JP2007177877A - Hydraulic shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic shock absorber for absorbing great input of abnormal upthrust on a wheel while preventing the sinking of the body of a bicycle when started. <P>SOLUTION: The hydraulic shock absorber 10 comprises: an on-off valve 70 provided on a communication passage 57 between each of oil chambers 38A, 38B of a cylinder 11 and a damping force adjusting part 60 for shutting off the communication passage 57 with electric external operation; a bypass line 58 bypassing the damping force adjusting part 60 and the on-off valve 57 and communicating the oil chambers 38A, 38B of the cylinder 11 with a reservoir 51; and a pressure side damping force generating part 90 provided on the bypass line 58 with no orifice. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydraulic shock absorber that is interposed between a vehicle body such as a bicycle or a motorcycle and wheels to absorb an impact from a road surface.

  The hydraulic shock absorber described in Patent Document 1 generates a damping force when oil passes through a passage communicating the damper main body and the reservoir and adjusts the generated damping force by adjusting the level of the generated damping force by inputting an external electrical signal. Part.

In the hydraulic shock absorber described in Patent Document 2, a manual adjustment unit that adjusts the amount of oil passing through the orifice in a passage that communicates the damper main body and the reservoir, and a bypass path that bypasses the manual adjustment unit from the outside It is assumed that an automatic adjustment unit that adjusts the amount of oil passing through the bypass passage by inputting an electrical signal is provided.
JP2001-304325 JP2001-294027

  According to the hydraulic shock absorber of Patent Document 1, when a rider depresses a pedal strongly at the start of a bicycle or the like, the damping force can be adjusted to be high with respect to the input from the rider or the drive chain, and the vehicle body can be prevented from sinking. However, in the state where the damping force is adjusted to be high, if there is a large input such as an abnormal push-up on the wheel, the hydraulic shock absorber is locked, and the vehicle body may fall over or the hydraulic shock absorber may be damaged.

  In the hydraulic shock absorber of Patent Document 2, even if the automatic adjustment unit is closed at the start of a bicycle or the like, the orifice constituting the manual adjustment unit allows the oil to flow, so that the sinking of the vehicle body cannot be prevented. Further, when there is a large input such as an abnormal push-up on the wheel, the large input cannot be absorbed only by the orifice constituting the manual adjustment unit.

  SUMMARY OF THE INVENTION An object of the present invention is to prevent a vehicle body from sinking and absorb a large input such as an abnormal push-up acting on a wheel at the start of a bicycle or the like in a hydraulic shock absorber.

  According to the first aspect of the present invention, a piston rod is inserted into the oil chamber of the cylinder, and a reservoir that compensates for the volume of the piston rod that advances and retreats into the oil chamber of the cylinder is communicated with the oil chamber of the cylinder through the communication path. In a hydraulic shock absorber provided with a force adjuster, an on-off valve is provided on the communication path between the oil chamber of the cylinder and the damping force adjuster to shut off the communication path by electrical operation from outside. And a bypass passage that connects the oil chamber of the cylinder and the reservoir are provided, and a compression-side damping force generation portion that does not have an orifice is provided on the bypass passage.

  According to a second aspect of the present invention, in the first aspect of the present invention, the on-off valve is further shut off for a predetermined time by an electric operation from the outside.

(Claim 1)
(a) When the rider sinks the pedal strongly at the start of a bicycle, etc., if the open / close valve is electrically operated from the outside to shut off the communication path of the damping force adjusting unit, the orifice of the damping force adjusting unit will be blocked. The damping force is set high with respect to the input from the rider or the drive chain, and the vehicle body can be prevented from sinking.

  (b) In the state where the on-off valve of (a) mentioned above shuts off the communication path of the damping force adjusting unit, when there is a large input such as abnormal pushing up on the wheel, the compression side damping force generating unit of the bypass path Allow and absorb large input. As a result, it is possible to avoid the vehicle body falling or the hydraulic shock absorber from being damaged due to a large input.

