WO2020179675A1

WO2020179675A1 - Solenoid valve and buffer

Info

Publication number: WO2020179675A1
Application number: PCT/JP2020/008371
Authority: WO
Inventors: 壮大島内; 宏一郎粟野; 隆久望月
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: JP2020143676A

Abstract

A solenoid valve (V) is provided with: a cylindrical holder (6) that has a port (6a); a spool (7) that is inserted into the holder (6) so as to be able to move back and forth in an axial direction; a biasing spring (8) that biases the spool (7) toward one side of the moving direction of the spool (7); a solenoid (9) that can apply thrust to the spool (7) so as to move toward the other side of the moving direction of the spool (7); a hydraulic lock chamber (RC) that is provided between the holder (6) and the spool (7) and that suppresses movement of the spool (7) with respect to the holder (6) when closed; a shutter (17) that can move back and forth in a direction coincident with the moving direction of the spool (7), and switches between opening and closing of the hydraulic lock chamber (RC); and a shutter spring (18) that biases the shutter (17) and positions the shutter (17) at a position causing the hydraulic lock chamber (RC) to open.

Description

Solenoid valve and shock absorber

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

Conventionally, as a solenoid valve, a cylindrical housing having a port for communicating the inside and the outside, a cylindrical spool slidably inserted into the housing, a spool spring for biasing the spool, and a spool spring There is known one provided with a solenoid that drives the spool against the urging force of the above (see, for example, Patent Document 1).

In such a solenoid valve, a solenoid drives the spool with respect to the housing, and the outer circumference of the spool faces the port to open and close the port, and the degree of opening of the port is adjusted to change the flow path area. To. If the solenoid valve configured in this way is provided in the middle of the passage through which the hydraulic oil passes when the shock absorber expands and contracts, the flow path resistance given to the flow of the hydraulic oil passing through the passage can be varied, and the damping of the shock absorber You can adjust the force.

JP2010-19319A

The solenoid valve is highly responsive to a command to change the flow passage area and can change the flow passage area. Therefore, it is suitable for adjusting the damping force of a shock absorber incorporated in a vehicle suspension. It facilitates the implementation of active control such as control.

However, in order to make the damping force of the shock absorber incorporated in the suspension of the vehicle variable, it is necessary to incorporate an electromagnetic valve into the shock absorber, and the vertical vibration is constantly input to the shock absorber while the vehicle is running. In particular, when traveling on a rough road or the like, a large acceleration that pushes up from the bottom acts on the shock absorber.

On the other hand, in the solenoid valve, the movable parts of the spool and solenoid are only elastically supported in the axial direction, not fixedly supported. Therefore, when the damping force is adjusted by incorporating the solenoid valve into the shock absorber, when the acceleration is input to the shock absorber, the spool is displaced by the inertial force and the opening of the solenoid valve changes. There is a problem that it cannot be exhibited.

Therefore, an object of the present invention is to provide a solenoid valve capable of suppressing a change in the flow passage area even when there is an external vibration input, and a shock absorber capable of exhibiting a desired damping force.

An electromagnetic valve for solving the above-mentioned problems is a holder having a tubular shape and having a port communicating between the inside and the outside, and a spool having a tubular shape and axially reciprocally inserted into the holder and capable of opening and closing the port. Provided between the holder and the spool, an urging spring that urges the spool in one direction of the spool movement, a solenoid that can apply a thrust to move the spool in the other direction of the spool movement, and a holder. Hydraulic lock chamber that restricts movement of the spool relative to the holder in one or the other direction when closed, and is capable of reciprocating in a direction that coincides with the spool moving direction and opening and closing of the hydraulic lock chamber. It is provided with a shutter for switching the shutter and a shutter spring for positioning the shutter at a position where the shutter is urged to open the hydraulic lock chamber.

According to the solenoid valve thus configured, when the vibration is input from the outside, the hydraulic lock chamber is closed by the shutter and the axial displacement of the spool with respect to the holder is suppressed.

