JP4870005B2 - Damping force generator - Google Patents

Description

  The present invention relates to a damping force generator suitable for use in a vehicle hydraulic shock absorber or the like.

  Conventionally, as a damping force generating device for a hydraulic shock absorber, as described in Patent Document 1, a piston can be slidably contacted with an inner periphery of a damper tube, and an oil chamber inside the damper tube is divided into two parts by a piston. In a damping force generating device having a flow path connecting two oil chambers and providing a disk valve on the downstream outlet face side of the flow path provided in the piston, the disk valve is disposed between the piston and the corresponding downstream outlet face. There is a type in which a watermark plate having a diameter smaller than that of the disc valve is sandwiched, and a damping force as shown in FIG. 10 is generated through a gap between the disc valve and the corresponding downstream outlet surface of the piston. In FIG. 10, Mid is a standard thickness of the watermark plate, High is an abolition of the watermark plate, and Low is a thickness of the watermark plate. Depending on the thickness of the watermark plate, the range of change in damping force can be increased when the piston moving speed is low, but after the piston reaches the middle and high speed range and the disc valve opens the piston flow path, the damping is attenuated. The change in force is small.

The damping force generator described in Patent Document 2 enables a piston to slide in contact with the inner periphery of a damper tube, divides the oil chamber inside the damper tube into two by the piston, and connects the two oil chambers to the piston. And a biasing force generating device provided with a disk valve on the downstream outlet surface side of the flow path provided in the piston, for biasing the outer periphery of the disk valve in close contact with the downstream outlet surface of the flow path of the piston There is a means for providing a damping force as shown in FIG. 11 by providing means and making it possible to adjust the urging force of the urging means from the outside. In FIG. 11, Mid is a biasing force exerted on the disk valve as standard, High is a biasing force exerted on the disk valve, and Low is a biasing force exerted on the disk valve. Due to the urging force exerted on the disk valve, the variation range of the damping force in the middle and high speed region of the piston can be increased, but since there is no orifice region, the damping force cannot be reduced in the low speed region of the piston, so the riding comfort is deteriorated.
Patent 3765017 JP 2-107840

  An object of the present invention is to provide a damping force generator capable of adjusting a damping force by an external operation, and to increase a variation range of the damping force in a wide range from a low speed region to a high speed region.

The invention according to claim 1 is provided with a flow path that allows the piston to be slidably contacted with the inner periphery of the damper tube, divides the oil chamber inside the damper tube into two by the piston, and connects the two oil chambers to the piston. In the damping force generator having a disk valve provided on the downstream outlet surface side of the provided flow path, the disk valve passes the outer periphery of the disk valve in a direction to close the gap through a gap with respect to the corresponding downstream outlet surface of the piston. By providing an urging means for urging and having an adjusting means for adjusting the urging force of the urging means from the outside, the urging force exerted on the disk valve by the urging means is adjusted by an externally operated adjusting means, whereby the disc The opening force of the valve and the initial clearance that the disc valve forms with respect to the downstream outlet surface of the piston are made adjustable .

In the invention of claim 2, the piston can be slidably contacted with the inner periphery of the damper tube, the oil chamber inside the damper tube is divided into two by the piston, and the pressure side flow path and the extension side flow connecting the two oil chambers to the piston In a damping force generator having a pressure path and an extension side disk valve on the downstream outlet surface side of the pressure side flow path and the extension side flow path, at least one of the pressure side disk valve and the extension side disk valve is provided. Has a biasing means for biasing the outer periphery of the disk valve in a direction to close the gap via a gap with respect to the corresponding downstream outlet surface of the piston, and has an adjustment means for adjusting the biasing force of the biasing means from the outside. and, by urging means for adjusting the biasing force on the disk valve by adjustment means which is externally operated, and the valve opening force of the disk valve, disk valve with respect to the downstream exit surface of the piston In which the to the initial gap was set to be adjustable.

  According to a third aspect of the present invention, in the second aspect of the present invention, in addition to the second aspect of the present invention, a disk plate having a diameter smaller than that of the disk valve is sandwiched between the disk valve and a corresponding downstream outlet surface of the piston, and the biasing means is provided on the disk valve. The outer periphery is biased rather than the outer diameter of the watermark plate.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the adjusting means further comprises an adjusting rod inserted through the hollow portion of the piston support member, and the biasing means is attached by an axial movement operation of the adjusting rod. The power is adjusted.

