JP2014005864A - Front fork device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a lateral damping performance difference, to enlarge an adjustment range of a damping force and further to obtain the stable damping force in a front fork device in which the damping force can be adjusted by using an actuator manually or in accordance with an electric signal while riding.SOLUTION: In a front fork device 1, one front fork 100 includes an actuator 111 which is capable of energizing a pressed-side damping valve 41A in a closing direction through a spring 117 pressurized by a push rod 113 inserted into a hollow part of a piston rod 23, and drives the push rod 113. Another front fork 200 includes an actuator 211 in which a bypass path 215 is provided in the hollow part of the piston rod 23 for communicating a piston rod side oil chamber 21A and a piston side oil chamber 21B, and which is capable of adjusting an aperture of the bypass path 215 by moving a needle valve 214 provided in a distal end portion of the push rod 213 inserted into the hollow part of the piston rod 23, and drives the push rod 23.

Description

  The present invention relates to a front fork device suitable for use in a motorcycle or the like.

  Conventionally, as described in Patent Documents 1 and 2, as a front fork device, there is a device that allows a damping force to be adjusted using an actuator manually or by an electric signal while riding.

  The front fork devices described in Patent Documents 1 and 2 have left and right front forks, and each front fork slidably fits the vehicle body side tube and the axle side tube, and the vehicle body side tube and the axle. A damper cylinder is built in one of the side tubes, and a piston rod provided on the other of the vehicle body side tube and the axle side tube is inserted into the hydraulic oil chamber of the damper cylinder.

  In the front fork devices described in Patent Literatures 1 and 2, a compression side damping valve and a compression side damping force adjusting device are provided in the damper cylinder of one front fork. Further, an extension side damping valve and an extension side damping force adjusting device are provided in the damper cylinder of the other front fork.

Patent No. 2559254 Patent No. 4762065

The front fork devices described in Patent Documents 1 and 2 have the following problems.
(1) In a front fork device that can adjust the damping force manually or with an electrical signal while riding, only one compression side damping valve is provided on one of the left and right front forks, and only the extension side damping valve is provided on the other side. The front fork device has a large difference in the left and right damping performance, and the steering stability is poor.

  (2) The left and right front forks are provided with damping force adjusting devices in damper cylinders built in the vehicle body side tube and the axle side tube. Only a small amount of hydraulic oil, which is part of the hydraulic oil pressurized in the damper cylinder, passes through these damping force adjusting devices. Therefore, the adjustment range of the damping force is small, and it is difficult to obtain a stable damping force.

  An object of the present invention is to reduce the difference between the left and right damping performance and increase the adjustment range of the damping force in a front fork device that can adjust the damping force using an actuator manually or with an electric signal while riding. The purpose is to obtain a stable damping force.

  The invention according to claim 1 has left and right front forks, each front fork slidably inserts an inner tube on the axle side into an outer tube on the vehicle body side, and a partition member on the inner periphery of the inner tube A hydraulic oil chamber at the lower part of the partition member, an oil reservoir chamber at the upper part, and a piston rod attached to the outer tube side is inserted into the hydraulic oil chamber through the partition member, A piston that slides in the hydraulic oil chamber is provided at the tip of the piston rod, and the hydraulic oil chamber of the inner tube is divided into a piston rod side oil chamber and a piston side oil chamber by a piston, and these two oil chambers are used as pistons. The front fork device is configured to be able to communicate with each of the provided pressure side flow path and the extension side flow path, and each of the two flow paths is provided with a pressure side damping valve and an extension side damping valve. The front fork has an actuator that drives the push rod while allowing the compression side damping valve to be urged in the closing direction by a spring pressurized by the push rod inserted into the hollow portion of the piston rod. The front fork is provided with a bypass passage communicating the piston rod side oil chamber and the piston side oil chamber in the hollow portion of the piston rod, and by moving the needle valve provided at the tip of the push rod inserted into the hollow portion of the piston rod. The opening of the bypass path can be adjusted, and an actuator for driving the push rod is provided.

