WO2020179681A1

WO2020179681A1 - Damper

Info

Publication number: WO2020179681A1
Application number: PCT/JP2020/008377
Authority: WO
Inventors: 隆久望月; 壮大島内; 宏一郎粟野
Original assignee: Ｋｙｂ株式会社
Priority date: 2019-03-04
Filing date: 2020-02-28
Publication date: 2020-09-10
Also published as: JP7051738B2; JP2020143681A

Abstract

This damper (D1, D2) is provided with: a telescopic tube member (T); a cylinder (1) that is coupled to an outer tube (10) or an inner tube (11); a piston that is inserted into the cylinder (1); a piston rod (3) that is coupled to the piston (2) and coupled to the outer tube (10) or the inner tube (11); a damper main body (S) that has a ring-shaped rod guide (14) that guides the movement of the piston rod; and a stroke sensor (42) that senses stroke displacement of the damper main body (S). The damper is provided with: a pipe member (17) that is mounted on the rod guide (14) and to which a sensed piece (42b) is attached; or a coupling pipe that accommodates the sensor main body and couples a cap (12, 12') and the piston rod (3).

Description

Buffer

The present invention relates to an improvement of a shock absorber.

The shock absorber is interposed between the outer tube and the inner tube, and a telescopic tube member having the outer tube and the inner tube slidably inserted into the outer tube. 2. Description of the Related Art There is a structure including a shock absorber body that generates a damping force when expanding and contracting, and is interposed between a vehicle body and a front wheel of a saddle type vehicle.

In such a shock absorber, a stroke sensor may be provided to detect the position of the piston rod with respect to the cylinder. The stroke sensor includes an annular magnet, a probe for detecting the position of the magnet, and a sensor body that holds the probe, and is incorporated into the shock absorber as follows. Specifically, the magnet is attached to the inner circumference of the rod guide that closes the open end of the cylinder and guides the movement of the piston rod, the probe is housed in the piston rod, and the sensor body is the upper end of the outer tube. It is housed in a cap that closes the open end. In the shock absorber thus configured, when the piston rod is relatively displaced in the axial direction with respect to the cylinder, the probe is also relatively moved with respect to the magnet. Therefore, the stroke displacement of the shock absorber can be detected by the stroke sensor ( For example, see Patent Document 1).

JP2016-161048A

When the shock absorber is applied to a saddle-mounted vehicle, the shock absorber tends to have a very long overall length, and the piston rod also becomes very long. The piston rod is connected to the outer tube via the cap and plays a role of connecting the shock absorber body to the outer tube, and thus is much longer than the stroke length of the shock absorber body.

On the other hand, in the stroke sensor, the sensor body is fixed to the cap and the probe is housed in the piston rod. Therefore, when the total length of the piston rod becomes long, the probe length becomes insufficient and the stroke displacement of the shock absorber can be detected. It may disappear.

Therefore, an object of the present invention is to provide a shock absorber capable of detecting stroke displacement even if the total length is long.

In order to solve the above problems, the shock absorber in the problem solving means is provided on one of a telescopic type tube member having an outer tube and an inner tube slidably inserted into the outer tube, and one of the outer tube and the inner tube. A cylinder to be connected, a piston that is movably inserted into the cylinder and divides the inside of the cylinder into an extension side chamber and a compression side chamber, and one end is connected to the piston and the other end is an outer tube and an inner tube. A shock absorber body housed in the tube member having a piston rod connected to the other end and an annular rod guide provided at the end of the cylinder for guiding the movement of the piston rod, and a shock absorber body. The stroke sensor includes a stroke sensor that detects the stroke displacement of the above, and the stroke sensor includes a detector connected to a cylinder, a rod-shaped probe housed in a piston rod to detect the position of the detector, and the probe. It has a sensor body to hold, and the detector is arranged on the outer periphery of the piston rod, and one end thereof is attached to the other end of a pipe member mounted on the anti-cylinder side of the rod guide.

According to the shock absorber thus configured, the detected element is arranged on the outer circumference of the piston rod, and one end thereof is attached to the other end of the pipe member mounted on the side opposite to the cylinder of the rod guide. The axial position of the child can be positioned at any position by the pipe member.

Further, the shock absorber in another problem-solving means is connected to one of the outer tube and the inner tube by a telescopic type tube member having an outer tube and an inner tube slidably inserted into the outer tube. A cylinder, a piston that is movably inserted into the cylinder to partition the inside of the cylinder into an extension chamber and a compression side chamber, and one end connected to the piston and the other end connected to the other of the outer tube and inner tube. And a shock absorber body accommodated in the tube member having an annular rod guide provided at the end of the cylinder for guiding the movement of the piston rod, and stroke displacement of the shock absorber body is detected. The stroke sensor includes a detection target connected to the cylinder, a rod-shaped probe that is housed in the piston rod to detect the position of the detection target, and a sensor main body that holds the probe. The detector is mounted on the inner circumference of the rod guide, and the sensor body is inside the connecting pipe that connects the cap and the piston rod that close the other opening of the outer tube and the inner tube. It is characterized by being contained.

In the shock absorber thus configured, the sensor main body is housed in the connecting pipe that connects the piston rod to the cap, and the axial position of the sensor main body can be positioned at any position by the connecting pipe. There is no need to make the length longer.

Also, the shock absorber may be attached to the outer circumference of the piston rod and may also include a cushion rubber, and the cushion rubber and the pipe member may collide with each other when the shock absorber main body is contracted most to regulate the contraction of the shock absorber main body. According to the shock absorber thus configured, by providing the pipe member, not only the axial position of the detected element is positioned, but also the cushion function is provided in cooperation with the cushion rubber to reduce the impact at the time of the most contraction. Can be demonstrated.

Further, the shock absorber may be provided with a coil spring which is arranged on the outer circumference of the connecting pipe and is interposed between the rod guide and the cap. In the shock absorber thus configured, since the connecting pipe that accommodates the sensor body can be arranged on the inner circumference of the coil spring, the sensor body can be installed at an arbitrary position within the coil spring and is less likely to be restricted by the probe length. At the same time, there is less restriction on the total length of the coil spring, and the degree of freedom in design is improved.

The shock absorber also includes a solenoid valve in the piston rod that adjusts the damping force generated by the shock absorber body, and the solenoid lead wire and probe of the solenoid valve may be housed in the piston rod. According to the shock absorber thus configured, since the probe of the stroke sensor and the lead wire are housed in the piston rod, it is possible to adjust the damping force using the solenoid valve and also detect the stroke of the shock absorber. It will be possible.

According to the shock absorber according to the present invention, the stroke displacement can be detected even if the total length is long.

FIG. 1 is a vertical sectional view of a shock absorber which is a shock absorber according to a first embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing a part of FIG. 1 in an enlarged manner. FIG. 3 is a damping force characteristic diagram showing characteristics of the compression side damping force with respect to the piston speed of the shock absorber which is the shock absorber according to the embodiment of the present invention. FIG. 4 is a vertical cross-sectional view of a shock absorber which is a shock absorber according to a second embodiment of the present invention.

The buffers D1 and D2 according to the embodiment of the present invention will be described below with reference to the drawings. The same reference numerals allotted throughout the several figures refer to the same or corresponding parts. Further, the shock absorbers D1 and D2 according to the embodiment of the present invention are used for a front fork that suspends the front wheels of a saddle-mounted vehicle. In the following description, the upper and lower sides with the front fork including the shock absorber D attached to the vehicle are simply referred to as “upper” and “lower” unless otherwise specified.

<First embodiment>
The shock absorber D1 of the first embodiment is connected to the inner tube 11 and a telescopic type tube member T having an outer tube 10 and an inner tube 11 slidably inserted into the outer tube 10. The cylinder 1 and the piston 2 which is movably inserted into the cylinder 1 to divide the inside of the cylinder 1 into an extension side chamber La and a compression side chamber Lb, one end is connected to the piston 2 and the other end is an outer tube. A shock absorber main body S having a piston rod 3 connected to 10 and an annular rod guide 14 provided at the end of the cylinder 1 to guide the movement of the piston rod 3 and housed in the tube member T. A stroke sensor 42 for detecting the stroke displacement of the shock absorber main body S is provided.