According to a fifth aspect of the present invention, in the second or third aspect of the present invention, the adjusting means further comprises an adjusting rod inserted through the hollow portion of the piston support member, and the biasing force of the biasing means is obtained by rotating the adjusting rod. It is intended to be adjusted.
The invention of claim 6 is the invention according to any one of claims 1 to 5, wherein the gap forms an annular shape along the outer periphery of the disk valve.

(Claims 1, 2 , 6 )
(a) The damping force generator includes an urging means for urging the outer periphery of the disc valve in a direction to close the gap via a gap with respect to a corresponding downstream outlet surface of the piston. An adjustment means for adjusting the urging force from the outside is provided. By increasing the urging force exerted on the disc valve by the urging means (High), the clearance formed by the disc valve with respect to the downstream outlet surface of the piston is reduced in the low speed region of the piston, thereby increasing the damping force. In the high speed range, the opening force of the disc valve is increased to increase the damping force. On the other hand, by reducing the urging force exerted on the disc valve by the urging means (Low), the clearance formed by the disc valve with respect to the downstream outlet surface of the piston is increased in the low speed region of the piston, thereby reducing the damping force. In the middle and high speed range, the opening force of the disc valve is reduced to reduce the damping force.

  That is, by adjusting the urging force exerted on the disc valve by the urging means by an externally operated adjusting means, not only the opening force of the disc valve but also the initial clearance of the disc valve is changed, thereby moving the piston moving speed. However, the variation range of the damping force can be increased in a wide range from the low speed range to the high speed range.

(Claim 3)
(b) A disc valve having a smaller diameter than the disc valve is sandwiched between the disc valve and the corresponding downstream outlet surface of the piston, and the urging means urges the outer circumference of the disc valve from the outer diameter of the disc plate. It was decided. Therefore, by adjusting the urging force of the urging means by the adjusting means, the outer side of the disc valve with respect to the watermark plate can be bent and deformed, and the initial gap of the disc valve can be changed stably.

(Claim 4)
(c) The adjustment rod, which is an adjustment means, is inserted into the hollow part of the piston support member, and the urging force of the urging means is adjusted by moving the adjustment rod in the axial direction, thereby easily adjusting the urging force of the urging means. it can.

(Claim 5)
(d) The urging force of the urging means can be easily adjusted by inserting the adjusting rod through the hollow portion of the piston support member and adjusting the urging force of the urging means by rotating this adjusting rod.

  1 is an overall view showing a hydraulic shock absorber, FIG. 2 is a cross-sectional view showing a damping force generating device, FIG. 3 is a cross-sectional view showing a damping force adjusting operation unit, FIG. 4 is a schematic view showing the damping force generating device, and FIG. Shows a piston bolt, (A) is a cross-sectional view, (B) is a plan view, FIG. 6 is a front view showing an adjustment bar, FIG. 7 shows a pressure side valve presser, (A) is a cross-sectional view, and (B) is a cross-sectional view. FIG. 8 is a sectional view, FIG. 8B is a plan view, FIG. 9 is a diagram showing damping force characteristics, and FIG. 10 is a diagram showing damping force characteristics. 11 is a diagram showing damping force characteristics.

  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 to the upper end opening of the outer tube 11, and vehicle body side mounting members 14 </ b> A and 14 </ b> B (not shown) 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 has a piston 26 slidably contacting the inner periphery of the inner tube 12 with a piston bolt 25 (FIG. 5) screwed to the tip of a piston rod 23 inserted into the inner tube 12 from the rod guide portion 19 </ b> A of the partition wall member 19. The oil chamber 21 is partitioned 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 a spring collar 32 </ b> A provided on 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, the spring load adjusting device 34 raises and lowers the lower spring receiver 32 so that the spring load of the suspension spring 33 can be adjusted.

