JP2007120677A - Hydraulic shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a hydraulic shock absorber for moving up and down a lower spring support from the outside, wherein a spring load is adjusted by moving up and down the lower spring support of a suspension spring provided on the bottom side of an inner tube. <P>SOLUTION: The hydraulic shock absorber 10 comprises the suspension spring 33 mounted in an operating oil chamber 21 of the inner tube 12 between an upper spring support 31 on the side of a piston rod 23 and the lower spring support 32 on the bottom side of the inner tube 12. The lower spring support 32 is supported by an adjusting bolt 71 provided on the bottom side of the inner tube 12 so as to face the outside at a position departing from an axle mounting hole 16 on the bottom side. The spring load of the suspension spring 33 is adjusted by moving up and down the lower spring support 32 by the threading operation of the adjusting bolt 71. <P>COPYRIGHT: (C)2007,JPO&INPIT

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 with a pump piston that vibrates when operated externally.
2-150439

  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.

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

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

  In 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, a partition member is provided on the inner periphery of the inner tube, and a hydraulic oil chamber is provided below the partition 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 slides in the hydraulic oil chamber on the tip of the piston rod. In the hydraulic shock absorber provided with a piston and having a suspension spring 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, The lower spring receiver is supported by an adjustment bolt provided on the bottom so that the bottom axle mounting hole is exposed to the outside, and the lower spring receiver is lifted and lowered by the adjustment bolt. It is obtained so as to adjust the spring load of the spring.

  According to a second aspect of the present invention, in the first aspect of the invention, the adjusting bolt is arranged obliquely with respect to a central axis passing through the axle mounting hole of the inner tube, and the adjusting bolt is pulled out to the inner surface of the bottom portion of the inner tube. It is supported in a state where it is stopped, the operation part of the adjustment bolt is exposed to the outside, the adjustment nut is screwed into the threaded part of the adjustment bolt that faces the inner tube, and the detent means provided inside the inner tube is used. The adjustment nut is prevented from rotating, and the back surface of the lower spring receiver is abutted against the tip of the adjustment nut.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the hydraulic oil chamber at the upper part of the lower spring receiver is sealed with respect to the rear chamber of the lower spring receiver within the inner tube.

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the hydraulic oil chamber at the top of the lower spring receiver is communicated with the back chamber of the lower spring receiver within the inner tube.

  According to a fifth aspect of the present invention, in the invention according to any one of the second to fourth aspects, the anti-rotation means comprises a washer clamped between the inner tube and the axle bracket, and the anti-rotation deformed slit provided in the washer. The modified nut is inserted through the deformed part.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, a slider is provided below the washer at the bottom of the inner tube, and the slider slide-guides the outer surface of the adjustment nut and prevents the adjustment bolt from being pushed in from the outside. To do.

(Claim 1)
(a) An adjustment bolt is rotatably provided on the bottom side of the inner tube, and parts workability and assemblability can be simplified as compared with those incorporating sliding parts such as a plunger.

  (b) Since the load of the suspension spring is directly supported by the adjustment bolt, the hydraulic oil sealing structure is simple and the operational reliability is improved.

  (c) Since the adjustment bolt is provided at the bottom so as to face the outside at the position where the axle mounting hole of the inner tube is removed, the spring load of the suspension spring can be adjusted without removing the hydraulic shock absorber from the axle.

(Claim 2)
(d) Under the condition that the adjustment nut is supported on the inner surface of the bottom of the inner tube to prevent it from coming off, the adjustment nut that has been prevented from rotating is moved linearly by rotating it from the outside, and the adjustment nut is supported on the back. The spring receiver can be raised and lowered.

(Claim 3)
(e) Inside the inner tube, the hydraulic oil chamber above the lower spring receiver is sealed against the back chamber of the lower spring receiver, so that the lower spring receiver moves up and down inside the inner tube. The oil level of the oil reservoir chamber is also raised and lowered via the oil chamber. Therefore, the spring load of the suspension spring is adjusted by raising and lowering the lower spring receiver, and the air chamber is expanded and contracted by the rise of the oil level of the oil reservoir chamber. As a result, the spring load of the air spring can also be adjusted.

(Claim 4)
(f) By connecting the hydraulic oil chamber above the lower spring receiver to the rear chamber of the lower spring receiver inside the inner tube, only the spring load of the suspension spring can be adjusted by raising and lowering the lower spring receiver.