Then, as shown in FIG. 1, in the present embodiment, the shock absorber D1 is a one-sided shock absorber that exerts a damping force only when contracted, and the solenoid valve V is used to reduce the pressure side damping force of the shock absorber D1. It can be adjusted. Although not shown, the shock absorber D1 is connected to a one-sided shock absorber that exerts a damping force only when extended by a bracket connected to the steering shaft of the saddle type vehicle. Therefore, the shock absorber D and the shock absorber that exerts a damping force only when extended form a pair to form a front fork that supports the front wheels of the saddle-ride type vehicle, and cooperate to vibrate the vehicle body of the saddle-ride type vehicle. Suppress.

First, the shock absorber D1 according to the first embodiment of the present invention will be specifically described. As shown in FIG. 2, the shock absorber D1 includes a telescopic tube member T including an outer tube 10 and an inner tube 11 slidably inserted into the outer tube 10.

Then, when the front wheels vibrate up and down, such as when the saddle riding type vehicle travels on an uneven road surface, the inner tube 11 moves in and out of the outer tube 10, and the tube member T expands and contracts. Expansion and contraction of the tube member T is also referred to as expansion and contraction of the shock absorber D1. The tube member T may be an upright type, the outer tube 10 may be an axle side tube, and the inner tube 11 may be a vehicle body side tube.

Subsequently, the upper end of the outer tube 10 which is the upper end of the tube member T is closed by the cap 12. On the other hand, the lower end of the inner tube 11 which is the lower end of the tube member T is closed by the bracket B on the axle side. Further, the cylindrical gap formed between the overlapping portion of the outer tube 10 and the inner tube 11 is closed by an annular seal member 13 that is attached to the lower end of the outer tube 10 and is in sliding contact with the outer circumference of the inner tube 11. ..

In this way, the inside of the tube member T is a closed space, and the shock absorber main body S is accommodated in the tube member T. The shock absorber body S has a cylinder 1 provided in an inner tube 11, a piston 2 slidably inserted in the cylinder 1, a lower end connected to the piston 2, and an upper end outside the cylinder 1. It has a piston rod 3 that protrudes and is connected to the cap 12. The piston rod 3 in the shock absorber body S is connected to the outer tube 10 via a cap 12 that closes the upper end of the outer tube 10 in FIG. 1, and the cylinder 1 is connected to the inner tube 11. Although the piston rod 3 is connected to the outer tube 10 and the cylinder 1 is connected to the inner tube 11, the tube member T is turned upside down from the state shown in FIG. 1 and the piston rod 3 is connected to the inner tube 11. The cylinder 1 may be connected to the outer tube 10 and the shock absorber body S may be housed in the tube member T.

Since the cap 12 is connected to the outer tube 10, the piston rod 3 is connected to the outer tube 10 and the cylinder 1 is connected to the inner tube 11. In this way, the shock absorber body S is interposed between the outer tube 10 and the inner tube 11. The cap 12 has a tubular shape and includes a sensor housing portion 12a screwed to the inner circumference of the outer tube 10 and a small-diameter piston rod connecting portion 12b extending from the lower end of the sensor housing portion 12a. The sensor body 42a of the stroke sensor 42 is housed in the sensor housing portion 12a. The piston rod 3 is inserted into the piston rod connecting portion 12b of the cap 12, screwed, and connected to the cap 12.

Further, an annular rod guide 14 is mounted on the upper end of the cylinder 1, and a piston rod 3 is slidably inserted inside the rod guide 14 in the axial direction. The rod guide 14 includes an annular main body 14a screwed to the inner circumference of the cylinder 1, and a socket 14b protruding from the main body 14a to the side opposite to the cylinder and having an outer diameter smaller than the outer diameter of the main body 14a. It closes the upper end opening of the cylinder 1 in FIG. 1 and guides the movement of the piston rod 3 in the axial direction.

A pipe member 17 through which the piston rod 3 is inserted is provided on the outer periphery of the socket 14b of the rod guide 14. The pipe member 17 includes a pipe 18 that is screwed onto the outer circumference of the socket 14b, and a cylindrical holder 19 that is mounted on the opposite cylinder side of the pipe 18. The holder 19 has a cylindrical shape and the outer circumference. In addition, a mounting cylinder portion 19a provided with a screw screwed to the inner circumference of the end of the pipe 18 on the side opposite to the cylinder, and a magnet 42b provided on the side opposite to the cylinder of the mounting cylinder portion 19a and serving as a detected element of the stroke sensor 42 are provided. It includes a holding cylinder portion 19b for holding and an annular cushion sheet member 19c attached to the opposite end of the holding cylinder portion 19b on the opposite side of the cylinder. The axial length of the pipe 18 is set so that the position of the magnet 42b can be positioned at an appropriate position. The magnet 42b is annular and has an inner circumference facing the outer circumference of the piston rod 3.

Further, a suspension spring 15 made of a coil spring is interposed between the rod guide 14 and the cap 12. Specifically, the upper end of the suspension spring 15 is supported by a spring receiver 23 fitted on the outer circumference of the piston rod connecting portion 12b of the cap 12. A cylindrical stopper 24 is mounted between the inner circumference of the spring receiver 23 and the outer circumference of the upper end of the piston rod 3, and an annular cushion rubber 25 mounted on the outer circumference of the piston rod 3 is used as the stopper 24. Is in contact with. The stopper 24 is in contact with the upper end of the cushion rubber 25 in FIG. 1, and restricts the movement of the cushion rubber 25 with respect to the piston rod 3 in FIG. 1 upward. On the other hand, a spring receiver 26 which is annular and has an inner diameter larger than that of the pipe 18 and supports the lower end of FIG. 1 of the suspension spring 15 is superposed on the outer periphery of the upper end of the main body portion 14a of FIG. There is. Therefore, the suspension spring 15 exerts an urging force that separates the outer tube 10 and the inner tube 11 to urge the shock absorber D1 in the extension direction.

When the shock absorber D1 expands and contracts and the inner tube 11 moves in and out of the outer tube 10, the piston rod 3 moves in and out of the cylinder 1 and the piston 2 moves up and down (axial direction) in the cylinder 1. When the shock absorber D1 contracts and the piston rod 3 enters the cylinder 1, the suspension spring 15 is compressed and exerts an elastic force to urge the shock absorber D in the extension direction. In this way, the suspension spring 15 exerts an elastic force according to the amount of compression to elastically support the vehicle body.

The shock absorber main body S of the present embodiment is a single rod type, and the piston rod 3 extends from one side of the piston 2 to the outside of the cylinder 1. However, the shock absorber main body S may be of the double rod type, and the piston rods may extend from both sides of the piston to the outside of the cylinder. Further, the piston rod 3 may project downward from the cylinder 1 and be connected to the axle side, and the cylinder 1 may be connected to the vehicle body side. The suspension spring 15 may be a spring other than a coil spring such as an air spring.

Subsequently, a liquid chamber L filled with a liquid such as hydraulic oil is formed in the cylinder 1, and this liquid chamber L is divided into an extension side chamber La and a compression side chamber Lb by a piston 2. The expansion side chamber here is the one of the two chambers partitioned by the piston that is compressed by the piston when the shock absorber extends. On the other hand, the pressure side chamber is one of the two chambers partitioned by the piston, which is compressed by the piston when the shock absorber contracts.

Further, outside the cylinder 1, more specifically, the space between the shock absorber main body S and the tube member T is a liquid reservoir R. In the liquid storage chamber R, the same liquid as the liquid in the cylinder 1 is stored, and a gas chamber G in which a gas such as air is sealed is formed above the liquid surface. As described above, the tube member T functions as an outer shell of the tank 16 for storing the liquid separately from the liquid in the cylinder 1.

