle valve 85 in the low speed region, and in the middle and high speed range, the extension side disc valve 42A is extended by the bending deformation. Generates side damping force. The above-described expansion and contraction vibration of the suspension spring 33 is suppressed by the compression side damping force and the extension side damping force.

  In the front fork 10, a stopper rubber 13A and a stopper plate 13B are fixed to the lower end surface of the cap 13 so that the upper end portion of the partition wall member 19 provided in the inner tube 12 abuts at the maximum compression stroke. Regulates the maximum compression stroke.

  The front fork 10 is engaged with a spring seat 51 that is crimped and fixed to a lower end surface of the partition wall member 19 on the upper end side of the inner tube 12 facing the piston rod side oil chamber 21A, and a stopper ring 52A provided on the piston rod 23. A rebound spring 53 is interposed between the spring seat 52. When the front fork 10 is fully extended, the partition wall member 19 presses the rebound spring 53 between the spring seat 52 and regulates the maximum extension stroke.

  However, in the front fork 10, the sectional area S1 of the annular oil chamber 17 formed by the annular gap between the outer tube 11 and the inner tube 12 is larger than the sectional area (area surrounded by the outer diameter) S2 of the piston rod 23. (S1> S2, where S1 ≧ S2 is acceptable).

  Further, the flow of oil from the oil reservoir chamber 22 to the piston rod side oil chamber 21A is allowed in the rod guide portion 19A of the partition wall member 19 in the pressure side stroke, and from the piston rod side oil chamber 21A in the oil stroke chamber 22 in the extension side stroke. A check valve 60 is provided to prevent the oil from flowing into the tank. A valve chamber 61 is provided on the inner periphery of the rod guide portion 19 </ b> A of the partition wall member 19, and a stepped portion 61 </ b> A on the upper end side of the valve chamber 61 and a backup on the aforementioned spring seat 51 provided on the lower end side of the valve chamber 61. A check valve 60 is accommodated between the spring 62. The check valve 60 is shorter than the gap between the stepped portion 61A and the spring seat 51, and a lateral groove is formed on the lower end surface. The check valve 60 is slidably in contact with the inner periphery of the valve chamber 61 provided in the rod guide portion 19 </ b> A of the partition wall member 19 so as to be vertically displaced. The outer periphery of the check valve 60 is between the inner periphery of the valve chamber 61 provided in the rod guide portion 19A of the partition wall member 19 and allows a flow of oil from the oil reservoir chamber 22 to the piston rod side oil chamber 21A. Form. The check valve 60 includes a bush 63 that is slidably supported by the piston rod 23 and is press-fitted into the inner periphery thereof. In the pressure side stroke, the check valve 60 moves along with the piston rod 23 entering the inner tube 12, moves downward, abuts against the spring seat 51, and forms a gap with the stepped portion 61A, thereby forming an oil reservoir. The oil in the chamber 22 can flow into the piston rod-side oil chamber 21A from the lateral groove through the gap with the stepped portion 61A via the outer periphery thereof. In the extension stroke, the check valve 60 moves along with the piston rod 23 that retreats from the inner tube 12, moves upward, abuts against the stepped portion 61A, closes the gap between the stepped portion 61A, and the piston rod The oil in the side oil chamber 21A is prevented from being discharged to the oil sump chamber 22 through the reverse path of the pressure side stroke described above.

  Further, since the rod guide portion 19 </ b> A of the partition wall member 19 does not seal the oil seal around the piston rod 23, the bush 63 press-fitted into the inner periphery of the check valve 60 is formed around the piston rod 23. A minute flow path (orifice) 64 (not shown) that connects the piston rod side oil chamber 21A and the oil reservoir chamber 22 is configured by the gap (or the minute gap formed by the check valve 60 and the stepped portion 61A). The minute channel 64 may be formed in the rod guide portion 19 </ b> A of the partition wall member 19 so as to communicate the piston rod side oil chamber 21 </ b> A and the oil reservoir chamber 22.

