JP2010007758A - Front fork - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve riding comfort of a motorcycle. <P>SOLUTION: In this front fork, a spring force adjusting mechanism having a suspension spring S energizing an inverted fork body in an extending direction and a damping part installed in an upright damper and adjusting a spring force of the suspension spring S, elevates a tubular spacer S1 serially connected with the suspension spring S by rotation of an adjuster 12 arranged to a cap member 11 closing an upper end opening of a vehicle body side tube 1. An actuator A capable of adjusting a magnitude of a damping force generated at the damping part in the damper extends downward from a bottom end of the cap member 11 closing the upper end opening of the vehicle body side tube 1, and is housed in a case part 11a located inside the tubular spacer S1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a front fork, and more particularly to an improvement in a front fork that is a hydraulic shock absorber that is mounted on the front wheel side of a two-wheeled vehicle and absorbs road surface vibrations that are input to the front wheel of the two-wheeled vehicle that is running.

  There have been various proposals for a front fork as a hydraulic shock absorber that is mounted on the front wheel side of a two-wheeled vehicle and absorbs road surface vibrations that are input to the front wheel of a traveling two-wheeled vehicle. In the proposal disclosed in No. 1, the damping force generated in the internal damping portion can be raised and lowered by driving the actuator accommodated in the same.

  That is, according to the proposal of this document disclosure, the front fork has an upright fork main body in which the lower end side portion of the vehicle body side tube is inserted into the upper end side portion of the wheel side tube so as to be able to protrude and retract.

  In this front fork, the damping force generated by the damping part inside the fork main body can be adjusted in height by driving an actuator which is also a control means of the fork main body.

Therefore, in this front fork, it is possible to realize the desired damping force generation state by driving the actuator by manual operation by the rider of the two-wheeled vehicle or automatic operation based on the detection by the sensors. Can improve.
Japanese Patent Laid-Open No. 2002-89610 (abstract, paragraphs 0006 to 0008, 0031, 0035, 0035, see FIG. 1 in the specification)

  However, in the proposals disclosed in the above-mentioned literature, there is no problem in that the riding comfort in a motorcycle can be improved, but it is pointed out that there is a minor problem when trying to obtain a more favorable riding comfort. there is a possibility.

  That is, the front fork connects the front wheel to the lower end of the fork main body and suspends the front wheel, but the upper end of the fork main body is integrally coupled to the fork bracket connecting the handle. The lower end is a free end that can move up and down.

  Therefore, in the past, in order to improve the stability at the lower end of the fork body against the run-out of the front wheel caused by shimmy etc. in a traveling motorcycle, the wheel side tube is made from a large-diameter outer tube that increases rigidity. That is, the fork main body is generally formed.

  However, if the front wheel on which the fork body is suspended in a two-wheeled vehicle that travels repeats up-and-down movement almost due to overcoming continuous road surface protrusions, the inertial force at that time is reduced, that is, the fork body is In recent years, it has been recognized that it is more preferable from the viewpoint of operability of the handlebar to use an inverted type to reduce the unsprung load.

  This invention was created based on the recognition that it is more preferable that the fork body is set upside down in a front fork in a motorcycle. An object of the present invention is to provide a front fork that is optimal for expecting an improvement in versatility so that the ride comfort in a motorcycle can be further improved.

  In order to achieve the above-described object, the configuration of the front fork according to the present invention is basically inserted into the lower end side portion of the vehicle body side tube having a large diameter so that the upper end side portion of the wheel side tube having a small diameter can be retracted. A fork main body, a suspension spring that is accommodated in the fork main body in the presence of a cylindrical spacer and urges the fork main body in the extending direction, and a vehicle body side in the upper end side portion of the cylinder body that is coupled to the wheel side tube There is a damper that allows the lower end side of the rod body coupled to the tube to be inserted and retracted, and a damper that is provided in the damper to generate a damping force and to adjust the level of the generated damping force. A spring force adjusting mechanism that allows the spring force of the suspension spring to be changed is rotatably disposed on the cap member that closes the upper end opening of the vehicle body side tube, and moves up and down with respect to the cap member when rotating. A front fork having a adjuster and a spring fork that can move up and down while adjoining the lower end of the adjuster and abuts the outer portion with the upper end of the cylindrical spacer, is driven by the input of an electrical signal. An actuator that enables adjustment of the level of damping force generated at the damping part in the damper extends downward from the lower end of the cap member that closes the upper end opening of the vehicle body side tube to lock the upper end of the suspension spring. Suppose that it is accommodated in the case part which exists inside the cylindrical spacer contact | abutted to a spring receiver.