Alternatively, a shutter may be slidably mounted on the outer circumference of the holder to form a solenoid valve. According to the solenoid valve configured in this way, the moving directions of the shutter and the spool can be matched by the holder, so that it is not necessary to add a component that guides the movement while matching the moving direction of the shutter with the moving direction of the spool. The cost can be reduced, the flow path resistance in the spool can be reduced, and unnecessary pressure loss does not occur.

Further, the solenoid valve may be configured so that the hydraulic lock chamber communicates with the spool when the shutter opens the hydraulic lock chamber. According to the solenoid valve configured in this way, it is possible to prevent a route that bypasses the port and goes back and forth between the outside of the holder and the inside of the spool via the hydraulic lock chamber, and the flow passage area can be adjusted accurately. ..

The shock absorber is a cylinder, a piston that is movably inserted into the cylinder in the axial direction and divides the inside of the cylinder into an expansion side chamber and a compression side chamber, is connected to the piston, and has one end protruding outside the cylinder. A piston rod, a hard side damping element that provides resistance to the flow of liquid from the compression side chamber to the expansion side chamber, a bypass path that bypasses the hard side damping element to connect the compression side chamber and the expansion side chamber, and the middle of the bypass path The solenoid valve provided in the above and the soft side damping element provided in series with the solenoid valve in the bypass path are provided, and the hard side damping element is configured to have an orifice and a leaf valve provided in parallel with the orifice. The soft damping element has a large-diameter orifice having an opening area larger than that of the orifice. According to the shock absorber configured in this manner, even if vibration is input to the shock absorber, fluctuations in the flow passage area of the solenoid valve are suppressed, so that the desired damping force can be exerted.

According to the solenoid valve of the present invention, it is possible to suppress the change of the flow passage area even if there is a vibration input from the outside, and the interference of the present invention can exert a desired damping force.

FIG. 1 is a vertical sectional view of a shock absorber which is a shock absorber according to an 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.

The solenoid valve V and the shock absorber D 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 absorber D according to the embodiment of the present invention is used for a front fork that suspends the front wheels of a saddle type 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.

As shown in FIG. 1 and FIG. 2, the solenoid valve V is a cylindrical holder 6 having a port 6a for communicating the inside and the outside, and is cylindrical and inserted in the holder 6 so as to be axially reciprocable. A spool 7 capable of opening and closing the port 6a, an urging spring 8 for urging the spool 7 toward one of the moving directions of the spool 7, and a thrust for moving the spool 7 toward the other in the moving direction of the spool 7. A solenoid 9 capable of applying pressure, a hydraulic pressure lock chamber RC provided between the holder 6 and the spool 7, a shutter 17 for switching between opening and closing of the hydraulic pressure lock chamber RC, and a liquid urging the shutter 17 for urging the liquid. A shutter spring 18 for positioning the shutter 17 is provided at a position where the pressure lock chamber RC is opened.

Then, as shown in FIG. 1, the solenoid valve V is applied to the shock absorber D. In the present embodiment, the shock absorber D is a one-sided shock absorber that exerts a damping force only when contracting, and the solenoid valve V is used for adjusting the pressure side damping force of the shock absorber D. Although not shown, the shock absorber D 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. The solenoid valve V may be used as a shock absorber that exerts a damping force only when it is extended.

First, the shock absorber D according to the embodiment of the present invention will be specifically described. As shown in FIG. 2, the shock absorber D 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 D. 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.

Since the cap 12 is connected to the outer tube 10, it can be said that the piston rod 3 is connected to the outer tube 10. Further, 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.

An annular head member 14 is attached to the upper end of the cylinder 1, and the piston rod 3 penetrates the inside of the head member 14 so as to be movable in the axial direction. The head member 14 slidably supports the piston rod 3. A suspension spring 15 made of a coil spring is interposed between the head member 14 and the cap 12.

When the shock absorber D 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.