(Claim 5)
(g) Since the washer sandwiched between the inner tube and the axle bracket is provided with a non-rotating slit for adjusting nut, the adjusting nut can be easily prevented from rotating.

(Claim 6)
(h) By providing a slider at the bottom of the washer at the bottom of the inner tube and slidingly guiding the outer surface of the adjustment nut with this slider, the adjustment nut arranged obliquely with respect to the central axis of the inner tube along with the adjustment bolt is Prevents falling by receiving a spring load acting along the central axis of the inner tube. Further, the adjustment bolt can be prevented from being pushed in from the outside.

  1 is a sectional view showing the whole hydraulic shock absorber, FIG. 2 is a lower sectional view of FIG. 1, FIG. 3 is a middle sectional view of FIG. 1, FIG. 4 is an upper sectional view of FIG. 6 is a front view showing the adjusting bolt, FIG. 7 is an adjusting nut, (A) is a side sectional view, (B) is a plan view, (C) is an end view, and FIG. 8 is a slider. (A) is a side view, (B) is a plan view, (C) is a front view, (D) is a rear view, FIG. 9 is a plan view showing a detent washer, and FIG. 10 shows a lower spring support. Sectional drawing, FIG. 11 is sectional drawing which shows the modification of a spring load adjusting device.

  The 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. 1 to 4, the hydraulic shock absorber 10 is disposed on the inner periphery of the lower end opening of the outer tube 11. The inner tube 12 is slidably inserted into the outer tube 11 via the fixed guide bush 11 </ b> A and the guide bush 12 </ b> A 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 hydraulic shock absorber 10 defines an inner circumference of the outer tube 11, an outer circumference of the inner tube 12, and an annular oil chamber 17 defined by the two guide bushes 11A and 12A.

  The hydraulic shock absorber 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 19 </ b> A of the partition wall member 19. The oil reservoir chamber 22 is partitioned 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.

  In the hydraulic shock absorber 10, the piston rod 23 attached to the outer tube 11 is slidably inserted into the rod guide portion 19 </ b> A of the partition wall member 19. Specifically, the hollow piston rod 23 is screwed to the lower end portion of the center portion of the cap 13, and this is fixed with the lock nut 25.

  The hydraulic shock absorber 10 fixes a piston 26 slidably in contact with the inner periphery of the inner tube 12 to a tip end of a piston rod 23 inserted into the inner tube 12 from the rod guide portion 19A of the partition wall member 19, and the oil chamber 21 is fixed to the piston. The piston rod side oil chamber 21A in which the rod 23 is accommodated and the piston side oil chamber 21B in which the piston rod 23 is not accommodated are partitioned. The piston 26 is fixed by a nut 27.

  The hydraulic shock absorber 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 hydraulic shock absorber 10 abuts the upper spring receiver 31 on the lower end surface of the piston 26 facing the piston-side oil chamber 21B, and the lower spring receiver 32 is seated on the bottom of the inner tube 12 formed by the axle bracket 15. A suspension spring 33 is interposed between a spring receiving portion 31 </ b> C and a lower spring receiving portion 32 provided at a stepped portion with the lowermost diameter reducing portion 31 </ b> B continuous with the tapered portion 31 </ b> A of the receiving 31. The hydraulic shock absorber 10 absorbs the impact force received from the road surface during traveling of the vehicle by the expansion and contraction vibration of the suspension spring 33.

The hydraulic shock absorber 10 includes a damping force generator 40 in the piston 26.
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 backed up by a valve stopper 41B. The extension side channel 42 is opened and closed by an extension side disk valve 42A 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 rod 23. The stopper ring 41C that is engaged with the piston rod 23, and the piston rod It is fixed by being sandwiched between nuts 27 that are screwed into the nut 23.

