JP2018040465A - Damping valve and cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damping valve that can prevent oscillation of a damping valve and does not cause any disturbance in a damp force waveform, and to provide a cylinder device applied with a damping valve.SOLUTION: A damping valve includes: a damp force adjustment passage and a fail passage arrayed in parallel; a downstream passage connected downstream of the damp force adjustment passage and the fail passage; a relief valve provided in the damp force adjustment passage; an on-off valve provided in the fail passage and set as normal open; a solenoid for adjusting valve opening pressure of the relief valve and closing the on-off valve when being energized; and an orifice provided in the downstream passage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a damping valve and a cylinder device.

  As the damping valve capable of adjusting the damping force, for example, a cylindrical valve seat body functioning as a relief valve in the housing, a valve body slidably inserted into the valve seat body, a switching valve, and a valve body Some include a spring that biases toward the seat body, and a proportional solenoid that provides thrust to the valve body and the switching valve.

  This switching valve opens and closes the flow path, and the switching valve can be switched between an open state and a closed state by a proportional solenoid, and the thrust of the proportional solenoid is applied to the valve body via the switching valve. It is possible to adjust the valve opening pressure at which the valve seats away from the valve seat (see, for example, Patent Document 1).

  This damping valve is used in a damper that suppresses vibrations of the vehicle body of the railway vehicle, and is provided in the middle of a damping force control circuit that communicates the rod side chamber of the damper and the reservoir. To control the damping force generated by the damper.

JP 2001-074154 A

  In this conventional damping valve, the damping force is controlled by the relief valve. However, when the valve is opened, the valve body tends to oscillate at a high frequency due to pressure fluctuation in the rod side chamber.

  When the valve body oscillates, the damping force waveform generated by the damper is disturbed, which not only deteriorates controllability when performing damping control of the vehicle body by adjusting the damping force, but also due to a sudden change in damping force. Therefore, there is a possibility that abnormal noise is generated and the abnormal noise is perceived in the vehicle body, which may cause discomfort to the passengers.

  Therefore, the present invention was devised in order to improve the above-mentioned problems, and an object of the present invention is to apply a damping valve and a damping valve to which the damping valve can be prevented from oscillating and the damping force waveform is not disturbed. In providing equipment.

  In the damping valve of the present invention, a damping force adjusting passage and a fail passage provided in parallel, a downstream passage connected downstream of the damping force adjusting passage and the fail passage, a relief valve provided in the damping force adjusting passage, A normally open on-off valve provided in the fail passage, a solenoid for adjusting the valve opening pressure of the relief valve when energized and closing the on-off valve, and an orifice provided in the downstream passage. In the damping valve configured as described above, an orifice is provided downstream of the relief valve, and the orifice exhibits a damping action that hinders the rapid opening / closing operation of the valve body of the relief valve and slows down the operation.

  The damping valve according to claim 2 includes a housing having a hollow portion, a first sleeve and a second sleeve inserted in series in the hollow portion, a first spool accommodated in the first sleeve, and a second sleeve. A second spool to be housed, and a relief valve is constituted by a spring for energizing the first spool and the first spool, and an on-off valve is constituted by the second sleeve and the second spool. The second sleeve includes a positioning portion for positioning the axial position with respect to the housing, a fixing portion fixed to the housing, and a spool hole provided outside the range from the positioning portion to the fixing portion. When the damping valve is configured in this way, the damping valve can be easily processed, and smooth operation of the first spool and the second spool can be realized.

  According to a third aspect of the present invention, the damping valve is provided with a fail valve that provides resistance to the liquid flow in the fail passage. The damping valve configured as described above provides resistance to the flow of liquid not only at the orifice but also at the failure time when the current supply to the solenoid is interrupted, so that the damping force characteristic at the time of failure can be tuned as desired, and Sometimes the damping force characteristics as intended can be demonstrated.

  Further, in the cylinder device according to claim 4, a first unload provided in a first passage that communicates the cylinder, the inside of which is divided into a rod side chamber and a piston side chamber by a piston, a tank, and the rod side chamber and the piston side chamber. A valve, a second unload valve provided in a second passage communicating the piston side chamber and the tank, a rectifying passage allowing only a flow from the piston side chamber to the rod side chamber, and only a flow from the tank to the piston side chamber. A suction passage to be allowed, a damping force adjusting passage and a fail passage provided in parallel, a downstream passage connected downstream of the damping force adjusting passage and the fail passage, a relief valve provided in the damping force adjusting passage, and a fail passage. A normally open on-off valve, a solenoid that adjusts the opening pressure of the relief valve when energized and closes the on-off valve, and a downstream passage And an orifice. According to the cylinder device configured as described above, it can function as a double-effect damper or a single-effect semi-active damper whose damping force can be adjusted during normal operation, and can function as a passive damper during failure.

  According to the damping valve and the cylinder device of the present invention, the oscillation of the damping valve can be prevented, and the damping force waveform is not disturbed.

It is a hydraulic-pressure circuit diagram of the cylinder apparatus provided with the damping valve in one embodiment. It is the figure which showed the damping force characteristic of the cylinder apparatus provided with the damping valve in one Embodiment. It is a hydraulic circuit figure in one modification of a cylinder device provided with a damping valve in one embodiment. It is sectional drawing of a specific damping valve. It is a partial cross section figure of one modification of a concrete damping valve.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, the damping valve DV in one embodiment is basically connected to the damping force adjusting passage TP and the fail passage FP provided in parallel, and downstream of the damping force adjusting passage TP and the fail passage FP. The downstream valve DP, the relief valve RV provided in the damping force adjustment passage TP, the normally open on-off valve OV provided in the fail passage FP, and the on-off valve OV while adjusting the valve opening pressure of the relief valve RV when energized. The solenoid Sol which closes and the orifice O provided in the downstream channel | path DP are comprised, and it is applied to the cylinder apparatus C in this example.

  The cylinder device C is divided into a cylinder 1, a piston 2 that is slidably inserted into the cylinder 1, a rod 3 that is inserted into the cylinder 1 and connected to the piston 2, and a piston 2 within the cylinder 1. The rod side chamber 4, the piston side chamber 5, the tank 6, the first unload valve 8 provided in the middle of the first passage 7 that communicates the rod side chamber 4 and the piston side chamber 5, and the piston side chamber 5 and the tank 6 communicate with each other. The second unload valve 10 provided in the middle of the second passage 9, the rectifying passage 11 that allows only the flow from the piston side chamber 5 to the rod side chamber 4, and the flow from the tank 6 to the piston side chamber 5 only. A suction passage 12 and a damping valve DV are provided, and a so-called single rod type cylinder device is configured. The damping valve DV is provided between the rod side chamber 4 and the tank 6 in the cylinder device C, and provides resistance to the flow of liquid discharged from the cylinder 1 to the tank 6.