  According to a second aspect of the present invention, in the first aspect of the invention according to the first aspect, the one front fork is provided with guide holes extending in the axial direction on both diametrical sides on the lower end side of the piston rod. Insert the protrusions on both sides of the pusher piece slidably into the piston rod, the lower end of the push rod inserted into the hollow part of the piston rod abuts the upper surface of the pusher piece, and both sides of the pusher piece protruding from the guide hole of the piston rod A spring retainer that abuts the protrusion from below is placed on the outer periphery of the lower end of the piston rod. A valve retainer spring is interposed between the spring retainer and the valve retainer that abuts the upper surface of the compression side damping valve. The push rod can be driven in the vertical direction.

  According to a third aspect of the present invention, in the first aspect of the present invention, the other front fork further includes a needle valve provided at the tip of the piston rod, and an upper end of the vertical hole of the bypass passage provided in the hollow portion of the piston rod. The valve seat can be moved forward and backward, and the actuator can drive the push rod in the vertical direction.

(Claim 1)
(a) In a front fork device that can adjust the damping force using an actuator manually or with an electric signal while riding, a compression damping valve and an extension damping valve are provided on one front fork, and the other front fork is also provided. A compression side damping valve and an extension side damping valve are provided. Therefore, there is no difference in the left and right damping performance of the front fork device, and the steering stability is good.

  (b) Each front fork was partitioned into a piston rod side oil chamber and a piston side oil chamber by a piston sliding in a large diameter hydraulic oil chamber defined on the inner periphery of the inner tube.

  Accordingly, all of the large amount of oil in the piston side oil chamber pressurized in the pressure side stroke passes through the pressure side damping valve, and the pressure side damping valve is biased in the closing direction by the spring that abuts the push rod driven by the actuator. Adjust the valve opening pressure of the compression side damping valve. Since a large amount of oil passes through the compression side damping valve, the adjustment range of the compression side damping force can be increased and a stable compression side damping force can be obtained.

  Also, a large amount of oil in the piston rod side oil chamber pressurized in the extension side stroke passes through the bypass passage, and the opening degree of the bypass passage is adjusted by a needle valve provided at the tip of the push rod driven by the actuator. Since a large amount of oil passes through the bypass, the adjustment range of the extension side damping force can be increased, and a stable extension side damping force can be obtained.

(Claim 2)
(c) One front fork is provided with guide holes extending in the axial direction on both diametrical sides on the lower end side of the piston rod, and both side protrusions of the pushing piece are slidably inserted into the guide hole of the piston rod, The lower end of the push rod inserted into the hollow portion of the piston rod abuts the upper surface of the pusher piece, and a spring bearing that abuts from below on both side protrusions of the pusher piece protruding from the guide hole of the piston rod The valve presser spring is interposed between the spring holder and the valve presser that abuts on the upper surface of the compression side damping valve, so that the actuator can drive the push rod in the vertical direction. Thereby, the valve opening pressure of the pressure side damping valve can be adjusted with a simple configuration in which one push rod inserted into the hollow portion of the piston rod is driven in the vertical direction by the actuator.

(Claim 3)
(d) The other front fork allows the needle valve provided at the tip of the piston rod to move forward and backward relative to the valve seat at the upper end of the vertical hole of the bypass passage provided in the hollow portion of the piston rod, and the actuator is a push rod. Can be driven in the vertical direction. Thereby, the opening degree of a bypass path can be adjusted with the simple structure which drives one push rod inserted in the hollow part of the piston rod to an up-down direction with an actuator.

FIG. 1 is a sectional view showing a front fork device. FIG. 2 is a sectional view showing one front fork. FIG. 3 is a lower cross-sectional view of FIG. 4 is a cross-sectional view of the middle part of FIG. FIG. 5 is a top sectional view of FIG. FIG. 6 is a sectional view showing the other front fork. FIG. 7 is a lower cross-sectional view of FIG. FIG. 8 is a cross-sectional view of the middle part of FIG. FIG. 9 is a top sectional view of FIG.

  A motorcycle front fork device 1 shown in FIG. 1 is capable of adjusting a damping force by using actuators 111 and 211, which will be described later, manually or by an electric signal while riding, and is parallel between a motorcycle body and an axle. Left and right front forks 100, 200.

  The left and right front forks 100 and 200 have the same basic structure and different damping force adjustment structures.