  Therefore, in the present invention, since the fork main body is set upside down, even if the front wheel to be suspended is moved up and down by, for example, getting over a road surface projection in a traveling motorcycle, the fork main body Compared to a case where the vehicle is an upright type, the inertia force at that time is reduced, the operability of the steering wheel is kept good, and the riding comfort in the two-wheeled vehicle is not deteriorated.

  In addition, in the present invention, in addition to the fork body being set upside down, the damping force generated in the internal damping portion of the damper can also be raised and lowered by driving the actuator accommodated therein. Therefore, the ride comfort in a motorcycle can be further improved.

  In the present invention, in addition to the above effects, the spring force of the suspension spring can be adjusted in height, so that the riding comfort in a two-wheeled vehicle can be further improved.

  Further, according to the present invention, the fork main body is inverted and the actuator is housed in the vehicle body side tube having a large diameter. Compared to the case where the actuator is accommodated, the actuator is more flexible.

  In the present invention, since the actuator is housed in the vehicle body side tube and does not protrude from the upper end of the fork main body, compared with the case where the actuator protrudes from the upper end of the fork main body, the appearance is significantly deteriorated and the handle is This will not cause a drop in operability.

  Further, in the present invention, the actuator is housed in the cylindrically formed case portion of the cap member that resides inside the cylindrical spacer, so that the fixing property of the actuator to the case portion is taken into consideration. Thus, even if the actuator has evolved and become smaller, it can be used.

  Hereinafter, the present invention will be described based on the illustrated embodiment. A front fork according to the present invention is mounted on the front wheel side of a two-wheeled vehicle and absorbs road surface vibrations inputted to the front wheel of the two-wheeled vehicle that is traveling. It is a shock absorber.

  And this front fork is in this invention, and as shown in FIG.1 and FIG.2, the fork main body is the wheel side which consists of a small diameter inner tube in the lower end side part of the vehicle body side tube 1 which consists of a large diameter outer tube. It is set to an inverted type that allows the upper end side portion of the tube 2 to be inserted and retracted.

  In this way, by setting the fork main body in an inverted type, as described above, even if the front wheel on which the fork main body is suspended moves up and down due to, for example, getting over a road surface protrusion, Compared with the case where the fork main body is set upright, the inertial force at that time is reduced, the operability of the steering wheel is kept good, and the riding comfort in the two-wheeled vehicle is not deteriorated.

  By the way, if you are driving a two-wheeled vehicle and the front wheels are subject to shake due to shimmy, etc., the steering of the front wheels will not be propagated to the steering wheel. It is preferable to increase the rigidity of the upper end side portion of the fork main body coupled to the side. Therefore, the fork main body is preferably set in an inverted type as in the present invention.

  Further, in the front fork, the fork main body is urged in the extending direction so that the wheel side tube 2 is pulled out from the vehicle body side tube 1 by the urging force of the suspension spring S installed under the presence of the spring force adjusting mechanism. Has been.

  As described above, since the fork main body has the spring force adjusting mechanism, the overall length of the suspension spring S can be changed, the strength of the spring force of the suspension spring S can be adjusted, and the riding comfort in the motorcycle can be improved.

  The suspension spring S is composed of a coil spring. As shown in FIG. 2, the lower end serving as the base end is carried on the cylinder body 3 side of the damper described later, and the tip serving as the upper end is formed of the cylindrical spacer S1 as shown in FIG. The cylindrical spacer S <b> 1 is locked to the lower end, and the tip that is the upper end is locked to the cap member 11 that closes the upper end opening of the vehicle body side tube 1 via a spring force adjusting mechanism described later.