  The rod side chamber 4 and the piston side chamber 5 are filled with hydraulic oil as a liquid, and the tank 6 is filled with gas in addition to the hydraulic oil. In addition, it is not necessary to compress and fill the inside of the tank 6 with a gas in particular. Although not shown, the cylinder device C is interposed between the carriage and the vehicle body by connecting the rod 3 to one of the carriage and the vehicle body of the railway vehicle and the cylinder 1 to the other of the carriage and the vehicle body. Since the cylinder device C is set to a single rod type, it is easier to ensure a stroke length than the double rod type cylinder device, and the overall length of the cylinder device C is shortened, so that it can be mounted on a railway vehicle. Will improve. Moreover, although the liquid which is a working medium of the cylinder apparatus C is made into hydraulic oil in this example, other liquids, such as water and aqueous solution, can also be utilized according to the use environment of the cylinder apparatus C.

  Hereinafter, each part of the damping valve DV and the cylinder device C will be described in detail. The cylinder 1 has a cylindrical shape, the right end in FIG. 1 is closed by a lid 13, and an annular rod guide 14 is attached to the left end in FIG. A rod 3 that is movably inserted into the cylinder 1 is slidably inserted into the rod guide 14. The rod 3 has one end protruding outside the cylinder 1, and the other end in the cylinder 1 is connected to a piston 2 that is slidably inserted into the cylinder 1.

  Note that the outer periphery of the rod guide 14 and the cylinder 1 are sealed by a seal member (not shown), whereby the inside of the cylinder 1 is maintained in a sealed state. The rod side chamber 4 and the piston side chamber 5 defined by the piston 2 in the cylinder 1 are filled with hydraulic oil as a liquid as described above.

  Further, in the case of this cylinder device C, the cross-sectional area of the rod 3 is made half of the cross-sectional area of the piston 2, and the pressure receiving area on the rod side chamber 4 side of the piston 2 is half of the pressure receiving area on the piston side chamber 5 side. The flow rate discharged from the cylinder 1 to the tank 6 through the damping valve DV is equal when the cylinder device C is extended and contracted.

  Returning, the lid 13 that closes the left end of the rod 3 in FIG. 1 and the right end of the cylinder 1 is provided with a mounting portion (not shown), and the cylinder device C is interposed between the vehicle body and the carriage in the railway vehicle. it can.

  In the cylinder device C of this example, the rod side chamber 4 and the piston side chamber 5 are communicated with each other by the first passage 7, and a first unload valve 8 is provided in the middle of the first passage 7. It has been. The first passage 7 communicates the rod side chamber 4 and the piston side chamber 5 outside the cylinder 1, but may be provided in the piston 2.

  The first unloading valve 8 is an electromagnetic on-off valve, and has a communication position for communicating the rod side chamber 4 and the piston side chamber 5 and a blocking position for disconnecting the communication between the rod side chamber 4 and the piston side chamber 5. When energized, the first passage 7 is opened to allow the rod side chamber 4 and the piston side chamber 5 to communicate with each other.

  Further, in the cylinder device C of this example, the piston side chamber 5 and the tank 6 are communicated with each other by the second passage 9, and a second unload valve 10 is provided in the middle of the second passage 9. ing. The second unloading valve 10 is an electromagnetic on-off valve, and has a communication position for communicating the piston side chamber 5 and the tank 6 and a blocking position for disconnecting the communication between the piston side chamber 5 and the tank 6. Sometimes the second passage 9 is opened to allow the piston side chamber 5 and the tank 6 to communicate with each other.

  As shown in FIG. 1, the cylinder device C of this example includes a rectifying passage 11 that allows only a flow from the piston side chamber 5 toward the rod side chamber 4. The rectifying passage 11 may be provided in addition to the piston 2. Further, the cylinder device C of this example includes a suction passage 12 that allows only a flow from the tank 6 toward the piston side chamber 5.

  Therefore, in the cylinder device C of this example, when the first unload valve 8 and the second unload valve 10 take the shut-off position, the rod side chamber 4 is compressed when extended by receiving an external force. The hydraulic oil is pushed out to the tank 6 through the damping valve DV, and the hydraulic oil is supplied from the tank 6 to the expanding piston side chamber 5 through the suction passage 12. Therefore, at the time of this extension operation, the cylinder device C exerts a damping force that resists the extension by giving resistance to the flow of hydraulic oil passing through the damping valve DV and increasing the pressure in the rod side chamber 4. In this case, the flow rate of the hydraulic oil passing through the damping valve DV is an amount obtained by multiplying the cross-sectional area of the piston 2 by the value obtained by subtracting the cross-sectional area of the rod 3 from the cross-sectional area of the piston 2.

  On the contrary, when the first unload valve 8 and the second unload valve 10 take the shut-off position and the cylinder device C contracts due to an external force, the piston side chamber 5 is compressed through the rectifying passage 11. The hydraulic oil moves to the rod side chamber 4. Further, when the cylinder device C is contracted, the rod 3 enters the cylinder 1, so that the volume of hydraulic oil into which the rod 3 enters the cylinder 1 becomes excessive in the cylinder 1 and enters the tank 6 through the damping valve DV. Discharged. At the time of this contraction operation, the cylinder device C gives a resistance to the flow of the hydraulic oil passing through the damping valve DV, and raises the pressure in the cylinder 1 to exert a damping force against the contraction. In this case, the amount of hydraulic oil passing through the damping valve DV is an amount obtained by multiplying the sectional area of the rod 3 by the amount of movement of the piston 2. Here, since the cross-sectional area of the rod 3 is set to a half of the cross-sectional area of the piston 2, if the movement amount of the piston 2 is the same even if the cylinder device C extends or contracts, the rod 3 is attenuated. The amount of hydraulic fluid passing through the valve DV is equal. Therefore, if the moving speed of the piston 2 is the same on both sides of expansion and contraction, the cylinder device C can exhibit an equal damping force.

  Since both the first unload valve 8 and the second unload valve 10 take the shut-off position when the power is not supplied, the cylinder device C of the present example must always withstand expansion and contraction in the event of a failure in which power cannot be supplied. Since it exhibits damping force, it functions as a passive damper.

  Further, in the cylinder device C of this example, when the first unload valve 8 is in the communication position and the second unload valve 10 is in the shut-off position, the rod side chamber 4 and the piston side chamber 5 pass through the first passage 7. However, the communication between the piston side chamber 5 and the tank 6 is cut off. In this state, when the cylinder device C receives an external force and contracts, the volume of hydraulic oil into which the rod 3 enters the cylinder 1 is discharged from the cylinder 1 to the damping valve DV, and similarly exhibits a damping force that counteracts the contraction. To do. On the other hand, when the cylinder device C is extended in this state, the hydraulic oil moves from the rod side chamber 4 that is contracted to the piston side chamber 5 that is expanded through the first passage 7, and the operation corresponding to the volume in which the rod 3 is retracted from the cylinder 1. Oil is supplied from the tank 6 into the cylinder 1 through the suction passage 12. Therefore, in this case, the hydraulic oil does not flow to the damping valve DV, so the cylinder device C does not exhibit a damping force.

  Further, in the cylinder device C of this example, when the first unload valve 8 is set to the shut-off position and the second unload valve 10 is set to the communication position, the communication between the rod side chamber 4 and the piston side chamber 5 is interrupted. The piston side chamber 5 and the tank 6 are communicated with each other through the second passage 9. In this state, when the cylinder device C is extended by receiving an external force, the hydraulic oil is discharged from the rod side chamber 4 to the damping valve DV as the rod side chamber 4 is reduced, and similarly exhibits a damping force that counteracts the extension. On the other hand, when the cylinder device C contracts in this state, the hydraulic oil moves from the piston side chamber 5 that is contracted to the rod side chamber 4 that is expanded via the rectifying passage 11 and the rod 3 enters the cylinder 1 to operate. Oil is discharged from the piston side chamber 5 into the tank 6 through the second passage 9. Therefore, in this case, the hydraulic oil does not flow to the damping valve DV, so the cylinder device C does not exhibit a damping force. As described above, the cylinder device C can function as a one-handed damper that exhibits a damping force by selecting either expansion or contraction.