  As shown in FIG. 1, the spring load adjusting device 34 has an adjustment bolt 34 </ b> A that faces 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). Provide at the bottom. A direction in which the slider 34B provided on the inner bottom of the axle bracket 15 (the surface that faces the lower end of the lower spring support 32) intersects the central axis of the inner tube 12 by the rotational force of the adjusting bolt 34A (the axis of the adjusting bolt 34A) Direction). The lower slope A1 of the lower spring receiver 32 is placed on the upper slope A2 of the slider 34B, and the lower spring receiver 32 is moved up and down by the adjustment bolt 34A to adjust the spring load of the suspension spring 33.

The front fork 10 includes a damping force generator 40 on the piston 26 (FIG. 2).
The damping force generator 40 includes a pressure side channel 41 and an extension side channel 42 (not shown) that connect the piston 26 to the rod side oil chamber 21A and the piston side oil chamber 21B. The downstream outlet surface of 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 downstream outlet surface of 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 generating device 40 generates a compression side damping force by the bending deformation of the compression side disk valve 41A in the compression side stroke. In the extension side stroke, the extension side damping force is generated by the bending deformation of the extension side disk valve 42A. 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 includes a spring seat 51 fixed to a lower end portion of the partition wall member 19 on the upper end side of the inner tube 12 facing the piston rod side oil chamber 21A using a retaining ring 51A, and a stopper ring 52A provided on the piston rod 23. A rebound spring 53 is interposed between the spring seat 52 and the latched 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.

  In the front fork 10, the cross-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 formed larger than the cross-sectional area (area surrounded by the outer diameter) S2 of the piston rod 23. (S1> S2).

  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 flange portion of the check valve 60 is sandwiched between the spring 62 and accommodated. The flange portion of the check valve 60 is shorter than the distance between the stepped portion 61 </ b> A and the spring seat 51. The check valve 60 is provided on 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 movable. 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, is displaced toward the spring seat 51, and forms a gap with the step portion 61A. The oil in the reservoir chamber 22 can flow into the piston rod side oil chamber 21A through the gap with the stepped portion 61A via its outer periphery. 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 an oil seal around the piston rod 23, a bush 63 that is 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 by an orifice that is formed in the rod guide portion 19 </ b> A of the partition wall member 19 and communicates the piston rod side oil chamber 21 </ b> A and the oil reservoir chamber 22.

  However, the damping force generator 40 has a compression side damping force adjustment device 40A that adjusts the compression side damping force by an external operation and an extension side damping force adjustment device 40B that adjusts the extension side damping force by an external operation as follows.

(Compression side damping force adjustment device 40A)
The compression side damping force adjusting device 40A sandwiches a compression plate 41C having a smaller diameter than the compression side disk valve 41A between the compression side disk valve 41A and the downstream outlet surface of the corresponding pressure side flow path 41 of the piston 26 (FIG. 4). The disc valve 41 </ b> A passes through a clearance with respect to the downstream outlet surface of the corresponding pressure side flow path 41 of the piston 26.

  The pressure-side damping force adjusting device 40A is configured to close the gap between the pressure-side disk valve 41A and the downstream outlet surface of the corresponding pressure-side flow path 41 of the piston 26 from the outer diameter of the watermark plate 41C in the pressure-side disk valve 41A. The pressure side urging means 70 for urging the outer periphery to bend and deform, and the pressure side adjusting means 90A for adjusting the urging force of the pressure side urging means 70 from the outside. This makes it possible to adjust the gap formed by the pressure side disk valve 41 </ b> A with respect to the downstream outlet surface of the corresponding pressure side flow path 41 of the piston 26.

  The compression side adjusting means 90A is screwed into the central hole of the expansion side adjuster 91B constituting the expansion side adjustment means 90B, which will be described later, inserted into the center hole of the cap 13, and rotates in the hollow portion of the piston rod 23. The lower end surface of the compression side adjuster 91A is brought into contact with the upper end surface of the adjustment rod 92 that is movably inserted in the direction and the axial direction, and the adjustment rod 92 can be moved and operated in the axial direction by screwing of the compression side adjuster 91A.