  The spring force adjusting mechanism includes an adjuster 12 that is screwed to the shaft core portion of the cap member 11 so as to be movable up and down, and has a lower end located in the upper end portion of the vehicle body side tube 1, and the adjuster 12 is provided at the lower end. The spring receiver 13 is adjacent.

  The spring receiver 13 has an outer peripheral side portion adjacent to the upper end of the cylindrical spacer S1 described above. Therefore, the spring receiver 13 is moved up and down in synchronization with the raising and lowering of the adjuster 12 to form a cylindrical spacer. Raise and lower S1.

  However, the spring receiver 13 is not capable of moving up and down indefinitely. The upper limit is when it comes into contact with the lower end of the cap member 11, and the lower limit is when the cylindrical case portion 11a is in contact with the lower end. This is when it comes into contact with the upper end of.

  Therefore, in this spring force adjusting mechanism, when the adjuster 12 is turned, the spring receiver 13 is raised and lowered to raise and lower the cylindrical spacer S1, and the upper end position of the suspension spring S is changed. The spring force of the suspension spring S is increased or decreased.

  Next, in this front fork, the damper accommodated in the fork main body is set upright as shown in FIG. 2, and is connected to the wheel side tube 2 to serve as a lower end side member. The lower end of the rod body 4 that is suspended from the shaft core portion of the vehicle body side tube 1 while being connected to the vehicle body side tube 1 in the upper end side portion of the cylinder body 3 standing on the shaft core portion of the side tube 2 and serving as the upper end side member. Insert the side part so that it can appear and disappear.

  The cylinder body 3 is, for example, a tightening bolt that penetrates the shaft core portion of the bottom member from below under a state where the lower end is seated on the inner bottom of a bottom member (not shown) that closes the lower end opening of the wheel side tube 2. The wheel side tube 2 is coupled by tightening (not shown).

  Although not shown, the cylinder body 3 has a communication hole that allows internal and external communication at the lower end portion, and the inside of the cylinder body 3 and the outside of the cylinder body 3 through the communication hole, that is, the wheel side tube 2 and During this, communication with the reservoir chamber R (see FIG. 2) in the fork main body is allowed.

  At this time, although not illustrated, many dampers have a base valve portion in the lower end portion of the cylinder body 3, and the hydraulic oil in the cylinder body 3 is outside the cylinder body 3. It has a damping valve that constitutes a damping part that generates a predetermined damping force when it flows into the reservoir chamber R through the communication hole, and a check valve in parallel therewith.

  In addition, the rod body 4 is basically screwed into the holder portion of the cap member 11 under the presence of the lock nut 41 at the upper end portion. The case portion 11a (see FIG. 1) formed in a cylindrical shape extending toward the end, that is, integrally connected to the cylindrical case portion 11a that houses an actuator A (see FIG. 1) to be described later, It is screwed to the bottom cap 14 corresponding to the holder part.

  The damper includes a piston body 5 that is slidably received in the cylinder body 3 while being held at the lower end portion of the rod body 4 and defines an upper chamber R1 and a lower chamber R2 in the cylinder body 3. Have.

  In this damper, the piston body 5 has a damping valve 51 that constitutes a damping portion, and is arranged in a bypass path that bypasses the damping valve 51 and allows communication between the upper chamber R1 and the lower chamber R2. Thus, the control valve 52 is provided to widen and narrow the flow passage area in the bypass passage.

  The damping valve 51 is composed of a laminated annular leaf valve that closes the downstream end of the expansion side port 5a that is opened in the piston body 5 so that the outer circumferential end can be freely opened by fixing the inner circumferential end. When the hydraulic fluid from the upper chamber R1 flows into the lower chamber R2 during the extension operation in which the piston body 5 moves up in the cylinder body 3, a predetermined extension side damping force is generated.

  The piston body 5 has a check valve 53 that constitutes a damping section referred to in the present invention in parallel with the above-described damping valve 51, and this check valve 53 is used for the damping valve 51 during the extension operation of the damper. Ensure operation.