Also, when the shock absorber D 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 extending 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 D 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 D may be a double rod type, and the piston rod 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.

Next, in the cylinder 1, a liquid chamber filled with a liquid such as hydraulic oil is formed, and this liquid chamber is divided by the piston 2 into the expansion side chamber La and the compression side chamber Lb. 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. And a cylindrical rod body 32 that extends. 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 fixed to the outer periphery of the shaft portion 30b with a nut N. Has been done.

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.

Also, the outer diameters of the solenoid case member 31 and the piston holding member 30 that house the solenoid valve V and the soft side damping element 50 are smaller than the inner diameter of the cylinder 1, so that the expansion side chamber La is not partitioned by these. ..

The soft-side damping element 50 is configured to have a leaf valve 50a stacked 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 5, 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. Further, when the differential pressure becomes large and becomes equal to or higher than the valve opening pressure of the leaf valve 50a, the outer peripheral portion of the leaf valve 50 bends, and the liquid passes through the gap formed between the outer peripheral portion and the valve case 5 to the 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. Between the biasing spring 8 that biases the spool 7 upward in FIG. 2, which is one of the moving directions, the solenoid 9 that can apply thrust to the spool 7 in the other moving direction, and between the holder 6 and the spool 7. The hydraulic pressure lock chamber RC provided in the above, a shutter 17 for switching between opening and closing of the hydraulic pressure lock chamber RC, and a shutter spring 18 for urging the shutter 17. 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. In addition, the holder 6 is provided at the large diameter portion 6b on the upper end side in FIG. 2, the small diameter portion 6c on the lower end side in FIG. 2, and the lower end of the small diameter portion 6c, and is provided on the inner circumference of the housing portion 30a of the piston holding member 30. The inner diameter of the large diameter portion 6b is larger than the inner diameter of the small diameter portion 6c, and the outer diameters of the large diameter portion 6b and the small diameter portion 6c are the same. The diameter is smaller than the inner diameter of the housing portion 30a. At the boundary between the large diameter portion 6b and the small diameter portion 6c of the holder 6, a step portion 6e facing upward in FIG. 2 is formed. The port 6a is provided in the large diameter portion 6b and communicates the inside and outside of the large diameter portion 6b. In addition to the port 6a, the holder 6 is a large-diameter portion 6b, is provided near the stepped portion 6e below the installation position of the port 6a, and has a hole 6f for communicating the inside and outside of the holder 6, and a small-diameter portion 6c. And a hole 6g which is provided in the holder 6 and communicates the inside and the outside of the holder 6.

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 has a large diameter portion 7a having a large outer diameter on the upper side in FIG. 2, a small diameter portion 7b having a small outer diameter on the lower side in FIG. 7a and a small-diameter portion 7b, a stepped portion 7c, an annular groove 7d provided on the outer circumference of the large-diameter portion 7a along the circumferential direction, and an annular groove opened from the inner circumference of the large-diameter portion 7a. A through hole 7e communicating with 7d, an annular groove 7f provided on the outer circumference of the small diameter portion 7b along the circumferential direction, and a through hole 7g opening from the inner circumference of the small diameter portion 7b and communicating with the annular groove 7f. It is configured with. In the spool 7, the large-diameter portion 7a is slidably contacted with the large-diameter portion 6b having the large inner diameter of the holder 6, and the small-diameter portion 7b is slidably contacted with the small-diameter portion 6c having the small inner diameter of the holder 6. It is slidably inserted. When the spool 7 is inserted into the holder 6 in this way, it is between the inner circumference of the small diameter portion 7b of the spool 7 and the inner circumference of the large diameter portion 6b of the holder 6 and between the step portion 6e and the step portion 7c. A hydraulic lock chamber RC is formed. The hydraulic lock chamber RC is always opposed to the hole 6f provided in the holder 6 and communicated with the hole 6f. Further, the annular groove 7f provided in the spool 7 faces the hole 6g provided in the small diameter portion 6c of the holder 6, and even if the spool 7 moves in the axial direction with respect to the holder 6, the annular groove 7f is always provided. And the communication with the hole 6g is maintained.