(Basic structure of front forks 100 and 200)
The front forks 100 and 200 are inverted front forks in which the outer tube 11 is disposed on the vehicle body side and the inner tube 12 is disposed on the axle side. As shown in FIGS. 2 to 5 and 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 lower end opening 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 and sealed to the upper end opening of the outer tube 11 in a liquid-tight manner, and a vehicle body side mounting member is 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 the bottom of the inner tube 12, and the axle bracket 15 is provided with an axle mounting hole 15A.

  The front forks 100 and 200 define 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 forks 100 and 200 are provided with a bottomed cup-shaped partition wall member 19 on the inner periphery of the upper end side of the inner tube 12 via an O-ring, etc., and are lower than the rod guide portion 19A at the bottom of the partition wall member 19. The hydraulic oil chamber 21 is partitioned and the oil reservoir chamber 22 is partitioned on the upper side. In the oil reservoir chamber 22, the lower region is an oil chamber 22A, and the upper region is an air chamber 22B. A guide bush 12 </ b> A provided on the outer periphery of the upper end portion protruding from the inner tube 12 of the partition wall member 19 is in sliding contact with the inner periphery of the outer tube 11.

  The front forks 100 and 200 slidably insert 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 lower end portion of the center portion of the cap 13, and this is fixed with the lock nut 24A.

  The front forks 100 and 200 fix a piston 26 slidably in contact with the inner periphery of the inner tube 12 to a piston bolt 25 screwed to a tip portion of a piston rod 23 inserted into the inner tube 12 from the rod guide portion 19A of the partition wall member 19. The oil chamber 21 is divided into a piston rod side oil chamber 21A in which the piston rod 23 is accommodated and a piston side oil chamber 21B in which the piston rod 23 is not accommodated. The piston 26 is fixed by a piston nut 27.

  The front forks 100 and 200 always communicate 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 forks 100, 200 have an upper spring receiver 31 attached to the lower end surface of the piston 26 facing the piston-side oil chamber 21B, and a lower spring receiver 32 disposed at the bottom of the inner tube 12 formed by the axle bracket 15. A main suspension spring 33 is interposed between the upper spring receiver 31 and the lower spring receiver 32. The entire main suspension spring 33 is immersed in the piston-side oil chamber 21B. The front forks 100 and 200 absorb the impact force received from the road surface when the vehicle travels by the expansion and contraction vibration of the main suspension spring 33. At this time, a spring load adjusting device 60 described later raises and lowers the lower spring receiver 32 so that the spring load of the main suspension spring 33 can be adjusted.

  The front forks 100 and 200 include a damping force generator 40 on the piston 26 (FIGS. 4 and 8).

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

  The front forks 100 and 200 are provided with a stopper rubber 44 and a stopper plate 45 in which the upper end portion of the partition wall member 19 provided on the inner tube 12 abuts at the maximum compression stroke on the lower end surface of the cap 13. Regulates the maximum compression stroke.

  The front forks 100 and 200 include a spring seat 46 fixed to the lower end surface of the partition wall member 19 on the upper end side of the inner tube 12 facing the piston rod side oil chamber 21A using a stopper ring 46A, and a stopper ring provided on the piston rod 23. A rebound spring 48 is interposed between the spring seat 47 locked to 47A. When the front forks 100 and 200 are fully extended, the spring seat 46 on the side of the partition member 19 presses the rebound spring 48 against the spring seat 47 to restrict the maximum extension stroke.

  However, in the front forks 100 and 200, the sectional area S1 of the annular oil chamber 17 formed by the annular gap between the outer tube 11 and the inner tube 12 is set to the sectional area (area surrounded by the outer diameter) S2 of the piston rod 23. It is formed larger (S1> S2).

  Further, the rod guide portion 19A and the spring seat 46 of the partition wall member 19 allow oil to flow from the oil reservoir chamber 22 to the piston rod side oil chamber 21A in the compression side stroke, and from the piston rod side oil chamber 21A in the extension side stroke. A check valve 50 is provided to block the flow of oil to the oil reservoir 22.

  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 small gap formed around the piston rod 23 by a bush press-fitted into the inner periphery of the check valve 50. Thus, a minute flow path (orifice) 51 (not shown) that communicates the piston rod side oil chamber 21A and the oil reservoir chamber 22 is formed. The minute channel 51 may be formed by an orifice means 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.