  In the case of the cylinder device C1, an air vent orifice 15 is provided so that air mixed in the cylinder 1 can be discharged from the rod side chamber 4 to the tank 6.

  Subsequently, as shown in FIG. 1, the damping valve DV includes a damping force adjusting passage TP, a fail passage FP, a downstream passage DP, a relief valve RV, an on-off valve OV, a solenoid Sol, and a downstream provided in parallel. And an orifice O provided in the passage DP. In this example, the damping valve DV is provided between the rod side chamber 4 and the tank 6 as described above. Specifically, the damping force adjusting passage TP and the fail passage FP provided in parallel are connected to the rod side chamber 4 and the downstream passage DP. One end of the downstream passage DP is connected to the damping force adjusting passage TP and the fail passage FP, and the other end is connected to the tank 6. Therefore, the rod side chamber 4 and the tank 6 are communicated with each other through the damping force adjusting passage TP, the fail passage FP, and the downstream passage DP.

  The relief valve RV is provided in the damping force adjustment passage TP, and the on-off valve OV is provided in the fail passage FP. The on-off valve OV is energized so as to be opened by a spring, and is an electromagnetic on-off valve that closes when thrust is received from the solenoid Sol. The on-off valve OV is a normally-open on-off valve that is energized by a spring when the solenoid Sol is not energized and communicates with the fail passage FP, and shuts off the fail passage FP when a predetermined amount of current is supplied to the solenoid Sol. Has been.

  The relief valve RV is driven by the thrust from the solenoid Sol via the on-off valve OV, and is energized by a spring to maximize the valve opening pressure when the solenoid Sol is not energized. . Further, when the solenoid Sol is energized and the on-off valve OV is set to the shut-off position, the thrust of the solenoid Sol acts on the relief valve RV as a force against the spring via the on-off valve OV. . Therefore, when the solenoid Sol is energized, it is possible to adjust the valve opening pressure of the relief valve RV according to the energization amount. When the energization amount is increased, the valve opening pressure of the relief valve RV is decreased. The valve opening pressure of the relief valve RV becomes maximum. Thus, in the damping valve DV of this example, the opening pressure of the relief valve RV can be adjusted and the opening / closing valve OV can be opened and closed with a single solenoid Sol.

  In this example, the fail passage FP is provided with a fail valve FV and a fail orifice A in parallel with the fail valve FV. The fail valve FV is opened when the pressure on the upstream side reaches a predetermined pressure in a state where the fail passage FP is communicated by the on-off valve OV. The valve opening pressure is the maximum valve opening of the relief valve RV. It is set to a value smaller than the pressure.

  Accordingly, when the solenoid valve Sol is energized in a normal state where the damping valve DV can function normally, the opening / closing valve OV can be shut off to adjust the valve opening pressure of the relief valve RV, and the cylinder device C can be expanded and contracted. The pressure in the rod side chamber 4 can be controlled. An orifice O is provided in the middle of the downstream passage DP, and the orifice O provides resistance to the flow of hydraulic oil. Therefore, the pressure in the rod side chamber 4 controlled by the relief valve RV is superimposed on the valve opening pressure of the relief valve RV with the resistance of the orifice O as an override. However, it is considered that the pressure override caused by the orifice O does not significantly affect the controllability of the pressure in the rod side chamber 4 by the relief valve RV.

  The damping valve DV is configured as described above, and when the cylinder device C extends, the valve opening pressure of the relief valve RV is adjusted according to the amount of current applied to the solenoid Sol, whereby the pressure in the rod side chamber 4 is adjusted. The damping force that is controlled to suppress the expansion generated by the cylinder device C is controlled. Further, when the cylinder device C contracts, the valve opening pressure of the relief valve RV is adjusted in accordance with the amount of current applied to the solenoid Sol, whereby the pressure in the rod side chamber 4 and the rod side chamber 4 is controlled. A damping force for suppressing the contraction generated by the device C is controlled.

Further, at the time of a failure in which the solenoid Sol cannot be energized (in an abnormal state), the on-off valve OV is opened to connect the fail passage FP, the fail valve FV is made effective, and the fail valve FV and the orifice O Demonstrate the damping force when the cylinder device C is expanded and contracted.

  Therefore, when the piston speed is in the low speed range, the normal damping force characteristic of the cylinder device C provided with the damping valve DV of this example is as shown by the line a in FIG. When the square characteristic appears and the piston speed increases and the relief valve RV opens, an override, which is the pressure loss of the orifice O, is superimposed on the opening pressure of the relief valve RV as shown by the line b in FIG. Characteristics appear. Note that the override of the orifice O increases as the piston speed increases, so that after the relief valve RV is opened, the damping coefficient gradually increases as the piston speed increases. The above-described damping force characteristic is a characteristic when the valve opening pressure of the relief valve RV is not changed, and the damping force of the cylinder device C can be adjusted by adjusting the valve opening pressure of the relief valve RV.

  When the first unload valve 8 and the second unload valve 10 are set to the shut-off position, the cylinder device C configured in this way causes the hydraulic oil to be transferred to the cylinder via the relief valve RV and the orifice O when it is extended or contracted by an external force. 1 is discharged into the tank 6. And if the valve opening pressure of the relief valve RV is adjusted by adjusting the energization amount supplied to the on-off valve OV, the damping force generated by the cylinder device C can be adjusted. Therefore, when the first unload valve 8 and the second unload valve 10 are set to the cutoff position in the normal state, the cylinder device C can function as a damper capable of adjusting the damping force on both sides of the expansion and contraction.

  Further, when the first unload valve 8 is in the communication position and the second unload valve 10 is in the cutoff position, and when the first unload valve 8 is in the cutoff position and the second unload valve 10 is in the communication position, As described above, the cylinder device C is in a mode in which a damping force is exerted only for either expansion or contraction. Therefore, for example, if this mode is selected, if the direction in which the damping force is exerted is the direction in which the vehicle body is vibrated by the vibration of the bogie of the railway vehicle, the damping force is not output in such a direction. The cylinder device C can be a one-effect damper. Therefore, the cylinder device C can easily realize the semi-active control based on the Carnop theory and function as a semi-active damper at normal times.

  On the other hand, when the power supply to the cylinder device C is interrupted for some reason, the first unload valve 8 and the second unload valve 10 take the cutoff position, and the cylinder device C functions as a passive damper as described above. In this state, the hydraulic oil is always discharged from the cylinder 1 when the cylinder device C expands and contracts. At this time, since the on-off valve OV is opened, the discharged hydraulic oil passes through the fail valve FV, the fail orifice A and the orifice O and flows into the tank 6. Therefore, during this failure, the fail valve FV, the fail orifice A and the orifice O provide resistance to the flow of the hydraulic oil, and the cylinder device C exhibits a damping force. When the expansion / contraction speed of the cylinder device C becomes high and the pressure in the rod side chamber 4 exceeds the valve opening pressure of the relief valve RV, the relief valve RV is also opened to allow the hydraulic oil to pass.

