WO2022137655A1

WO2022137655A1 - Vehicle shock absorber and suspension device

Info

Publication number: WO2022137655A1
Application number: PCT/JP2021/032390
Authority: WO
Inventors: 勇太松原
Original assignee: Ｋｙｂモーターサイクルサスペンション株式会社
Priority date: 2020-12-21
Filing date: 2021-09-03
Publication date: 2022-06-30
Also published as: JP2022097782A

Abstract

A vehicle shock absorber (D1) comprises: a shock absorber main unit (1) having a cylinder (10) that is couplable to a vehicle-body (B) of a vehicle (V), a piston (11) that is axially movably inserted into the cylinder (10) interior and divides the cylinder (10) interior into an extension-side chamber (R1) and a compression-side chamber (R2), and a rod (12) one end of which is coupled to the piston (11) and which is axially movably inserted into the cylinder (10) interior, and another end of which is couplable to a wheel (W) side of the vehicle (V); a reservoir (2) provided with a reservoir cylinder (13), and a free piston (14) that is axially movably inserted into the reservoir cylinder (13) interior and divides the reservoir cylinder (13) interior into a gas chamber (G) and a liquid chamber (L) interconnected with the compression-side chamber (R2); and a stroke sensor (3) for detecting stroke displacement in the shock absorber main unit (1), the stroke sensor (3) having a detected element (3c) coupled to the free piston (14), and a rod-like probe (3b) coupled to the reservoir cylinder (13) at one end thereof and housed in the reservoir cylinder (13) for detecting the position of the detected element (3c).

Description

Vehicle shock absorbers and suspensions

The present invention relates to a vehicle shock absorber and a suspension device.

The vehicle shock absorber is interposed between the vehicle body and the wheels to generate damping force during expansion and contraction to suppress vibration between the vehicle body and the wheels. Further, the shock absorber for a vehicle may be used by being incorporated in a suspension device that supports a steering wheel on the front side of a saddle-mounted vehicle.

Such a vehicle shock absorber has, for example, an outer tube connected to the vehicle body side, an inner tube slidably inserted into the outer tube and connected to the wheel side, and a reservoir cylinder at the upper end of the outer tube. A cylinder connected via a cylinder, a first piston that is slidably inserted into the cylinder and divides the inside of the cylinder into an extension side chamber and a compression side chamber, and a first piston that is connected to the first piston and is movably inserted into the cylinder. A cylindrical first rod whose lower end is connected to the inner tube, a tubular second rod connected to a cap that closes the upper end of the outer tube, and a reservoir cylinder attached to the outer periphery of the second rod. It is provided with a second piston that separates the cylinder from the cylinder and a free piston that is slidably inserted into the reservoir cylinder to divide the inside of the reservoir cylinder into an air chamber and a liquid chamber.

The vehicle shock absorber configured in this way allows the liquid to pass through the passages provided in the first piston and the second piston during expansion and contraction, and gives resistance to the flow of the liquid passing through the passages by a leaf valve to itself. Generates a damping force that prevents the expansion and contraction of the piston.

Further, in the conventional vehicle shock absorber, for example, as disclosed in JP6764051B, an elongated rod-shaped conductor member mounted on the tip of the second rod and a conductor member housed in the first rod and inside the conductor member. Is provided with a stroke sensor equipped with an elongated cylindrical coil unit through which the vehicle is movably inserted, and detects stroke displacement during expansion and contraction in order to grasp the running state and other aspects of the vehicle (for example, Patent Document 1). reference).

Japanese Patent No. 6764051

In the vehicle shock absorber configured in this way, the position of the conductor member is detected by the coil unit fixed to the inner tube connected to the wheel side, and the electric signal generated by the coil unit is transmitted to the control device or the like. The wiring connected to the coil unit is drawn out from the lower end of the inner tube and connected to a control device or the like installed on the vehicle body side.

As described above, in the conventional vehicle shock absorber, the wiring is inevitably arranged near the road surface on which the vehicle travels because the wiring is pulled out from the wheel side of the vehicle shock absorber. It may interfere and deteriorate.

Further, in the conventional buffer for vehicles, the stroke sensor is composed of a conductor member connected to the outer tube attached to the vehicle body side via the second rod and a coil unit fixed to the inner tube attached to the wheel side. Therefore, when a bending moment is input to the shock absorber for a vehicle, the conductor member and the coil unit may come into contact with each other and deteriorate.

Further, in the conventional vehicle shock absorber, in order to detect the stroke displacement in the total stroke length from the maximum extension to the maximum contraction, a conductor member and a coil unit having a length of at least the stroke length are required, and the stroke sensor is required. Will be long and the cost will increase.

As described above, the conventional vehicle shock absorber has problems such as deterioration of the stroke sensor and an increase in cost, and the suspension device incorporating the vehicle shock absorber also has the same problem.

Therefore, an object of the present invention is to provide a vehicle shock absorber and a suspension device that can protect the stroke sensor and reduce the cost.

In order to achieve the above object, the vehicle shock absorber of the present invention has a cylinder that can be connected to the vehicle body side of the vehicle, and is inserted into the cylinder so as to be movable in the axial direction, and the inside of the cylinder is divided into an extension side chamber and a compression side chamber. A shock absorber body having a piston partitioned into a piston, a rod having one end connected to the piston and movably inserted into the cylinder in the axial direction, and a rod having the other end connectable to the wheel side of the vehicle, a reservoir cylinder and a reservoir. A reservoir equipped with a free piston that is movably inserted into the cylinder and divides the inside of the reservoir cylinder into a liquid chamber that communicates with the air chamber and the compression side chamber, and the stroke displacement of the shock absorber body is detected. A stroke sensor is provided, and the stroke sensor has a detector connected to a free piston and a probe connected to one end of the reservoir cylinder and housed in the reservoir cylinder to detect the position of the detected element. There is.

In the vehicle shock absorber configured in this way, the position of the detector that moves integrally with the free piston can be detected by the probe, and the free piston has a one-to-one relationship with the axial position of the rod with respect to the cylinder. Since the axial position in the reservoir can be detected, the stroke displacement of the vehicle shock absorber can be detected.

Since the vehicle shock absorber configured in this way is provided with the stroke sensor in the reservoir having a degree of freedom in the installation location with respect to the shock absorber body, the wiring of the stroke sensor can be arranged at a position away from the road surface. ..

Further, in the vehicle shock absorber configured in this way, since the stroke sensor is housed in the reservoir and the displacement of the free piston is detected, the stroke sensor does not have to be long and is bent into the vehicle shock absorber. The probe can be protected because it is less susceptible to deformation even when a moment is applied, and the stroke sensor only needs to detect the stroke displacement of the free piston in the reservoir, so it should be at least the total length of the rod or cylinder. The overall length of the probe can be shortened compared to conventional vehicle shock absorbers that must be set.

FIG. 1 is a cross-sectional view of a vehicle shock absorber according to a first embodiment of the present invention applied to a front fork. FIG. 2 is a front view of the suspension device of the present invention applied to a saddle-mounted vehicle. FIG. 3 is a cross-sectional view of another front fork in the suspension device of the present invention. FIG. 4 is an enlarged cross-sectional view of a reservoir portion of the vehicle shock absorber according to the first embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view of a reservoir portion of a vehicle shock absorber according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view of a vehicle shock absorber according to a third embodiment of the present invention applied to a front fork.

Hereinafter, the present invention will be described based on the embodiments shown in the figure. As shown in FIGS. 1 and 4, the vehicle shock absorber D1 according to the first embodiment of the present invention includes a shock absorber main body 1, a reservoir 2, and a stroke sensor 3. Further, as shown in FIG. 2, the vehicle shock absorber D1 of the first embodiment has an outer tube 4 as a vehicle body side tube connected to a vehicle body B of a saddle-type vehicle V as a vehicle, and an outer tube. It is housed in a stretchable body T1 provided with an inner tube 5 as an axle side tube connected to a front wheel W which is a steering wheel of a saddle-mounted vehicle V by being slidably inserted into the 4 and is accommodated in the stretchable body T1. Together with the body T1, it constitutes the front fork F1.