The operation of the front forks 100 and 200 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 supplied from the oil reservoir 22 through the check valve 50.

  In the compression side stroke, a compression side damping force is generated by the bending deformation of the compression side disk valve 41A.

(Extension process)
The hydraulic oil corresponding to the retraction volume of the piston rod 23 that retreats from the inner tube 12 in the extension stroke is transferred from the annular oil chamber 17 to the oil chamber 21 </ b> A on the inner periphery of the inner tube 12 through the oil hole 28 of the inner tube 12. . At this time, since the volume decrease ΔS1 (discharge amount) of the annular oil chamber 17 is larger than the volume decrease ΔS2 of the piston rod 23, the excess of (ΔS1−ΔS2) of the oil discharge amount from the annular oil chamber 17 Is discharged to the oil reservoir chamber 22 through the micro flow channel 51.

  In the extension side stroke, the extension side damping force is generated by the bending deformation of the extension side disk valve 42A. Further, the extension side damping force due to the passage resistance of the micro flow path 51 is also generated.

  The front forks 100 and 200 have a spring load adjustment device 60 that moves the spring receiver 32 up and down and adjusts the spring load of the suspension spring 33. The spring receiver 32 is divided into a spring receiving base portion 32A and a spring receiving cylinder portion 32B. The lower end portion of the spring receiving cylinder portion 32B is automatically centered on the upper end portion of the spring receiving base portion 32A, the spring receiving cylinder portion 32B is loosely inserted into the inner periphery of the inner tube 12, and the suspension spring 33 is connected to the spring receiving cylinder portion 32B. Sit on the top edge of the.

  As shown in FIGS. 3 and 7, the spring load adjusting device 60 is incorporated in a small-diameter closing hole 16 </ b> B following the large-diameter opening hole 16 </ b> A into which the lower end portion of the inner tube 12 in the axle bracket 15 is screwed. The spring load adjusting device 60 inserts an adjustment bolt 61 facing the outside at a position where the axle mounting hole 15A of the axle bracket 15 is removed from the outside of the axle bracket 15 into the small diameter blocking hole 16B, and the bottom surface 16C of the small diameter blocking hole 16B ( The slider 62 provided on the slide surface (the surface facing the lower end of the spring support 32) is linear in the direction intersecting the central axis of the inner tube 12 (the axial direction of the adjustment bolt 61) by the rotational force of the adjustment bolt 61. Make it movable. The lower inclined surface A1 of the spring receiving base portion 32A of the spring receiver 32 is placed on the upper inclined surface A2 of the slider 62, and the spring receiver 32 is supported on the axle bracket 15 via the adjusting bolt 61 and the slider 62. The spring receiver 32 (spring receiving base portion 32 </ b> A and spring receiving cylinder portion 32 </ b> B) is moved up and down by the rotation of the adjusting bolt 61 to adjust the spring load of the suspension spring 33.

(Damping force adjustment structure of front fork 100)
The front fork 100 has a damping force adjusting device 110. The damping force adjusting device 110 adjusts the set load of the spring 117 that urges the compression side disc valve 41A of the front fork 100 in the closing direction to adjust the compression side damping force due to the bending deformation of the compression side disc valve 41A.

  The front fork 100 is loaded with an actuator 111 in an annular recess 13A that faces the upper center of the cap 13 that is sealed in the upper end opening of the outer tube 11. An attachment collar 112 that is liquid-tightly inserted into and screwed into the annular recess 13 </ b> A of the cap 13 presses the actuator 111 liquid-tightly from above, and fixes the actuator 111 to the annular recess 13 </ b> A of the cap 13. The actuator 111 includes a stepping motor or a solenoid that is operated manually or by an electric signal while a motorcycle occupant is on the vehicle, and the tip driver 111A moves up and down in the axial direction within the annular recess 13A of the cap 13.

  The front fork 100 has a push rod 113 inserted in the hollow portion of the piston rod 23. The leading end convex surface of the actuator 111A of the actuator 111 abuts on the upper end concave surface of the upper end contactor 113A fixedly provided on the upper end portion of the push rod 113 via the connecting member 113L, and drives the push rod 113 in the vertical direction. to enable. The lower end contact 113B of the push rod 113 urges the compression side disk valve 41A in the closing direction by a spring 117 that pressurizes as follows.