  The control valve 52 is composed of a needle valve body that moves forward and backward by a vertical movement of a control rod 54 formed of a push rod arranged at the axial center portion of the rod body 4, and the needle valve body has a pointed end portion present in the bypass path. Thus, an annular flow channel appears on the outer periphery of the tip, and the flow rate of the hydraulic oil passing through the annular flow channel is controlled.

  The needle valve body is provided with an urging spring 55 on the outer periphery, and is constantly urged in the retreating direction, which is the ascending direction by the spring force of the urging spring 55. The actuator moves forward by driving the actuator A, which is connected to the upper end of the control rod 53, to reduce the flow rate of hydraulic oil passing through the annular flow path.

  Therefore, in the front fork in which the fork main body and the damper are formed as described above, when the suspension spring S is contracted to be compressed by the input of the axial force from the vehicle body side or the wheel side, The rod body 4 contracts in the cylinder body 3 in synchronism with the movement of the fork main body.

  In the damper that operates to contract, the piston body 5 in the cylinder body 3 descends in the cylinder body 3, and the hydraulic oil in the lower chamber R <b> 2 passes through the check valve 54 disposed in the piston body 5. At this time, an amount of hydraulic oil equivalent to the intrusion rod volume integral surplus in the lower chamber R2 flows into the reservoir chamber R outside the cylinder body 3 via the damping valve in the base valve portion in the cylinder body 3 at this time. The hydraulic oil passes through the damping valve in the base valve portion, and a predetermined damping force is generated.

  Contrary to the above, when the fork body extends so that the wheel side tube 2 protrudes from the vehicle body side tube 1, the damper is extended, and in the extended damper, the piston body 5 is a cylinder. The hydraulic oil in the upper chamber R1 rises in the body 3 and flows out to the lower chamber R2 through the damping valve 51 disposed in the piston body 5, and at this time, it corresponds to the exit rod volume lacking in the lower chamber R2. A predetermined amount of hydraulic oil is supplied from the reservoir chamber R into the cylinder body 3 and the hydraulic oil passes through the damping valve 51 to generate a predetermined damping force.

  When the control valve 52 located in the bypass path that bypasses the damping valve 51 of the piston body 5 is advanced or retracted by the advancement / retraction of the control rod 53 regardless of whether the damper is in the extension operation or the contraction operation. The flow rate of hydraulic oil passing through the bypass passage is controlled, and the damping force generated by the damping valve 51 provided in the piston body and the damping portion having the damping valve disposed in the base valve portion can be adjusted. .

  As described above, in the damper, not only the damping unit can generate a predetermined damping force, but also the level of the generated damping force can be adjusted by driving the actuator A as a driving source. The fork body to be equipped, that is, the front fork, can further improve the riding comfort in a motorcycle.

  The control valve 52 moves forward by driving the actuator A, that is, by projecting the output shaft P by exciting the solenoid built in the actuator A, and when releasing the excitation to the solenoid, the spring of the biasing spring 55 is moved. The output shaft P is immersed by reversing the force.

  The above-mentioned actuator A is basically housed in a cylindrically formed case portion 11a of the cap member 11, and is driven by an electric signal input from the outside of the fork main body in this state.

  Since the actuator A is housed in the vehicle body side tube 1 in this way, it does not protrude from the upper end of the fork main body. Does not cause a decrease in handle operability.

  An electric signal from the outside of the fork main body is input by a manual operation by a rider of the two-wheeled vehicle or by an automatic operation based on detection by sensors provided in a main part of the two-wheeled vehicle.

  The lead wire C for inputting the electrical signal to the actuator A is inserted through the shaft core portion of the adjuster 12 and penetrates through the central portion of the spring receiver 13 adjacent to the lower end of the adjuster 12. Connected to.

  The actuator A is accommodated in the cylindrical case portion 11a with the lower end portion screwed to the bottom cap 14, and the bottom cap 14 closes the lower end opening of the cylindrical case portion 11a in this state. By being screwed so as to be fixed, it is fixed in the cylindrical case portion 11a.