Further, when the spool 7 is inserted into the holder 6, the spool 6 opens and closes the port 6a provided in the holder 6. Specifically, when the annular groove 7d provided in the large diameter portion 7a of the spool 7 faces the port 6a of the holder 6, the spool 7 allows the port 6a to communicate with the inside of 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 annular groove 7d 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 with respect to the holder 6 in FIG. 2 and the port 6a does not completely face the annular groove 7d and is closed at the outer periphery of the large diameter portion 7a of the spool 7, the port 6a and the inside of the spool 7 are closed. The bypass road 3a is cut off by cutting off the communication with.

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 19 fitted to the inner periphery of the housing portion 30a of the piston holding member 30 and the flange portion 6d of the holder 6 and having an outer periphery below the urging spring 8. It is fixed to the piston rod 3. The inner circumference of the biasing spring 8 is fitted into an annular recess 7h 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. When the spool 7 is displaced downward in FIG. 2 with respect to the holder 6, an urging force that returns the spool 7 to the original position is exerted. While the spool 7 is biased by the biasing force of the biasing spring 8, it is positioned at the uppermost position as shown in FIG. 2 in a state where the spool 7 receives no thrust from the solenoid 9 that opposes the biasing force of the biasing spring 8. The annular groove 7d 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 harness 90 that supplies electric power to the solenoid 9 projects outward through the inside of the rod body 32 and is connected to a power source.

Then, when the solenoid 9 is energized through the harness 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 annular groove 7d 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.

Next, a shutter 17 is provided on the outer periphery of the holder 6. The shutter 17 has a cylindrical shape and is slidably in contact with the outer periphery of the holder 6 and is capable of reciprocating in the vertical direction in FIG. 2, which is the direction coinciding with the moving direction of the spool 7. An annular groove 17a is provided on the inner circumference of the shutter 17. A C ring 24 is mounted on the outer periphery of the holder 6 as a stopper for defining the upper limit of movement of the shutter 17 in FIG. An annular spring receiver 17b is provided on the outer periphery of the shutter 17, and the shutter spring 18 interposed between the spring receiver 17b and the flange portion 6d of the holder 6 causes the shutter 17 to move upward in FIG. Is biased and positioned so that the upper end abuts the C ring 24.

When the shutter 17 is located at the upper limit position where it abuts the C ring 24, the annular groove 17a formed on the inner peripheral side faces the

holes

6f and 6g provided in the holder 6. The hole 6f communicates with the hydraulic lock chamber RC, and the hole 6g always faces the annular groove 7f regardless of the position of the spool 7 and communicates the hole 6g with the spool 7. Therefore, when the shutter 17 is in contact with the C ring 24, the hydraulic lock chamber RC is communicated with the spool 7 through the annular groove 17a, and the hydraulic lock chamber RC is opened by the shutter 17. When the hydraulic lock chamber RC is opened in this way, the spool 7 can freely move in and out of the hydraulic lock chamber RC even if the spool 7 moves vertically with respect to the holder 6 in FIG. It does not hinder the movement of 7.

On the other hand, when the shutter 17 moves downward in FIG. 2 against the urging force of the shutter spring 18 and the annular groove 7f cannot face the hole 6f, the hole 6f is blocked by the inner circumference of the shutter 17 and the liquid is liquid. The pressure lock chamber RC is closed. When the hydraulic lock chamber RC is closed, even if the spool 7 tries to move in the vertical direction in FIG. 2 with respect to the holder 6, the liquid cannot enter or leave the hydraulic lock chamber RC. When the spool 7 moves in the direction of compressing the hydraulic lock chamber RC, the pressure in the hydraulic lock chamber RC rises to suppress the movement of the spool 7, and conversely, the spool 7 expands the hydraulic lock chamber RC. When moving in the direction indicated by the arrow, the pressure in the hydraulic lock chamber RC is reduced and the movement of the spool 7 is suppressed. Therefore, when the hydraulic lock chamber RC is opened by the shutter 17, the spool 7 can freely move in the axial direction with respect to the holder 6, but when the hydraulic lock chamber RC is closed by the shutter 17, the spool 7 is The movement of the holder 6 in the axial direction is suppressed.