  As described above, the cylinder device C functions as a double-effect damper or a single-effect semi-active damper whose damping force can be adjusted during normal operation, and can function as a passive damper during failure.

  In the damping valve DV of the present invention, an orifice O is provided downstream of the relief valve RV. The orifice O has a characteristic that hinders a change in the flow rate of the hydraulic oil when the flow rate of the hydraulic oil passing through the orifice O fluctuates at a high frequency. Here, when the valve body of the relief valve RV suddenly opens and closes, the flow rate of the hydraulic oil that attempts to pass through the downstream orifice O changes in a vibrational manner at a high frequency, so that the orifice O suppresses fluctuations in the flow rate. To work. When the relief valve RV is opened, the back pressure acting on the valve body of the relief valve RV increases. Conversely, when the relief valve RV is closed, the back pressure acting on the valve body of the relief valve RV is increased. Decreases and prevents the relief valve RV from opening and closing sharply. Thus, the orifice O exhibits a damping action that hinders the rapid opening / closing operation of the valve body of the relief valve RV and slows down the operation. Therefore, in the damping valve DV of the present invention, even if the pressure fluctuation occurs in the rod side chamber 4 when the damping force of the cylinder device C is controlled by the relief valve RV, the damping valve exhibits the relief valve RV by the damping action exhibited by the orifice O. High frequency vibration can be suppressed. Therefore, according to the damping valve DV of the present invention, the oscillation of the relief valve RV can be suppressed, the waveform of the damping force generated by the cylinder device C is not disturbed, and the controllability of the vehicle body damping control by adjusting the damping force is achieved. Can be improved, and a sudden change in damping force can be avoided to prevent the generation of abnormal noise.

  Further, the damping valve DV of the present example includes a fail valve FV and a fail orifice A that give resistance to the flow of hydraulic oil in the fail passage FP. In the damping valve DV configured as described above, not only the orifice O but also the fail valve FV and the fail orifice A give resistance to the flow of hydraulic oil at the time of failure when the current supply to the solenoid Sol is interrupted. The characteristic of the orifice O is set so as not to affect the controllability by the relief valve RV that functions effectively during normal operation. However, the characteristic of the fail valve FV is set independently of other valves. Is possible. Therefore, according to the damping valve DV of this example, the damping force characteristic at the time of failure can be tuned as desired, and the damping force characteristic as intended at the time of failure can be exhibited. It should be noted that the function of the fail valve FV may be integrated with the on-off valve OV so as to provide resistance to the flow of hydraulic fluid flowing through the fail passage FP at the communication position of the on-off valve OV. Further, when the damping force is exerted by the orifice O at the time of failure, the fail valve FV may be eliminated. The fail valve FV is a relief valve or a pressure regulating valve. As shown in FIG. 4, a relief valve with an orifice may be used, or the orifice may be a separate body.

  Further, in the cylinder device C of the present example, the first passage 7 that communicates the cylinder 1, the tank 6, and the rod side chamber 4 and the piston side chamber 5, the interior of which is partitioned by the piston 2 into the rod side chamber 4 and the piston side chamber 5. Only the first unloading valve 8 provided in the second unloading valve 10 provided in the second passage 9 communicating with the piston side chamber 5 and the tank 6, and only the flow from the piston side chamber 5 toward the rod side chamber 4. A rectifying passage 11 that is allowed, a suction passage 12 that allows only a flow from the tank 6 toward the piston side chamber 5, and a damping valve DV are provided. According to the cylinder device C configured as described above, it can function as a double-effect damper or a single-effect semi-active damper whose damping force can be adjusted during normal operation, and can function as a passive damper during failure.

  If the cylinder device C is provided with a pump P that sucks hydraulic oil from the tank 6 and supplies it to the rod side chamber 4 as shown in FIG. 3, the cylinder device C can be actively expanded and contracted to function as an actuator. Further, in this way, the cylinder device C can function as a one-effect actuator damper that exerts thrust only by extension or contraction by switching between opening and closing of the first unload valve 8 and the second unload valve 10. Therefore, in this cylinder device C, it is not necessary to stop the driving of the pump P and switch the drive for switching the state of the actuator and the semi-active damper.

  In the above description, the damping valve DV has been described in principle. However, the damping valve DV having the specific structure shown in FIG. 4 will be described below. As shown in FIG. 4, the specific damping valve DV includes a housing H having a hollow portion 21, a first sleeve 22 and a second sleeve 23 inserted in series in the hollow portion 21, and the first sleeve 22. A first spool 24 to be accommodated and a second spool 25 to be accommodated in the second sleeve 23 are provided.

  Hereinafter, each part of the damping valve DV will be described in detail. First, the housing H is provided with the 1st housing H1 and the 2nd housing H2 with which the side part of the 1st housing H1 is mounted | worn in this example. The hollow portion 21 is provided in the first housing H1 and opens from the outside of the first housing H1. In this case, the hollow portion 21 communicates from both axial ends of the first housing H1 to the outside. In this example, the hollow portion 21 is opened from both ends of the first housing H1, but may be opened from one end side to form a bag hole.

  Further, the hollow portion 21 provided in the first housing H1 includes, in order from the right end side in FIG. 4, a spring support mounting portion 21a to which the spring support 27 is mounted, and a sleeve in which the first sleeve 22 and the second sleeve 23 are stored. The housing portion 21b and a second sleeve mounting portion 21c to which the second sleeve 23 is mounted are provided.

  The spring support mounting portion 21a is formed at the right end of the first housing H1 in FIG. 4, and a screw portion 21d is provided on the left side in FIG. 4, and the inner diameter on the right side in FIG. It has a large diameter and forms a part of the hollow portion 21.

  The sleeve accommodating portion 21b has a tip portion 21e formed with an inner diameter larger than the screw portion 21d on the left side in FIG. 4 of the screw portion 21d, and a tip portion 21e with an inner diameter on the left side of the tip portion 21e in FIG. An intermediate portion 21f formed with a larger diameter than the intermediate portion 21f and a rear end portion 21g formed with an inner diameter larger than that of the intermediate portion 21f on the left side in FIG. 4 of the intermediate portion 21f. Is part of. A step portion 21h is formed between the front end of the sleeve accommodating portion 21b and the rear end of the spring support mounting portion 21a. The second sleeve mounting portion 21 c is formed at the left end of the first housing H <b> 1 in FIG. 4 and forms a part of the hollow portion 21.

  Further, in this example, the first housing H1 opens in the radial direction from the outer peripheral side and communicates with the tip portion 21e, and the second port opens in the radial direction from the outer peripheral side and communicates with the intermediate portion 21f. A port 21j, a third port 21k that opens in the radial direction from the outer periphery side and communicates with the rear end 21g, and a fourth port 21m that opens from the outer periphery to the inner periphery and communicates with the passage 29 in the middle. Although not shown, the first port 21 i is connected to the tank 6 in the cylinder device C, and the second port 21 j is connected to the rod side chamber 4 in the cylinder device C. A plug 50 having an orifice O is mounted on the inner periphery of the first port 21i of the first housing H1.