(Claim 2)
(c) By shutting off the on / off valve of (a) above for a certain period of time by electrical operation from the outside, only while the vehicle speed of a bicycle or the like increases from the start to a certain speed (for example, set the timer to 5 seconds) ) The orifice of the damping force adjusting unit is disabled, and thereafter, the orifice of the damping force adjusting unit is automatically brought into a normal operating state to ensure steering stability.

  1 is a plan view showing a hydraulic shock absorber, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 5 is an enlarged cross-sectional view around the piston in FIG. 4, FIG. 6 is an enlarged cross-sectional view around the adjuster in FIG. 4, and FIG. 7 is a cross-sectional view around the communication path of the base valve device. 8 is an enlarged sectional view showing the damping force adjusting section and the on-off valve in FIG. 7, FIG. 9 is a sectional view showing the periphery of the bypass path of the base valve device, and FIG. 10 is an enlarged view of the compression side damping force generating section in FIG. FIG. 11 is a block diagram showing a control system.

  As shown in FIGS. 1 to 3, the hydraulic shock absorber 10 includes a hollow piston rod 12 inserted into a cylinder 11 and a suspension spring 13 interposed between the cylinder 11 and the outside of the piston rod 12.

  The cylinder 11 includes a vehicle body side mounting member 14, and the piston rod 12 includes a wheel side mounting member 15. A spring receiver adjustment ring 16 is screwed to the outer peripheral portion of the cylinder 11 with a spring receiver 17, and a spring receiver 18 is fixed to the piston rod 12. A suspension spring 13 is interposed between the spring receiver 17 and the spring receiver 18. And the set length of the suspension spring 13 can be adjusted by screwing the spring receiving adjustment ring 16. The elastic force of the suspension spring 13 absorbs the impact force that the vehicle receives from the road surface.

  The cylinder 11 includes a rod guide 21 through which the piston rod 12 passes. The rod guide 21 is liquid-tightly attached to the cylinder 11 via an O-ring 22 and allows the piston rod 12 to slide in a liquid-tight manner on an inner diameter portion including an oil seal 23, a bush 24 and a dust seal 25. The cylinder 11 is provided with a pressure side bumper 26 outside the rod guide 21, and at the time of maximum compression, the pressure side bumper 26 is abutted against a bumper stopper 27 provided in the piston rod 12 so that the maximum compression stroke can be regulated. Further, the cylinder 11 includes a washer 28 and an extension side bump rubber 29 inside the rod guide 21.

  The hydraulic shock absorber 10 includes a piston valve device (extension-side damping force generation device) 30 and a base valve device (compression-side damping force generation device) 50. The hydraulic shock absorber 10 suppresses expansion and contraction vibration of the cylinder 11 and the piston rod 12 due to the absorption of the impact force by the suspension spring 13 by the damping force generated by the piston valve device 30 and the base valve device 50.

(Piston valve device 30) (FIGS. 4 to 6)
As shown in FIGS. 2 to 5, the piston valve device 30 has a hollow piston bolt 31 screwed onto the end of the piston rod 12 inserted into the cylinder 11, and a piston 32 and a first pressure side plate valve 33 </ b> A. The second pressure side plate valve 33B, the extension side plate valve 34A, and the valve stopper 35 are inserted and fixed with nuts 36.

  The piston 32 is provided with an O-ring 37A and a piston ring 37B on the outer periphery, and slidably contacts the inside of the cylinder 11. The piston-side oil chamber 38A in which the piston rod 12 is not housed and the rod in which the piston rod 12 is housed. The side oil chamber 38B is partitioned. The piston 32 includes a first pressure side plate valve 33A for damping at low speed and a second pressure side plate valve 33B for deceleration at high speed, and allows the piston side oil chamber 38A and the rod side oil chamber 38B to communicate with each other. 33 and an expansion side flow path 34 that includes an expansion side plate valve 34A and allows the piston side oil chamber 38A and the rod side oil chamber 38B to communicate with each other.