If the acceleration in the direction of pushing up from below is not applied to the shock absorber D, or if the acceleration is extremely small even if applied, the acceleration transmitted to the piston rod 3 is also small. It is maintained in a position where the RC is opened. In this case, the spool 7 can move freely with respect to the holder 6, but since the acceleration is small, even if the spool 7 vibrates with respect to the holder 6, the flow path area of the solenoid valve V does not fluctuate significantly. ..

On the other hand, when the shock absorber D is input with the vibration that pushes up from below and the shock absorber D contracts, the vibration is also transmitted to the piston rod 3 and the acceleration toward the upward side acts. Therefore, the holder 6 assembled to the piston rod 3 moves upward, but the shutter 17 is elastically supported by the shutter spring 18 and is allowed to move in the axial direction with respect to the holder 6. It tries to stay in place by inertial force. As a result, the shutter 17 moves downward relative to the holder 6 in FIG. 2 and closes the hydraulic lock chamber RC, so that axial displacement of the spool 7 with respect to the holder 6 is suppressed. As described above, in the solenoid valve V, when a large acceleration acts from below, the hydraulic lock chamber RC is closed by the shutter 17, so that the positional relationship between the spool 7 and the holder 6 does not change, and even if a large acceleration acts. The flow path area does not change. Therefore, even if vibration is input to the shock absorber D, the fluctuation of the flow path area of the solenoid valve V is suppressed and the damping force generated by the shock absorber D is stabilized, so that the shock absorber D exhibits the desired damping force. it can.

Subsequently, in the shock absorber D of the present embodiment, 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, the flow rate of the hard side damping element 21 is adjusted. A second damping force adjusting portion for manual adjustment is provided. 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 increases in both the low speed region and the medium and high speed regions, and the compression side damping force with respect to the piston speed increases. 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.

Also, the liquid equivalent to 3 volumes of the piston rod that has entered the cylinder 1 when the shock absorber D contracts is discharged from the expansion 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 D does not exert a damping force on the extension side. As described above, the shock absorber D forms a front fork by forming a pair with a shock absorber that generates a damping force only when the vehicle is extended. Therefore, when the front wheels are separated from the vehicle body, the damping is performed only when the vehicle is extended. A shock absorber that exerts power suppresses vibration of the vehicle body.

The operation and effect of the solenoid valve V and the shock absorber D including the solenoid valve V according to the embodiment of the present invention will be described below.

The solenoid valve V includes a holder 6 having a port 6a that is tubular and communicates the inside and the outside, a spool 7 that is axially reciprocally inserted into the holder 6 and that can open and close the port 6a, and a spool 7. An urging spring 8 that urges the spool 7 toward one of the moving directions, a solenoid 9 that can apply a thrust to move the spool 7 toward the other in the moving direction of the spool 7, and a holder 6 and the spool 7. When it is provided and closed, the hydraulic lock chamber RC that restricts the movement of the spool 7 with respect to the holder 6 in one or the other movement direction, and is reciprocable in a direction that matches the movement direction of the spool 7. A shutter 17 for switching between opening and closing of the hydraulic lock chamber RC and a shutter spring 18 for urging the shutter 17 to position the shutter 17 at a position where the hydraulic lock chamber RC is opened are provided.

According to the solenoid valve V configured in this manner, when the vibration is input from the outside, the hydraulic lock chamber RC is closed by the shutter 17 and the axial displacement of the spool 7 with respect to the holder 6 is suppressed. The change in area can be suppressed. Therefore, according to the shock absorber D to which the solenoid valve V is applied, even if vibration is input to the shock absorber D, the fluctuation of the flow passage area of the solenoid valve V is suppressed and the damping force generated by the shock absorber D is stabilized. The shock absorber D can exhibit the desired damping force.