The liquid reservoir chamber R inside the tank 16 is communicated with the expansion side chamber La, and the pressure of the expansion side chamber La is always substantially the same pressure (tank pressure) as the pressure in the tank 16 (liquid reservoir chamber R). Further, the liquid storage chamber R is separated from the compression side chamber Lb by a valve case 4 fixed to the lower end of the cylinder 1. The valve case 4 is provided with a suction passage 4a that communicates the pressure side chamber Lb and the liquid storage chamber R with a suction valve 40 that opens and closes the suction passage 4a.

The suction valve 40 is an extension-side check valve, which opens the suction passage 4a when the shock absorber D extends, and allows the liquid to flow from the liquid reservoir chamber R to the pressure-side chamber Lb through the suction passage 4a. When the shock absorber D contracts, the suction passage 4a is kept closed. Although the suction valve 40 of the present embodiment is a leaf valve, it may be a poppet valve or the like.

In addition, the piston 2 is formed with an expansion side passage 2a and a compression side passage 2b that communicate the expansion side chamber La and the compression side chamber Lb, and also includes an expansion side check valve 20 that opens and closes the expansion side passage 2a and a compression side passage 2b. A hard-side damping element 21 that provides resistance to the flow of liquid from the pressure-side chamber Lb toward the extension-side chamber La is mounted.

The hard-side damping element 21 is configured to have a leaf valve 21a stacked on the upper side of the piston 2 and an orifice 21b provided in parallel with the leaf valve 21a.

The leaf valve 21a is a thin annular plate formed of metal or the like, or a laminated body formed by stacking the annular plates, has elasticity, and is attached to the piston 2 in a state in which the outer peripheral side is allowed to bend. The pressure of the pressure side chamber Lb acts in a direction to bend the outer peripheral portion of the leaf valve 21a upward. Further, the orifice 21b is formed by a notch provided on the outer peripheral portion of the leaf valve 21a that is detached and seated on the valve seat (not indicated) of the piston 2R, but is formed by a stamp or the like provided on the valve seat. It may be formed.

The pressure side chamber Lb is compressed by the piston 2 when the shock absorber D contracts, and its internal pressure rises, and becomes higher than the pressure in the extension side chamber La. When the piston speed is in the low speed range when the shock absorber D contracts and the differential pressure between the compression side chamber Lb and the extension side chamber La is less than the valve opening pressure of the leaf valve 21a, the liquid passes through the orifice 21b. Resistance is given to the flow of the liquid while moving from the pressure side chamber Lb to the expansion side chamber La. Further, when the differential pressure becomes large and becomes equal to or higher than the valve opening pressure of the leaf valve 21a, the outer peripheral portion of the leaf valve 21a bends, and the liquid passes through the gap formed between the outer peripheral portion and the piston 2 to the pressure side chamber Lb. To the extension side chamber La, resistance is imparted to the liquid flow.

As described above, the hard side damping element 21 having the orifice 21b and the leaf valve 21a parallel to the orifice 21b is a liquid that goes from the compression side chamber Lb to the extension side chamber La when the shock absorber D contracts. Is the first damping element on the pressure side that provides resistance to the flow of. The resistance of the compression-side hard damping element 21 results from the orifice 21b when the piston speed is in the low speed range, and from the leaf valve 21a when the piston speed is in the medium to high speed range.

On the other hand, the extension-side check valve 20 opens the extension-side passage 2a when the shock absorber D extends, and allows the liquid to flow through the extension-side passage 2a from the expansion-side chamber La to the compression-side chamber Lb. When D contracts, the extension side passage 2a is maintained in a closed state. The extension side check valve 20 of the present embodiment is a leaf valve, but may be a poppet valve or the like. Furthermore, the extension-side passage 2a and the extension-side check valve 20 may be omitted as long as the liquid is not sufficiently sucked into the cylinder 1.

Next, the piston rod 3 is provided with a damping force adjusting unit for changing the flow rate of the liquid passing through the hard side damping element 21. The damping force adjusting unit includes a solenoid valve V that can change the flow path area provided in the middle of the bypass path 3a that bypasses the hard side damping element 21 and communicates the extension side chamber La and the compression side chamber Lb, and the bypass path. The soft side damping element 50 provided in series with the solenoid valve V is provided in the middle of 3a.

More specifically, as shown in FIG. 2, the piston rod 3 is connected to the piston holding member 30 located at the tip thereof, the solenoid case member 31 connected to the terminal side thereof, and further connected to the terminal side thereof to the outside of the cylinder 1. It has a tubular rod body 32 that extends and is connected to the cap 12. The piston holding member 30 includes a bottomed cylindrical housing portion 30a and a shaft portion 30b protruding downward from a bottom portion of the housing portion 30a. The annular piston 2 is provided on the outer periphery of the shaft portion 30b and has a hard side damping element. It is fixed with a nut N together with 21.

Also, a valve case 5 is fixed to the inner circumference of the cylindrical portion of the housing portion 30a to partition the inside into an upper chamber 30c and a lower chamber 30d. The valve case 5 is formed with a passage 5a that communicates the upper chamber 30c and the lower chamber 30d, and the soft side damping element 50 is provided in the passage 5a. Further, the shaft portion 30b of the piston holding member 30 is formed with a vertical hole 30e that opens downward and communicates with the inside of the housing portion 30a. The vertical hole 30e connects the lower chamber 30d and the pressure side chamber Lb. ..

Subsequently, the solenoid case member 31 includes a tubular portion 31a screwed onto the outer circumference of the upper end of the housing portion 30a. A lateral hole 31b that opens laterally is formed in the tubular portion 31a, and the extension side chamber La and the inside of the solenoid case member 31 are communicated with each other by the lateral hole 31b. A solenoid valve V is provided in the middle of the passage connecting the lateral hole 31b and the upper chamber 30c.

In the present embodiment, a bypass path having a lateral hole 31b, an upper chamber 30c, a lower chamber 30d, and a vertical hole 30e formed in the solenoid case member 31 or the piston holding member 30 and bypassing the hard side damping element 21. 3a is formed. The solenoid valve V and the soft side damping element 50 are provided in series in the middle of the bypass 3a.

Further, the outer diameters of the solenoid case member 31 and the piston holding member 30 accommodating the solenoid valve V and the hard side damping element 50 are smaller than the inner diameter of the cylinder 1, and consideration is given so that they do not partition the extension side chamber La. ..

The hard side damping element 50 is configured to have a leaf valve 50a laminated on the upper side of the valve case 5 and an orifice 50b provided in parallel with the leaf valve 50a.

The leaf valve 50a is a thin annular plate formed of metal or the like, or a laminated body in which the annular plates are stacked, has elasticity, and is attached to the valve case 5 in a state in which the outer peripheral side is allowed to bend. Then, the pressure of the lower chamber 30d acts in the direction of bending the outer peripheral portion of the leaf valve 50a upward. Further, the orifice 50b is formed by a notch provided on the outer peripheral portion of the leaf valve 50a which is seated on and off the valve seat of the valve case 5R, but may be formed by stamping or the like provided on the valve seat. Good.

The pressure in the lower chamber 30d becomes higher than the pressure in the upper chamber 30c when the shock absorber D is contracted and the solenoid valve V opens the bypass passage 3a. When the piston speed is in the low speed range when the shock absorber D contracts and the differential pressure between the upper chamber 30c and the lower chamber 30d is less than the opening pressure of the leaf valve 50a, the liquid passes through the orifice 50b. From the lower chamber 30d to the upper chamber 30c, that is, from the pressure side chamber Lb to the extension side chamber La, resistance is imparted to the flow of the liquid. When the differential pressure becomes larger than the valve opening pressure of the leaf valve 50a, the outer peripheral portion of the leaf valve 50a bends, and the liquid passes through the gap formed between the outer peripheral portion and the valve case 5 to form a lower chamber. From 30d to the upper chamber 30c, that is, from the pressure side chamber Lb to the extension side chamber La, resistance is given to the flow of the liquid.

