Oil Damper System

Abstract

To provide an oil damper system which enables improvement of maintainability of an oil damper whose damping performance is changed.SOLUTION: A damping valve unit 10 is provided at a uniflow type cylinder unit, has a valve body 14 which is biased by a pressure-adjusting spring 16, and is configured to absorb energy through action in which a working fluid F flowing from a working fluid outflow chamber of the cylinder unit to an outer cylinder moves the valve body against a spring force. The pressure-adjusting spring of the damping valve unit is formed as return means which returns a control oil f to control cylinder units so that control piston rods are respectively returned to initial positions.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an oil damper system that can improve maintainability, and is directed to an oil damper that has variable damping performance. [Background technology]

[0002] Oil dampers are known that are installed between the ground and a building to absorb earthquake energy in order to attenuate earthquake motions acting on the vibration input side and the vibration damping target side, for example, a building supported on the ground by seismic isolation bearings.

[0003] An example of this type of oil damper is known from Patent Document 1. The "oil damper for a seismic isolation device" in Patent Document 1 is an oil damper for a seismic isolation device that, when used in combination with a seismic isolation bearing, constitutes a seismic isolation device and absorbs and attenuates the energy of earthquake shaking in order to suppress relative displacement between the foundation and the upper building during an earthquake, and includes a first cylinder connected to one of the foundation and the upper building, a first piston slidably provided within the first cylinder and dividing the first cylinder into two oil chambers, left and right, a first hydraulic cylinder having a piston rod with a pressing portion that is provided integrally with the first piston and connected to the other of the foundation and the upper building, a communication passage that connects the two oil chambers to each other outside the first hydraulic cylinder, a valve body provided midway in the communication passage and that opens and closes the communication passage, a movable spring seat, and a spring that is provided between the valve body and the spring seat and biases the valve body toward the closing side. a damping valve that generates a damping force by opening the valve body with hydraulic pressure supplied from the oil chamber of the first cylinder as the first piston of the first hydraulic cylinder is displaced; a second cylinder that communicates with the back side of the spring seat of the damping valve; a second piston that is slidably provided within the second cylinder; and a second piston rod that has an engaging portion and is integral with the second piston, the second hydraulic cylinder being actuated when the engaging portion is pressed by the pressing portion of the first piston rod when the displacement of the first piston reaches a predetermined value, and introducing hydraulic pressure from within the second cylinder to the back side of the spring seat to compress the spring via the spring seat and increase the spring force of the spring, thereby strengthening the damping force. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4442770 Summary of the Invention [Problem to be solved by the invention]

[0005] The oil damper disclosed in the background art is an excellent device that, when the displacement of the first piston reaches a predetermined value, introduces hydraulic pressure from within the second cylinder of the second hydraulic cylinder to the back side of the spring seat of the damping valve, increasing the spring force of the spring that biases the valve body to open and close the communication passage that communicates with the first hydraulic cylinder, thereby strengthening the damping force, and can change the damping performance in accordance with the stroke of the first piston rod caused by seismic motion.

[0006] In this oil damper, a spring that returns oil from the damping valve to the second hydraulic cylinder is provided inside the second cylinder that generates hydraulic pressure that introduces hydraulic pressure to the back side of the spring seat.

[0007] When this spring moves, the protective surface film on the inside of the second cylinder and the spring itself can peel off, becoming debris that gets mixed into the oil, causing the oil to deteriorate prematurely and requiring more frequent maintenance.

[0008] In addition to incorporating a spring into the damping valve, a separate spring that returns oil is provided in the second hydraulic cylinder, and because these springs are installed in different locations, there is a possibility that the maintenance work required to adjust the performance of the oil damper will be complicated.