  The piston valve device 30 has a damping force adjusting device 40. As shown in FIGS. 5 and 6, the damping force adjusting device 40 passes a damping force adjusting rod 42 operated by the slider device 41 through the hollow portions of the piston rod 12 to the piston bolt 31 so as to freely advance and retract. With the needle valve 43 at the tip, the opening area of the bypass flow path 44 between the piston side oil chamber 38A and the rod side oil chamber 38B provided in the piston bolt 31 can be adjusted.

  The slider device 41 includes an adjustment holder 45 that is press-fitted and fixed to the wheel side mounting portion 15 of the piston rod 12 from a direction orthogonal to the axial direction of the piston rod 12, an adjuster 46 that is pivotally attached to the adjustment holder 45, and an adjuster. A ball 48 that is urged by a set spring 47 in a direction perpendicular to the axis 46 and engageable with an engagement recess on the side of the adjustment holder 45, and a slider 49 that is screwed to the threaded portion of the adjuster 46. Is done. The adjuster 46 is supported by the adjustment holder 45 on the operation end side provided with the dial 46A, and is supported by the wheel side mounting portion 15 on the counter-operation end side, and is rotated by the dial 46A, so that the ball 48 is positioned at plural positions in the circumferential direction of the adjustment holder 45. The adjuster 46 can be engaged with each of the engaging recesses arranged (equally arranged) in order, and the adjuster 46 can be set to the rotational operation stop position with a sense of moderation. On the other hand, the slider 49 is guided by a guide 15A provided on the wheel side mounting portion 15 so as to be reciprocally movable in the axial direction while being screwed to the screw portion of the adjuster 46. As a result, the slider device 41 can move the slider 49 forward and backward in a direction orthogonal to the axial direction of the adjustment rod 42 by rotating the adjuster 46.

  The tip needle valve 43 of the adjustment rod 42 is liquid-tightly inserted into the hollow portion of the piston rod 12 via the O-ring 43 </ b> A, and adjusts the opening area of the bypass channel 44. At this time, the adjustment rod 42 is brought into pressure contact with the tapered surface 49A of the slider 49 by the thrust force based on the hydraulic pressure of the piston-side oil chamber 38A of the cylinder 11.

  That is, in the piston valve device 30, the taper surface 49 </ b> A of the slider 49 is brought into contact with the proximal end rod end 42 </ b> A of the adjustment rod 42, and the slider 49 is operated based on a rotation operation applied to the dial 46 </ b> A of the adjuster 46 of the slider device 41. The adjustment rod 42 is advanced and retracted in the axial direction by advance and retreat, and the opening area of the bypass flow path 44 is adjusted by the movement of the needle valve 43 at the tip of the adjustment rod 42.

  In the bypass passage 44 of the piston bolt 31, a ball valve 31 </ b> B that is prevented from coming off by a pin 31 </ b> A that is pierced in the radial direction of the piston bolt 31 can be seated at an opening end facing the piston-side oil chamber 38 </ b> A. Thus, only the flow from the rod side oil chamber 38B to the piston side oil chamber 38A is allowed in the bypass flow path 44. Thereby, the damping force adjusting device 40 operates only in the extension stroke of the hydraulic shock absorber 10.

  Therefore, when the hydraulic shock absorber 10 is compressed, the oil in the piston-side oil chamber 38A passes through the pressure-side flow path 33, and when the relative speed between the cylinder 11 and the piston rod 12 is low, the first pressure-side plate valve 33A is bent and deformed. It flows into the side oil chamber 38B and obtains a compression side damping force. Further, when the relative speed between the cylinder 11 and the piston rod 12 is high, the oil in the piston side oil chamber 38A bends and deforms the second pressure side plate valve 33B and flows into the rod side oil chamber 38B to obtain a compression side damping force.