  In the pressure side urging means 70, elongated guide holes 23 </ b> A extending in the axial direction are provided on both diametrical sides on the lower end side of the piston rod 23, and both side protrusions of the pushing piece 71 are formed in the guide holes. 23A is slidably inserted in the axial direction with almost no play. The lower end surface of the adjusting rod 92 inserted into the hollow portion of the piston rod 23 directly contacts the upper surface of the pushing piece 71, and the non-adjustment of the adjusting bar 93 engaged with the lower end portion of the adjusting rod 92 as will be described later. The circular cross section is loosely inserted in a circular hole provided in the center of the push piece 71 so as to be axially movable.

  Around the lower end portion (piston bolt 25) of the piston rod 23, there are a spring receiver 72 that abuts against the protrusions on both ends of the pushing piece 71 from below, and a valve retainer 73 that abuts on the upper surface (rear surface) of the compression side disk valve 41A. The valve retainer spring 74 is interposed between the spring receiver 72 and the valve retainer 73. The spring receiver 72 has a cup shape and abuts with both side protrusions of the pushing piece 71 at the lower end of the inner periphery of the cup, and the spring 74 is seated on the upper peripheral flange of the cup. As shown in FIG. 7, the valve retainer 73 includes an annular retainer 73 </ b> A that contacts the outer diameter of the upper surface of the compression-side disk valve 41 </ b> A as described above continuously (or even intermittently), and the piston bolt 25. A slide portion 73B that is slidably guided on the outer periphery of the upper end and an oil passage 73C that communicates the piston rod side oil chamber 21A with the pressure side passage 41 and the extension side passage 42 are provided, and a spring 74 is seated on the outer periphery step portion.

  When the pressure side adjusting means 90A moves the adjusting rod 92 in the axial direction as described above, the pressing piece 71 with which the lower end surface of the adjusting rod 92 abuts moves the spring receiver 72 up and down to move the valve pressing spring 74. The set load of the spring 74 is adjusted from the outside. As a result, the set load of the spring 74 is biased with an appropriate biasing force in the direction of closing the pressure side disk valve 41A via the valve presser 73, and as a result, the pressure side disk valve 41A is in the corresponding pressure side flow path 41 of the piston 26. Adjust the clearance to the downstream exit surface.

Therefore, the operation in the compression side stroke of the damping force generator 40 is as follows.
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 low speed region of the piston 26 in this pressure side stroke, the pressure side adjusting means 90A is pressurized as described above in the process in which the oil in the piston side oil chamber 21B moves to the rod side oil chamber 21A through the pressure side flow path 41 of the piston 26. The pressure-side disc valve 41A, which is set by adjusting the urging force of the urging means 70, is given a passage resistance of a gap formed by the piston 26 with respect to the downstream outlet surface of the corresponding pressure-side flow path 41, The compression side damping force resulting from this is generated.

  Further, in the middle and high speed range of the piston 26 in the pressure side stroke, the pressure side adjusting means 90A is in the process in which the oil in the piston side oil chamber 21B moves to the rod side oil chamber 21A through the pressure side channel 41 of the piston 26. In this way, by adjusting the urging force of the pressure side urging means 70, the pressure side disk valve 41A is pushed open while the valve opening force of the pressure side disk valve 41A is adjusted, and the pressure side disk valve 41A is bent at this time. Generates compression-side damping force due to deformation.

  FIG. 9 shows the damping force characteristic of the compression side damping force of the damping force generator 40, and Mid shows the damping force characteristic when the urging force exerted on the compression side disk valve 41A by the compression side urging means 70 is in an intermediate state. High indicates a damping force characteristic when the urging force exerted on the pressure side disk valve 41A by the pressure side urging means 70 is increased (FIG. 4A). In the low speed region of the piston 26, the pressure side disk valve 41A has a downstream outlet of the piston 26. The damping force is increased by reducing the gap formed on the surface, and the damping force is increased by increasing the valve opening force of the pressure side disk valve 41A in the middle and high speed range of the piston 26. Low indicates a damping force characteristic when the urging force exerted on the pressure side disk valve 41A by the pressure side urging means 70 is reduced (FIG. 4B), and the pressure side disk valve 41A is located downstream of the piston 26 in the low speed region of the piston 26. The damping force is reduced by increasing the gap formed with respect to the surface, and the damping force is reduced by reducing the valve opening force of the compression side disk valve 41A in the middle and high speed range of the piston 26. That is, by adjusting the urging force exerted on the pressure side disk valve 41A by the pressure side biasing means 70 by the pressure side adjusting means 90A, not only the valve opening force of the pressure side disk valve 41A but also the initial clearance of the pressure side disk valve 41A is changed. Thus, the variation range of the compression side damping force can be increased in a wide range of the moving speed of the piston 26 from the low speed range to the high speed range.