  That is, guide holes 23A having a long hole extending in the axial direction are provided on both sides in the diametrical direction on the lower end side of the piston rod 23, and both side protrusions of the pushing piece 114 extend axially without play in the guide holes 23A. Is slidably slidable. The tip protrusion of the lower end contact 113B of the push rod 113 inserted into the hollow portion of the piston rod 23 is loosely inserted into a circular hole provided in the center of the push piece 114, and the lower end contact 113B of the push rod 113 is The tip step surface directly contacts the upper surface of the push piece 114.

  Around the lower end portion (piston bolt 25) of the piston rod 23, there are a spring receiver 115 that abuts the protrusions on both ends of the pressing piece 114 from below, and a valve retainer 116 that abuts the upper surface (rear surface) of the compression side disk valve 41A. The valve retainer spring 117 is interposed between the spring receiver 115 and the valve retainer 116. The spring receiver 115 has a cup shape, and abuts with both side protrusions of the pushing piece 114 and the washer 118 at the lower end of the inner periphery of the cup, and the spring 117 is seated on the upper peripheral flange of the cup. The valve presser 116 is a slide that is slidably guided to the outer periphery of the upper end of the piston bolt 25, and an annular presser 116A that continuously and continuously (or even intermittently) contacts the appropriate outer diameter position on the upper surface of the compression side disk valve 41A. 116B and an oil passage 116C that communicates the piston rod side oil chamber 21A with the pressure side passage 41 and the extension side passage 42, and a spring 117 is seated on the outer circumferential step portion. The precompression force of the spring 117 pushes the push rod 113 upward, causing the upper end contact 113 </ b> A of the push rod 113 to contact the driver 111 </ b> A of the actuator 111.

  When the driver 111A of the actuator 111 moves up and down as described above and moves the push rod 113 in the axial direction, the pushing piece 114 with which the push rod 113 abuts moves the spring receiver 115 up and down to move the valve. The presser spring 117 is expanded and contracted to adjust the set load of the spring 117. As a result, the set load of the spring 117 biases the pressure side disc valve 41A in the closing direction via the valve presser 116, and the pressure side damping force due to the bending deformation of the pressure side disc valve 41A can be adjusted. The valve presser 116 can be replaced with one having a different diameter of the presser part 116A. The valve presser 116 provided with the large-diameter presser part 116A presses the outer peripheral side of the compression side disk valve 41A, so that the piston speed can be reduced. Increase the damping force. The valve presser 116 provided with the small-diameter presser part 116A presses the inner peripheral side of the compression side disc valve 41A, and increases the damping force in the middle to high speed range of the piston speed.

(Damping force adjustment structure of front fork 200)
The front fork 200 has a damping force adjusting device 210. The damping force adjusting device 210 adjusts the opening degree of the bypass passage 215 provided in the hollow portion of the piston rod 23 and adjusts the extension side damping force due to the passage resistance of the bypass passage 215.

  The front fork 200 has an actuator 211 loaded in an annular recess 13 </ b> A facing the upper center of the cap 13 sealed in the upper end opening of the outer tube 11. A mounting collar 212 that is inserted in a liquid-tight manner into the annular recess 13A of the cap 13 and screwed presses the actuator 211 in a liquid-tight manner from above, and fixes the actuator 211 to the annular recess 13A of the cap 13. The actuator 211 includes a stepping motor or a solenoid that is operated manually or by an electric signal while a motorcycle occupant is on the vehicle, and the tip driver 211A moves up and down in the axial direction within the annular recess 13A of the cap 13.

  The front fork 200 has a push rod 213 inserted in the hollow portion of the piston rod 23. The convex end surface of the driver 211A of the actuator 211 abuts on the upper end concave surface of the upper end contact 213A that is fixedly provided on the upper end of the push rod 213 via the connecting member 213L, and drives the push rod 213 in the vertical direction. to enable. A needle valve 214 is fixedly provided at the lower end of the push rod 213. A spring 216 is interposed between the intermediate step surface of the needle valve 214 and the piston bolt 25 at the lowermost end of the hollow portion of the piston rod 23, and the precompression force of the spring 216 pushes the push rod 213 upward, The upper end contact 213A of the push rod 213 is brought into contact with the driver 211A of the actuator 211.