  Further, the second housing H2 mounted on the side of the first housing H1 forms the housing H in cooperation with the first housing H1. The second housing H2 includes a valve hole 28 as a hole that opens in parallel to the hollow portion 21 from the outside at the left end in FIG. 4, and a passage 29 that opens from the inner periphery to the valve hole 28. In this example, a part of the passage 29 is formed by a hole opened from the right end in FIG. 4 of the second housing H2, and therefore the right end opening end of the hole in FIG. The second housing H <b> 2 is provided with a fifth port 31 that opens from the inner periphery and communicates with the valve hole 28.

  When the second housing H2 is mounted on the first housing H1, the passage 29 and the second port 21j are opposed to communicate with each other, and the fifth port 31 and the third port 21k are opposed to communicate with each other. It should be noted that the first housing H1 and the second housing H2 may be a single component rather than separate.

  The inner diameter of the valve hole 28 is larger than the inner diameter of the opening end connected to the valve hole 28 in the passage 29, and the opening end of the passage 29 to the valve hole 28 is located in the valve seat 28. 34, a valve body 35 that is separated from and seated on the valve seat 34 is accommodated. Further, a spring 16 for energizing the valve body 35 toward the valve seat 34 side is accommodated in the valve hole 28, and a lid 37 functioning as a spring receiver is screwed to the left end side of the valve hole 28. The valve hole 28 is closed. The spring 16 is sandwiched between the lid 37 and the valve body 35 in a compressed state so that the biasing force of the spring 16 that biases the valve body 35 can be adjusted by adjusting the mounting position of the lid 37 with respect to the valve hole 28. It has become. The valve seat 34, the valve body 35, the spring 16 and the lid 37 constitute a fail valve FV.

  The valve body 35 is provided with a fail orifice A. The fail orifice A is arranged in parallel with the fail valve FV, and communicates with the passage 29 even when the fail valve FV is closed.

  Accordingly, when hydraulic oil is introduced from the outside through the fourth port 21m and the pressure in the passage 29 exceeds the valve opening pressure of the fail valve FV, the valve body 35 is retracted from the valve seat 34 and opened, and the passage 29 is opened. Is communicated with the fifth port 31.

  The first sleeve 22 has a stepped cylindrical shape with the outer diameter on the right end side in FIG. 4 smaller than the outer diameter on the rear end side on the left end side in FIG. Two annular grooves 22a and 22b formed side by side are provided.

  The first sleeve 22 includes an inner peripheral large diameter portion 22c provided on the inner periphery on the front end side, and an inner peripheral small diameter portion 22d having a smaller diameter than the inner peripheral large diameter portion 22c provided on the inner periphery on the rear end side. ing. Further, the first sleeve 22 has a through hole 22e that opens from the annular groove 22a and communicates with the inner peripheral large diameter portion 22c, a through hole 22f that opens from the annular groove 22b and communicates with the inner peripheral small diameter portion 22d, and a rear end. A through hole 22h is provided that opens and opens into a step portion 22g formed between the inner peripheral large diameter portion 22c and the inner peripheral small diameter portion 22d.

  A seal ring 38 is mounted on the outer periphery of the first sleeve 22 along the circumferential direction between the annular groove 22a and the annular groove 22b, and seals along the circumferential direction on the rear end side of the annular groove 22b. A ring 39 is attached.

  The first sleeve 22 configured as described above is inserted into the hollow portion 21 of the first housing H1 from the small diameter side, the small diameter portion is fitted into the distal end portion 21e, and the large diameter portion is an intermediate portion in the first housing H1. It fits in the part 21f and is accommodated in the sleeve accommodating part 21b in the hollow part 21. Then, the seal rings 38 and 39 are brought into close contact with the inner periphery of the sleeve accommodating portion 21b of the first housing H1, and the space between the annular groove 22a and the annular groove 22b is sealed. The annular groove 22a faces and communicates with the first port 21i provided on the first housing H1, and the annular groove 22b faces and communicates with the second port 21j provided on the first housing H1. Is done. Therefore, the passage 29 communicates with the first sleeve 22 through the second port 21j, the annular groove 22b, and the through hole 22f. The first port 21i communicates with the first sleeve 22 through the annular groove 22a and the through hole 22e, and further communicates with the fourth port 21m.

  The second sleeve 23 has a stepped cylindrical shape with the outer diameter on the right end side in FIG. 4 smaller than the outer diameter on the rear end side on the left end side in FIG. 4, and is provided on the rear end side. 4, a cylindrical collar 23a that rises to the left in FIG. 4, a flange 23b provided on the outer periphery of the rear end of the collar 23a, an annular groove 23c provided between the small diameter portion and the large diameter portion, and an outer periphery of the collar 23a. And a screw part 23d as a fixing part provided on the head.

  Further, the second sleeve 23 is formed in a cylindrical shape, and a spool hole Sh is formed in the inside thereof. The spool hole Sh is provided with an inner peripheral large diameter portion 23e having a large inner diameter on the way. Further, the second sleeve 23 includes a through hole 23f that opens from the annular groove 23c and communicates with the inner peripheral large diameter portion 23e. Note that seal rings 40 and 41 are mounted on the outer periphery of the second sleeve 23 along the circumferential direction in the axial direction with respect to the annular groove 23c.

  The second sleeve 23 configured in this manner is positioned in the axial direction with the flange 23b coming into contact with the rear end surface which is the left end surface in FIG. 4 of the first housing H1, and the opening of the hollow portion 21 of the first housing H1. Attached to the end. Specifically, the second sleeve 23 is fixed to the first housing H1 by screwing a screw portion 23d as a fixing portion to a second sleeve mounting portion 21c formed in the hollow portion 21. Then, the second sleeve 23 has a small diameter portion fitted in the intermediate portion 21f of the first housing H1, and a large diameter portion fitted in the rear end portion 21g of the first housing H1. Be contained. A recess 23g is provided at the right end of the second sleeve 23 in FIG. 4, and the recess 23g faces the through hole 22h that opens at the rear end, which is the left end of the first sleeve 22 in FIG. Through the inner circumferential large diameter portion 22 c in the first sleeve 22. Further, the inner diameter of the recess 23g is smaller than the outer diameter of the first sleeve 22 and larger than the inner diameter of the second sleeve 23, and the right end face of the second sleeve 23 in FIG. Opposite the end face. Therefore, when the second sleeve 23 is attached to the first housing H <b> 1, it functions as a retainer for the first sleeve 22 accommodated in the hollow portion 21.

  When the second sleeve 23 is accommodated in the hollow portion 21 as described above, the seal rings 40 and 41 are brought into close contact with the inner periphery of the sleeve accommodating portion 21b of the first housing H1, and the annular groove 23c is formed in the second sleeve 23. It does not communicate with other places via the outer periphery. Further, the annular groove 23c faces and communicates with the third port 21k provided in the first housing H1. Therefore, the fifth port 31 of the second housing H2 communicates with the second sleeve 23 via the third port 21k, the annular groove 23c, and the through hole 23f.