As described above, the soft side damping element 50 having the orifice 50b and the leaf valve 50a parallel to the orifice 50b makes the compression side bypass path 3a from the compression side chamber Lb to the extension side chamber when the shock absorber D contracts. A second damping element on the pressure side that provides resistance to the flow of liquid towards La. The resistance of the soft-side damping element 50 results from the orifice 50b when the piston speed is in the low speed range, and from the leaf valve 50a when the piston speed is in the medium to high speed range.

Further, the leaf valve 50a of the soft side damping element 50 is a valve having a lower valve rigidity (easy to bend) as compared with the leaf valve 21a of the hard side damping element 21, and when the flow rate is the same, it gives to the flow of liquid. Resistance (pressure loss) is small. In other words, the liquid is more likely to pass through the leaf valve 50a than the leaf valve 21a under the same conditions. Further, the orifice 50b of the soft-side damping element 50 is a large-diameter orifice having a larger opening area than the orifice 21b of the hard-side damping element 21, and when the flow rates are the same, the resistance (pressure loss) given to the liquid flow is small.

Next, as shown in FIG. 2, the solenoid valve V includes a cylindrical holder 6 fixed in the piston rod 3, a cylindrical spool 7 reciprocatingly inserted in the holder 6, and a cylindrical spool 7. It includes an urging spring 8 that urges the spool 7 upward in FIG. 2, which is one of the moving directions, and a solenoid 9 that can apply thrust to the spool 7 in the other in the moving direction. Then, the solenoid valve V adjusts the position of the spool 7 in the holder 6 to adjust the opening degree.

More specifically, the holder 6 is located above the valve case 5 in the piston rod 3, one end in the axial direction to the upper side (the solenoid case member 31 side), and the other end to the lower side (the valve case 5 side). The piston rod 3 is arranged along the central axis of the piston rod 3 in the facing state. Further, the holder 6 is formed with one or more ports 6a penetrating in the radial direction. The port 6a communicates with the extension side chamber La through the lateral hole 31b of the solenoid case member 31, and is opened and closed by the spool 7.

The spool 7 is cylindrical and is slidably inserted into the holder 6 so that it can be reciprocated in the vertical direction in FIG. More specifically, the spool 7 includes a port 7a that can face the port 6a in correspondence with the port 6a, and moves in the vertical direction to open and close the port 6a provided in the holder 6. Specifically, in a state where the port 7a of the spool 7 faces the port 6a of the holder 6, the spool 7 communicates the port 6a into the spool 7. The port 6a communicates with the extension side chamber La through a lateral hole 31b provided in the solenoid case member 31. On the other hand, the inside of the spool 7 is communicated with the pressure side chamber Lb through the upper chamber 30c, the passage 5a provided in the valve case 5, the lower chamber 30d and the vertical hole 30e. Therefore, the solenoid valve V is provided in the middle of the bypass passage 3a, and when the port 6a communicates with the inside of the spool 7, the solenoid valve V is opened to open the bypass passage 3a, and the expansion side chamber La and the pressure side are opened through the bypass passage 3a. It communicates with the chamber Lb.

When the spool 7 moves with respect to the holder 6, the area where the port 6a faces the port 7a changes, so that the flow passage area can be changed according to the axial position of the spool 7 with respect to the holder 6. When the spool 7 moves downward in FIG. 2 with respect to the holder 6 and the port 6a does not completely face the port 7a and is blocked at the outer circumference of the spool 7, the communication between the port 6a and the inside of the spool 7 is cut off. The bypass path 3a is blocked.

A plate 70 is laminated on the upper end of the spool 7, and a plunger 9a of the solenoid 9 which will be described later is in contact with the plate 70. On the other hand, the biasing spring 8 contacts the lower end of the spool 7 and biases the spool 7 upward in FIG. 2, which is one of the moving directions. The biasing spring 8 is a spiral spring that exerts a biasing force that returns the inner periphery to its original position when the inner periphery is displaced in the vertical direction in FIG. 2 relative to the outer periphery. The urging spring 8 is sandwiched between a cylindrical collar 22 fitted to the inner periphery of the housing portion 30a of the piston holding member 30 and the lower end of the holder 6, and the piston rod has an outer periphery below the urging spring 8. It is fixed at 3. The inner circumference of the biasing spring 8 is fitted into an annular recess 7b provided on the outer circumference of the lower end of the spool 7 in FIG. 2, and the biasing spring 8 moves the spool 7 upward relative to the holder 6 in FIG. The spool 7 is urged toward one of the moving directions, and when the spool 7 is displaced downward in FIG. 2 with respect to the holder 6, the spool 7 exerts an urging force to return the spool 7 to the original position. While the spool 7 is urged by the urging force of the urging spring 8, the spool 7 is positioned at the uppermost position as shown in FIG. 2 in a state where the solenoid 9 does not receive a thrust opposed to the urging force of the urging spring 8. The port 7a is not opposed to the port 6a. Therefore, the solenoid valve V shuts off the bypass passage 3a when not energized.

The solenoid 9 of the solenoid valve V is housed in the solenoid case member 31, and although not shown in detail, a cylindrical stator including a coil and a cylindrical movable member movably inserted in the stator. It has an iron core and a plunger 9a which is attached to the inner circumference of the movable iron core and whose tip abuts on the plate 70. The lead wire 90 that supplies electric power to the solenoid 9 is made into a wire harness, passes through the inside of the rod body 32, projects outward, and is connected to a power source.

Then, when the solenoid 9 is energized through the lead wire 90, the movable iron core is pulled downward, the plunger 9a moves downward, and the spool 7 is pushed down against the urging force of the urging spring 8. Then, the port 7a and the port 6a are opposed to each other and the solenoid valve V is opened. Further, the relationship between the opening degree of the solenoid valve V and the energization amount to the solenoid 9 is a proportional relationship having a positive proportional constant, and the opening degree increases as the energization amount increases. Further, when the solenoid 9 is de-energized, the solenoid valve V is closed.

As described above, the solenoid valve V of the present embodiment is of a normally closed type, and the biasing spring 8 urges the spool 7, which is its valve element, in the closing direction, and the solenoid 9 applies thrust in the opening direction to the spool 7. To give to. Further, the opening degree increases in proportion to the energization amount of the solenoid valve V, and as the opening degree increases, the flow passage area of the bypass passage 3a increases. Therefore, it can be said that the flow passage area of the bypass passage 3a increases in proportion to the amount of electricity supplied to the solenoid valve V.

Further, in the rod body 32 of the piston rod 3, a rod-shaped probe 42c held by the sensor body 42a housed in the sensor housing portion 12a of the cap 12 and extending downward from the sensor body 42a in FIG. It is inserted with 90. Then, the lead wire 90 of the solenoid 9 is pulled out of the shock absorber D1 via the inside of the rod body 32 and the inside of the cap 12. In this embodiment, a gap is provided between the outer circumference of the sensor main body 42a and the inner circumference of the sensor accommodating portion 12a for passing the lead wire 90, and the lead wire 90 passes by the side of the sensor main body 42a. It is pulled out of the shock absorber D1.

In this way, since the probe 42c of the stroke sensor 42 and the lead wire 90 are housed in the piston rod 3, it is possible to adjust the damping force using the solenoid valve V and to detect the stroke of the shock absorber D1. Become.

The stroke sensor 42 includes a magnet 42b as a detected element connected to the cylinder 1 via the pipe member 17, a rod-shaped probe 42c housed in the piston rod 3 for detecting the position of the magnet 42b, and a probe 42c. It has a sensor body 42a that holds the above. In the present embodiment, the stroke sensor 42 is a magnetostrictive sensor including a sensor main body 42a having an electronic circuit that applies a pulse signal to the magnetostrictive wire in the probe 42c to detect the position of the magnet 42b. If the stroke sensor 42 has a detection target held by the pipe member 17, a probe housed in the piston rod 3 to detect the position of the detection target, and a sensor main body holding the probe, It may be a slot talk sensor using a detection principle other than the above.