Further, as shown in FIGS. 1 to 4, the front fork F1 is slidably inserted into the outer tube 4 as a vehicle body side tube connected to the vehicle body B of the saddle-mounted vehicle V and the outer tube 4. A stretchable body T2 provided with an inner tube 5 as an axle side tube connected to a front wheel W which is a steering wheel of a saddle-mounted vehicle V, and a damping force variable shock absorber D2 housed in the stretchable body T2. It constitutes a suspension device S for suspending the front wheel W of the saddle-mounted vehicle V in a pair with another front fork F2 provided with the above.

First, the front fork F1 accommodating the vehicle shock absorber D1 of the first embodiment will be specifically described. As shown in FIG. 1, the front fork F1 is a telescopic type and inverted type telescopic body including an outer tube 4 and an inner tube 5 slidably inserted into the outer tube 4. It is equipped with T1.

Then, when the front wheel W vibrates up and down due to the saddle-mounted vehicle V traveling on an uneven road surface, the inner tube 5 moves in and out of the outer tube 4, and the telescopic body T1 expands and contracts. As described above, when the stretchable body T1 expands and contracts, the vehicle shock absorber D1 housed inside the outer tube 4 and the inner tube 5 also expands and contracts to generate a damping force. The telescopic body T1 may be an upright type in which the outer tube is the axle side tube and the inner tube is the vehicle body side tube.

The upper end of the outer tube 4, which is the upper end of the stretchable body T1, is closed by the cap 6. On the other hand, the lower end of the inner tube 5, which is the lower end of the stretchable body T1, is closed by the bracket 7 on the axle side. Further, an annular sealing member 8 that is in sliding contact with the outer periphery of the inner tube 5 is provided on the inner circumference of the lower end of the outer tube 4, and the space inside the outer tube 4 and the inner tube 5 is a closed space. ..

In this way, the inside of the stretchable body T1 is a closed space, and the shock absorber D1 for a vehicle is housed in the stretchable body T1. Further, the outside of the shock absorber D1 for a vehicle inside the telescopic body T1 is a liquid storage chamber R3 for storing the liquid together with the gas.

Subsequently, the vehicle shock absorber D1 includes a shock absorber main body 1, a reservoir 2, and a stroke sensor 3. The shock absorber main body 1 has a cylinder 10, a piston 11 that is movably inserted into the cylinder 10 and is divided into an extension side chamber R1 and a compression side chamber R2 in which the inside of the cylinder 10 is filled with a liquid, and one end thereof. It includes a rod 12 that is connected to the piston 11 and is movably inserted into the cylinder 10 in the axial direction.

The upper end of the cylinder 10 in FIG. 1 in the shock absorber body 1 is connected to the outer tube 4 via the reservoir cylinder 13 forming the reservoir 2, and is indirectly saddle-mounted via the outer tube 4 and the reservoir cylinder 13. It can be connected to the vehicle body B in the vehicle V. Further, the lower middle end of FIG. 1 of the rod 12 is connected to a bracket 7 that closes the lower end of the inner tube 5, and can be indirectly connected to the axle of the front wheel W of the saddle-mounted vehicle V via the bracket 7. ing. As described above, the cylinder 10 of the shock absorber main body 1 can be connected to the vehicle body B of the saddle-mounted vehicle V, and the rod 12 can be connected to the front wheel W which is the wheel of the saddle-mounted vehicle V. However, the cylinder 10 may be directly connected to the vehicle body B, or the rod 12 may be directly connected to the axle of the wheel.

Further, the reservoir 2 has a reservoir cylinder 13, a cap 6 that closes one end of the reservoir cylinder 13, and an air chamber that is movably inserted into the reservoir cylinder 13 in the axial direction and is filled with gas in the reservoir cylinder 13. It is provided with a free piston 14 that is divided into a liquid chamber L that is filled with G and a liquid and communicates with the compression side chamber R2. The liquid used for the shock absorber D1 for a vehicle is a hydraulic oil in the present embodiment, but a liquid other than the hydraulic oil can also be used. Further, the gas is preferably an inert gas such as nitrogen, but the atmosphere can also be used.

Hereinafter, each part of the vehicle shock absorber D1 will be described in detail. As shown in FIG. 1, the cylinder 10 has a cylindrical shape, and a reservoir cylinder 13 is screwed to the outer periphery of the upper end. In the present embodiment, the reservoir cylinder 13 has a diameter larger than that of the cylinder 10, and the screw portion 13a provided on the outer periphery of the upper end is screwed to the inner circumference of the upper end of the outer tube 4 and connected to the outer tube 4. ing. Further, a cap 6 is screwed into the upper end opening of the reservoir cylinder 13 to close the outer tube 4 and the upper end opening of the reservoir cylinder 13. A cylindrical rod guide 15 through which the rod 12 is inserted is mounted on the inner circumference of the lower end of the cylinder 10, and the lower end of the cylinder 10 is closed.

As shown in FIG. 1, the lower end of the rod 12 is connected to a bracket 7 that closes the lower end of the outer tube 4, and the upper end side is inserted into the cylinder 10. Further, on the inner circumference of the inner tube 5 which is the upper end of the bracket 7, a tubular oil lock case 17 provided with a flange-shaped spring receiver 17a for supporting the lower end of the suspension spring 16 is mounted on the outer circumference. ..

Further, a spring receiver 18 that supports the upper end of the suspension spring 16 is mounted on the outer periphery of the cylinder 10. The spring receiver 18 has a cylindrical shape in which the upper end fitted to the outer periphery of the cylinder 10 has the minimum diameter and the diameter increases toward the lower side, and the spring receiver 18 is provided with a hole 18a on the side portion. The suspension spring 16 is interposed between the spring receiver 17a and the spring receiver 18 in the oil lock case 17. The spring receiver 18 is mounted on the outer periphery of the cylinder 10 in a state where the movement of the spring receiver 18 is restricted upward with respect to the cylinder 10, and the force received from the suspension spring 16 is transmitted to the outer tube 4 via the cylinder 10. There is. Therefore, the suspension spring 16 exerts an elastic force that pushes the outer tube 4 upward and the inner tube 5 downward to separate them from each other.

Further, an annular oil lock piece 15a is attached to the outer periphery of the lower end of FIG. 1 of the rod guide 15. When the outer tube 4 and the inner tube 5 approach each other and the front fork F1 contracts to near the maximum contraction, the oil lock piece 15a attached to the outer periphery of the rod guide 15 invades the oil lock case 17. An appropriate gap is provided between the outer circumference of the oil lock piece 15a and the inner circumference of the oil lock case 17, and resistance is provided to the flow of hydraulic oil flowing out from the inside of the oil lock case 17. Therefore, when the oil lock piece 15a enters the oil lock case 17, the pressure inside the oil lock case 17 rises and further contraction of the front fork F1 is hindered, so that the impact at the time of maximum contraction of the front fork F1 is alleviated. Will be done.

Returning, as shown in FIG. 1, a piston 11 is mounted on the outer periphery of the upper end of the rod 12 inserted into the cylinder 10. The piston 11 is in sliding contact with the inner circumference of the cylinder 10 and can move in the axial direction which is the vertical direction with respect to the cylinder 10. As described above, the inside of the cylinder 10 is divided into the extension side chamber R1 and the compression side chamber R2. It is partitioned. Further, the piston 11 includes an extension side port 11a and a compression side port 11b that communicate the extension side chamber R1 and the compression side chamber R2. An extension side leaf valve 20 that opens and closes the outlet end of the extension side port 11a is laminated on the compression side chamber R2 side of the piston 11 in a state of being fixed to the outer periphery of the rod 12, and is laminated on the extension side chamber R1 side of the piston 11. The check valve 21 that opens and closes the outlet end of the compression side port 11b is laminated in a state of being fixed to the outer periphery of the rod 12.