  The flange 23b is configured to block a part of the opening end of the valve hole 28 as a hole at the left end in FIG. 1, so that the lid 37 attached to the valve hole 28 is detached from the second housing H2. Can be prevented. Therefore, there is no possibility that the fail valve FV provided in the second housing H2 will come out of the second housing H2.

  In this example, in the state where the second sleeve 23 is positioned and attached to the first housing H1 in the axial direction, the axial length of the first sleeve 22 is the right end of the second sleeve 23 in FIG. It is set to be shorter than the length in the axial direction from the end surface to the step portion 21 h in the hollow portion 21. Therefore, even if the second sleeve 23 is attached to the first housing H1, the first sleeve 22 is not sandwiched between the second sleeve 23 and the stepped portion 21h in a compressed state, and the first sleeve 22 and the second sleeve 23 are not connected to each other. It is designed not to receive power. The length in the axial direction of the first sleeve 22 may be set to be equal to the length in the axial direction from the end surface of the right end in FIG. 4 of the second sleeve 23 to the step portion 21 h in the hollow portion 21. . Even in this case, it is possible to prevent the axial force from being applied to the first sleeve 22 and the second sleeve 23.

  Further, in this example, the second sleeve 23 is positioned in the axial direction with the flange 23b contacting the first housing H1, and the positioning portion is the flange 23b. The fixing portion of the second sleeve 23 is a screw portion 23d in this example, and the spool hole Sh is formed with respect to the second sleeve 23 from a flange 23b as a positioning portion to a screw portion 23d as a fixing portion. It is provided outside the range between. In this case, since the flange 23b (positioning part), the screw part 23d (fixing part), and the spool hole Sh are arranged in series in the axial direction, the spool hole Sh has a flange 3b (positioning part) with respect to the second sleeve 23. And the screw portion 23d (fixed portion) may be provided at a position shifted in the axial direction.

  In this way, neither the compressive load nor the tensile load can be applied to the portion of the spool hole Sh of the second sleeve 23. That is, the positioning portion positions the second sleeve 23 in the axial direction, and the fixing portion is a portion that fixes the second sleeve 23 to the first housing H1. A load may act. However, when the spool hole Sh is arranged as described above, no load is applied to the portion of the second sleeve 23 where the spool hole Sh is provided, and deformation of the spool hole Sh can be prevented.

  In FIG. 4, the second sleeve 23 is screwed to the first housing H1. However, the screw groove and the screw portion 23d of the second sleeve mounting portion 21c are abolished, and the flange 23b and the housing H are bolted. The two sleeves 23 may be fixed to the first housing H1. In this case, the positioning portion and the fixing portion become the flange 23b, and the spool hole Sh is also provided outside the range from the positioning portion to the fixing portion with respect to the second sleeve 23. Even in this case, it is possible to prevent the axial load from acting on the portion of the second sleeve 23 where the spool hole Sh is provided.

  Further, as shown in FIG. 5, the screw groove 23d of the second sleeve mounting portion 21c and the screw portion 23d on the outer periphery of the collar 23a of the second sleeve 23 are abolished, and a cylindrical inner screw portion 60 is formed on the outer periphery of the flange 23b. And the second sleeve 23 may be fixed to the first housing H1 by screwing the inner peripheral screw portion 60 around the outer periphery of the first housing H1. In this case, the flange 23b contacts the end of the first housing H1, and the second sleeve 23 is positioned in the axial direction. Therefore, the positioning portion in the second sleeve 23 is the flange 23b, and the fixing portion is the inner peripheral screw portion 60. It becomes. On the second sleeve 23, the spool hole Sh is provided outside the range between the flange 23b of the positioning portion and the inner peripheral screw portion 60 of the fixing portion. Even in this case, it is possible to prevent the axial load from acting on the portion of the second sleeve 23 where the spool hole Sh is provided. In the case where the inner peripheral screw portion 60 is provided on the outer periphery of the flange 23b, even if the spool hole Sh is provided at a position overlapping the inner peripheral screw portion when viewed from the radial direction, the inner flange portion 23b and the inner portion of the positioning portion are positioned on the second sleeve 23. Since it is provided outside the range between the peripheral screw portion 60, it is possible to prevent the axial load from acting on the portion of the second sleeve 23 where the spool hole Sh is provided.

  The first spool 24 is accommodated in the first sleeve 22 so that the movement in the axial direction is guided. Specifically, the first spool 24 extends to the right from the sliding shaft portion 24a slidably inserted into the inner peripheral small diameter portion 22d of the first sleeve 22 and the right end of the sliding shaft portion 24a in FIG. A small-diameter shaft portion 24b and a truncated cone-shaped valve body 24c provided at the right end of the small-diameter shaft portion 24b in FIG. 4 are provided.

  The sliding shaft portion 24 a has an outer diameter larger than that of the small diameter shaft portion 24 b and is in sliding contact with the inner peripheral small diameter portion 22 d of the first sleeve 22. The movement in the direction is guided without any axial movement. The small diameter shaft portion 24 b has an outer diameter smaller than the inner diameter of the inner peripheral small diameter portion 22 d and faces the through hole 22 f provided in the first sleeve 22. Further, the first spool 24 moves in the axial direction with respect to the first sleeve 22, but the sliding shaft portion 24a does not completely close the opening of the through hole 22f.

  The valve body 24c has an outer diameter larger than the inner diameter of the inner peripheral small diameter portion 22d. The opening edge at the right end in FIG. 4 of the inner peripheral small diameter portion 22d is used as the valve seat 42 in the axial direction of the first spool 24. Can move to and from the valve seat 42.

  Further, a spring receiver 27 is mounted on the spring receiver mounting portion 21a in the hollow portion 21 of the first housing H1. The spring receiver 27 has a bottomed cylindrical shape and is provided with a screw portion 27a on the outer periphery. The screw portion 27a is screwed into a screw portion 21d provided in the hollow portion 21 of the first housing H1. It can be attached to one housing H1. Further, the spring receiver 27 includes a seal ring 43 that is mounted along the circumferential direction at an outer circumferential position that avoids the screw portion 27a. When the spring receiver 27 is mounted on the first housing H1 as described above, the seal ring 43 comes into close contact with the inner periphery of the spring receiver mounting portion 21a in the hollow portion 21, and the spring receiver 27 illustrates the hollow portion 21 of the first housing H1. 4 Middle right end is liquid-tightly closed.

  A spring S is interposed between the spring receiver 27 and the right end in FIG. 4 of the valve body 24c of the first spool 24, and the urging force of the spring S causes the valve body 24c to act as the valve body 24c. It is biased in the direction of seating on the seat 42. Thus, the relief valve RV is comprised by the 1st spool 24 provided with the valve body 24c, the 1st sleeve 22 which has the valve seat 42, and the spring S. FIG. When no external force is applied to the first spool 24 other than the spring S, the valve body 24c is pressed against the valve seat 42 to close the valve, and the valve opening pressure of the relief valve RV is maximized. Then, a thrust is applied to push the first spool 24 in the direction to open the valve body 24c against the urging force of the spring S. When this thrust is adjusted, the pressing force of the valve body 24c to the valve seat 42 is adjusted, The valve opening pressure of the relief valve RV can be adjusted.