In the solenoid valve V of the present embodiment, the direction in which the shutter spring 18 urges the shutter 17 is the upper part in FIG. 2, but the direction in which the shutter spring 18 urges the shutter 17 is the lower part in FIG. The hydraulic lock chamber RC may be closed when 17 moves upward with respect to the holder 6 due to vibration input. When the solenoid valve V is configured in this manner, the shutter 17 closes the hydraulic lock chamber RC against a vibration input that pushes the solenoid valve V and the shock absorber downward. Therefore, depending on whether the shutter 17 moves in one or the other moving direction of the spool 7, the hydraulic lock chamber RC is closed depending on the direction of the acceleration input to the solenoid valve V and the shock absorber. You just have to decide.

Further, in the solenoid valve V of the present embodiment, the shutter 17 is slidably mounted on the outer periphery of the holder 6. In the solenoid valve V configured in this way, the holder 6 can cause the shutter 17 and the spool 7 to move in the same direction. Therefore, a component for guiding the movement of the shutter 17 while matching the movement direction of the shutter 17 with the movement direction of the spool 7. The cost can be reduced because no additional is required. Further, if the shutter 17 is provided on the outer circumference of the holder 6, the inner peripheral diameter of the holder 6 and the inner peripheral diameter of the spool 7 can be largely secured, so that the flow path resistance in the spool 7 can be reduced, and an extra pressure loss is caused. You don't have to.

It should be noted that the annular groove 17a of the shutter 17 is abolished and a hole for communicating inside and outside is provided instead, the hole 6g of the holder 6 and the annular groove 7f and the through hole 7g of the spool 7 are abolished, and the hydraulic lock chamber RC is opened. In this case, the hole of the shutter 17 may be opposed to the hole 6f and the inner circumference of the shutter 17 may be opposed to the hole 6f when closing the hydraulic lock chamber RC. As described above, the hydraulic lock chamber RC may be communicated with the outside of the holder 6, but in the solenoid valve V of the present embodiment, the hydraulic lock chamber RC has a state in which the shutter 17 opens the hydraulic lock chamber RC. At the spool 7 communicates with. In the solenoid valve V configured as described above, the hydraulic lock chamber RC formed between the holder 6 and the spool 7 is not communicated with the outside of the holder 6, so that a sliding gap is generated between the holder 6 and the spool 7. Does not communicate with the outside of the holder 6 via the hydraulic lock chamber RC. Therefore, the sliding gap between the holder 6 and the spool 7 is communicated with the outside of the holder 6 via the hydraulic lock chamber RC, and the liquid passes through the port 6 a when moving between the outside of the holder 6 and the inside of the spool 7. It is possible to prevent a route other than the route from being formed, and it is possible to accurately adjust the flow passage area.

Further, the shock absorber D according to the present embodiment includes a cylinder 1, a piston 2 that is movably inserted into the cylinder 1 in the axial direction and divides the inside of the cylinder 1 into an extension side chamber La and a compression side chamber Lb. A piston rod 3 which is connected to the piston 2 and has one end protruding outside the cylinder 1 is provided.

Further, the shock absorber D separates the hard side damping element 21 that imparts 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. The bypass valve 3a is provided with a solenoid valve V capable of changing the passage area of the bypass passage 3a and a soft damping element 50 provided in the bypass passage 3a in series with the solenoid valve V. 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 D contracts is 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 to high speed range, The valve characteristics are unique to leaf valves. Then, if the opening area of the bypass path 3a is changed by the solenoid valve V, among the liquids that move from the compression side chamber Lb to the extension side chamber La when the shock absorber D contracts, the hard side damping element 21 and the soft side damping element 50 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.