The extension side leaf valve 20 is a laminated leaf valve configured by laminating a plurality of annular plates in the vehicle shock absorber D1 of the present embodiment, and the inner circumference is fixed to the outer circumference of the rod 12 to form an outer circumference. Side deflection is allowed. Further, the extension side leaf valve 20 gives resistance to the flow of the hydraulic oil when the hydraulic oil moves from the extension side chamber R1 to the compression side chamber R2 via the extension side port 11a, and the hydraulic oil flows from the compression side chamber R2 to the extension side chamber R1. Stop moving towards.

The check valve 21 is formed of an annular plate in the vehicle shock absorber D1 of the present embodiment, and the inner circumference is fixed to the outer periphery of the rod 12 to allow bending on the outer peripheral side. Further, the check valve 21 allows the flow of hydraulic oil moving from the compression side chamber R2 to the extension side chamber R1 via the compression side port 11b without substantially resistance, and the hydraulic oil moves from the extension side chamber R1 to the compression side chamber R2. To prevent. The check valve 21 may be a damping valve that gives resistance to the flow of hydraulic oil passing through the compression side port 11b.

The rod 12 is hollow and has a passage P that bypasses the extension side port 11a and the compression side port 11b of the piston 11 and communicates the extension side chamber R1 and the compression side chamber R2. It is provided with a needle valve N capable of changing the flow path area of the above. The needle valve N can move in the rod 12 in the axial direction by the rotation operation of the adjuster A provided at the lower end of the bracket 7, and the flow path area of the passage P can be changed.

The reservoir 2 includes a reservoir cylinder 13, a cap 6, and a free piston 14, and also includes a tubular rod 22 made of a non-magnetic material, one end of which is connected to the cap 6 and housed in the reservoir cylinder 13. The free piston 14 is annular and is slidably mounted on the outer circumference of the tubular rod 22. The outer circumference is slidably contacted with the inner circumference of the reservoir cylinder 13, and the inside of the reservoir cylinder 13 is the air chamber G and the liquid chamber L. It is divided into.

The tubular rod 22 is made of aluminum in the vehicle shock absorber D1 of the present embodiment. Since the tubular rod 22 may be made of a non-magnetic material, it may be made of non-magnetic stainless steel such as SUS304 or synthetic resin if there is no problem in terms of strength, in addition to aluminum. Further, a valve holding member 26 to which the valve case 23 is mounted together with the base valve 24 and the check valve 25 is screwed to the outer periphery of the lower end of the cylindrical rod 22 in FIG.

Subsequently, the valve case 23 has an annular shape, and as described above, is attached to the outer periphery of the lower end of the middle end of FIG. 1 of the cylindrical rod 22 connected to the cap 6 via the valve holding member 26. In this way, the valve case 23 is axially positioned by the tubular rod 22 and housed in the reservoir cylinder 13. The valve case 23 is fitted to the inner circumference of the reservoir cylinder 13, and is immovably fixed to the cylinder 10 by the tubular rod 22. As described above, the inside of the reservoir cylinder 13 is filled with the compression side chamber R2 and the reservoir 2. It is divided into.

As shown in FIGS. 1 and 4, the valve case 23 includes a discharge port 23a that communicates the compression side chamber R2 and the liquid chamber L, and a suction port 23b that communicates the compression side chamber R2 and the liquid chamber L. .. A base valve 24 that opens and closes the outlet end of the discharge port 23a is laminated on the liquid chamber L side of the valve case 23 in a state of being fixed to the outer periphery of the tubular rod 22, and is laminated on the compression side chamber R2 side of the valve case 23. Is laminated with a check valve 25 that opens and closes the outlet end of the suction port 23b fixed to the outer periphery of the tubular rod 22.

The base valve 24 is a laminated leaf valve configured by laminating a plurality of annular plates in the vehicle shock absorber D1 of the present embodiment, and the inner circumference is fixed to the outer circumference of the tubular rod 22 to be the outer circumference. Side deflection is allowed. Further, the base valve 24 allows only the flow of the hydraulic oil moving from the compression side chamber R2 to the liquid chamber L via the discharge port 23a to give resistance to the flow of the hydraulic oil, and the hydraulic oil is the compression side chamber R2. Prevents movement from to the extension chamber R1.

The check valve 25 is formed of an annular plate in the vehicle shock absorber D1 of the present embodiment, and the inner circumference is fixed to the outer circumference of the tubular rod 22 to allow bending on the outer peripheral side. Further, the check valve 25 allows the flow of hydraulic oil moving from the liquid chamber L to the compression side chamber R2 via the suction port 23b without substantially resistance, and the hydraulic oil moves from the compression side chamber R2 toward the liquid chamber L. To prevent.

The base valve 24, the valve case 23, and the check valve 25 configured in this way are assembled to the shaft portion 26a of the valve holding member 26 and screwed to the tip of the shaft portion 26a at the lower end of FIG. Is fixed to the valve holding member 26. The valve holding member 26 is screwed to the outer periphery of the tubular rod 22 in FIG. 4 and assembled to the tubular rod 22.

Subsequently, a bottomed cylindrical free piston 14 is slidably mounted on the outer circumference of the tubular rod 22 and above the valve case 23 in FIG. 1. The bottom portion 14a of the free piston 14 is annular, and a tubular rod 22 is inserted on the inner peripheral side. Further, the free piston 14 has a cylinder portion 14b slidably contacted with the inner circumference of the reservoir cylinder 13, and the inside of the reservoir cylinder 13 is divided into a liquid chamber L filled with hydraulic oil and an air chamber G filled with gas. is doing. Further, a pressure spring 28 made of a coil spring is interposed between the bottom 14a of the free piston 14 and the cap 6 in a compressed state, and the free piston 14 is inside the pressure spring 28 and the air chamber G. The pressure of the liquid chamber is always urged in the direction of compressing the L side of the liquid chamber. A spring receiver 29 is interposed between the bottom portion 14a of the free piston 14 and the pressure spring 28. The spring receiver 29 includes a tubular portion 29a arranged in an annular gap between the pressure spring 28 and the tubular rod 22, and a flange 29b provided on the outer periphery of the lower end of FIG. 4 of the tubular portion 29a. The flange 29b supports the end of the pressure spring 28. Therefore, the spring receiver 29 is always pressed against the bottom 14a of the free piston 14 by the urging force of the pressure spring 28, and when the free piston 14 moves in the axial direction with respect to the tubular rod 22, it is integrated with the free piston 14. It is displaced with respect to the cylindrical rod 22.

As described above, in the vehicle shock absorber D1 of the present embodiment, the free piston 14 is urged by the pressure spring 28 to apply a compressive force to the liquid chamber L, so that the cylinder communicates with the liquid chamber L. The extension side chamber R1 and the compression side chamber R2 in 10 are pressurized to increase the rigidity of the oil column. Since the gas is dissolved in the hydraulic oil, the hydraulic oil exhibits elasticity, and when the apparent elastic modulus of the hydraulic oil becomes low, the damping force generation response of the vehicle shock absorber D1 deteriorates, but as described above, the cylinder. By pressurizing the inside of 10, the rigidity of the oil column can be increased and the damping force generation response of the vehicle shock absorber D1 can be improved.

A hole 13b leading to the outside of the vehicle shock absorber D1 is provided on the side of the reservoir cylinder 13 of the cylinder 10. The hole 13b is maintained in a state of being closed by the free piston 14 when the cylinder portion 14b of the free piston 14 faces each other, but the amount of hydraulic oil in the liquid chamber L becomes larger than the specified amount and the free piston When 14 retreats above the hole 13b, the hydraulic oil in the liquid chamber L is discharged to the liquid storage chamber R3 outside the vehicle shock absorber D1 through the hole 13b, and the pressure inside the cylinder 10 becomes excessively high. Can be prevented.