Then, the probe 42c is always inserted into the magnet 42b as a detector together with the piston rod 3. Specifically, the length of the pipe member 17 that determines the axial position of the magnet 42b is always the probe even if the shock absorber body S makes a full stroke and the piston rod 3 moves up and down with respect to the cylinder 1 in FIG. 42c is set to be located on the inner circumference of the magnet 42b which is the detected element.

As described above, in the shock absorber D1 of the present embodiment, a telescopic tube member T having the outer tube 10 and the inner tube 11 slidably inserted into the outer tube 10, the outer tube 10, and the inner tube. 11, a cylinder 1 connected to one side, a piston 2 movably inserted into the cylinder 1 in the axial direction to divide the cylinder 1 into an expansion side chamber La and a compression side chamber Lb, and one end thereof is connected to the piston 2. And a piston rod 3 having the other end connected to the other of the outer tube 10 and the inner tube 11, and an annular rod guide 14 provided at the end of the cylinder 1 for guiding the movement of the piston rod 3. A shock absorber main body S housed in the tube member T and a stroke sensor 42 for detecting stroke displacement of the shock absorber main body S are provided, and the stroke sensor 42 includes a magnet (detection target) 42b connected to the cylinder 1. , A rod-shaped probe 42c that is housed in the piston rod 3 to detect the position of the magnet (detection target) 42b, and a sensor main body 42a that holds the probe 42c, and the magnet (detection target) 42b is It is arranged on the outer periphery of the piston rod 3 and one end is attached to the other end of the pipe member 17 mounted on the anti-cylinder side of the rod guide 14.

In the shock absorber D1 configured as described above, the magnet 42b as the detected element is arranged on the outer circumference of the piston rod 3 and one end thereof is attached to the other end of the pipe member 17 mounted on the side opposite to the cylinder of the rod guide 14. However, the axial position of the magnet 42b can be positioned at any position by the pipe member 17. Therefore, even if the total length of the probe 42c of the stroke sensor 42 is shorter than that of the rod main body 32 of the piston rod, the probe 42c can always be installed at a position facing the magnet (detected object) 42b, so that the total length of the piston rod 3 becomes extremely long. Even with the dual-purpose shock absorber D1, the problem that the probe length is insufficient and the stroke displacement cannot be detected is solved. As described above, according to the shock absorber D1 of the present invention, the stroke displacement can be detected even if the total length is long.

Further, in the present embodiment, the pipe member 17 faces the cushion rubber 25 mounted on the outer circumference of the piston rod 3, and when the shock absorber D1 contracts the most, it collides with the cushion rubber 25 and collides with the cushion rubber 25. Regulate further contraction. As described above, according to the shock absorber D1 of the present embodiment, by providing the pipe member 17, not only the axial position of the magnet 42b as the detected element is positioned, but also the cushion rubber 25 cooperates with the shock absorber D1. A cushioning function that alleviates the shock at the time of the most contraction of the container D1 can be exhibited.

Subsequently, the shock absorber D1 of the present embodiment adjusts the flow rate of the hard side damping element 21 in addition to the damping force adjusting unit for automatically adjusting the flow rate of the hard side damping element 21 including the solenoid valve V. It is equipped with a second damping force adjustment unit for manual adjustment. As shown in FIG. 1, the second damping force adjusting portion is provided in the bottom portion of the shock absorber D, and the flow passage area of the discharge passage 4b that connects the pressure side chamber Lb and the liquid reservoir R is manually set. It is configured to have a manual valve 41 that can be changed by operation.

The manual valve 41 includes a needle-shaped valve body 41a which is seated on and detached from an annular valve seat (not shown) provided in the middle of the discharge passage 4b. When the manual valve 41 is rotationally operated, the valve body 41a moves closer to the valve seat depending on the rotation direction, and the flow passage area of the discharge passage 4b is adjusted to be small or large. In the present embodiment, when the solenoid valve V is normally energized normally, the valve body 41a is seated on the valve seat and the manual valve 41 blocks the communication of the discharge passage 4b.

Summarizing the above, as shown in FIG. 1, the shock absorber D includes a cylinder 1 and a piston 2 that is slidably inserted into the cylinder 1 and divides the inside of the cylinder 1 into an extension side chamber La and a compression side chamber Lb. The piston rod 3 has a tip connected to the piston 2 and a distal end protruding outside the cylinder 1, and a tank 16 connected to the expansion side chamber La in the cylinder 1, and the pressure in the expansion side chamber La is the tank pressure. It has become.

Further, the shock absorber D is provided with an extension side passage 2a, a compression side passage 2b, and a bypass passage 3a as passages for communicating the extension side chamber La and the compression side chamber Lb. The expansion side passage 2a is provided with an expansion side check valve 20 that allows only one-way flow of liquid from the expansion side chamber La to the compression side chamber Lb, and the liquid from the compression side chamber Lb to the expansion side chamber La is 2b or the bypass 3a.

The pressure side passage 2b is provided with an orifice 21b and a leaf valve 21a arranged in parallel with the orifice 21b, and a hard side damping element 21 that gives resistance to the flow of liquid. On the other hand, the bypass passage 3a is configured to have an orifice 50b having a larger opening area than the orifice 21b and a leaf valve 50a arranged in parallel with the leaf valve 21a and having a valve rigidity lower than that of the leaf valve 21a. A soft side damping element 50 having a reduced resistance is provided.

Further, the bypass path 3a is provided with a solenoid valve V in series with the soft side damping element 50, and the flow path area of the bypass path 3a can be changed by adjusting the amount of electricity supplied to the solenoid valve V. ing. The solenoid valve V is a normally closed type and is set so as to increase the flow passage area of the bypass passage 3a in proportion to the energization amount.

Further, the shock absorber D is provided with a suction passage 4a and a discharge passage 4b as passages that connect the pressure side chamber Lb and the tank 16 to each other. The suction passage 4a is provided with a suction valve 40 that allows only one-way flow of the liquid from the tank 16 to the pressure side chamber Lb. On the other hand, the discharge passage 4b is provided with a normally closed manual valve 41 that is opened and closed by manual operation.

The shock absorber D is configured as described above, and when the shock absorber D contracts, the piston rod 3 invades into the cylinder 1 and the piston 2 compresses the compression side chamber Lb. Normally, the manual valve 41 closes the discharge passage 4b. Therefore, when the shock absorber D contracts, the liquid in the pressure side chamber Lb moves to the extension side chamber La through the pressure side passage 2b or the bypass passage 3a. A resistance is given to the flow of the liquid by the hard side damping element 21 or the soft side damping element 50, and a compression side damping force due to the resistance is generated.

In addition, when the shock absorber D contracts in a normal state, the distribution ratio of the liquid passing through the hard damping element 21 and the soft damping element 50 changes depending on the flow passage area of the bypass passage 3a, whereby the damping coefficient is large or small. The compression-side damping force generated as a result is adjusted in magnitude.

Specifically, as described above, the hard-side damping element 21 and the soft-side damping element 50 are configured to have the

orifices

21b and 50b and the

leaf valves

21a and 50a arranged in parallel with the

orifices

21b and 50b, respectively. Therefore, the damping force characteristic becomes an orifice characteristic proportional to the square of the piston speed peculiar to the orifice when the piston speed is in the low speed range, and becomes the piston speed peculiar to the leaf valve when the piston speed is in the medium to high speed range. The valve characteristics are proportional.