The operation of the front fork 10 is as follows.
(Pressure side stroke)
The hydraulic oil corresponding to the volume of the piston rod 23 entering the inner tube 12 in the compression side stroke is transferred from the inner oil chamber 21 </ b> A of the inner tube 12 to the annular oil chamber 17 through the oil hole 28 of the inner tube 12. At this time, since the volume increase ΔS1 (replenishment amount) of the annular oil chamber 17 is larger than the volume increase ΔS2 of the piston rod 23, the required amount of oil supplied to the annular oil chamber 17 is insufficient (ΔS1−ΔS2). Minutes are replenished from the oil reservoir 22 through the check valve 60.

  In the compression side stroke, as described above, a compression side damping force is generated by the passage resistance of the bypass passage 45 whose opening degree is adjusted by the needle valve 85 in the low speed region, and in the middle and high speed region, the compression side is deformed by the deformation of the compression side disk valve 41A. Generates a damping force.

(Extension process)
The hydraulic oil corresponding to the retraction volume of the piston rod 23 that retreats from the inner tube 12 in the extension stroke is transferred from the annular oil chamber 17 to the oil chamber 21 </ b> A on the inner periphery of the inner tube 12 through the oil hole 28 of the inner tube 12. . At this time, since the volume decrease ΔS1 (discharge amount) of the annular oil chamber 17 is larger than the volume decrease ΔS2 of the piston rod 23, the excess of (ΔS1−ΔS2) of the oil discharge amount from the annular oil chamber 17 Is discharged to the oil reservoir 22 through the micro flow path 64.

  In the extension side stroke, as described above, the extension side damping force is generated by the passage resistance of the bypass passage 45 whose opening degree is adjusted by the needle valve 85 in the low speed region, and the extension side disk valve 42A is bent in the middle and high speed region. The expansion side damping force is generated by the deformation. Further, the extension side damping force due to the passage resistance of the micro flow path 64 is also generated.

Hereinafter, the damping force adjusting device 40A will be described.
As shown in FIG. 3, the damping force adjusting device 40A is provided with only one push rod 70 having a non-circular cross section that is movable in the rotational direction and the axial direction in the hollow portion of the piston rod 23, in this embodiment, a D-shaped cross section. The first adjustment unit 80 that moves the push rod 70 in the rotational direction and the second adjustment unit 90 that moves the push rod 70 in the axial direction are coaxially arranged on the upper portion of the front fork 10 and on the extension of the push rod 70. . Then, the damping force adjusting device 40A is configured such that the needle valve 85 slidably engaged in the non-circular cross section of the push rod 70 is screwed into the hollow portion of the piston rod 23, and the needle valve is rotated by the rotation of the first adjusting portion 80. 85 is screwed, and the opening degree of the bypass passage 45 is adjusted by the needle valve 85, so that the damping force due to the passage resistance of the bypass passage 45 can be adjusted. Further, the damping force adjusting device 40A urges the pressure side disk valve 41A in the closing direction by a spring 95 that abuts the push rod 70 in the axial direction, and is caused by bending deformation of the pressure side disk valve 41A. The compression side damping force can be adjusted. Hereinafter, the structure of the first adjusting unit 80 and the second adjusting unit 90, the damping force adjusting structure using the needle valve 85, and the damping force adjusting structure using the spring 95 will be described.

(Structure of the 1st adjustment part 80 and the 2nd adjustment part 90) (FIG. 3)
The cap 13 constituting the cap assembly is screwed in a liquid-tight manner to the upper end opening of the outer tube 11 via the O-ring 13C. An attachment collar 24 is screwed to the lower end opening side of the cap 13, and an upper end portion of the piston rod 23 is screwed to the attachment collar 24 and fixed by a lock nut 24 </ b> A.

  The first adjustment portion 80 is liquid-tightly inserted from the lower end opening side of the center hole of the cap 13 through an O-ring 81, and is engaged with the intermediate step portion of the cap 13 in the axial direction and is prevented from coming off upward. Along with the flat washer 82 placed on the upper end surface of the mounting collar 24 screwed to the lower end opening side of the cap 13, it is abutted in the axial direction and is prevented from coming down downward. The cap 13 is rotatably provided using 80A. The lower end surface of the first adjusting portion 80 that comes into contact with the flat washer 82 has a lateral groove, and both side protrusions of the engagement piece 83 are engaged with the lateral groove with almost no play in the rotation direction. The outer periphery of the non-circular cross section (D-shaped cross section) of the push rod 70 passes through a non-circular hole (D-shaped hole) provided at the center of the engagement piece 83, and engages with almost no play in the rotation direction. Make it slidable in the direction. Thereby, the 1st adjustment part 80 can move the push rod 70 to a rotation direction.