  Further, in this fixing, the elastic material 11b is arranged between the upper end of the actuator A and the upper end of the cylindrical case portion 11a to prevent rattling in the cylindrical case portion 11a of the actuator A. Has been.

  Therefore, in the present invention, since the actuator A is accommodated in the cylindrical case portion 11a under the distribution of the elastic material 11b, for example, even if the actuator A evolves and becomes smaller, the elastic material 11b. By considering the configuration of the, it becomes possible to use it.

  Thus, the actuator A is accommodated inside the vehicle body side tube 1 having a large diameter so that the actuator A is accommodated in the vehicle body side tube composed of a small diameter inner tube. Compared to the case of the upright type, the actuator A can be provided with a degree of freedom.

  In the present invention, since the fork main body is set upside down, the damping force generated in the internal damping portion can be raised and lowered by driving the actuator A accommodated therein. The ride comfort can be further improved.

  As described above, the actuator A is composed of a solenoid. In short, the actuator A may be any drive source, and although not shown, a stepping motor may be used instead of the solenoid.

  When a stepping motor is used as a drive source, the rotation of the motor is converted into a linear motion of the control rod 53 by an appropriate conversion means, and the specific structure of the conversion means is a well-known structure. May be selected.

It is a front view which shows the upper end side of one front fork by one Embodiment by this invention in a partial cross section. It is a fragmentary longitudinal cross-sectional view which expands and shows the principal part in the front fork of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body side tube 2 Wheel side tube 3 Cylinder body 4 Rod body 5 Piston body 11 Cap member 11a Case part 12 Adjuster 13 Spring receiver 51 Damping valve 52 Control valve 53 Control rod A Actuator R1 Upper chamber R2 Lower chamber S Suspension spring S1 Spacer

Claims (3)

A fork main body in which the upper end side portion of the small-diameter wheel side tube is removably inserted into the lower end side portion of the vehicle body side tube having a large diameter, and the fork is accommodated in the fork main body under the arrangement of a cylindrical spacer. A suspension spring that urges the main body in the extending direction, a damper that allows the lower end side portion of the rod body coupled to the vehicle body side tube to be inserted into and retracted into the upper end side portion of the cylinder body coupled to the wheel side tube, and the damper A spring force adjusting mechanism that is provided inside and enables a damping force to be generated and has a damping portion that enables a height adjustment of the generated damping force, and a spring force adjusting mechanism that can change the spring force of the suspension spring is provided at the upper end of the vehicle body side tube. An adjuster that is rotatably disposed on the cap member that closes the opening and moves up and down with respect to the cap member at the time of rotation, and can be moved up and down while being adjacent to the lower end of the adjuster, and has an outer portion that is cylindrical. In a front fork having a spring support that abuts on the upper end of a pacer, an actuator that is driven by an electric signal input and can adjust the level of a damping force generated at a damping portion in the damper is provided on the vehicle body side. The cap member that closes the upper end opening of the tube extends downward from the lower end of the cap member, and is housed in a case portion that lies on the inner side of a cylindrical spacer that abuts a spring receiver that locks the upper end of the suspension spring. A front fork characterized by that. The damper body is slidably accommodated in the cylinder body while being held at the lower end portion of the rod body, and has a piston body that defines an upper chamber and a lower chamber in the cylinder body, and this piston body constitutes a damping portion. It has a damping valve and a control valve composed of a needle valve body that is arranged in a bypass passage that bypasses the damping valve and allows communication between the upper chamber and the lower chamber and widens the flow passage area in the bypass passage. The control valve moves forward by driving the actuator under the control rod consisting of a push rod while interposing an urging spring that urges the control valve in the backward direction to narrow the flow path area in the bypass passage. The front fork according to claim 1. A biasing spring that is interposed in the control valve when the drive source is released or when the drive direction is changed, by moving the control rod forward when driving the drive source built in the actuator to advance the control valve present in the bypass path The front fork according to claim 2, wherein the control valve and the control rod are moved backward by the urging force.

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