  The piston bolt 25 screwed to the tip of the piston rod 23 has a lateral hole 215A formed in a diametrical direction so as to open to the piston rod side oil chamber 21A, and a piston side oil chamber 21B orthogonal to the lateral hole 215A. A vertical hole 215 </ b> B is formed so as to open in the axial direction so as to open. The horizontal hole 215A and the vertical hole 215B form a bypass passage 215 that bypasses the pressure side passage 41 and the extension side passage 42 and communicates the piston rod side oil chamber 21A and the piston side oil chamber 21B. A valve seat 215 </ b> S to which the needle valve 214 contacts and separates is formed at the upper end portion of the vertical hole 215 </ b> B in the bypass passage 215.

  When the driver 211A of the actuator 211 moves up and down as described above to move the push rod 213 in the axial direction, the needle valve 214 at the lower end portion of the push rod 213 is provided in the bypass passage 215 provided in the hollow portion of the piston rod 23. The valve seat 215S at the upper end of the vertical hole 215B moves forward and backward. As a result, the opening degree of the bypass passage 215 is adjusted, and as a result, the compression-side and extension-side damping forces, mainly the extension-side damping force, due to the passage resistance of the bypass passage 215 can be adjusted.

According to the present embodiment, the following operational effects can be obtained.
(a) In the front fork device 1 in which the damping force can be adjusted by using the actuators 111 and 211 manually or by an electric signal while riding, a pressure side disk valve 41A and an extension side disk valve 42A are provided on one front fork 100. The other front fork 200 is also provided with a compression side disk valve 41A and an extension side disk valve 42A. Therefore, there is no difference in the left and right damping performance of the front fork device 1, and the steering stability is good.

  (b) Each front fork 100, 200 is made to move the hydraulic oil chamber 21 to the piston rod side oil chamber 21A and the piston by the piston 26 sliding in the large-diameter hydraulic oil chamber 21 defined on the inner periphery of the inner tube 12. It partitioned into the side oil chamber 21B.

  Accordingly, all of the large amount of oil in the piston side oil chamber 21B pressurized in the pressure side stroke passes through the pressure side disk valve 41A, and the pressure side disk valve 41A is closed by the spring 117 that abuts on the push rod 113 driven by the actuator 111. The valve opening pressure of the pressure side disc valve 41A is adjusted by urging the valve. Since a large amount of oil passes through the compression side disk valve 41A, the adjustment range of the compression side damping force can be increased, and a stable compression side damping force can be obtained.

  In addition, a large amount of oil in the piston rod side oil chamber 21A pressurized in the extension side stroke passes through the bypass passage 215, and the needle valve 214 provided at the tip of the push rod 213 driven by the actuator 211 opens the bypass passage 215. Adjust the degree. Since a large amount of oil passes through the bypass 215, the adjustment range of the extension side damping force can be increased, and a stable extension side damping force can be obtained.

  (c) One front fork 100 is provided with guide holes 23A extending in the axial direction on both sides in the diametrical direction on the lower end side of the piston rod 23, and both sides of the pushing piece 114 are slidable in the guide holes 23A of the piston rod 23. The lower end surface of the push rod 113 inserted into the hollow portion of the piston rod 23 comes into contact with the upper surface of the pusher piece 114, and is lowered below both side protrusions of the pusher piece 114 protruding from the guide hole 23A of the piston rod 23. A spring retainer 115 that abuts on the outer periphery of the piston rod 23 is disposed on the outer periphery of the piston rod 23, and a valve retainer spring 117 is interposed between the spring retainer 115 and the valve retainer 116 that abuts on the upper surface of the pressure side disk valve 41A. The actuator 111 can drive the push rod 113 in the vertical direction. Thereby, the valve opening pressure of the pressure side disk valve 41A can be adjusted with a simple configuration in which one push rod 113 inserted into the hollow portion of the piston rod 23 is driven in the vertical direction by the actuator 111.

  (d) The other front fork 200 advances and retracts the needle valve 214 provided at the tip of the piston rod 23 with respect to the valve seat 215S at the upper end of the vertical hole 215B of the bypass passage 215 provided in the hollow portion of the piston rod 23. The actuator 211 can drive the push rod 213 in the vertical direction. Thereby, the opening degree of the bypass 215 can be adjusted with a simple configuration in which one push rod 213 inserted into the hollow portion of the piston rod 23 is driven in the vertical direction by the actuator 211.