  The second adjustment unit 90 is liquid-tightly inserted through the O-ring 91 from the lower end opening side of the center hole of the first adjustment unit 80, and is engaged with the intermediate step portion of the first adjustment unit 80 in the axial direction. It is prevented from coming out upward. The lower end surface of the second adjustment portion 90 abuts with the upper end surface of the push rod 70 passing through the non-circular hole of the engagement piece 83 engaged with the first adjustment portion 80 in the axial direction without any gap. To do. The push rod 70 is urged upward by a spring force of a spring 95 described later, and the upper end surface of the push rod 70 always abuts with the lower end surface of the second adjustment unit 90. The second adjustment unit 90 is screwed to the first adjustment unit 80 using the operation groove 90A on the upper end surface, and can move the push rod 70 in the axial direction.

(Damping force adjustment structure using needle valve 85) (FIG. 3)
An inner base 84 is inserted into the lower end portion of the hollow portion of the piston rod 23, and the lower end surface of the piston rod 23 and the inner diameter step portion of the piston bolt 25 clamp and fix the lower end flange of the inner base 84. The inner base 84 may be press-fitted into the hollow portion of the piston rod 23. In this way, the needle valve 85 is liquid-tightly inserted into the inner periphery of the inner base 84 fixed to the piston rod 23, and the threaded portion of the intermediate portion of the needle valve 85 is screwed to the inner periphery of the piston bolt 25. The non-circular cross section of the upper end portion of the needle valve 85, that is, the non-circular cross section portion having a D-shaped cross section in this embodiment, is generally within the non-circular cross section of the lower end portion of the push rod 70 inserted into the hollow portion of the piston rod 23. It is engaged so that it can slide in the axial direction and engage in the rotational direction without play.

  As described above, when the first adjusting unit 80 moves the push rod 70 in the rotational direction, the needle valve 85 engaged with the push rod 70 in the rotational direction is screwed with respect to the piston bolt 25, and the piston bolt 25, the opening and closing of the bypass passage 45 can be adjusted with respect to the valve seat at the upper end of the vertical hole of the bypass passage 45, and the damping force on the compression side and the extension side due to the passage resistance of the bypass passage 45 can be adjusted. To.

  When the first adjustment unit 80 screwes the needle valve 85 via the push rod 70, the needle valve 85 is idled with respect to the center hole of the pushing piece 92 for the spring 95 described later, and the spring 95 Will not be affected.

(Damping force adjustment structure using spring 95) (FIG. 3)
On both sides in the diameter direction on the lower end side of the piston rod 23, long hole-shaped guide holes 23A extending in the axial direction are provided. It is possible to be engaged. The lower end surface of the push rod 70 inserted into the hollow portion of the piston rod 23 directly contacts the upper surface of the pushing piece 92, and the non-feed of the needle valve 85 engaged with the lower end portion of the push rod 70 as described above. The circular cross section is loosely inserted into a circular hole provided in the center of the push piece 92 so as to be axially movable.

  Around the lower end portion (piston bolt 25) of the piston rod 23, there are a spring receiver 93 that abuts against the protrusions on both ends of the pushing piece 92 from below, and a valve retainer 94 that abuts on the upper surface (rear surface) of the compression side disk valve 41A. The valve retainer spring 95 is interposed between the spring receiver 93 and the valve retainer 94. The spring receiver 93 has a cup shape and abuts with both side protrusions of the pushing piece 92 at the lower end of the inner periphery of the cup, and the spring 95 is seated on the upper peripheral flange of the cup. The valve retainer 94 is a slide that is slidably guided on the outer periphery of the upper end of the piston bolt 25, and an annular retainer 94A that continuously contacts the entire circumference (or intermittently) at an appropriate outer diameter position on the upper surface of the compression side disk valve 41A. An oil passage 94C that communicates the portion 94B and the piston rod side oil chamber 21A to the pressure side passage 41, the extension side passage 42, and the bypass passage 45 is provided, and a spring 95 is seated on the outer circumferential step portion.