When the amount of electricity to the solenoid valve V is increased to increase the opening degree, the flow rate of the bypass passage 3a increases, the proportion of the liquid passing through the hard damping element 21 decreases, and the liquid passing through the soft damping element 50 decreases. Increases the proportion of. Since the orifice 50b of the soft side damping element 50 is a large-diameter orifice having a larger opening area than the orifice 21b of the hard side damping element 21, the damping coefficient is increased in the soft mode in which the proportion of the liquid toward the soft side damping element 50 increases. Becomes smaller in both the low speed range and the medium and high speed range, and the compression side damping force generated with respect to the piston speed becomes small. When the amount of current supplied to the solenoid valve V is maximized, the damping coefficient is minimized and the compression side damping force generated with respect to the piston speed is minimized.

On the contrary, when the amount of electricity supplied to the solenoid valve V is reduced to reduce the opening degree, the flow rate of the bypass path 3a is reduced, the proportion of the liquid passing through the hard side damping element 21 is increased, and the soft side damping element 50 is used. The proportion of liquid passing through is reduced. Then, the damping coefficient becomes large and the compression side damping force with respect to the piston speed becomes large. Then, when the energization of the solenoid valve V is cut off and the solenoid valve V is closed, the communication of the bypass path 3a is cut off, so that the total flow rate passes through the hard side damping element 21. Then, the damping coefficient becomes maximum, and the compression side damping force generated with respect to the piston speed becomes maximum.

Thus, when the distribution ratio of the liquid passing through the hard damping element 21 and the soft damping element 50, which are the first and second damping elements, is changed by the solenoid valve V, the damping coefficient becomes large and small, as shown in FIG. Then, the slope of the characteristic line showing the damping force characteristic on the compression side changes. Then, the compression side damping force is adjusted between the hard mode in which the inclination of the characteristic line is maximized to increase the damping force generated and the soft mode in which the inclination is minimized to decrease the damping force generated.

Then, in the soft mode, the slope of the characteristic line showing the damping force characteristic becomes smaller in both the low speed region and in the middle/high speed region, and in the hard mode, the slope of the characteristic line showing the damping force property becomes smaller in the low speed region and the middle/high speed region. It gets bigger in both. Therefore, the change in the damping force characteristic from the orifice characteristic to the valve characteristic is gradual in any mode.

Further, the soft side damping element 50 has a leaf valve 50a having low valve rigidity in parallel with the orifice 50b. Therefore, even if a valve with high valve rigidity and high valve opening pressure is adopted as the leaf valve 21a of the hard side damping element 21 and the adjustment range in the direction of increasing the compression side damping force is increased, the damping force in the soft mode is increased. Does not become too large.

Also, at the time of failure (normal time), the energization of the solenoid valve V is cut off and the mode is switched to the hard mode. At this time, if the manual valve 41 is opened, the liquid in the compression side chamber Lb passes through not only the compression side passage 2b but also the discharge passage 4b, so that the flow rate of the liquid passing through the hard side damping element 21 is reduced. The compression side damping force is reduced.

Further, the liquid for 3 volumes of the piston rod that has entered the cylinder 1 when the shock absorber D1 is contracted is discharged from the extension side chamber La to the tank 16.

On the contrary, when the shock absorber D is extended, the extension side check valve 20 opens, and the liquid in the extension side chamber La moves to the compression side chamber Lb through the extension side passage 2a. At this time, the liquid can pass through the extension check valve 20 without any resistance. Further, the extension side chamber La is communicated with the tank 16 and is maintained at the tank pressure. Therefore, the shock absorber D1 does not exert a damping force on the extension side. As described above, the shock absorber D1 forms a front fork by forming a pair with a shock absorber that generates a damping force only during extension, so when the front wheel is separated from the vehicle body, the shock absorber D1 is attenuated only during extension. A shock absorber that exerts power suppresses the vibration of the vehicle body.

The shock absorber D1 according to the present embodiment includes a cylinder 1, a piston 2 that is movably inserted in the cylinder 1 in the axial direction, and divides the inside of the cylinder 1 into an expansion side chamber La and a compression side chamber Lb, and this piston. 2 and a piston rod 3 having one end protruding outside the cylinder 1.

Further, the shock absorber D1 separates the hard side damping element 21 that provides resistance to the flow of the liquid from the compression side chamber Lb toward the expansion side chamber La, and the pressure side chamber Lb and the expansion side chamber La by bypassing the hard side damping element 21. An electromagnetic valve V capable of changing the flow path area of the bypass path 3a communicating with the bypass path 3a and a soft side damping element 50 provided in series with the electromagnetic valve V on the bypass path 3a are provided. The hard damping element 21 has an orifice 21b and a leaf valve 21a provided in parallel with the orifice 21b. On the other hand, the soft side damping element 50 has an orifice (large diameter orifice) 50b having an opening area larger than that of the orifice 21b.

According to the above configuration, the characteristic of the damping force generated when the shock absorber D1 contracts becomes the orifice characteristic peculiar to the orifice when the piston speed is in the low speed range, and when the piston speed is in the medium and high speed range, it becomes the orifice characteristic. The valve characteristics are peculiar to leaf valves. Then, if the opening area of the bypass passage 3a is changed by the solenoid valve V, of the liquid that moves from the compression side chamber Lb to the expansion side chamber La when the shock absorber D1 contracts, the hard side damping element 21 and the soft side damping element 50 of the liquid. Since the distribution ratio of the flow rate passing through each changes, both the damping coefficient when the piston speed is in the low speed range and the damping coefficient when the piston speed is in the medium and high speed range can be freely set, and the piston speed can be set to the medium and high speed range. The adjustment range of the compression side damping force in a certain case can be increased.

Further, in the soft mode in which the opening area of the bypass path 3a is increased, both the damping coefficient when the piston speed is in the low speed range and the damping coefficient when the piston speed is in the medium and high speed range become small. On the other hand, in the hard mode in which the opening area of the bypass path 3a is reduced, both the damping coefficient when the piston speed is in the low speed region and the damping coefficient when the piston speed is in the medium and high speed region are large. Therefore, when the characteristic of the compression side damping force changes from the orifice characteristic in the low speed region to the valve characteristic in the medium and high speed region, the change in the slope of the characteristic line becomes gentle in any mode. As a result, when the shock absorber D according to the present embodiment is mounted on a vehicle, it is possible to reduce the discomfort caused by the change in the inclination and improve the ride comfort of the vehicle.

Also, in the shock absorber D1 of the present embodiment, the piston 2 is connected to the other end of the piston rod 3 to form a single rod type. Further, the shock absorber D includes a tank 16 connected to the extension side chamber La, and a suction valve 40 that allows only the flow of liquid from the tank 16 to the compression side chamber Lb. With this configuration, the tank 16 can compensate for the volume of the piston rod 3 that moves in and out of the cylinder 1. Furthermore, the shock absorber D1 can be a one-sided shock absorber that exerts a damping force only in the compression stroke.

Further, in the shock absorber D1 of the present embodiment, the solenoid valve V is set so that the opening degree changes in proportion to the energization amount. With this configuration, the opening area of the bypass 3a can be changed steplessly.

Further, the shock absorber D1 of the present embodiment includes a manual valve 41 in which the flow path area of the discharge passage 4b communicating the compression side chamber Lb and the tank 16 can be changed by manual operation. According to this configuration, even if the solenoid valve V is closed at the time of failure, the compression side damping force generated by manually opening the manual valve 41 is reduced. For this reason, it is possible to prevent the compression side damping force in the fail mode from becoming excessive, and it is possible to improve the ride comfort of the vehicle.

Further, in the shock absorber D1 of the present embodiment, a tubular holder 6 in which a port 6a in which the solenoid valve V is connected to the bypass path 3a is formed and a port 6a that is reciprocally inserted into the holder 6 are inserted. A tubular spool 7 that can be opened and closed, an urging spring 8 that urges the spool 7 in one direction of movement of the spool 7, and a thrust force in the direction opposite to the urging force of the urging spring 8 is applied to the spool 7. And a solenoid 9 for giving it.

Here, for example, like the solenoid valve described in JP2010-7758A, a needle valve that can reciprocate as a valve body is provided, and the opening degree is increased or decreased by increasing or decreasing the gap formed between the tip of the needle valve and the valve seat. When changing, the stroke amount of the valve element must be increased in order to increase the adjustment range of the opening, but this may not be possible.