  The damping force generator 40 is provided on the piston rod 23 by screwing an adjustment rod 43 into the center of the cap 13 in a liquid-tight manner, and inserting a needle valve 44 fixed to the adjustment rod 43 into the hollow portion of the piston rod 23. The opening degree of the bypass passage 45 is adjusted by the vertical movement of the needle valve 44. 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 generating device 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 44 in the low speed region, and the bending deformation of the compression side disk valve 41A in the medium to 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 44 in the low speed range, and in the middle and high speed range, the extension side disc valve 42A is extended by 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 hydraulic shock absorber 10, a stopper rubber 13 </ b> A and a stopper plate 13 </ b> B 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 hydraulic shock absorber 10 includes a spring seat 51 that is caulked and fixed to a lower end surface facing the piston rod side oil chamber 21A of the partition wall member 19 on the upper end side of the inner tube 12, and a valve stopper 41B provided on the upper end surface side of the piston 26. A rebound spring 52 is interposed therebetween. When the hydraulic shock absorber 10 is fully extended, the partition member 19 pressurizes the rebound spring 52 with the valve stopper 41B, thereby restricting the maximum extension stroke.

  However, in the hydraulic shock absorber 10, the sectional area S 1 of the annular oil chamber 17 formed by the annular gap between the outer tube 11 and the inner tube 12 is determined from the sectional area (area surrounded by the outer diameter) S 2 of the piston rod 23. It is formed large (S1> S2, but S1 ≧ S2 is also 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 53. The check valve 60 is shorter than the distance between the stepped portion 61A and the spring seat 51, and a lateral groove 62 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 and moves downward in FIG. 3 to abut against the spring seat 51 and to form a gap with the step portion 61A. The oil in the piston rod side oil chamber 21 </ b> A can be discharged from the lateral groove 62 to the oil reservoir chamber 22 through the outer periphery of the piston rod side oil chamber 21 </ b> A through the gap with the stepped portion 61 </ b> A. In the extension stroke, the check valve 60 moves along with the piston rod 23 that retreats from the inner tube 12 and moves upward in FIG. 3 to collide with the stepped portion 61A and close the gap with the stepped portion 61A. The oil in the piston rod side oil chamber 21A is prevented from being discharged to the oil reservoir 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 hydraulic shock absorber 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 44 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 29 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 44 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 spring load adjusting device 70 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 FIG. 5, the spring load adjusting device 70 is an adjustment provided so as to face the outside at a position where the axle mounting hole 16 of the axle bracket 15 constituting the bottom portion of the inner tube 12 is removed (by the side of the axle mounting hole 16). The lower spring receiver 32 is supported by the bolt 71, and the lower spring receiver 32 is lifted and lowered by the adjustment bolt 71 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 flange of the adjusting bolt 71 from the side facing the inside of the inner tube 12 with respect to the large-diameter hole of the step-like operation hole 15A formed obliquely with respect to the central axis passing through 16) 71A is inserted. As shown in FIG. 6, the adjustment bolt 71 has an inner end surface of the operation portion 71A as a flange surface 71B, a screw portion 71C, and a tool locking hexagon hole 71D on the outer end surface of the operation portion 71A. An O-ring 71E is fitted into the outer peripheral groove of the portion 71A. The adjusting bolt 71 is liquid-tightly inserted into the large-diameter hole of the operation hole 15A together with the O-ring 71E with the operation part 71A, and the outer end surface of the operation part 71A is connected to the large-diameter hole and small-diameter of the operation hole 15A of the axle bracket 15. The hexagonal hole 71D of the operation portion 71A is exposed to the outside from the small diameter hole of the operation hole 15A while being supported by the stepped surface of the hole and prevented from coming outside.

  (2) An adjusting nut 72 is screwed onto the threaded portion 71C of the adjusting bolt 71 that faces the inside of the inner tube 12. As shown in FIG. 7, the adjusting nut 72 has a cylindrical deformed portion 72B standing from a stopper surface 72A projecting on both sides, and has a threaded portion 72C on the inner periphery of the deformed portion 72B. An abutting surface 72D that abuts the back surface of 32 is used. For example, the deformed portion 72B includes a two-sided width portion on a cylindrical outer surface. The adjusting nut 72 is screwed into the threaded portion 71C of the adjusting bolt 71 from the stopper surface 72A side. The stopper surface 72A abuts on the lower surface of a non-rotating washer 74, which will be described later, and restricts the rising stroke end of the adjusting nut 72. The stopper surface 72 </ b> A and the abutting surface 72 </ b> D are parallel to each other and oblique to the central axis of the adjustment nut 72, and are in surface contact with the lower surface of the non-rotating washer 74 and the back surface of the lower spring receiver 32.