  As described above, when the second adjusting portion 90 moves the push rod 70 in the axial direction, the pushing piece 92 with which the lower end surface of the push rod 70 abuts moves the spring receiver 93 up and down to move the valve holding spring. 95 is expanded and contracted, and the set load of the spring 95 is adjusted. As a result, the set load of the spring 95 biases the pressure side disc valve 41A in the closing direction via the valve presser 94, and the pressure side damping force due to the bending deformation of the pressure side disc valve 41A can be adjusted. The valve presser 94 can be exchanged with one having a different diameter of the presser part 94A. The valve presser 94 having the large-diameter presser part 94A presses the outer peripheral side of the pressure side disk valve 41A, so that the piston speed can be reduced. Increase the damping force. The valve presser 94 provided with the small-diameter presser part 94A presses the inner peripheral side of the pressure side disc valve 41A, and increases the damping force in the middle to high speed range of the piston speed.

  When the second adjustment unit 90 moves the pushing piece 92 via the push rod 70, the push rod 70 and the pushing piece 92 are moved in the axial direction with respect to the needle valve 85, and the needle valve 85 is affected. do not do.

  The front fork 10 has the following operational effects by including the damping force adjusting device 40A.

  (a) The first adjustment unit 80 and the second adjustment unit 90 are coaxially arranged on the upper portion of the front fork 10 and on the extension of the push rod 70, and the first adjustment unit 80 and the push rod 70 are simply coupled in the rotation direction. The front fork 10 can be configured to easily couple the second adjusting portion 90 and the push rod 70 in the axial direction, to reduce the number of components, and to prevent malfunction.

  (b) Since the first adjusting portion 80 and the second adjusting portion 90 are coaxially arranged on the upper portion of the front fork 10, the present invention can be applied to the front fork 10 that can be adjusted only from the upper end surface of the outer tube 11. Moreover, since the 1st adjustment part 80 and the 2nd adjustment part 90 do not have the directionality in the circumferential direction of the outer tube 11, the circumferential direction assembly position to the vehicle body side attachment members 14A and 14B becomes arbitrary, and assembly property Is good.

  (c) The push rod 70 has a single hollow non-circular cross section, and the needle valve 85 is slidably engaged in the non-circular cross section of the push rod 70. Since the needle valve 85 is housed in the inner diameter of the push rod 70, the space for arranging the needle valve 85 around the outer periphery of the push rod 70 is not necessary, and the applicability to the thin front fork 10 of the piston rod 23 is good.

  (d) The first adjusting portion 80 is rotatably provided on the cap 13 on the upper portion of the front fork 10, and the engaging piece 83 is engaged with the groove provided on the end surface of the first adjusting portion 80 in the rotation direction. The outer periphery of the non-circular cross section of the push rod 70 is engaged in the rotational direction with a non-circular hole provided in the joint piece 83 and is slidable in the axial direction. Further, the second adjusting portion 90 is screwed into the center hole of the first adjusting portion 80, and the end surface of the second adjusting portion 90 and the end surface of the push rod 70 passing through the non-circular hole of the engaging piece 83 and the shaft. Made possible to collide with direction. Accordingly, the first adjusting unit 80 and the second adjusting unit 90 are compactly arranged coaxially on the upper portion of the front fork 10, and the rotational force of the first adjusting unit 80 is simply transmitted to the push rod 70, and the second adjusting unit 90. The axial force can be directly transmitted to the push rod 70.

  Hereinafter, the spring load adjusting device 100 that raises and lowers the lower spring receiver 32 and adjusts the spring load of the suspension spring 33 will be described.

  As shown in FIGS. 2 and 4, the spring load adjusting device 100 is an adjustment bolt that faces the outside at a position where the axle mounting hole 16 of the axle bracket 15 that forms the bottom of the inner tube 12 is removed (by the side of the axle mounting hole 16). 101 is provided at the bottom. A direction in which the slider 102 provided on the inner bottom portion of the axle bracket 15 (the surface facing the lower end portion of the lower spring support 32) intersects the central axis of the inner tube 12 by the rotational force of the adjustment bolt 101 (the axis of the adjustment bolt 101). Direction). The lower slope A1 of the lower spring receiver 32 is placed on the upper slope A2 of the slider 102, and the lower spring receiver 32 is moved up and down by the adjustment bolt 101 to adjust the spring load of the suspension spring 33. Specifically, it is as follows.