  When the relief valve RV is opened, the damping force adjusting passage TP configured in the fourth port 21m, the annular groove 22b, the through hole 22f, and the inner peripheral small diameter portion 22d is opened. On the other hand, when the valve body 24c is seated on the valve seat 42 and the relief valve RV is closed, the connection between the inner peripheral small diameter portion 22d and the inner peripheral large diameter portion 22c is cut off, and the damping force adjusting passage TP is cut off. It becomes. In this example, the downstream passage DP is configured by the inner peripheral large diameter portion 22c, the through hole 22e, the annular groove 22a, and the first port 21i. As described above, the downstream passage DP includes the first port 21i. An orifice O is provided by a plug 50 attached to the. Further, as described above, the first port 21 i is connected to the tank 6 in the cylinder device C, and the second port 21 j is connected to the rod side chamber 4 in the cylinder device C. Therefore, the upstream of the damping force adjusting passage TP in which the relief valve RV is installed is communicated with the rod side chamber 4 and the downstream of the downstream passage DP is communicated with the tank 6 as in the cylinder device C shown in FIG. The damping force of the cylinder device C can be adjusted by adjusting the valve opening pressure of the relief valve RV.

  A valve body side spring receiver 44 is interposed between the spring S and the first spool 24. In this example, the spring S is a coil spring, and the right end in FIG. 4 of the valve body side spring receiver 44 is loosely fitted to the inner periphery of the spring S, so that the misalignment between the axis of the spring S and the first spool 24 is prevented. It can be absorbed by the valve body side spring receiver 44. As a result, the biasing force of the spring S acts on the first spool 24 without deviation in the radial direction, so that the valve opening pressure of the first spool 24 is stabilized without variation.

  The second spool 25 is accommodated in the second sleeve 23 and guided for movement in the axial direction. Further, the right end in FIG. 4 can come into contact with the left end in FIG. 4 of the first spool 24. Specifically, the second spool 25 includes a sliding shaft portion 25a that is slidably inserted into the spool hole Sh of the second sleeve 23, and a columnar shape that extends rightward from the right end in FIG. 4 of the sliding shaft portion 25a. 4 and a convex portion 25c that is provided at the right end of the valve portion 25b in FIG. 4 and protrudes in the axial direction.

  The sliding shaft portion 25 a is in sliding contact with the spool hole Sh of the second sleeve 23, and the movement of the second spool 25 in the axial direction is guided by the second sleeve 23 without running out.

  The outer diameter of the valve portion 25b is set to a diameter that is in sliding contact with the spool hole Sh provided in the second sleeve 23, and the right end of the valve portion 25b is disposed to the right of the inner peripheral large diameter portion 23e in the spool hole Sh. The communication between the passage hole 23f provided in the second sleeve 23 and the spool hole Sh is cut off.

  Further, a flange 25d is provided at the rear end of the sliding shaft portion 25a, which is the left end in FIG. 4, and a coil spring 45 is interposed between the right end of the flange 25d in FIG. 4 and the second sleeve 23. It is disguised. The second spool 25 is urged by the coil spring 45 toward the left in FIG. In a state where an external force other than the urging force of the coil spring 45 does not act, the second spool 25 has the valve portion 25b positioned in the inner peripheral large diameter portion 23e with respect to the second sleeve 23, as shown in FIG. A flow path composed of the through hole 23f and the spool hole Sh is communicated.

  Further, a solenoid Sol is mounted on the left side of the second sleeve 23 in FIG. 4, and a rightward thrust in FIG. 4 is applied to the second spool 25 by the plunger 51 of the solenoid Sol by energizing the solenoid Sol. It is supposed to be. Further, the thrust applied to the second spool 25 can be adjusted by adjusting the energization amount of the solenoid Sol. This thrust applies a force in a direction opposite to the coil spring 45 to the second spool 25, so that the second spool 25 resists the urging force of the coil spring 45 and the tip of the valve portion 25 b is moved into the inside of the second sleeve 23. It can be moved to the right from the circumferential large diameter portion 23e. Therefore, the flow path can be communicated and blocked by moving the second spool 25 in the axial direction depending on whether or not the solenoid Sol is energized. As described above, the second sleeve 23, the second spool 25, and the coil spring 45 constitute an on-off valve OV that is normally open to open and close the flow path, and this on-off valve OV is connected to the solenoid Sol. The electromagnetic on-off valve opens and closes the flow path when energized.

  When the on-off valve OV is opened, a fail passage FP including a passage 29, a valve hole 28, a fifth port 31, a third port 21k, an annular groove 23c, a through hole 23f, a spool hole Sh, a recess 23g, and a through hole 22h. Is in a communication state. Since the fail passage FP communicates with the inner peripheral large diameter portion 2c of the first sleeve 22, the fail passage FP joins the damping force adjustment passage TP at the inner peripheral large diameter portion 22c, and both communicate with the downstream passage DP. . When the fail passage FP is in a communicating state, the fail valve FV provided in the valve hole 28 is also opened, and the pressure introduced from the fourth port 21m reaches the opening pressure of the fail valve FV. Then, the fail valve FV is opened, and the pressure in the rod side chamber 4 can be discharged to the tank 6 through the fail passage FP and the downstream passage DP. In the state where the on-off valve OV is closed, the connection of the flow path formed by the through hole 23f and the spool hole Sh is cut off, and the fail passage FP is cut off.

  Further, the thrust applied to the second spool 25 can be adjusted by the energization amount of the solenoid Sol. When the second spool 25 is closed and the second spool 25 is brought into contact with the first spool 24, the second spool 25 is closed. The thrust of the solenoid Sol can be transmitted to the first spool 24 via the spool 25.

  Thus, since the thrust of the solenoid Sol in the direction opposite to the spring S can be applied to the first spool 24, the thrust applied to the first spool 24 is adjusted by adjusting the energization amount of the solenoid Sol, and the relief valve The valve opening pressure of RV can be adjusted.

  In this way, the damping valve DV can function as a damping force reduction by applying the cylinder device C. In the damping valve DV in the present invention, an orifice O is provided downstream of the relief valve RV. The orifice O has a characteristic that hinders a change in the flow rate of the hydraulic oil when the flow rate of the hydraulic oil passing through the orifice O varies at a high frequency. Here, when the valve body of the relief valve RV suddenly opens and closes, the flow rate of the hydraulic oil that attempts to pass through the downstream orifice O changes in a vibrational manner at a high frequency, so that the orifice O suppresses fluctuations in the flow rate. To work. When the relief valve RV is opened, the back pressure acting on the valve body of the relief valve RV increases. Conversely, when the relief valve RV is closed, the back pressure acting on the valve body of the relief valve RV is increased. Decreases and prevents the relief valve RV from opening and closing sharply. Thus, the orifice O exhibits a damping action that hinders the rapid opening / closing operation of the valve body of the relief valve RV and slows down the operation. Therefore, even in the case of a specific damping valve DV, even if pressure fluctuation occurs in the rod side chamber 4 when the damping force of the cylinder device C is controlled by the relief valve RV, the relief is exerted by the damping action exerted by the orifice O. High frequency vibration of the valve RV can be suppressed. Therefore, according to this specific damping valve DV, the oscillation of the relief valve RV can be suppressed, the waveform of the damping force generated by the cylinder device C is not disturbed, and the vehicle body damping control is controlled by adjusting the damping force. This improves the performance, avoids sudden changes in damping force, and prevents abnormal noise.