Specifically, if the stroke amount of the needle valve is increased, the movable space of the needle valve increases and it becomes difficult to secure the accommodation space. Further, if the stroke amount of the solenoid plunger is increased in order to increase the stroke amount of the needle valve, the solenoid design must be changed, which is complicated. Furthermore, if it is attempted to increase the stroke of the needle valve without changing the design of the solenoid, parts are needed to increase the travel of the needle valve relative to the travel of the plunger, increasing the number of parts and accommodating space. It becomes difficult to secure.

On the other hand, in the solenoid valve V of the present embodiment, the port 6a formed in the holder 6 is opened and closed by the spool 7 that is reciprocally inserted in the cylindrical holder 6, whereby the solenoid valve V Is designed to open and close. Therefore, if a plurality of ports 6a are formed in the circumferential direction of the holder 6 or have a shape that is long in the circumferential direction, the stroke of the spool 7 that is the valve body of the solenoid valve V can be increased without increasing the stroke amount of the solenoid valve V. The opening can be increased. Therefore, the adjustment range of the opening degree of the solenoid valve V can be increased, and the adjustment range of the compression side damping force can be easily increased.

Further, according to the above configuration, the relationship between the opening degree of the solenoid valve V and the energization amount can be easily changed. For example, if the relationship between the opening degree of the solenoid valve V and the energized amount is made negatively proportional and the opening degree is to be reduced as the energized amount increases, the port 6a is positioned so that the port 6a opens to the maximum when the energized amount is not energized. , Or a port 7a for opening this port 6a may be arranged. As described above, the relationship between the opening degree of the solenoid valve V and the energization amount can be freely changed, and the presence or absence of the manual valve 41 can be selected according to the change.

<Second embodiment>
As shown in FIG. 4, the shock absorber D2 of the second embodiment is slidably inserted into the outer tube 10 and the outer tube 10 in the same manner as the shock absorber D1 of the first embodiment. A telescopic type tube member T having an inner tube 11, a cylinder 1 connected to the inner tube 11, and an extension side chamber La and a compression side chamber Lb which are inserted into the cylinder 1 so as to be movable in the axial direction. 2, a piston rod 3 having one end connected to the piston 2 and the other end connected to the outer tube 10, and an annular member provided at the end of the cylinder 1 for guiding the movement of the piston rod 3. A shock absorber main body S having the rod guide 14 and housed in the tube member T, and a stroke sensor 42 for detecting a stroke displacement of the shock absorber main body S are provided.

In the shock absorber D1 of the first embodiment, the pipe member 17 is provided in the rod guide 14 and the magnet 42b as the detected element of the stroke sensor 42 is positioned by the pipe member 17, but the second embodiment is used. In the shock absorber D2 of this embodiment, as shown in FIG. 4, the pipe member 17 is eliminated, the magnet 42b is attached to the rod guide 14, and the sensor body 42a is connected to the cap 12' and the piston rod 3. It differs in that it is held at 43.

Hereinafter, the difference between the buffer D1 of the first embodiment and the buffer D2 of the second embodiment will be described in detail, and the structures common to the shock absorbers D1 and D2 will be duplicated. Detailed description is omitted.

In the shock absorber D2 of the second embodiment, the magnet 42b as a detector is attached to the rod guide 14. As shown in FIG. 4, the rod guide 14 has an annular main body portion 14a that fits into the cylinder 1 and a tubular oil lock case 14c that protrudes from the main body portion 14a toward the opposite cylinder side in FIG. It has and. Further, a magnet 42b is mounted on the inner circumference of the main body portion 14a of the rod guide 14, and the piston rod 3 is slidably inserted, and the rod guide 14 guides the movement of the piston rod 3. When the annular magnet 42b is attached to the inner circumference of the rod guide 14 and the piston rod 3 is inserted into the inner circumference of the main body 14a of the rod guide 14, the inner circumference of the magnet 42b becomes the outer circumference of the piston rod 3. To face.

Further, in the shock absorber D2 of the second embodiment, a tubular cap 12'is screwed to the upper end of the outer tube 10, and the outer circumference of the upper end of the connecting pipe 43 in FIG. 4 is screwed to the inner circumference of the cap 12'. Is screwed on. The inner circumference of the lower end of FIG. 4 of the connecting pipe 43 is screwed to the outer circumference of the upper end of the rod body 32 of FIG. 4 of the piston rod 3, and the cap 12'and the piston rod 3 are connected via the connecting pipe 43. Has been done.

The cap 12 ′ has a cylindrical shape, and the outer peripheral threaded cylindrical portion 12 a ′ screwed to the inner circumference of the outer tube 10 and the outer peripheral threaded cylindrical portion 12 a ′ are connected to the lower side in FIG. It is provided with an inner peripheral screw cylinder portion 12b'screwed to.

The connecting pipe 43 is tubular and includes a large-diameter housing cylinder 43a for housing the sensor body 42a, and a connecting cylinder 43b having a smaller diameter than the housing cylinder 43a connected to the cylinder side of the housing cylinder 43a. There is. The upper end of the accommodating cylinder portion 43a of the connecting pipe 43 is connected to the inner peripheral screw cylinder portion 12b'of the cap 12'by screw fastening, and the connecting cylinder portion 43b of the connecting pipe 43 is connected to the upper end of the piston rod 3.

Further, a suspension spring 15 made of a coil spring is interposed between the rod guide 14 and the cap 12'. The suspension spring 15 is arranged on the outer periphery of the connecting pipe 43 and is interposed between the rod guide 14 and the cap 12'to urge the shock absorber D2 in the extension direction. Specifically, the upper end of the suspension spring 15 is supported by the spring receiver 23 fitted to the outer periphery of the piston rod connecting portion 12b'of the cap 12', and the lower end of the suspension spring 15 in FIG. 4 is the rod guide 14. It is supported by a spring receiver 27 that is stacked on the end of the oil lock case 14c.

An annular oil lock piece 44 is mounted on the outer periphery of the piston rod 3, and when the shock absorber D2 contracts to the vicinity of the stroke end, the oil lock piece 44 enters the oil lock case 14c provided in the rod guide 14. The pressure inside the oil lock case 14c increases to prevent the shock absorber D2 from contracting. As described above, in the shock absorber D2 of the present embodiment, since the pipe member 17 is abolished, the oil lock case 14c can be installed on the rod guide 14, and the oil lock function for alleviating the impact at the time of maximum contraction of the shock absorber D1 is exhibited. it can.

The sensor body 42a of the stroke sensor 42 is housed and fixed in the housing tube 43a of the connecting pipe 43, and the probe 42c extending from the sensor body 42a is inserted into the connecting tube 43b and the rod body 32. Has been done. Also in the shock absorber D2 of the present embodiment, the lead wire 90 of the solenoid 9 is housed in the rod body 32 together with the probe 42c, and is outside the shock absorber D2 via the connecting pipe 43 and the cap 12'. Have been pulled out to.

Then, the probe 42c is always inserted into the magnet 42b as a detector together with the piston rod 3. Specifically, the length of the connecting pipe 43 that determines the axial position of the sensor body 42a is always the same even when the shock absorber body S makes a full stroke and the piston rod 3 moves up and down with respect to the cylinder 1 in FIG. The probe 42c is set so as to be located on the inner circumference of the magnet 42b which is the detected element.

The stroke sensor 42 is housed in the rod guide 14, the probe housed in the piston rod 3 to detect the position of the body to be detected, and the stroke sensor 42 is housed in the connecting pipe 43 while holding the probe. If it has a sensor body, it may be a Slotalk sensor using a detection principle other than the above.

Even in the shock absorber D2 of the second embodiment, the tube member T is turned upside down from the state shown in FIG. 4, and the piston rod 3 is connected to the inner tube 11 via the connecting pipe 43 and the cap 12'. Then, the cylinder 1 may be connected to the outer tube 10 to accommodate the shock absorber body S in the tube member T.