  (1) A central axis passing through the axle mounting hole 16 of the axle bracket 15 before being screwed into the lower end opening of the inner tube 12 (in the state where the axle bracket 15 is attached to the inner tube 12, the axle mounting hole of the inner tube 12 The distal end shaft portion 101A and the proximal end boss portion 101B of the adjusting bolt 101 are rotatably inserted into the mounting holes 15A and 15B that are orthogonally arranged (same as the central axis passing through 16). The mounting hole 15A is a blocking hole, the mounting hole 15B is a through hole, and a retaining ring 103 is engaged with the opening of the mounting hole 15B in which the proximal end boss 101B is pivotally attached with an O-ring. 101 is retained.

  (2) When the adjustment bolt 101 is pivotally attached to the axle bracket 15 as described in (1) above, the washer 104, the slider 102, and the nut 105 are inserted into the middle portion of the adjustment bolt 101. That is, the washer 104 is abutted against the step surface formed by the boss portion 101B on the proximal end side of the adjustment bolt 101. The washer 104 has a quadrilateral shape, and the lower side of the washer 104 is held against the slide surface 106 at the inner bottom of the axle bracket 15 and is prevented from rotating. A slider 102 is inserted into the leading end side of the adjusting bolt 101, and an accompanying nut 105 attached to the slider 102 is screwed into the threaded portion. As shown in FIG. 5, the nut 105 includes a nut portion 105 </ b> A, and has a quadrilateral plate 105 </ b> B continuous to the nut portion 105 </ b> A. The slider 102 has a four-sided shape as shown in FIG. 6 and has a hole to be inserted into the adjusting bolt 101. The slider 102 is held against the slide surface 106 of the axle bracket 15 and is prevented from rotating, and the upper side is connected to the upper slope A2. To do.

  (3) Insert the lower spring receiver 32 into the axle bracket 15. As shown in FIG. 7, the lower spring receiver 32 has a lower end protrusion 32B protruding from the bottom of the bottomed cylindrical portion 32A, and in a side view, one end surface of the lower end protrusion 32B is a lower slope A1, and the other end surface is a lower vertical surface. The lower slope A1 and the lower vertical plane B intersect with each other at an acute angle. The lower spring receiver 32 includes a U-shaped detent groove 32C that extends from the lower slope A1 to the lower vertical surface B and opens below the lower end protrusion 32B at the center of the lower end protrusion 32B when viewed from the front. As shown in FIG. 4, the lower spring receiver 32 inserted into the axle bracket 15 has a lower end protrusion 32B sandwiched between the slider 102 and the washer 104, and a lower slope A1 placed on the upper slope A2 of the slider 102 and a lower part. The vertical surface B is brought into contact with the end surface of the washer 104. At this time, the anti-rotation groove 32 </ b> C of the lower spring receiver 32 is prevented from rotating with respect to the central axis of the axle bracket 15 by sandwiching the intermediate portion of the adjustment bolt 101.

  When the lower spring receiver 32 is inserted into the axle bracket 15, a washer 107 for supporting the distal end portion of the inner tube 12 is loaded on the step portion 15 </ b> C at the inner bottom portion of the axle bracket 15. The washer 107 is assembled around the lower end protrusion 32B of the lower spring receiver 32 and is locked to the bulging portions 32D provided on both ends of the lower end protrusion 32B to be prevented from falling off.

  (4) The axle bracket 15 is inserted into the lower end portion of the inner tube 12 via the O-ring 108 and screwed. The inner tube 12 is inserted into the annular gap between the inner periphery of the axle bracket 15 and the cylindrical portion 32A of the lower spring receiver 32 with almost no gap. At this time, as shown in FIG. 2, the upper end surface of the cylindrical portion 32A of the lower spring support 32 (3) protrudes from the upper end surface of the axle bracket 15 by H, and the upper end portion of the cylindrical portion 32A is the inner end first. Assembling the inner tube 12 and the axle bracket 15 by inserting the lower end portion of the inner tube 12 into the annular gap between the cylindrical portion 32A and the inner periphery of the axle bracket 15 after insertion into the inner circumference of the tube 12 Make good. In this assembly, even if the axle bracket 15 is turned upside down, the washer 107 is restrained by the presence of the O-ring 108 loaded in the annular groove of the axle bracket 15 and does not fall off.