  (3) In the axle bracket 15, a step hole 15B is provided immediately below the inner periphery where a non-turn washer 74, which will be described later, is disposed, and the flange 73A of the slider 73 is fitted into the step hole 15B. As shown in FIG. 8, the slider 73 has a U-shaped cylindrical guide 73B extending obliquely downward from the flange portion 73A, and an obliquely downward cylindrical outer surface sandwiched between two width portions of the deformed portion 72B of the adjusting nut 72 is arranged on the guide 73B. Slide guide with arc guide surface. Further, the slider 73 has the lower end stopper portion 73C of the guide 73B opposed to the flange surface 71B of the operation portion 71A of the adjustment bolt 71 inserted into the operation hole 15A of the axle bracket 15, and is external to the operation hole 15A. By pushing the flange surface 71B of the adjustment bolt 71 pushed in from the stopper portion 73C, the pushing-in is made impossible.

  (4) The axle bracket 15 is screwed into the lower end opening of the inner tube 12. At this time, the non-turn washer 74 is clamped between the lower end surface of the inner tube 12 and the inner peripheral step surface of the axle bracket 15. As shown in FIG. 9, the non-rotating washer 74 includes a non-rotating deformed slit 74A, and the deformed portion 72B of the adjusting nut 72 (2) is inserted into the deformed slit 74A. Thereby, the adjustment nut 72 is prevented from rotating by the non-rotating washer 74 with respect to the screwing of the adjusting bolt 71, and moves up and down by linearly moving in the deformed slit 74A.

  (5) The lower spring receiver 32 is inserted into the inner periphery of the inner tube 12, and the back surface of the lower spring receiver 32 is abutted against the abutting surface 72 </ b> D of the end of the adjusting nut 72. As shown in FIG. 10, the lower spring receiver 32 has an inverted cup shape, the back surface of the cup bottom is abutted against the abutting surface 72D of the adjusting nut 72, and the O-ring 75 is fitted into the cup outer peripheral groove. The lower spring receiver 32 is fluid-tightly fitted to the inner periphery of the inner tube 12 together with the O-ring 75, and the upper oil chamber 21 of the lower spring receiver 32 is connected to the back chamber 76 of the lower spring receiver 32 (adjustment bolt 71 and lower spring receiver). 32, a space for storing the adjusting nut 72, the collar 73, and the non-rotating washer 74). 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.

  When the adjustment bolt 71 is screwed through the operation portion 71A of the adjustment bolt 71 with a tool inserted into the operation hole 15A of the axle bracket 15 in the assembled state of the hydraulic shock absorber 10, the adjustment nut 72 moves up and down. The lower spring receiver 32 that abuts the adjustment nut 72 moves 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.

According to the present embodiment, the following operational effects can be obtained.
(a) The adjustment bolt 71 is rotatably provided on the bottom side of the inner tube 12, and the parts workability and assemblability can be simplified as compared with those incorporating sliding parts such as a plunger.

  (b) The load of the suspension spring 33 is directly supported by the adjusting bolt 71, and the hydraulic oil sealing structure is simple and the operational reliability is improved.

  (c) Since the adjustment bolt 71 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 can be applied even when the hydraulic shock absorber 10 is not removed from the axle. Can be adjusted.

  (d) While the adjustment bolt 71 is supported on the inner surface of the bottom portion of the inner tube 12 so as to prevent it from coming off, the adjustment nut 72 that is prevented from rotating is linearly moved by rotating from the outside, and the adjustment nut 72 is supported on the back surface. The lower spring receiver 32 can be moved up and down.

  (e) By sealing the hydraulic oil chamber 21 at the upper part of the lower spring receiver 32 with respect to the back chamber 76 of the lower spring receiver 32 inside the inner tube 12, the lower spring receiver 32 inside the inner tube 12 is sealed. The raising / lowering also raises / lowers the oil level of the oil reservoir 22 through the hydraulic oil chamber 21 of the inner tube 12. Therefore, the spring load of the suspension spring 33 is adjusted by raising and lowering the lower spring receiver 32, and the air chamber is expanded and contracted by raising the oil level of the oil reservoir chamber 22. As a result, the spring load of the air spring can also be adjusted.