(Extension side damping force adjustment device 40B)
In the extension side damping force adjusting device 40B, a spreading plate 42C having a diameter smaller than that of the extension side disk valve 42A is sandwiched between the extension side disk valve 42A and the downstream outlet surface of the extension side channel 42 corresponding to the piston 26 (see FIG. 4) The extension-side disc valve 42A passes through a gap with respect to the downstream outlet surface of the extension-side flow path 42 corresponding to the piston 26.

  The extension side damping force adjustment device 40B is configured to close the gap between the extension side disk valve 42A and the downstream outlet surface of the corresponding extension side flow path 42 of the piston 26 in the direction of closing the plate 42C in the extension side disk valve 42A. There is provided an extension side urging means 80 for urging the outer periphery to bend and deform rather than its outer diameter, and an extension side adjustment means 90B for adjusting the urging force of the extension side urging means 80 from the outside. This makes it possible to adjust the gap formed by the extension side disk valve 42A with respect to the downstream outlet surface of the extension side flow path 42 corresponding to the piston 26.

  The expansion side adjusting means 90B is provided with a rotation side adjuster 91B rotatably in the center hole of the cap 13, enabling the adjustment plate 92A engaged with the inner surface of the expansion side adjuster 91B to be rotated, and the non-circular hole of the adjustment plate 92A. The adjustment rod 92 is rotatably operated by engaging the outer periphery of the non-circular cross section of the upper end portion of the adjustment rod 92 described above, and the adjustment bar 93 (see FIG. 6) is arranged on the inner periphery of the non-circular cross section of the lower end portion of the adjustment rod 92. The non-circular cross-sectional portion of () is engaged so as to be relatively movable in the axial direction so that the adjusting bar 93 can be rotated. Further, the intermediate thread portion 93 </ b> A of the adjustment bar 93 is screwed to the inner base 94 that is clamped and fixed between the lower end surface of the piston rod 23 and the inner diameter step portion of the piston bolt 25. As a result, the extension side adjusting means 90B rotates the adjustment bar 93 as described above, whereby the adjustment bar 93 is screwed with respect to the inner base 94 of the piston bolt 25 and can be moved in the axial direction.

  In the extension side urging means 80, the stopper pin 81 passes through the tip of the protruding end of the adjusting bar 93 protruding from the lower end of the piston rod 23, and the stopper pin 81 and around the protruding end of the adjusting bar 93 A spring retainer 82 that engages from above and a valve retainer 83 that abuts the lower surface (rear surface) of the extension-side disc valve 42A are disposed, and a valve retainer spring 84 is interposed between the spring retainer 82 and the valve retainer 83. . As shown in FIG. 8, the valve retainer 83 includes an annular retainer 83 </ b> A that makes contact with the outer diameter position of the lower surface of the expansion-side disk valve 42 </ b> A as described above continuously (or intermittently), and an adjustment bar 93. And a slide portion 83B that is slidably guided on the outer periphery of the projecting end, and a spring 84 is seated on the outer peripheral step portion.

  When the extension side adjusting means 90B rotates the adjustment rod 92 and moves the adjustment bar 93 in the axial direction as described above, the stopper pin 81 penetrating the adjustment bar 93 moves the spring receiver 82 up and down. The valve presser spring 84 is expanded and contracted, and the set load of the spring 84 is adjusted from the outside. As a result, the set load of the spring 84 is urged with an appropriate urging force in the direction of closing the extension side disk valve 42A via the valve presser 83, and the extension side disk valve 42A is in the corresponding extension side flow path 42 of the piston 26. Adjust the clearance to the downstream exit surface.