  (5) A cup-shaped spring collar 109 is liquid-tightly fitted to the upper end opening of the cylindrical portion 32A of the lower spring receiver 32 via an O-ring 109A, and the flange of the spring collar 109 is mounted on the upper end surface of the cylindrical portion 32A. Put. The lower spring receiver 32 and the spring collar 109 keep the inner space sealed and integrated in a cavity, reducing the amount of oil to be injected into the oil chamber 21 of the inner tube 12 and reducing the weight. Thereafter, the suspension spring 33 is inserted into the inner tube 12, and the suspension spring 33 is supported by the lower spring receiver 32 through the flange of the spring collar 109.

  When the adjustment bolt 101 is screwed in a state where the front fork 10 is assembled, the lower spring receiver 32 is in sliding contact with the inner periphery of the inner tube 12 via the lower inclined surface A1 of the lower spring receiver 32 and the upper inclined surface A2 of the slider 102. Go up and down. The lower spring receiver 32 adjusts the initial length of the suspension spring 33 and the spring load of the suspension spring 33 between the upper spring receiver 31 on the piston rod 23 side.

  As shown in FIG. 7, the spring load adjusting device 100 includes a longitudinal groove 32E extending over the entire length of the cylindrical portion 32A on the outer periphery of the cylindrical portion 32A of the lower spring receiver 32 that is in sliding contact with the inner periphery of the inner tube 12. The oil chamber 21 in the upper part of the spring receiver 32 is communicated with the back chamber 21C of the lower spring receiver 32, and the oil in the oil chamber 21 can be supplied to and discharged from the back chamber 21C as the lower spring receiver 32 moves up and down.

  In the spring load adjusting device 100, as shown in FIG. 9, the slider 102 is separated from the slider 102 by providing a screw portion 102A (nut portion) directly on the slider 102 or fitting and fixing a nut to the slider 102. The nut 105 to be used is unnecessary, and the number of parts can be reduced.

According to the present embodiment, the following operational effects can be obtained.
(a) The horizontal movement of the slider 102, which moves linearly by the rotational force of the adjusting bolt 101, moves up and down the lower spring receiver 32 via the contact between the lower slope A1 of the lower spring receiver 32 and the upper slope A2 of the slider 102. Converted.

  (b) Since the adjustment bolt 101 is provided at the bottom so as to face the outside at the position where the axle mounting hole 16 of the inner tube 12 is removed, the spring load of the suspension spring 33 is adjusted even when the front fork 10 is not removed from the axle. it can.

  (c) The load of the suspension spring 33 is directly supported by the slider 102 and the adjusting bolt 101 without using the pump piston or the hydraulic oil pressurizing chamber, and the hydraulic oil sealing structure is simple and sufficient. Workability and assembly are simplified, and operational reliability is improved.

  (d) By setting the lower slope A1 of the lower spring receiver 32 and the upper slope A2 of the slider 102 to the same slope and bringing them into full contact, a sufficient spring load adjustment width and durability can be secured.

  (e) A lower end protrusion 32B (lower part) of the lower spring support 32 is provided between the end face of the washer 104 provided on one end side of the adjusting bolt 101 and the upper slope A2 of the slider 102 provided on the other end side of the adjusting bolt 101. By sandwiching the vertical surface B and the lower inclined surface A1), a mechanism for moving the lower spring receiver 32 up and down by the adjusting bolt 101 and the slider 102 can be easily configured.

  (f) Since the hydraulic oil chamber 21 at the upper part of the lower spring receiver 32 communicates with the rear chamber 21C of the lower spring receiver 32 inside the inner tube 12, only the spring load of the suspension spring 33 is increased by raising and lowering the lower spring receiver 32. Can be adjusted.