  (f) Since the washer 74 that is clamped between the inner tube 12 and the axle bracket 15 is provided with the non-rotating deformed slit 74A for the adjusting nut 72, the adjusting nut 72 can be easily prevented from rotating.

  (g) A slider 73 is provided at the bottom of the washer 74 at the bottom of the inner tube 12, and the outer surface of the adjusting nut 72 is slid and guided by the slider 73, so that the adjusting bolt 71 and the central axis of the inner tube 12 are obliquely crossed. The arranged adjustment nut 72 is prevented from falling down due to a spring load acting along the central axis of the inner tube 12. Further, the adjustment bolt 71 can be prevented from being pushed in from the outside.

  The modification of FIG. 11 is different from the embodiment of FIG. 5 in that the O-ring 75 is not provided on the outer periphery of the lower spring receiver 32, and the through hole 32A is provided at the bottom of the cup of the lower spring receiver 32. Inside the inner tube 12, the oil chamber 21 above the lower spring receiver 32 is communicated with the back chamber 76 of the lower spring receiver 32. According to this, only the spring load of the suspension spring 33 can be adjusted by raising and lowering the lower spring receiver 32 caused by the screwing of the adjusting bolt 71.

  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 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 cross-sectional view showing the spring load adjusting device. FIG. 6 is a front view showing the adjustment bolt. FIG. 7 shows an adjusting nut, (A) is a side sectional view, (B) is a plan view, and (C) is an end view. FIG. 8 shows a slider, (A) is a side view, (B) is a plan view, (C) is a front view, and (D) is a rear view. FIG. 9 is a plan view showing a non-rotating washer. FIG. 10 is a sectional view showing the lower spring receiver. FIG. 11 is a sectional view showing a modification of the spring load adjusting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hydraulic buffer 11 Outer tube 12 Inner tube 15 Axle bracket 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 33 Suspension spring 71 Adjustment bolt 71A Operation part 71B Flange portion 71C Screw portion 72 Adjust nut 72B Deformed portion 73 Slider 74 Non-rotating washer (rotating prevention means)
74A Profile slit 76 Back room

Claims (6)

Insert the inner tube on the axle side slidably into the outer tube on the vehicle body side,
A partition member is provided on the inner periphery of the inner tube, a hydraulic oil chamber is defined in the lower portion of the partition member, and an oil reservoir chamber is defined in the upper portion.
A piston rod 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 of the piston rod;
In the hydraulic oil chamber of the inner tube, in the hydraulic shock absorber having a suspension spring interposed between the upper spring receiver on the piston rod side and the lower spring receiver on the bottom side of the inner tube,
The lower spring receiver is supported by an adjusting bolt provided on the bottom so as to face the outside at a position where the axle mounting hole at the bottom of the inner tube is removed, and the lower spring receiver is moved up and down by screwing of the adjusting bolt. A hydraulic shock absorber that adjusts a load. The adjustment bolt is obliquely arranged with respect to the central axis passing through the axle mounting hole of the inner tube, and the adjustment bolt is supported on the inner surface of the bottom portion of the inner tube in a state of being prevented from coming off to the outside, and an operation portion of the adjustment bolt is provided. To the outside,
Screw the adjusting nut onto the threaded part of the adjusting bolt facing the inner tube,
The adjustment nut is prevented from rotating by the detent means provided inside the inner tube,
2. The hydraulic shock absorber according to claim 1, wherein a rear surface of the lower spring receiver is abutted against a tip portion of the adjustment nut.   The hydraulic shock absorber according to claim 1 or 2, wherein a hydraulic oil chamber at an upper portion of the lower spring receiver is sealed with respect to a rear chamber of the lower spring receiver within the inner tube.   The hydraulic shock absorber according to claim 1 or 2, wherein a hydraulic oil chamber in an upper part of the lower spring receiver is communicated with a rear chamber of the lower spring receiver in the inner tube.   The said rotation prevention means consists of a washer clamped between an inner tube and an axle bracket, The deformed part of the adjustment nut was inserted in the deformed slit for rotation prevention provided in the washer. Hydraulic shock absorber.   6. The hydraulic shock absorber according to claim 5, wherein a slider is provided at a lower portion of the washer at the bottom of the inner tube, and the slider slide-guides the outer surface of the adjustment nut and prevents the adjustment bolt from being pushed in from the outside.

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