[0009] The present invention was devised in view of the above-mentioned problems in the conventional art, and aims to provide an oil damper system that can improve maintainability, targeting an oil damper that has variable damping performance. [Means for solving the problem]

[0010] The oil damper system according to the present invention comprises an outer cylinder connected to one of the vibration input side and the vibration damping target side, a piston rod connected to the other of the vibration input side and the vibration damping target side, an inner cylinder provided inside the outer cylinder in which hydraulic oil is stored, the inner cylinder having a hydraulic oil outflow chamber and a hydraulic oil inflow chamber partitioned by a piston connected to the piston rod, and when the piston reciprocates, the hydraulic oil in the hydraulic oil outflow chamber flows out to the outer cylinder and flows in one direction from the outer cylinder to the hydraulic oil inflow chamber, a uniflow type cylinder unit having a valve body biased by a spring member, and the hydraulic oil flowing from the hydraulic oil outflow chamber to the outer cylinder moves the valve body against the spring force, thereby absorbing energy, a damping valve unit having a transmission member for transmitting the amount of extension and retraction stroke of the piston rod that moves the piston, and a transmission member provided along the extension and retraction stroke direction of the piston rod, the transmission member being connected to the piston and the transmission member being connected to the piston. and a control oil supply system that supplies the control oil discharged from each of the pair of control cylinder units to the damping valve unit when an excessive protruding stroke or excessive retracting stroke occurs in the piston rod that exceeds a predetermined protruding and retracting stroke amount, by the transmission member, and the control oil supply system that supplies the control oil discharged from each of the pair of control cylinder units to the damping valve unit, and the damping valve unit is characterized in that it is provided with a spring seat that is provided on the opposite side of the valve body across the spring member, and is moved so as to compress the spring member by control oil supplied from the control oil supply system, and increases the spring force of the spring member in accordance with the excessive protruding stroke amount and excessive retracting stroke amount, and return means that returns control oil to each of the control cylinder units to return each of the control piston rods to their initial positions.

[0011] The returning means is characterized in that the spring member is set to have a spring force that presses the spring seat so as to cause the control oil to flow out to the control oil supply system.

[0012] The return means is characterized in that it is a shim that is arranged between the spring seat and the valve body, overlapping with the spring member, and causes the spring member to press the spring seat so as to cause the control oil to flow out into the control oil supply system.

[0013] The return means is characterized in that it is a return spring formed with a spring constant smaller than that of the spring member, is arranged in parallel with the spring member between the spring seat and the valve body, and presses the spring seat from the valve body side so as to cause the control oil to flow out into the control oil supply path.

[0014] The return means returns the control oil to each of the control cylinder units when the flow of hydraulic oil that moves the valve body ceases. [Effects of the Invention]

[0015] The oil damper system according to the present invention can improve maintainability for oil dampers that are designed to have variable damping performance. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an explanatory diagram illustrating a hydraulic circuit of a preferred embodiment of an oil damper system according to the present invention. FIG. [Figure 2] FIG. 2 is a plan view showing the device configuration of the oil damper system of FIG. 1 in an installed state. [Figure 3] FIG. 2 is a side view showing the device configuration of the oil damper system of FIG. 1 in an installed state. [Figure 4] FIG. 2 is a cross-sectional view illustrating a damping valve unit provided in the oil damper system of FIG. 1. [Figure 5] FIG. 2 is a cross-sectional view illustrating a control cylinder unit provided in the oil damper system of FIG. 1. [Figure 6] FIG. 5 is a cross-sectional view showing a modified example of the damping valve unit shown in FIG. [Figure 7] FIG. 5 is a cross-sectional view showing another modified example of the damping valve unit shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an oil damper system according to the present invention will be described in detail below with reference to the accompanying drawings.

[0018] Fig. 1 is an explanatory diagram illustrating a hydraulic circuit of an oil damper system according to this embodiment. Fig. 2 is a diagram showing a plan view of the device configuration of the oil damper system of Fig. 1 in an installed state. Fig. 3 is a diagram showing a side view of the device configuration of the oil damper system of Fig. 1 in an installed state. Fig. 2 may be a side view of the installed state, and Fig. 3 may be a plan view of the installed state.

[0019] The oil damper system 1 of this embodiment is installed between the vibration input side and the vibration damping target side, for example, between the ground 2 or the foundation of a building 3 that moves integrally with the ground 2 to absorb earthquake energy, and the building 3 supported on the foundation by seismic isolation bearings.

[0020] However, it goes without saying that the oil damper system 1 according to this embodiment may be provided in any vibration transmission system for the purpose of vibration damping.

[0021] The oil damper system 1 according to this embodiment is mainly composed of a uniflow type cylinder unit 4.