  In the front fork 10, the lower spring receiver 32 is liquid-tightly fitted to the inner periphery of the inner tube 12 inside the inner tube 12 by fitting an O-ring into the outer peripheral groove of the lower spring receiver 32. In combination, the oil chamber 21 above the lower spring receiver 32 may be sealed in a liquid-tight manner with respect to the rear chamber 21C of the lower spring receiver 32. According to this, the raising and lowering of the lower spring receiver 32 inside the inner tube 12 also raises and lowers the oil level of the oil reservoir chamber 22 via the hydraulic oil chamber 21 of the inner tube 12. Accordingly, the spring load of the suspension spring 33 is adjusted by raising and lowering the lower spring receiver 32, and the air chamber 22B is expanded and contracted by the rise of the oil level of the oil reservoir chamber 22. As a result, the spring load of the air spring can also be adjusted.

  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.

FIG. 1 is a sectional view showing the entire hydraulic shock absorber. FIG. 2 is a sectional view showing the spring load adjusting device. FIG. 3 is a cross-sectional view showing the damping force adjusting device. FIG. 4 is an enlarged view of a main part of FIG. FIG. 5 shows a nut, (A) is a front view, and (B) is a sectional view. 6A and 6B show a slider, FIG. 6A is a front view, FIG. 6B is a side view, and FIG. 6C is a cross-sectional view taken along line CC in FIG. 7A and 7B show a lower spring support, FIG. 7A is a front view, FIG. 7B is a cross-sectional view, and FIG. 7C is a plan view. 8A and 8B show a lower end portion of the lower spring receiver, in which FIG. 8A is a bottom view and FIG. 8B is a sectional view taken along line BB in FIG. FIG. 9 shows a modified example of the slider, in which (A) is a front view and (B) is a side view.

Explanation of symbols

10 Front fork (hydraulic shock absorber)
11 Outer tube 12 Inner tube 15 Axle bracket 15A Mounting hole 16 Axle mounting hole 19 Partition member 21 Hydraulic oil chamber 22 Oil reservoir chamber 23 Piston rod 26 Piston 31 Upper spring receiver 32 Lower spring receiver
32B Lower end protrusion
32C Non-rotating groove
32D bulging portion 33 suspension spring 100 spring load adjustment device 101 adjustment bolt 102 slider 104 washer
107 washer
108 O-ring A1 Lower slope A2 Upper slope B Lower vertical plane

Claims (3)

The inner tube on the axle side is slidably inserted into the outer tube on the vehicle body side, and the axle bracket is screwed to the lower end of the inner tube,
A partition member is provided on the inner periphery of the inner tube, a hydraulic oil chamber is defined in the lower part of the partition member, and an oil reservoir chamber is defined in the upper part.
A piston support member attached to the outer tube side is inserted into the hydraulic oil chamber through the partition member, and a piston that slides in the hydraulic oil chamber is provided at a tip portion of the piston support member;
In the hydraulic shock absorber in which the suspension spring is interposed between the upper spring receiver on the piston support member side and the lower spring receiver on the axle bracket side in the hydraulic oil chamber of the inner tube,
Stop the lower spring holder against the axle bracket and insert it into the axle bracket.
The axle bracket has an adjustment bolt facing the outside at a position where the axle mounting hole of the axle bracket is removed, and a spring load adjustment device that adjusts the spring load of the suspension spring by raising and lowering the lower spring receiver by rotating the adjustment bolt. ,
A washer incorporated around the lower end projection of the lower spring holder and locked to the bulging portion provided at the tip of the lower end projection is prevented from falling off, and loaded on the stepped portion of the axle bracket.
The tip of the inner tube that is screwed to the axle bracket is supported by the washer ,
Detent groove provided in the lower end projections of the receiving lower spring at sandwiching the intermediate portion of the adjusting bolt of the spring load adjusting apparatus, a hydraulic shock which receives said spring, characterized in Rukoto been detent to axle bracket vessel. 2. The hydraulic shock absorber according to claim 1 , wherein the washer is restrained by an O-ring loaded in an annular groove of the axle bracket and does not fall off when the inner tube and the axle bracket are assembled. 3. The spring load adjusting device abuts a washer against a step surface on one end side of the adjusting bolt, and inserts a slider on the other end side of the adjusting bolt, and the slider is attached to the center axis of the inner tube by the rotational force of the adjusting bolt. It is possible to move straight in the direction intersecting
The hydraulic shock absorber according to claim 1 or 2 , wherein the lower slope of the lower spring receiver is placed on the upper slope of the slider, and the lower vertical surface of the lower spring receiver is brought into contact with the end face of the washer.

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