  Further, even in the case of a specific damping valve DV, the fail passage FP is provided with a fail valve FV that provides resistance to the flow of hydraulic oil, so that the damping force characteristic at the time of failure can be tuned as desired, and at the time of failure Demonstrates the desired damping force characteristics.

  Further, in a specific damping valve DV, a first housing H1 (housing H) having a hollow portion 21, a first sleeve 22 and a second sleeve 23 inserted in series in the hollow portion 21, and the first sleeve 22 And a second spool 25 accommodated in the second sleeve 23. Further, a flange 23b (positioning portion) for positioning the second sleeve 23 in an axial position with respect to the first housing H1 (housing H), and a screw portion 23d (fixing portion) fixed to the first housing H1 (housing H), And a spool hole Sh provided outside the range from the flange 23b (positioning portion) to the screw portion 23d (fixed portion). When the damping valve DV is configured in this manner, the load of the axial load on the portion of the second sleeve 23 where the spool hole Sh is provided is prevented, and the first sleeve 22 accommodated in the hollow portion 21 is also axially These can be prevented from coming off without applying a tensile load or a compressive load. Therefore, distortion does not arise in the inner peripheral shape in which the first spool 24 and the second spool 25 of the first sleeve 22 and the second sleeve 23 are accommodated. This eliminates the need for highly accurate management of the dimensions of the first sleeve 22, the second sleeve 23, and the first housing H1, and allows the first sleeve 22 and the second sleeve 23 to be processed without shaping the inner periphery thereof. The movement of the one spool 24 and the second spool 25 in the axial direction is guaranteed. From the above, according to the damping valve DV, it is easy to process and the smooth operation of the first spool 24 and the second spool 25 can be realized.

  Further, in the damping valve DV in this example, the spool hole Sh is provided in the first housing H1 (housing H) from the flange 23b (positioning portion) and the screw portion 23d (fixed portion) with respect to the second sleeve 23. . If the damping valve DV is configured in this way, the portion of the second sleeve 23 where the spool hole Sh is provided can be accommodated in the first housing H1 (housing H), and the overall length of the damping valve DV can be shortened.

  In the damping valve DV in this example, the axial length of the first sleeve 22 is set to be shorter than the axial length from the end surface of the second sleeve 23 to the step portion 21h in the hollow portion 21. ing. Therefore, even if the second sleeve 23 is attached to the first housing H1, the first sleeve 22 is not clamped between the second sleeve 23 and the stepped portion 21h, and the first sleeve 22 and the second sleeve 23 are not compressed. It is possible to reliably realize a state in which no axial force acts. In addition, dimensional management with respect to the first sleeve 22, the second sleeve 23, and the first housing H1 becomes easier.

  In the damping valve DV in this example, the positioning portion is a flange 23b provided on the outer periphery of the second sleeve 23, and the flange 23b abuts on an end surface of the first housing H1 (housing H), and the second sleeve 23 is provided. Is positioned with respect to the first housing H1 (housing H). If the damping valve DV is configured in this way, the second sleeve 23 can be positioned with respect to the housing H with a simple configuration. Further, when the flange 23b is fixed to the first housing H1 with a bolt, the flange 23b can function as both a positioning portion and a fixing portion, and the overall length of the second sleeve 23 and hence the overall length of the damping valve DV can be shortened. 23 and the first sleeve 22 do not need to be loaded with torque, and the distortion of the inner peripheral shape of both can be more effectively prevented.

  The orifice O may be provided separately from the housing H because it may be provided in the damping force adjusting passage TP and the downstream passage DP from the fail passage FP to the tank 6.

  Although the preferred embodiments of the present invention have been described in detail above, modifications, variations, and changes can be made without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1 ... Cylinder, 2 ... Piston, 3 ... Rod, 4 ... Rod side chamber, 5 ... Piston side chamber, 6 ... Tank, 7 ... 1st channel | path, 8 ... First unloading valve, 9 ... second passage, 10 ... second unloading valve, 11 ... rectifying passage, 12 ... suction passage, 21 ... hollow part, 22 ... first One sleeve, 223, second sleeve, 23b, flange (positioning portion, fixed portion), 23d, screw portion (fixed portion), 24, first spool, 24c, valve body, 25 ... second spool, 42 ... valve seat, C ... cylinder device, DP ... downstream passage, DV ... damping valve, FP ... fail passage, FV ... fail valve, H ... Housing, O ... Orifice, OV ... Open / close valve, RV ... Relief valve, Sh ... Spoo Hole, Sol · · · solenoid, TP · · · damping force control passage

Claims (4)

A damping force adjusting passage;
A fail passage provided in parallel with the damping force adjusting passage;
A downstream passage connected downstream of the damping force adjusting passage and the fail passage;
A relief valve provided in the damping force adjusting passage;
A normally open on-off valve provided in the fail passage;
A solenoid that adjusts the opening pressure of the relief valve when energized and closes the on-off valve;
A damping valve comprising an orifice provided in the downstream passage. A housing having a hollow portion;
The relief valve includes a cylindrical first sleeve inserted into the hollow portion and having the damping force adjusting passage, and a valve provided in the first sleeve so as to be axially movable in the first sleeve. A first spool having a valve body that can be seated on a seat; and a spring that is accommodated in the hollow portion and biases the first spool in a direction to seat the valve body on the valve seat;
The on-off valve is inserted into the hollow portion in series with the first sleeve and has a cylindrical second sleeve having at least a part of the fail passage, and is accommodated in the second sleeve and is attached to the second sleeve. A second spool guided so as to be movable in the axial direction,
The second sleeve includes a positioning portion for positioning an axial position with respect to the housing, a fixing portion fixed to the housing, and a second portion at a position outside the range from the positioning portion to the fixing portion of the second sleeve. A spool hole into which the spool is slidably inserted;
The solenoid moves the second spool in the axial direction to open and close the on-off valve, and applies thrust to the first spool via the second spool to adjust the valve opening pressure of the relief valve. The damping valve according to claim 1. The damping valve according to claim 1, further comprising a fail valve that provides resistance to a liquid flow in the fail passage. A cylinder,
A piston slidably inserted into the cylinder;
A rod inserted into the cylinder and connected to the piston;
A rod side chamber and a piston side chamber partitioned by the piston in the cylinder;
A tank,
A first unload valve provided in a first passage communicating the rod side chamber and the piston side chamber to open and close the first passage;
A second unload valve provided in a second passage communicating the piston side chamber and the tank to open and close the second passage;
A rectifying passage that allows only a flow from the piston side chamber to the rod side chamber;
A suction passage that allows only a flow from the tank toward the piston-side chamber;
A damping force adjusting passage;
A fail passage provided in parallel with the damping force adjusting passage;
A downstream passage connected downstream of the damping force adjusting passage and the fail passage;
A relief valve provided in the damping force adjusting passage;
A normally open on-off valve provided in the fail passage;
A solenoid that adjusts the opening pressure of the relief valve when energized and closes the on-off valve;
An orifice provided in the downstream passage,
The cylinder device, wherein an upstream of the damping force adjusting passage and the fail passage is connected to the rod side chamber, and the downstream passage is connected to the tank.

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