  Further, when the hydraulic shock absorber 10 is extended, when the relative speed between the cylinder 11 and the piston rod 12 is low, the oil in the rod side oil chamber 38B passes through the bypass flow path 44 with the needle valve 43 to the piston side oil chamber 38. The expansion side damping force is generated by the throttle resistance of the needle valve 43 during the flow. This damping force is adjusted by rotating the adjuster 46 of the slider device 41.

  When the hydraulic shock absorber 10 is extended and the relative speed between the cylinder 11 and the piston rod 12 is medium to high, the oil in the rod side oil chamber 38B passes through the extension side flow path 34 to bend and deform the extension side valve 34A. It is guided to the piston side oil chamber 38A and produces an extension side damping force.

(Base valve device 50) (FIGS. 7 to 11)
In the base valve device 50, a reservoir 51 is integrated with the cylinder 11, and an oil chamber 54 and a gas chamber 55 are sealed by a diaphragm type (or a free piston type) partition member 53 inside the reservoir 51 sealed with a cap 52. It is divided into and. The cap 52 is provided with a gas filling valve 56 that fills the gas chamber 55 with pressurized gas.

  As shown in FIGS. 7 and 8, the base valve device 50 is provided with a communication passage 57 that connects the oil chambers 38 </ b> A and 38 </ b> B of the cylinder 11 to the oil chamber 54 of the reservoir 51 at the connecting portion between the cylinder 11 and the reservoir 51. The volume of the piston rod 12 entering / exiting the 11 oil chambers 38 </ b> A and 38 </ b> B is compensated by the reservoir 51, and a manual damping force adjusting unit 60 is provided in the communication path 57.

  As shown in FIG. 8, the damping force adjusting unit 60 screws the adjustment holder 61 inserted into the cylinder 11 via the O-ring 61 </ b> A, and fixes the orifice collar 62 between the cylinder 11 and the adjustment holder 61. The adjuster 63 is pivotally supported by the adjust holder 61 via the O-ring 63A, and is urged by the set spring 64 in the direction perpendicular to the axis of the adjuster 63 so that it can be engaged with the engaging recess on the adjust holder 61 side. A ball 65 is provided, and a needle bolt 66 that is coaxial with the adjuster 63 and is engaged in a concave-convex manner in the rotational direction is screwed to the adjustment holder 61, and the needle valve 67 at the tip of the needle bolt 66 moves to move the orifice area of the orifice collar 62. Adjust. The adjuster 63 includes a dial 68. The adjuster 63 is rotated by the dial 68, and the balls 65 are sequentially engaged with the engaging recesses arranged (equally arranged) at a plurality of positions in the circumferential direction of the adjust holder 61, and the adjuster 63 is moved to the rotation operation stop position. The setting can be changed with a sense of moderation. The damping force adjusting unit 60 adjusts the orifice area of the orifice collar 62 by rotating the needle bolt 66 in the axial direction by a rotation operation applied to the dial 68 of the adjuster 63 and moving the needle valve 67 at the tip of the needle bolt 66.

  As shown in FIGS. 7 and 8, the base valve device 50 is connected to the communication passage 57 between the piston-side oil chamber 38 </ b> A of the cylinder 11 and the damping force adjusting device 60 by electrical operation from the outside. There is provided an on-off valve 70 for shutting off.

  As shown in FIG. 8, the on-off valve 70 is slidably loaded in the axial direction of the valve chamber 71 provided across the intermediate portion of the communication passage 57 in the cylinder 11, and has a hole on the opening end side of the valve chamber 71. A cap 72 is screwed and fixed, and a coil spring 73 is interposed between the closed end of the valve chamber 71 and the on-off valve 70. At a standby position (the right half of the on-off valve 70 in FIG. 8) where the on-off valve 70 is pressed against the cap 72 by the biasing force of the coil spring 73, the annular passage 70A provided on the outer periphery of the on-off valve 70 is on both sides of the valve chamber 71. The communication paths 57, 57 are conducted. On the inner periphery of the valve chamber 71, O-rings 74A and 74B are loaded in the annular grooves provided on both sides in the axial direction across the communication passage 57, and the on-off valve 70 seals the annular passage 70A with the O-rings 74A and 74B on both sides. In a stopped state, the valve chamber 71 is slidably brought into contact with the shut-off work position (the left half of the on-off valve 70 in FIG. 8) in the direction in which the coil spring 73 is pressurized from the standby position. The communication path 57 is shut off.