Accordingly, the operation of the extension side stroke of the damping force generator 40 is as follows.
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 low speed range of the piston 26 in this extension side stroke, the extension side adjusting means 90B moves in the process of the oil in the rod side oil chamber 21A moving to the piston side oil chamber 21B through the extension side flow path 42 of the piston 26. In this way, the clearance formed by adjusting the urging force of the expansion side urging means 80 and the expansion side disk valve 42A with respect to the downstream outlet surface of the expansion side flow path 42 corresponding to the piston 26 is set. Passage resistance is given, and the extension side damping force resulting from this is generated.

  Further, in the middle and high speed range of the piston 26 in the extension side stroke, the extension side adjusting means 90B is in the process of the oil in the rod side oil chamber 21A moving to the piston side oil chamber 21B through the extension side flow path 42 of the piston 26. As described above, by adjusting the urging force of the expansion side urging means 80, the expansion side disk valve 42A is pushed open while adjusting the valve opening force of the expansion side disk valve 42A. The expansion side damping force due to the bending deformation of the expansion side disk valve 42A is generated.

  The damping force characteristic of the extension side damping force of the damping force generator 40 is the same as the damping force characteristic shown in FIG. 9 in the compression side stroke.

According to the present embodiment, the following operational effects can be obtained.
(a) In the damping force generator 40, the compression-side disk valve 41A (or the expansion-side disk valve 42A) passes through a gap with respect to the corresponding downstream outlet surface of the piston 26, and the compression-side disk valve 41A (or The pressure side biasing means 70 (or extension side biasing means 80) for biasing the outer periphery of the extension side disk valve 42A) is provided, and the biasing force of the pressure side biasing means 70 (or extension side biasing means 80) is adjusted from the outside. The pressure side adjusting means 90A (or the extension side adjusting means 90B) is provided. By increasing the urging force exerted on the compression side disk valve 41A (or the expansion side disk valve 42A) by the compression side urging means 70 (or the expansion side urging means 80), the compression side disk valve 41A in the low speed region of the piston 26 is obtained. (Or the expansion side disk valve 42A) reduces the clearance formed with respect to the downstream outlet surface of the piston 26 to increase the damping force. In the middle and high speed range of the piston 26, the compression side disk valve 41A (or the expansion side disk valve 42A) The damping force is increased by increasing the valve opening force. On the other hand, by reducing the urging force exerted on the pressure side disk valve 41A (or the extension side disk valve 42A) by the pressure side biasing means 70 (or the extension side biasing means 80), the pressure side disk is reduced in the low speed region of the piston 26. The valve 41A (or the expansion side disk valve 42A) increases the clearance formed with respect to the downstream outlet surface of the piston 26 to reduce the damping force. In the middle and high speed range of the piston 26, the compression side disk valve 41A (or the expansion side disk valve 42A). ) To reduce the damping force.

  That is, the urging force exerted on the pressure side disk valve 41A (or the extension side disk valve 42A) by the pressure side biasing means 70 (or the extension side biasing means 80) by the pressure side adjustment means 90A (or the extension side adjustment means 90B) operated externally. By adjusting not only the valve opening force of the pressure side disc valve 41A (or the extension side disc valve 42A) but also the initial clearance of the pressure side disc valve 41A (or the extension side disc valve 42A), the piston 26 When the moving speed is in a wide range from the low speed range to the high speed range, the variation range of the damping force can be increased.

  (b) Between the pressure side disk valve 41A (or the extension side disk valve 42A) and the corresponding downstream outlet surface of the piston 26, a swash plate 41C (or a smaller diameter than the pressure side disk valve 41A (or the extension side disk valve 42A)). The pressure side biasing means 70 (or the extension side biasing means 80) is placed outside the watermark plate 41C (or the watermark plate 42C) of the pressure side disk valve 41A (or the extension side disk valve 42A). The outer periphery was biased rather than the diameter. Therefore, by adjusting the urging force of the pressure side urging means 70 (or the expansion side urging means 80) by the pressure side adjustment means 90A (or the expansion side adjustment means 90B), the pressure side disk valve 41A (or the expansion side disk valve 42A) is adjusted. The initial gap of the compression side disk valve 41A (or the extension side disk valve 42A) can be stably changed by flexing and deforming the outer side with respect to the watermark plate 41C (or the watermark board 42C).