The stroke sensor 3 is a sensor body 3a held by the cap 6, a rod-shaped probe 3b extending from the sensor body 3a and inserted into the tubular rod 22, and a detector to be mounted on the spring receiver 29. It is equipped with an annular magnet 3c. In the present embodiment, the stroke sensor 3 is a magnetostrictive sensor provided with a sensor body 3a having an electronic circuit that gives a pulse signal to the magnetostrictive wire in the probe 3b to detect the position of the magnet 3c. The stroke sensor 3 includes a detector that is held by a component that can move in the reservoir cylinder 13 in the axial direction together with the free piston 14 or the free piston 14, and a probe that can detect the position of the detector. If it has, it may be a slot talk sensor using a detection principle other than the above. As described above, the magnet 3c to be detected may be directly mounted on the free piston 14, or may be mounted on a component that can move in the reservoir cylinder 13 in the axial direction together with the free piston 14. ..

As described above, as described above, the cap 6 is screwed to the inner circumference of the upper end in FIG. 4 of the reservoir cylinder 13, and is opened from the upper end in FIG. 4 to accommodate the sensor body 3a of the stroke sensor 3 and the accommodating recess 6a. 4 The middle and lower ends are provided with a tubular portion 6b into which the outer periphery of the upper end of the tubular rod 22 is screwed, and a through hole 6c that opens from the bottom of the accommodating recess 6a and leads into the tubular portion 6b.

The sensor body 3a in the stroke sensor 3 is housed in the housing recess 6a of the cap 6 and is fixed by the seal member 6d mounted on the inner circumference of the upper end of the housing recess 6a. The seal member 6d prevents the intrusion of water, dust, etc. into the accommodating recess 6a, and fixes and protects the sensor body 3a. The seal of the accommodating recess 6a and the fixing and protection of the sensor main body 3a may be realized by a seal member other than the above-mentioned seal member 6d. Further, the wiring 3d extending from the sensor main body 3a penetrates the seal member 6d and is drawn out to the outside of the front fork F1 and is connected to an external device (not shown).

In the vehicle shock absorber D1 of the present embodiment, the sensor body 3a is held by the cap 6 and integrated with the probe 3b, but the probe 3b is integrated with the free piston 14 or the free piston 14 and is a reservoir cylinder. As long as the position of the detected element held by the component that can move in the axial direction in 13 can be detected, the probe 3b may be separated from the probe 3b. Therefore, the probe 3b may be housed in the vehicle shock absorber D1 and the sensor main body 3a may be arranged outside the vehicle shock absorber D1 or the front fork F1. Further, in the vehicle shock absorber D1 of the present embodiment, the magnet 3c is adhered to the inner circumference of the cylinder portion 29a of the spring receiver 29 which is integrally displaced with the free piston 14 and is displaced in the axial direction with respect to the reservoir cylinder 13. ing. Although the magnet 3c is held by the spring receiver 29 in this way, it may be directly attached to the free piston 14. When the free piston 14 is urged by a gas spring that utilizes the elastic force exerted by the gas in the air chamber G instead of the coil spring, the magnet 3c may be directly attached to the free piston 14. ..

The probe 3b projects into the tubular rod 22 through the through hole 6c of the cap 6. In the vehicle shock absorber D1 of the present embodiment, the probe 3b is connected to the reservoir cylinder 13 via the integrated sensor body 3a and the cap 6, but the magnet is opposed to the inner circumference of the magnet 3c. If the position of 3c can be detected, it may be connected to the reservoir cylinder 13 regardless of whether it is direct or indirect.

The length of the probe 3b is set to the valve holding member 26 in which at least the free piston 14 is the lower stroke end in FIG. 4 with respect to the cylindrical rod 22 in the structure of the vehicle shock absorber D1 of the present embodiment. The length is set so that the position of the magnet 3c, which is the detector, can be detected within the range from the abutting position to the position where the hole 13b of the reservoir cylinder 13 which is the upper stroke end in FIG. 4 is opened. Further, as described above, since the tubular rod 22 is made of a non-magnetic material, the probe 3b can detect the position of the magnet 3c without being disturbed by the tubular rod 22.

The vehicle shock absorber D1 is configured as described above, and its operation will be described below. First, when the front fork F1 is extended, the piston 11 connected to the rod 12 with respect to the cylinder 10 moves downward in FIG. 1 due to the relative axial separation between the outer tube 4 and the inner tube 5. do. The extension side chamber R1 in the cylinder 10 is compressed and contracted by the movement of the piston 11, and the compression side chamber R2 in the cylinder 10 is expanded by the movement of the piston 11. The hydraulic oil in the extension side chamber R1 to be compressed pushes open the extension side leaf valve 20 and moves to the compression side chamber R2 which is expanded through the extension side port 11a of the piston 11. Since the extension side leaf valve 20 resists the flow of hydraulic oil passing through the extension side port 11a, the pressure of the extension side chamber R1 becomes higher than the pressure of the compression side chamber R2, and the vehicle shock absorber D1 hinders its own extension. Demonstrates the extension side damping force.

When the shock absorber D1 for a vehicle is extended, the rod 12 withdraws from the cylinder 10 and the hydraulic oil for the volume of the rod 12 withdrawing from the cylinder 10 is insufficient in the compression side chamber R2 in the cylinder 10. Since the hydraulic oil is insufficient in the compression side chamber R2 in this way, the pressure in the compression side chamber R2 drops below the pressure in the reservoir 2, and the check valve 25 bends to open the suction port 23b. Therefore, the hydraulic oil deficient in the compression side chamber R2 is supplied from the liquid chamber L of the reservoir 2 to the compression side chamber R2 through the suction port 23b. In the reservoir 2, the free piston 14 moves downward to shrink the liquid chamber L and expand the air chamber G because the hydraulic oil moves from the liquid chamber L to the compression side chamber R2, and the rod 12 exits from the cylinder 10. Compensation for the volume to be made is made. As described above, when the front fork F1 is extended, the vehicle shock absorber D1 is extended together, and the extension side leaf valve 20 generates an extension side damping force that hinders the extension of the front fork F1.

Subsequently, when the front fork F1 contracts, the piston 11 connected to the rod 12 with respect to the cylinder 10 moves upward in FIG. 1 as the outer tube 4 and the inner tube 5 approach each other in the axial direction. Moving. The compression side chamber R2 in the cylinder 10 is compressed and contracted by the movement of the piston 11, and the extension side chamber R1 in the cylinder 10 is expanded by the movement of the piston 11. The hydraulic oil in the compressed side chamber R2 pushes open the check valve 21 and moves to the extended side chamber R1 which passes through the compression side port 11b of the piston 11 and is expanded. Since the check valve 21 gives almost no resistance to the flow of hydraulic oil passing through the compression side port 11b, the pressure in the compression side chamber R2 and the pressure in the extension side chamber R1 are substantially equal.

When the shock absorber D1 for a vehicle contracts, the rod 12 invades the cylinder 10, and the hydraulic oil for the volume of the rod 12 invading the cylinder 10 becomes excessive in the cylinder 10. The excess hydraulic oil in the cylinder 10 in this way pushes open the base valve 24, passes through the discharge port 23a of the valve case 23, and moves to the liquid chamber L of the reservoir 2. Since the base valve 24 resists the flow of hydraulic oil passing through the discharge port 23a, the vehicle shock absorber D1 exerts a compression side damping force that hinders its own contraction in order to increase the overall pressure in the cylinder 10. In the reservoir 2, the hydraulic oil is discharged from the cylinder 10 into the liquid chamber L, so that the free piston 14 retracts upward to expand the liquid chamber L and shrink the air chamber G, and the rod 12 causes the cylinder 10. Compensation for the volume that penetrates inside is made. Further, when the front fork F1 contracts, the cylinder 10 moves downward in FIG. 1 in the inner tube 5, and the oil level of the hydraulic oil in the liquid reservoir R3 rises with the movement of the cylinder 10 to collect the liquid. The hydraulic oil in the chamber R3 may pass through the hole 18a of the spring receiver 18. The hole 18a functions as a throttle valve for the flow through which the hydraulic oil passes. Therefore, when the front fork F1 contracts, the vehicle shock absorber D1 also contracts, and the base valve 24 generates a compression side damping force that hinders the contraction of the front fork F1, and the oil level passes through the hole 18a of the spring receiver 18. In this case, the front fork F1 can add a damping force that prevents contraction due to the spring receiver 18 to the compression side damping force of the vehicle shock absorber D1.