Further, in the shock absorber D of the present embodiment, the soft side damping element 50 is configured to have the orifice (large diameter orifice) 50b and a leaf valve 50a provided in parallel with the orifice 50b. In this way, if the soft-side damping element 50 is also provided with the leaf valve 50a, even if the leaf valve 21a of the hard-side damping element 21 has a high valve rigidity and a high valve opening pressure, the damping force in the soft mode is high. It doesn't become excessive. That is, according to the above configuration, a valve having high valve rigidity can be used as the leaf valve 21a of the hard damping element 21. Then, since the adjustment range of the damping force increases in the direction of increasing the compression side damping force, the adjustment range of the compression side damping force can be further increased when the piston speed is in the middle and high speed range.

Also, in the shock absorber D 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 D can be a one-sided shock absorber that exerts a damping force only in the compression stroke.

Further, in the shock absorber D 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 D of the present embodiment is provided with a manual valve 41 capable of manually changing the flow passage area of the discharge passage 4b that connects the pressure side chamber Lb and the tank 16. 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 D of the present embodiment, a cylindrical holder 6 in which a port 6a for connecting the solenoid valve V to the bypass 3a is formed, and a port 6a inserted in the holder 6 so as to be reciprocally movable. A cylindrical spool 7 that can be opened and closed, an urging spring 8 that urges the spool 7 in one of the moving directions of the spool 7, and a thrust in the direction opposite to the urging force of the urging spring 8 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, when it is desired to make the relationship between the opening degree of the solenoid valve V and the energization amount negatively proportional and to decrease the opening degree as the energization amount increases, the port 6a is located at a position where the port 6a is opened to the maximum when deenergized. Alternatively, an annular groove 7d for opening the 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.

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. The present application claims priority based on Japanese Patent Application No. 2019-038122 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, 3a... Bypass passage, 6... Holder, 6a... Port, 7... Spool, 8... Energizing Spring, 9 ... solenoid, 17 ... shutter, 18 ... shutter spring, 20 ... hard side damping element, 50 ... soft side damping element, D ... shock absorber, La ... Extension side chamber, Lb ... compression side chamber, V ... solenoid valve

Claims

It ’s a solenoid valve,
A holder that is tubular and has a port that communicates inside and outside,
A spool that is cylindrical and is inserted into the holder so as to be reciprocally movable in the axial direction and that can open and close the port;
An urging spring that urges the spool toward one of the moving directions of the spool,
A solenoid capable of applying thrust to the spool to move the spool toward the other side in the moving direction,
A hydraulic lock chamber provided between the holder and the spool and closed to prevent the spool from moving in one or the other direction with respect to the holder.
A shutter capable of reciprocating in a direction coinciding with the moving direction of the spool, and switching between opening and closing of the hydraulic lock chamber,
An electromagnetic valve comprising: a shutter spring that biases the shutter to position the shutter at a position where the hydraulic lock chamber is opened.
The solenoid valve according to claim 1.
The shutter is a solenoid valve slidably mounted on the outer circumference of the holder.
The solenoid valve according to claim 1.
The hydraulic lock chamber is an electromagnetic valve that communicates with the spool when the shutter opens the hydraulic lock chamber.
It ’s a shock absorber,
Cylinder and
A piston that is movably inserted in the cylinder in the axial direction to partition the inside of the cylinder into an expansion side chamber and a compression side chamber,
A piston rod that is connected to the piston and one end of which protrudes out of the cylinder.
A hard side damping element that resists the flow of liquid from the compression side chamber to the extension side chamber,
A bypass path that bypasses the hard side damping element and connects the compression side chamber and the extension side chamber with each other;
The solenoid valve according to any one of claims 1 to 3, which is provided in the middle of the bypass passage,
The bypass path is provided with a soft damping element provided in series with the solenoid valve.
The hard-side damping element is configured to have an orifice and a leaf valve provided in parallel with the orifice,
The soft-side damping element has a large-diameter orifice having an opening area larger than that of the orifice.