  (c) The adjustment rod 92, which is the pressure side adjustment means 90A, is inserted into the hollow portion of the piston rod 23, and the urging force of the pressure side urging means 70 is adjusted by the axial movement operation of the adjustment rod 92. The urging force of 70 can be easily adjusted.

  (d) The adjustment rod 92 as the extension side adjusting means 90B is inserted into the hollow portion of the piston rod 23, and the adjustment force of the extension side urging means 80 is adjusted by the rotation operation of the adjustment rod 92. The biasing force of the means 80 can be easily 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 an overall view showing a hydraulic shock absorber. FIG. 2 is a sectional view showing the damping force generator. FIG. 3 is a cross-sectional view showing the damping force adjusting operation unit. FIG. 4 is a schematic diagram showing a damping force generator. FIG. 5 shows a piston bolt, (A) is a cross-sectional view, and (B) is a plan view. FIG. 6 is a front view showing the adjustment bar. 7A and 7B show the pressure side valve presser, where FIG. 7A is a sectional view and FIG. 7B is a plan view. 8A and 8B show the extension side valve presser, where FIG. 8A is a sectional view and FIG. 8B is a plan view. FIG. 9 is a diagram showing damping force characteristics. FIG. 10 is a diagram showing damping force characteristics. FIG. 11 is a diagram showing damping force characteristics.

Explanation of symbols

12 Inner tube (damper tube)
21 Oil chamber 21A Rod side oil chamber 21B Piston side oil chamber 23 Piston rod (piston support member)
26 Piston 40 Damping force generator 41 Pressure side flow path 41A Pressure side disk valve 41C Strike plate 42 Stretch side flow path 42A Stretch side disk valve 42C Strike plate 70 Pressure side biasing means 80 Extension side biasing means 90A Pressure side adjustment means 90B Extension Side adjustment means 92 Adjustment rod

Claims (6)

The piston can slide on the inner circumference of the damper tube,
Divide the oil chamber inside the damper tube into two parts with a piston,
It has a channel that connects two oil chambers to the piston,
In the damping force generator provided with a disk valve on the downstream outlet surface side of the flow path provided in the piston,
Adjusting means for adjusting the urging force of the urging means from the outside by providing an urging means for urging the outer periphery of the disc valve in a direction to close the gap via a gap with respect to the corresponding downstream outlet surface of the piston. have,
By adjusting the urging force exerted on the disc valve by the urging means by an externally operated adjusting means, the opening force of the disc valve and the initial clearance that the disc valve forms with respect to the downstream outlet surface of the piston can be adjusted. A damping force generator characterized by comprising: The piston can slide on the inner circumference of the damper tube,
Divide the oil chamber inside the damper tube into two parts with a piston,
It has a pressure side channel and an extension side channel that connect two oil chambers to the piston,
In the damping force generating device provided with the compression side disk valve and the extension side disk valve on the downstream outlet surface side of the compression side channel and the extension side channel,
There is provided an urging means for urging the outer periphery of the disc valve in a direction in which at least one of the compression side disc valve and the extension side disc valve has a gap with respect to the corresponding downstream outlet surface of the piston in the direction of closing the gap. Adjusting means for adjusting the urging force of the urging means from the outside ,
By adjusting the urging force exerted on the disc valve by the urging means by an externally operated adjusting means, the opening force of the disc valve and the initial clearance that the disc valve forms with respect to the downstream outlet surface of the piston can be adjusted. A damping force generator characterized by comprising:   A disk plate having a smaller diameter than that of the disk valve is sandwiched between the disk valve and a corresponding downstream outlet surface of the piston, and the biasing means biases the outer periphery of the disk valve beyond the outer diameter of the disk plate. 2. A damping force generator according to 2. The adjusting means comprises an adjusting rod inserted through the hollow portion of the piston support member,
The damping force generator according to claim 2 or 3, wherein the biasing force of the biasing means is adjusted by an axial movement operation of the adjusting rod. The adjusting means comprises an adjusting rod inserted through the hollow portion of the piston support member,
4. The damping force generator according to claim 2, wherein the biasing force of the biasing means is adjusted by rotating the adjusting rod. The damping force generator according to any one of claims 1 to 5, wherein the gap forms an annular shape along the outer periphery of the disc valve.

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