  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.

  The present invention has left and right front forks, each front fork slidably inserts an inner tube on the axle side into an outer tube on the vehicle body side, and provides a partition member on the inner periphery of the inner tube, A hydraulic oil chamber is defined in the lower part of 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 the tip of the piston rod A piston that slides in the hydraulic oil chamber is provided in the section, and the hydraulic oil chamber of the inner tube is divided into a piston rod side oil chamber and a piston side oil chamber by the piston, and these two oil chambers are provided in the piston. In the front fork device that enables communication with each of the passage and the extension side flow path, and provides each of the two flow paths with the compression side damping valve and the extension side damping valve, One of the front forks has an actuator that drives the push rod while allowing the compression side damping valve to be biased in the closing direction by a spring pressurized by the push rod inserted into the hollow portion of the piston rod. The fork is provided with a bypass passage that communicates the piston rod side oil chamber and the piston side oil chamber in the hollow portion of the piston rod, and the bypass passage is formed by the movement of the needle valve provided at the tip of the push rod inserted into the hollow portion of the piston rod. The degree of opening is adjustable, and an actuator for driving the push rod is provided. As a result, the front fork device that can adjust the damping force using an actuator manually or with an electric signal while riding, reduces the difference between the left and right damping performance, increases the adjustment range of the damping force, and provides stable damping. You can gain power.

DESCRIPTION OF SYMBOLS 1 Front fork device 11 Outer tube 12 Inner tube 19 Partition member 21 Hydraulic oil chamber 21A Piston rod side oil chamber 21B Piston side oil chamber 22 Oil reservoir chamber 23 Piston rod 26 Piston 41 Pressure side flow path 41A Pressure side disk valve (pressure side damping valve)
42 Stretching side flow path 42A Stretching side disk valve (stretching side damping valve)
DESCRIPTION OF SYMBOLS 100 Front fork 110 Damping force adjustment apparatus 111 Actuator 111A Driver 113 Push rod 114 Pushing piece 115 Spring receiving 116 Valve holder 117 Valve holder spring 200 Front fork 211 Actuator 211A Driver 213 Push rod 214 Needle valve 215 Bypass path 215A Side hole 215B Vertical hole 215S Valve seat

Claims (3)

Have left and right front forks,
Each front fork
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;
The hydraulic oil chamber of the inner tube is divided into a piston rod side oil chamber and a piston side oil chamber by a piston, and these two oil chambers can be communicated with each other by a pressure side channel and an extension side channel provided in the piston. In the front fork device in which each of the two flow paths is provided with a compression side damping valve and an extension side damping valve,
One front fork has an actuator that drives the push rod while allowing the compression side damping valve to be biased in the closing direction by a spring pressurized by the push rod inserted into the hollow portion of the piston rod,
The other front fork has a bypass passage that connects the piston rod side oil chamber and the piston side oil chamber in the hollow part of the piston rod, and the movement of the needle valve provided at the tip of the push rod inserted into the hollow part of the piston rod A front fork device characterized in that the opening degree of the bypass passage can be adjusted by an actuator and an actuator for driving the push rod is provided. The one front fork is
A guide hole extending in the axial direction is provided on both sides in the diameter direction on the lower end side of the piston rod,
Engage the protrusions on both sides of the pusher piece so that they can slide into the piston rod guide hole.
The lower end surface of the push rod inserted into the hollow portion of the piston rod hits the upper surface of the pusher piece,
A spring receiver that abuts from below on both side protrusions of the push piece protruding from the guide hole of the piston rod is arranged on the outer periphery of the lower end portion of the piston rod,
A valve presser spring is interposed between the spring holder and the valve presser that abuts the upper surface of the compression side damping valve.
The front fork device according to claim 1, wherein the actuator is configured to drive the push rod in the vertical direction. The other front fork is
The needle valve provided at the tip of the piston rod can be moved forward and backward with respect to the valve seat at the upper end of the vertical hole of the bypass passage provided in the hollow portion of the piston rod.
The front fork device according to claim 1, wherein the actuator is configured to drive the push rod in the vertical direction.

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