As described above, in the shock absorber D2 of the present embodiment, the telescopic type tube member T having the outer tube 10 and the inner tube 11 slidably inserted into the outer tube 10, the outer tube 10 and the inner tube A cylinder 1 connected to one of the elevens, a piston 2 movably inserted into the cylinder 1 in the axial direction to partition the inside of the cylinder 1 into an extension side chamber La and a compression side chamber Lb, and one end connected to the piston 2. It also has a piston rod 3 whose other end is connected to the other of the outer tube 10 and the inner tube 11, and an annular rod guide 14 provided at the end of the cylinder 1 to guide the movement of the piston rod 3. A shock absorber body S housed in the tube member T and a stroke sensor 42 for detecting the stroke displacement of the shock absorber body S are provided, and the stroke sensor 42 includes a magnet (detected element) 42b connected to the cylinder 1. The piston (detector) 42b has a rod-shaped probe 42c that is housed in the piston rod 3 and detects the position of the magnet (detector) 42b, and a sensor body 42a that holds the probe 42c. It is mounted on the inner circumference of the rod guide 14, and the sensor body 42a is housed inside a connecting pipe 43 that connects the cap 12'that closes the opening of the outer tube 10 and the piston rod 3.

In the shock absorber D2 configured in this way, the sensor body 42a of the stroke sensor 42 is housed in the connecting pipe 43 that connects the piston rod 3 to the cap 12', and the axial position of the sensor body 42a is connected to the connecting pipe 43. Can be positioned at any position. Further, in the shock absorber D2, since the cap 12'and the piston rod 3 are connected by the connecting pipe 43, the total length of the piston rod 3 is not adjusted to the total length of the shock absorber D2, but is suitable for the stroke length of the shock absorber body S. It is sufficient to make the length longer, and it is not necessary to make the piston rod length longer. From the above, according to the shock absorber D2 of the present invention, it is not necessary to lengthen the total length of the piston rod 3 even if the total length of the shock absorber D2 is long, and the probe 42c of the stroke sensor 42 is always magnetized (detected element) 42b. It can be installed at a position facing. Therefore, even if the shock absorber D2 for a saddle vehicle has a very long overall length, the problem that the stroke displacement cannot be detected due to the insufficient probe length is solved. From the above, according to the shock absorber D2 of the present invention, the stroke displacement can be detected even if the total length is long.

Further, the shock absorber D2 of the present embodiment includes a suspension spring (coil spring) 15 arranged on the outer periphery of the connecting pipe 43 and interposed between the rod guide 14 and the cap 12'. In the shock absorber D2 configured in this way, since the connecting pipe 43 accommodating the sensor body 42a can be arranged on the inner circumference of the suspension spring (coil spring) 15, the sensor body 42a can be arbitrarily placed in the suspension spring (coil spring) 15. The probe can be installed at the position (1), and the length of the suspension spring (coil spring) 15 is less likely to be restricted by the probe length. Therefore, the degree of freedom in designing the shock absorber D2 is improved.

In the present embodiment, the shock absorbers D1 and D2 are single-acting shock absorbers that exert a damping force only during contraction, but instead of the hard side damping element 21 in the compression side passage 2b, the compression side chamber Lb to the expansion side chamber La are replaced. A check valve that allows only the flow of the liquid toward the expansion side passage 2a is provided as a damping passage, and a hard side damping element that provides resistance to the flow of the liquid toward the compression side chamber Lb from the expansion side chamber La is provided. Instead of the side damping element 50, a soft side damping element that provides resistance to the flow of liquid from the expansion side chamber La to the compression side chamber Lb is provided, and the suction valve 40 in the suction passage 4a is eliminated, and the discharge passage 4b and the manual valve 41 are provided. May be abolished and the shock absorbers D1 and D2 may be used as shock absorbers that exert a damping force only when extended. When the shock absorber D is configured in this way, the damping coefficient increases or decreases when the distribution ratio of the liquid passing through the hard side damping element and the soft side damping element is changed by the electromagnetic valve V, so that the characteristic line showing the damping force characteristic on the extension side. The inclination of is changed in the same manner as the shock absorbers D1 and D2 that exert damping force only on the compression side.

Further, in each of the embodiments, when it is not necessary to make the damping force characteristics when the piston speed is in the normal speed range to be the valve characteristics, only the solenoid valve V is provided in the bypass passage 3a and the soft side damping element 50 is provided. May be omitted, or the hard-side damping element 21 may be omitted and the damping force on both sides of contraction, extension or expansion and contraction may be adjusted only by the solenoid valve V.

The preferred embodiments of the present invention have been described above in detail, but modifications, variations, and changes can be made without departing from the scope of the claims. This application claims priority based on Japanese Patent Application No. 2019-038127 filed with the Japan Patent Office on March 4, 2019, and the entire contents of this application are incorporated herein by reference.

1... Cylinder, 2... Piston, 3... Piston rod, 10... Outer tube, 11... Inner tube, 12, 12'... Cap, 14... Rod guide, 15 ... Suspension spring (coil spring), 17... Pipe member, 25... Cushion rubber, 42... Stroke sensor, 42a... Sensor body, 42b... Magnet (detector), 42c ... Probe, 43... Connection pipe, 90... Lead wire, D1, D2... Buffer, La... Extension side chamber, Lb... Pressure side chamber, S... Buffer body, T ... tube member, V ... solenoid valve

Claims

It ’s a shock absorber,
A telescopic tube member having an outer tube and an inner tube slidably inserted into the outer tube;
A cylinder connected to one of the outer tube and the inner tube, a piston movably inserted into the cylinder to partition the inside of the cylinder into an extension side chamber and a compression side chamber, and one end to the piston. A piston rod connected to the other end of the outer tube and the inner tube, and an annular rod guide provided at the end of the cylinder for guiding the movement of the piston rod. A shock absorber body housed in the tube member,
It is equipped with a stroke sensor that detects the stroke displacement of the shock absorber body.
The stroke sensor includes a detection target connected to the cylinder, a rod-shaped probe that is housed in the piston rod to detect the position of the detection target, and a sensor main body that holds the probe. ,
The shock absorber is arranged on the outer periphery of the piston rod and has one end attached to the other end of a pipe member mounted on the side opposite to the cylinder of the rod guide.
The shock absorber according to claim 1.
It is mounted on the outer circumference of the piston rod and has a cushion rubber.
A shock absorber that restricts the shrinkage of the shock absorber body by the abutment of the cushion rubber and the pipe member when the shock absorber body is contracted most.
It ’s a shock absorber,
A telescopic tube member having an outer tube and an inner tube slidably inserted into the outer tube;
A cylinder connected to one of the outer tube and the inner tube, a piston movably inserted into the cylinder to partition the inside of the cylinder into an extension side chamber and a compression side chamber, and one end to the piston. A piston rod connected to the other end of the outer tube and the inner tube, and an annular rod guide provided at the end of the cylinder for guiding the movement of the piston rod. A shock absorber body housed in the tube member,
It is equipped with a stroke sensor that detects the stroke displacement of the shock absorber body.
The stroke sensor includes a detection target connected to the cylinder, a rod-shaped probe that is housed in the piston rod to detect the position of the detection target, and a sensor main body that holds the probe. ,
The detector is mounted on the inner circumference of the rod guide.
A shock absorber, wherein the sensor body is housed inside a connecting pipe that connects the piston rod and a cap that closes the other opening of the outer tube and the inner tube.
The shock absorber according to claim 3, wherein
A shock absorber comprising a coil spring which is disposed on the outer circumference of the connecting pipe and is interposed between the rod guide and the cap.
The shock absorber according to any one of claims 1 to 4.
An electromagnetic valve for adjusting the damping force generated by the shock absorber body is provided in the piston rod.
A shock absorber that houses a lead wire of a solenoid of the solenoid valve and the probe in the piston rod.