  The electromagnetic solenoid 80 is screwed to the mounting plate 81, covered with a cover 82 that is bolted to the cylinder 11 together with the mounting plate 81, and is fixed to the cylinder 11. As shown in FIG. 11, the electromagnetic solenoid 80 is excited by a controller 84 that receives an ON signal of the pushbutton switch 83, causes the plunger 80A to protrude, and causes the on-off valve 70 on which the plunger 80A is coaxially abutted to the standby state described above. Push from the position to the blocking work position. A power supply terminal 85 is connected to a battery or a DC power source. The controller 84 excites the electromagnetic solenoid 80 as described above for a predetermined time set in the built-in timer, and shuts off the communication path 57 by the on-off valve 70 for the predetermined time. After the elapse of the predetermined time, the electromagnetic solenoid 80 is demagnetized, and the on-off valve 70 is automatically returned to the standby position by the biasing force of the coil spring 73.

  As shown in FIGS. 9 and 10, the base valve device 50 bypasses the damping force adjusting unit 60 and the on-off valve 70 at the connecting portion between the cylinder 11 and the reservoir 51, and connects the oil chambers 38 </ b> A and 38 </ b> B of the cylinder 11 and the reservoir 51. A bypass path 58 that communicates with the oil chamber 54 is provided, and a compression-side damping force generator 90 that does not have an orifice is provided on the bypass path 58.

  As shown in FIG. 10, the compression-side damping force generation unit 90 screws a plug bolt 91 inserted into the cylinder 11 via an O-ring 91 </ b> A, and attaches a piston 92 sandwiched between the cylinder 11 and the plug bolt 91 to an O-ring. The piston 92 is fixed to the cylinder 11 through 92A, and a flow path 93 is provided in the piston 92. A bolt 94 is fixed to the center of the piston 92 with a nut 95. Between the washer 96 and the piston 92 around the bolt 94, a pressure side plate valve 97 that opens the flow path 93 in the compression stroke, and a flow path 93 are provided. A check valve 98 that conducts in the extension stroke and a valve spring 98A that supports the check valve 98 on the back surface are provided.

  Therefore, when the hydraulic shock absorber 10 is compressed in a normal operation state, the oil corresponding to the volume of the piston rod 12 entering the cylinder 11 passes through both the communication passage 57 and the bypass passage 58 from the piston-side oil chamber 38A. Thus, the oil can be discharged into the oil chamber 54 of the reservoir 51. At this time, when the relative speed between the cylinder 11 and the piston rod 12 is low, the compression side damping force is obtained by the throttle resistance of the needle valve 67 of the damping force adjusting unit 60 provided in the communication path 57. This damping force is adjusted by adjusting the position of the needle valve 67 by the adjuster 63. Further, when the relative speed between the cylinder 11 and the piston rod 12 is medium to high, the oil passing through the bypass path 58 from the piston side oil chamber 38A deflects and deforms the pressure side plate valve 97 of the pressure side damping force generation unit 90, and the oil in the reservoir 51 It is guided to the chamber 54 and generates a compression side damping force.

  When the hydraulic shock absorber is extended, the oil corresponding to the retraction volume of the piston rod 12 retreating from the cylinder 11 is returned from the oil chamber 54 of the reservoir 51 through the check valve 98 of the bypass path 58 to the piston side oil chamber 38A.

  However, the hydraulic shock absorber 10 prevents the vehicle body from sinking as follows when starting a bicycle or the like.