Here, when the vehicle shock absorber D1 expands, the free piston 14 moves downward in the reservoir 2 in FIG. 4, and when the vehicle shock absorber D1 contracts, the free piston 14 moves in the reservoir 2. Is moved upward in FIG. The amount of movement of the free piston 14 during expansion and contraction of the vehicle shock absorber D1 is proportional to the volume of the rod 12 entering and exiting the cylinder 10. Specifically, the amount of movement of the free piston 14 is the volume of the rod 12 entering or exiting the cylinder 10 when the shock absorber D1 for a vehicle expands and contracts, considering the rod 12 as a solid body. It is equal to the value divided by the area facing the liquid chamber L. Here, since the stroke sensor 3 can detect the position of the free piston 14, the amount of hydraulic oil entering and exiting the reservoir 2 can be grasped. Further, the axial position of the free piston 14 with respect to the reservoir cylinder 13 and the cross-sectional area of the rod 12 when the vehicle shock absorber D1 is fully extended or contracted are known because they are design matters. Since the amount of hydraulic oil entering and exiting the reservoir 2 is nothing but the volume of the rod 12 entering and exiting the cylinder 10, the current hydraulic oil in the liquid chamber L from the current position of the free piston 14 detected by the stroke sensor 3. By grasping the amount, it is possible to know how much the rod 12 currently penetrates into the cylinder 10, that is, the stroke displacement of the vehicle shock absorber D1. As described above, there is a one-to-one relationship between the axial position of the free piston 14 in the reservoir 2 and the axial position of the rod 12 with respect to the cylinder 10 of the vehicle shock absorber D1. If the position is detected, the stroke displacement of the vehicle shock absorber D1 can be detected. The above-mentioned external device (not shown) processes the current position of the free piston 14 detected by the stroke sensor 3 to obtain the stroke displacement of the vehicle shock absorber D1.

The vehicle shock absorber D1 of the present embodiment is a cylinder 10 that can be connected to the vehicle body B side in the saddle-mounted vehicle (vehicle) V, and is inserted into the cylinder 10 so as to be movable in the axial direction. A piston 11 that divides the inside into an extension side chamber R1 and a compression side chamber R2, one end of which is connected to the piston 11 and is movably inserted into the cylinder 10 in the axial direction, and the other end is a saddle-type vehicle (vehicle) V. The shock absorber body 1 having the rod 12 that can be connected to the front wheel (wheel) W side, and the reservoir cylinder 13 and the reservoir cylinder 13 are movably inserted in the axial direction and the inside of the reservoir cylinder 13 is the air chamber G. The reservoir 2 provided with the free piston 14 partitioned from the liquid chamber L communicated with the compression side chamber R2 and the stroke sensor 3 for detecting the stroke displacement of the shock absorber main body 1 are provided, and the stroke sensor 3 is a free piston 14. It has a magnet (detected element) 3c connected to and a rod-shaped probe 3b whose one end is connected to the reservoir cylinder 13 and housed in the reservoir cylinder 13 to detect the position of the magnet (detected element) 3c. is doing.

In the vehicle shock absorber D1 configured in this way, the position of the magnet 3c as a detector that moves integrally with the free piston 14 can be detected by the probe 3b, and the position of the rod 12 in the axial direction with respect to the cylinder 10 can be detected. Since the axial position of the free piston 14 having a one-to-one relationship in the reservoir 2 can be detected, the stroke displacement of the vehicle shock absorber D1 can be detected.

Since the vehicle shock absorber D1 configured in this way is provided with the stroke sensor 3 in the reservoir 2 having a degree of freedom in the installation location with respect to the shock absorber main body 1, the wiring 3d of the stroke sensor 3 is laid from the road surface. The wiring 3d can be protected from flying objects by being able to be arranged at a separated position.

Further, in the vehicle shock absorber D1 configured in this way, since the stroke sensor 3 is housed in the reservoir 2 and the displacement of the free piston 14 is detected, the stroke sensor 3 does not have to be long, and the vehicle. Even if a bending moment acts on the shock absorber D1, it is less likely to be affected by deformation, so that the probe 3b can be protected. That is, since the stroke sensor 3 only needs to detect the stroke displacement of the free piston 14 in the reservoir 2, it is compared with the conventional vehicle shock absorber that must be set to at least the total length of the rod or cylinder. The total length of the probe 3b can be shortened. Therefore, according to the vehicle shock absorber D1 configured in this way, the total length of the probe 3b of the stroke sensor 3 can be shortened as compared with the conventional vehicle shock absorber, and the manufacturing cost can be reduced. If the area of the bottom portion 14a of the free piston 14 is made larger than the cross-sectional area of the rod 12, the displacement of the free piston 14 can be reduced with respect to the displacement of the rod 12 with respect to the cylinder 10, so that the total length of the probe 3b can be further shortened. ..

From the above, according to the vehicle shock absorber D1 of the present embodiment, the stroke sensor 3 can be protected and the cost can be reduced.

Further, the vehicle shock absorber D1 of the present embodiment is formed of a cap 6 in which the reservoir 2 closes one end of the reservoir cylinder 13 and a non-magnetic material having one end connected to the cap 6 and housed in the reservoir cylinder 13. The free piston 14 has an annular shape and is slidably mounted on the outer periphery of the tubular rod 22 so as to be slidably contacted with the inner circumference of the reservoir cylinder 13, and the probe 3b of the stroke sensor 3 is attached. It is housed in the tubular rod 22. In the vehicle shock absorber D1 configured in this way, the probe 3b is protected by the tubular rod 22 and the free piston 14 is moved in the axial direction by the tubular rod 22 even when a bending moment is applied to the vehicle shock absorber D1. Since the probe 3b can accurately detect the position of the free piston 14, the stroke displacement of the vehicle shock absorber D1 can be detected accurately.

Further, the vehicle shock absorber D1 of the present embodiment is mounted on the outer periphery of the other end of the tubular rod 22 to partition the liquid chamber L and the compression side chamber R2, and discharge the pressure side chamber R2 and the liquid chamber L to communicate with each other. The valve case 23 having the port 23a and the suction port 23b opens and closes the discharge port 23a, and allows only the flow of hydraulic oil (liquid) passing through the discharge port 23a from the compression side chamber R2 toward the liquid chamber L and operates. It is provided with a base valve 24 that resists the flow of oil (liquid) and a check valve 25 that opens and closes the suction port 23b and allows only the flow of hydraulic oil (liquid) from the liquid chamber L to the compression side chamber R2. .. According to the vehicle shock absorber D1 configured in this way, a stroke is provided in the tubular rod 22 provided for installing the base valve 24 and the check valve 25 for generating the compression side damping force of the vehicle shock absorber D1. Since the probe 3b of the sensor 3 can be installed, the stroke sensor 3 can be installed at low cost.

The vehicle shock absorber D1 of the present embodiment has a pressure spring (coil spring) 28 for urging the free piston 14 toward the liquid chamber L side, and the free piston 14 and the pressure spring (coil spring) 28. An annular spring receiver 29 interposed between the and is provided, and the spring receiver 29 is provided at one end of a cylinder portion 29a and a cylinder portion 29a arranged on the inner circumference of the pressure spring (coil spring) 28. It has a flange 29b that supports one end of the compression spring (coil spring) 28, and a magnet (detected element) 3c is mounted on the inner circumference of the tubular portion 29a of the spring receiver 29. According to the vehicle shock absorber D1 configured in this way, since the magnet (detected element) 3c is mounted on the inner circumference of the cylinder portion 29a of the spring receiver 29, the inside of the cylinder 10 is pressurized spring (coil spring). ) 28 can prevent the magnet (detected element) 3c from interfering with the pressurized spring (coil spring) 28 while pressurizing the magnet (detected element) 3c. Further, according to the vehicle shock absorber D1 configured in this way, since the magnet (detected element) 3c is mounted on the spring receiver 29, the size of the pressure spring (coil spring) 28 is changed. However, there is a case where the magnet (detected element) 3c can be installed only by changing the design of the spring receiver 29 without requiring the design change of the free piston 14, which is advantageous in terms of cost.

Further, since the vehicle shock absorber D1 of the present embodiment is configured by connecting the reservoir cylinder 13 to the vehicle body B side end of the cylinder 10, the wiring 3d of the stroke sensor 3 is connected to the road surface of the vehicle shock absorber D1. Since it can be arranged on the vehicle body B side, which is the farthest upper end, deterioration of the wiring 3d can be effectively prevented.

The vehicle shock absorber D1 converts vibration energy input from the outside into thermal energy while the vehicle is running to attenuate the vibration, so that heat is generated during expansion and contraction and the temperature of the internal hydraulic oil (liquid) rises. Rise. Further, the temperature of the hydraulic oil (liquid) in the vehicle shock absorber D1 also changes due to the influence of the temperature of the atmosphere surrounding the vehicle shock absorber D1. Since the volume of the hydraulic oil (liquid) changes when the temperature changes, the amount of hydraulic oil (liquid) that enters and exits the liquid chamber L of the reservoir 2 when the rod 12 strokes the cylinder 10 by a certain amount also operates. It changes according to the temperature of the oil (liquid). Therefore, if the coefficient of thermal expansion of the hydraulic oil (liquid) used for the vehicle shock absorber D1 is grasped in advance and the temperature of the hydraulic oil (liquid) is detected, the volume change due to the temperature change is corrected for the vehicle. The stroke displacement of the shock absorber D1 can be detected more accurately. Specifically, for example, as shown by the broken line in FIG. 1, a temperature sensor TS for detecting the temperature of the hydraulic oil (liquid) in the reservoir 2 or the cylinder 10 is provided in the vehicle shock absorber D1 and serves as a reference. The temperature is set and the difference between the reference temperature and the temperature detected by the temperature sensor TS is obtained. The amount of hydraulic oil (liquid) in the reservoir 2 can be grasped by multiplying the area of the free piston 14 facing the liquid chamber L by the current position of the free piston 14. Assuming that the coefficient of thermal expansion is β, the difference is t, the amount of hydraulic oil (liquid) in the reservoir 2 is V, and the amount of hydraulic oil (liquid) in the reservoir 2 at the reference temperature is V ₀ , V ₀ = It becomes V / (1 + β · t). Further, since the total amount of hydraulic oil (total amount of liquid) in the initial cylinder 10 and the liquid chamber L of the reservoir 2 is known, the temperature of the hydraulic oil (liquid) in the cylinder 10 and the hydraulic oil in the reservoir 2 (the total amount of liquid) are known. Assuming that the temperature of the liquid) is equal, if V ₀ is subtracted from the total hydraulic oil amount (total liquid amount), the hydraulic oil (liquid) amount in the cylinder 10 at the reference temperature can be grasped. By subtracting the execution volume in the cylinder 10 from the amount of hydraulic oil (liquid) in the cylinder 10, how much the rod 12 actually penetrates into the cylinder 10, that is, the actual stroke displacement of the vehicle shock absorber D1. Can be detected. Therefore, if the temperature sensor TS is provided on the vehicle shock absorber D1 to detect the temperature of the hydraulic oil (liquid), the stroke displacement of the vehicle shock absorber D1 can be detected more accurately regardless of the temperature change. In this way, if the temperature of the hydraulic oil (liquid) is detected by the temperature sensor TS and the stroke displacement is corrected, an accurate stroke displacement can be obtained in response to the temperature change of the hydraulic oil (liquid). The stroke displacement correction by the temperature sensor TS may be performed by the above-mentioned external device that captures the signal of the stroke sensor 3, or the signal of the temperature sensor TS is input to the sensor body 3a of the stroke sensor 3 and the sensor body 3a is used. The correction process may be performed with. Further, although it is desirable that the temperature sensor TS detects the temperature in the cylinder 10 or the liquid chamber L, the temperature sensor TS may detect the temperature of the hydraulic oil (liquid) in the liquid storage chamber R3. It should be noted that the installation of the temperature sensor TS is not essential because the stroke displacement of the vehicle shock absorber D1 can be detected with a certain degree of accuracy without providing the temperature sensor TS.

Next, another front fork F2 paired with the front fork F1 already described in detail in the suspension device S will be described. As shown in FIG. 3, the front fork F2 is provided with a damping force variable shock absorber D2 equipped with a damping force adjusting valve DV instead of the stroke sensor 3 in the configuration of the vehicle shock absorber D1 and the reservoir 38. Is different. Therefore, the same components as those of the front fork F1 already described in the description of the other front forks F2 are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, the other front fork F2 includes a cap 30, a tubular guide rod 31, a valve holding member 32 screwed to the outer periphery of the lower middle end of FIG. 3, which is the tip of the guide rod 31, and a valve. The reservoir 38 is provided with a valve case 23, a base valve 24, a check valve 25, and a free piston 14 held by the holding member 32.

Then, the damping force adjusting valve DV is attached to the needle valve 33, which can be moved in the axial direction to the annular valve seat 32d provided in the valve holding member 32, and the cap 30 to move in the axial direction by the rotation operation with respect to the cap 30. It is configured to include a possible adjuster 34 and a control rod 35 that transmits the axial displacement of the adjuster 34 to the needle valve 33.

The cap 30 includes an accommodating portion 30a that rotatably accommodates the adjuster 34 in the axial center portion and has a screw groove on the inner circumference, and a socket 30b in which the upper end of the guide rod 31 is screwed at the lower end in FIG. There is. Further, the accommodating portion 30a is communicated with the socket 30b. The adjuster 34 is screwed into the screw groove of the accommodating portion 30a and accommodated in the accommodating portion 30a, and can move in the axial direction with respect to the cap 30 when rotated by an operation from the outside.

Further, the tip of the adjuster 34 is in contact with the control rod 35 inserted in the guide rod 31. The valve holding member 32 is connected to an annular connecting portion 32a which is cylindrical and is screwed to the outer periphery of the lower end in FIG. 3 of the guide rod 31, and a tubular valve holding shaft 32b extending downward from the connecting portion 32a. It includes a port 32c that opens from the outer periphery of the portion 32a and leads into the valve holding shaft 32b, and an annular valve seat 32d provided in the valve holding shaft 32b.

The valve holding member 32 includes a valve case 23 fitted to the outer periphery of the valve holding shaft 32b, a base valve 24, and a check valve 25 with a nut 27 screwed to the outer periphery of the lower end of the valve holding shaft 32b and a connecting portion 32a. It is held by sandwiching it with. Since the tip of the valve holding shaft 32b in the valve holding member 32 faces the compression side chamber R2 and the port 32c faces the liquid chamber L, the valve holding member 32 has a discharge port 23a in the valve holding shaft 32b and in the port 32c. A bypass path is formed by detouring and communicating the compression side chamber R2 and the liquid chamber L.

Further, the needle valve 33 is provided with a needle at the tip and is inserted into the guide rod 31 so as to be movable in the axial direction, and the needle at the tip is projected into the valve holding shaft 32b of the valve holding member 32. Then, the needle valve 33 shuts off the bypass path when the needle at the tip is brought into contact with the annular valve seat 32d, and opens the bypass path when the needle is separated from the annular valve seat 32d. Further, the needle valve 33 can change the size of the flow path area of the bypass path by moving the needle away from the annular valve seat 32d and moving it closer to the annular valve seat 32d.

Since the pressure of the compression side chamber R2 acts on the needle at the tip of the needle valve 33, the needle valve 33 is urged by the pressure and is pressed so as to always abut on the other end of the control rod 35. Therefore, when the operator rotates and the adjuster 34 moves in the axial direction with respect to the cap 30, the needle valve 33 is also displaced in the axial direction through the control rod 35, the bypass path is opened and closed, and the flow path area is changed.

In the damping force variable shock absorber D2 configured in this way, the flow rate of the hydraulic oil passing through the discharge port 23a during the contraction operation in which the rod 12 invades the cylinder 10 can be adjusted by changing the flow path area of the bypass path. , The damping force at the time of contraction can be adjusted.