  (1) When the rider turns on the pushbutton switch 83, the controller 84 closes the on-off valve 70 for a certain period of time as described above, and the communication path 57 is shut off. As a result, the orifice collar 62 of the damping force adjusting unit 60 The orifice is blocked. As a result, the damping force generated by the base valve device 50 of the hydraulic shock absorber 10 is increased, and the fluffy feeling of the hydraulic shock absorber 10 can be eliminated when the pedal is strongly depressed by the rider, and the vehicle body can be prevented from sinking. It can be used for traveling a bicycle or the like without losing the rider's tension.

  (2) When a large input such as an abnormal push-up is applied to a wheel of a bicycle or the like, the compression side damping force generation unit 90 of the bypass passage 58 opens the compression side plate valve 97 to allow the oil flow and absorb the large input. . Thereby, the fall of the vehicle body caused by the large input or the breakage of the hydraulic shock absorber 10 can be avoided.

According to the present embodiment, the following operational effects can be obtained.
(a) When the rider sinks the pedal strongly at the start of a bicycle or the like, if the on-off valve 70 is electrically operated from the outside to shut off the communication path 57 of the damping force adjusting unit 60, the orifice of the damping force adjusting unit 60 The (orifice collar 62) is disabled, the damping force is set high with respect to the input from the rider or the drive chain, and the vehicle body can be prevented from sinking.

  (b) In the state where the on-off valve 70 of (a) described above shuts off the communication path 57 of the damping force adjusting unit 60, when there is a large input such as abnormal pushing up on the wheel, the compression side damping force generating unit 90 of the bypass path 58. Allows oil flow and absorbs large inputs. Thereby, the fall of the vehicle body resulting from a large input or the breakage of the hydraulic shock absorber 10 can be avoided.

  (c) By shutting off the on-off valve 70 of the above (a) for a certain period of time by an external electric operation, only while the vehicle speed of a bicycle or the like increases from the start to a certain speed (for example, set the timer to 5 seconds) In this case, the orifice of the damping force adjusting unit 60 is disabled, and thereafter, the orifice of the damping force adjusting unit 60 is automatically brought into a normal operating state, thereby ensuring steering stability.

  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 plan view showing a hydraulic shock absorber. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view showing the piston valve device. FIG. 5 is an enlarged cross-sectional view around the piston of FIG. FIG. 6 is an enlarged cross-sectional view around the adjuster of FIG. FIG. 7 is a cross-sectional view showing the periphery of the communication path of the base valve device. 8 is an enlarged cross-sectional view of the damping force adjusting portion and the on-off valve of FIG. FIG. 9 is a cross-sectional view showing the periphery of the bypass path of the base valve device. FIG. 10 is an enlarged cross-sectional view of the compression-side damping force generation portion of FIG. FIG. 11 is a block diagram showing the control system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hydraulic buffer 11 Cylinder 12 Piston rod 38A, 38B Oil chamber 51 Reservoir 57 Communication path 58 Bypass path 60 Damping force adjustment part 70 On-off valve 80 Electromagnetic solenoid 83 Pushbutton switch 84 Controller 90 Pressure side damping force generation part

Claims (2)

A piston rod is inserted into the oil chamber of the cylinder, and a reservoir that compensates for the volume of the piston rod that advances and retreats into the oil chamber of the cylinder is communicated with the oil chamber of the cylinder through a communication path, and a damping force adjusting portion is provided in the communication path. In hydraulic shock absorber,
An open / close valve is provided on the communication path between the oil chamber of the cylinder and the damping force adjusting unit to shut off the communication path by an external electric operation,
A hydraulic shock absorber, characterized in that a bypass passage that bypasses the damping force adjusting portion and the on-off valve, communicates the oil chamber of the cylinder and the reservoir is provided, and a compression-side damping force generating portion that does not have an orifice is provided on the bypass passage.   The hydraulic shock absorber according to claim 1, wherein the on-off valve is shut off for a predetermined time by an external electric operation.

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