The front fork F2 incorporating the damping force variable shock absorber D2 capable of adjusting the damping force during contraction and the front fork F1 incorporating the stroke sensor 3 but not having the damping force adjusting function during contraction are The suspension device S is configured in pairs.

More specifically, the suspension device S includes an outer tube 4 and an inner tube 5 inserted into the outer tube 4 so as to be movable in the axial direction, and includes a body B and a front wheel W of a saddle-type vehicle (vehicle) V. A pair of telescopic bodies T1 and T2 interposed between them, a vehicle shock absorber D1 that is housed inside one of the stretchable bodies T1 and T2 and expands and contracts as the one stretchable body T1 expands and contracts, and expands and contracts. A variable damping force buffer that is housed inside the other of the bodies T1 and T2 and expands and contracts as the other expansion and contraction body T2 expands and contracts to generate a damping force, and at least the damping force at the time of contraction can be adjusted. A device D2 is provided, and the damping force of each of the stretchable bodies T1 and T2 at the time of contraction can be adjusted only by the variable damping force shock absorber D2. According to the suspension device configured in this way, it is possible to adjust the damping force at the time of contraction by the other damping force variable shock absorber D2 while detecting the stroke displacement by the one vehicle shock absorber D1. Since the damping force at the time can be adjusted only with the damping force variable shock absorber D2, it is not necessary to install a damping force adjusting valve for adjusting the damping force at the time of contraction in the vehicle shock absorber D1 incorporating the stroke sensor 3. .. Therefore, according to the suspension device S configured in this way, the structure is not complicated even if the stroke sensor 3 is installed, and the damping force on the contraction side can be adjusted while detecting the stroke displacement. Further, since the stroke sensor 3 is incorporated in the reservoir 2 of the vehicle shock absorber D1, the suspension device S can protect the stroke sensor 3 and reduce the cost as in the vehicle shock absorber D1.

In order to enable the stroke displacement of the vehicle shock absorber D3 and the damping force on the contraction side to be adjusted with one front fork F3, for example, the reservoir 38 portion of the damping force variable shock absorber D2 shown in FIG. The configuration may be changed as in the vehicle shock absorber D3 of the second embodiment shown in FIG. Specifically, in the vehicle shock absorber D3 of the second embodiment, the adjuster 36 screwed to the cap 30 and the control rod 37 inserted into the guide rod 31 are formed into a tubular shape, and the probe of the stroke sensor 3 is formed. 3b is inserted into the adjuster 36 and the control rod 37, a magnet 3c as a detector is attached to the spring receiver 29, and the wiring 3e extending from the probe 3b is pulled out of the vehicle shock absorber D3 to be a vehicle shock absorber. It is connected to a sensor body (not shown) installed outside D3. The configuration of the other vehicle shock absorber D3 is the same as that of the damping force variable shock absorber D2.

In the vehicle shock absorber D3 configured in this way, when the operator rotates the adjuster 36 with respect to the cap 30 to move it in the axial direction, the needle valve 33 moves closer to the annular valve seat 32d and the bypass path is reached. It is possible to open and close and change the flow path area. Further, the guide rod 31 and the control rod 37 are non-magnetic materials in the case of the vehicle shock absorber D3, and the position of the magnet 3c can be detected by the probe 3b.

As described above, if the vehicle shock absorber D3 configured in this way is used, although the structure is complicated, it is possible to detect the stroke displacement and adjust the damping force on the contraction side with one front fork F3.

Finally, the vehicle shock absorber D4 according to the third embodiment of the present invention will be described. As shown in FIG. 6, the vehicle shock absorber D4 includes a shock absorber main body 40, a reservoir 41 arranged in parallel with the shock absorber main body 40, and a stroke sensor 42.

As shown in FIG. 6, the shock absorber main body 40 is inserted into the cylinder 43 so as to be movable in the axial direction, and the inside of the cylinder 43 is filled with hydraulic oil as a liquid, and the extension side chamber R4 and the compression side chamber. It includes a piston 44 divided into R5 and a rod 45 having one end connected to the piston 44 and inserted into the cylinder 43 so as to be movable in the axial direction.

The cylinder 43 is a cylinder whose upper end is closed in FIG. 6, and can be connected to the vehicle body of a saddle-mounted vehicle (not shown) via an eye-shaped bracket 43a provided at the upper end. Further, on the inner circumference of the lower end of the cylinder 43, a rod guide 46 that pivotally supports the rod 45 and guides the movement of the rod 45 with respect to the cylinder 43 in the axial direction is provided together with the seal member 47. On the other hand, the rod 45 can be connected to the rear wheel of a saddle-type vehicle (not shown) via an eye-shaped bracket 45a provided at the lower end of FIG.

The piston 44 has an extension side port 44a and a compression side port 44b that communicate the extension side chamber R4 and the compression side chamber R5, and a resistance to the flow of hydraulic oil from the extension side chamber R4 to the compression side chamber R5 provided in the extension side port 44a. It is provided with an extension side damping valve 44c and a compression side damping valve 44d provided in the compression side port 44b to resist the flow of hydraulic oil from the compression side chamber R5 to the extension side chamber R4. The rod 45 is provided with a passage for communicating the extension side chamber R4 and the compression side chamber R5 by bypassing the extension side port 44a and the compression side port 44b, and a needle valve or the like capable of changing the flow path area of the passage is provided in the passage. It may be provided so that the damping force of the vehicle shock absorber D4 can be adjusted.

A connecting portion 43b for connecting the reservoir 41 is provided on the side portion of the upper end of the cylinder 43. On the other hand, the reservoir 41 is formed of a reservoir cylinder 48 in which the upper end in FIG. 6 is held by the connecting portion 43b, a cap 49 for closing the lower end in the middle of FIG. 6 of the reservoir cylinder 48, and a non-magnetic material having one end attached to the cap 49. The tubular rod 50 is slidably mounted on the outer periphery of the tubular rod 50, and is slidably contacted with the inner circumference of the reservoir cylinder 48 to form the inside of the reservoir cylinder 48 into the liquid chamber L1 and the air chamber G1. An annular free piston 51 for partitioning and a gas spring (not shown) for urging the free piston 51 in a direction of compressing the liquid chamber L1 by the elastic force of the gas in the air chamber G1 are provided.

The upper liquid chamber L1 in FIG. 6 in the reservoir cylinder 48 is communicated with the compression side chamber R5 in the cylinder 43 by the discharge port 43c and the suction port 43d provided in the connecting portion 43b of the cylinder 43. Further, the discharge port 43c is provided with a base valve 43e that allows only the flow of hydraulic oil from the compression side chamber R5 to the liquid chamber L1 and provides resistance to the flow of hydraulic oil. Further, the suction port 43d is provided with a check valve 43f that allows only the flow of hydraulic oil from the liquid chamber L1 to the compression side chamber R5. As described above, the connecting portion 43b in the cylinder 43 functions as a valve case.

Further, the stroke sensor 42 includes a sensor body 42a held by the cap 49, a rod-shaped probe 42b extended from the sensor body 42a and inserted into the tubular rod 50 connected to the cap 49, and a free piston 51. It is provided with a magnet 42c as an annular object to be detected, which is mounted on the cylinder rod 50 and arranged on the outer periphery of the tubular rod 50. Therefore, the stroke sensor 42 can detect the current position of the free piston 51 with respect to the reservoir cylinder 48 in the axial direction. The signal output by the stroke sensor 42 is input to the external device (not shown) via the wiring 42d extending from the sensor body 42a and being drawn out of the reservoir 41.

When the shock absorber body 40 in the vehicle shock absorber D4 configured in this way is extended, the piston 44 moves downward in FIG. 6 in the cylinder 43, so that the hydraulic oil in the extension side chamber R4 to be compressed is expanded. It passes through the side port 44a and the extension side damping valve 44c and moves to the compression side chamber R5. Then, since the extension side damping valve 44c gives resistance to the flow of hydraulic oil passing through the extension side port 44a, the pressure of the extension side chamber R4 becomes higher than the pressure of the compression side chamber R5, and the vehicle shock absorber D4 owns the extension. Demonstrate the extension side damping force that hinders.

When the shock absorber D4 for a vehicle is extended, the rod 45 withdraws from the cylinder 43, and the hydraulic oil for the volume of the rod 45 withdrawing from the cylinder 43 is insufficient in the compression side chamber R5 in the cylinder 43. Since the hydraulic oil is insufficient in the compression side chamber R5 as described above, the pressure in the compression side chamber R5 drops below the pressure in the reservoir 41, and the check valve 43f bends to open the suction port 43d. Therefore, the hydraulic oil deficient in the compression side chamber R5 is supplied from the liquid chamber L1 of the reservoir 41 to the compression side chamber R5 through the suction port 43d. In the reservoir 41, the free piston 51 moves upward to shrink the liquid chamber L1 and expand the air chamber G1 because the hydraulic oil moves from the liquid chamber L1 to the compression side chamber R5, and the rod 45 exits from the cylinder 43. Compensation for the volume to be made is made.

Further, when the shock absorber body 40 in the vehicle shock absorber D4 contracts, the piston 44 moves upward in FIG. 6 in the cylinder 43, so that the hydraulic oil in the compressed side chamber R5 is compressed to the compression side port 44b and the compression side. It passes through the damping valve 44d and moves to the extension side chamber R4. The compression side damping valve 44d resists the flow of hydraulic oil through the compression side port 44b, causing a difference between the pressure in the compression side chamber R5 and the pressure in the extension side chamber R4.

When the shock absorber D4 for a vehicle contracts, the rod 45 invades the cylinder 43, and the hydraulic oil for the volume of the rod 45 invading the cylinder 43 becomes excessive in the cylinder 43. The excess hydraulic oil in the cylinder 43 in this way pushes open the base valve 43e, passes through the discharge port 43c, and moves to the liquid chamber L1 of the reservoir 41. The base valve 43e resists the flow of hydraulic oil through the discharge port 43c, thus increasing the overall pressure in the cylinder 43. Therefore, the vehicle shock absorber D4 exerts a compression side damping force that hinders its own contraction by the compression side damping valve 44d and the base valve 43e. In the reservoir 41, the hydraulic oil is discharged from the cylinder 43 into the liquid chamber L1, so that the free piston 51 retracts upward to expand the liquid chamber L1 and shrink the air chamber G1, and the rod 45 causes the cylinder 43. Compensation for the volume that penetrates inside is made.

Even in the vehicle shock absorber D4 of the present embodiment, the current position of the free piston 51 can be detected by the stroke sensor 42, so that the stroke displacement of the vehicle shock absorber D4 can be detected.

Since the reservoir cylinder 48 is arranged sideways with respect to the cylinder 43 in the shock absorber main body 40 and is a separate body of the vehicle shock absorber D4 configured in this way, the stroke sensor 42 housed in the reservoir 41 is accommodated. Since the wiring 42d can be arranged at a position away from the road surface, the wiring 42d can be protected from flying objects.

Further, in the vehicle shock absorber D4 configured in this way, since the stroke sensor 3 is housed in the reservoir 41 and the displacement of the free piston 51 is detected, the stroke sensor 3 does not have to be long, so that it is manufactured. The cost can be reduced.

Further, according to the vehicle shock absorber D4, since the reservoir cylinder 48 is separate from the cylinder 43, even if a bending moment acts on the shock absorber main body 40, the bending moment is hardly loaded on the reservoir 41. Therefore, according to the vehicle shock absorber D4, the stroke sensor 42 can be more effectively protected because the structure is such that the bending moment does not act on the stroke sensor 42.

From the above, according to the vehicle shock absorber D4 of the present embodiment, the stroke sensor 42 can be protected and the cost can be reduced. Although the reservoir cylinder 48 is arranged in parallel with the cylinder 43 in the figure, it may be arranged laterally in a posture other than parallel to the cylinder 43. Therefore, the reservoir cylinder 48 may be arranged so as to have an axis on a plane orthogonal to the axis of the cylinder 43, for example. Further, the vehicle shock absorber D4 has a bypass path and a bypass path that communicate the compression side chamber R5 and the liquid chamber L1 by bypassing the discharge port 43c and the suction port 43d in order to enable adjustment of the damping force on the contraction side. May be provided with a variable damping valve such as a needle valve that can change the flow path area of the bypass path.

Although the preferred embodiments of the present invention have been described in detail above, they can be modified, modified and modified as long as they do not deviate from the claims.

This application claims priority based on Japanese Patent Application No. 2020-210919 filed with the Japan Patent Office on December 21, 2020, and the entire contents of this application are incorporated herein by reference.

Claims

It ’s a shock absorber for vehicles.
A cylinder that can be connected to the vehicle body side of the vehicle, a piston that is movably inserted into the cylinder and is divided into an extension side chamber and a compression side chamber in which the inside of the cylinder is filled with liquid, and one end of the piston. A shock absorber body having a rod connected to the cylinder and movably inserted into the cylinder and having a rod whose other end can be connected to the wheel side of the vehicle.
A reservoir having a reservoir cylinder and a free piston that is axially movably inserted into the reservoir cylinder and divides the inside of the reservoir cylinder into an air chamber and a liquid chamber that communicates with the compression side chamber.
It is equipped with a stroke sensor that detects the stroke displacement of the shock absorber body.
The stroke sensor is for a vehicle having a detector connected to the free piston and a probe having one end connected to the reservoir cylinder and housed in the reservoir cylinder to detect the position of the detector. Shock absorber.
The vehicle shock absorber according to claim 1.
The reservoir is
A cap that closes one end of the reservoir cylinder and
It has a tubular rod formed of a non-magnetic material, one end of which is connected to the cap and housed in the reservoir cylinder.
The free piston is annular and is slidably mounted on the outer circumference of the tubular rod and slidably contacts the inner circumference of the reservoir cylinder.
The probe is a vehicle shock absorber housed in the tubular rod.
The vehicle shock absorber according to claim 2.
A valve case that is connected to the other end side of the tubular rod and has a discharge port and a suction port that separate the liquid chamber from the compression side chamber and communicate the compression side chamber and the liquid chamber with each other.
A base valve that opens and closes the discharge port, allows only the flow of the liquid that passes through the discharge port from the compression side chamber toward the liquid chamber, and provides resistance to the flow of the liquid.
A vehicle shock absorber provided with a check valve that opens and closes the suction port and allows only the flow of the liquid from the liquid chamber to the compression side chamber.
The vehicle shock absorber according to claim 1.
A coil spring that urges the free piston toward the liquid chamber side,
An annular spring receiver interposed between the free piston and the coil spring is provided.
The spring receiver has a tubular portion arranged on the inner circumference of the coil spring and a flange provided at one end of the tubular portion to support one end of the coil spring.
The detector is a vehicle shock absorber mounted on the inner circumference of the cylinder portion of the spring receiver.
The vehicle shock absorber according to claim 1.
The reservoir cylinder is a vehicle shock absorber connected to the vehicle body side end of the cylinder.
The vehicle shock absorber according to claim 1.
The reservoir cylinder is a vehicle shock absorber arranged on the side of the cylinder.
The vehicle shock absorber according to claim 1.
A vehicle shock absorber provided with a temperature sensor that detects the temperature of the liquid.
It ’s a suspension device,
A pair of telescopic bodies interposed between the vehicle body and the front wheels, including an outer tube and an inner tube that is axially movable and inserted into the outer tube.
The vehicle shock absorber according to claim 1, 2, 3, 4, 5 or 7, which is housed inside one of the stretchable bodies and expands and contracts with the expansion and contraction of the one stretchable body.
The damping force is variable, which is housed inside the other of the stretchable bodies and expands and contracts as the other stretchable body expands and contracts to generate a damping force, and at least the damping force at the time of contraction can be adjusted. Equipped with a shock absorber,
A suspension device capable of adjusting the damping force of each stretchable body at the time of contraction only by the variable damping force shock absorber.