[0022] The uniflow type cylinder unit 4 itself is known and is configured to include an outer cylinder 5, a hydraulic oil reservoir 6 provided inside the outer cylinder 5 and storing hydraulic oil F while maintaining a free surface, an inner cylinder 7 provided inside the outer cylinder 5, a piston 8 provided inside the inner cylinder 7 so as to slide freely in a liquid-tight manner and to divide the interior of the inner cylinder 7 into two hydraulic oil outlet chambers R1 and R2, a piston rod 9 connected integrally to the piston 8, which penetrates the inner cylinder 7 and protrudes liquid-tightly outward from the outer cylinder 5 and is slidable, a first damper check valve 11 provided between the hydraulic oil reservoir 6 and the hydraulic oil inlet chamber R2 and which allows hydraulic oil F to flow only from the hydraulic oil reservoir chamber 6 to the hydraulic oil inlet chamber R2 and blocks backflow, and a second damper check valve 12 provided on the piston 8 and which allows hydraulic oil F to flow only from the hydraulic oil inlet chamber R2 to the hydraulic oil outlet chamber R1 and blocks backflow.

[0023] In the uniflow type cylinder unit 4, when the piston 8 moves back and forth, the hydraulic oil in the hydraulic oil outflow chamber R1 flows out to the outer cylinder 5, and at the same time, the hydraulic oil flows from the outer cylinder 5 into the hydraulic oil inflow chamber R2, so that the hydraulic oil flows in one direction.

[0024] The pressure-receiving area of ​​the piston 8 on the hydraulic oil outflow chamber R1 side to which the piston rod 9 is connected is a value obtained by subtracting the cross-sectional area of ​​the piston rod 9, and is set to half of that on the hydraulic oil inflow chamber R2 side.

[0025] The oil damper system 1 is basically configured by providing a damping valve unit 10 that generates an energy absorption effect between the hydraulic oil outflow chamber R1 of the cylinder unit 4 and the hydraulic oil reservoir chamber 6 in the outer cylinder 5.

[0026] As shown in Figure 4, the damping valve unit 10 is composed of a valve body 13 having a hydraulic oil inlet port P1 connected to the hydraulic oil outflow chamber R1 of the inner cylinder 7 and a hydraulic oil outflow port P2 connected to the hydraulic oil storage chamber 6, a valve element 14 that is movably provided within the valve body 13 and is moved to open and close the hydraulic oil inlet port P1, a spring seat 15 that is arranged within the valve body 13 on the opposite side to the valve element 14 and is movably provided in a liquid-tight state relative to the valve body 13, and a pressure regulating spring 16 as a spring member that is sandwiched within the valve body 13 between the spring seat 15 and the valve element 14 and is supported by the spring seat 15 to bias the valve element 14.

[0027] That is, the valve body 14 is disposed at one end of the pressure adjustment spring 16, and the spring seat 15 is disposed at the other end of the pressure adjustment spring 16.

[0028] In the damping valve unit 10, the pressure regulating spring 16 biases the valve body 14 toward the hydraulic oil inlet port P1, and the biasing force of the pressure regulating spring 16 causes the valve body 14 to close the hydraulic oil inlet port P1, thereby isolating the hydraulic oil outlet chamber R1 from the hydraulic oil reservoir 6. On the other hand, the valve body 14 opens the hydraulic oil inlet port P1 against the biasing force of the pressure regulating spring 16, thereby connecting the hydraulic oil inlet port P1 to the hydraulic oil outlet port P2, and thereby connecting the hydraulic oil outlet chamber R1 to the hydraulic oil reservoir 6.

[0029] In the damping valve unit 10, when the hydraulic oil is pushed by the piston 8 and flows from the hydraulic oil outflow chamber R1 toward the outer cylinder 5, the hydraulic oil inflow port P1 is opened by the action of moving the valve body 14 against the spring force of the pressure regulating spring 16, causing a pressure loss in the hydraulic oil and absorbing energy.

[0030] The valve body 13 of the damping valve unit 10 is further provided with an introduction port P3, which will be described later, facing the rear surface of the spring seat 15 (the side opposite to the side where the pressure adjustment spring 16 is installed).

[0031] The operation of the uniflow type cylinder unit 4 is such that when the piston rod 9 is pulled out from the outer cylinder 5 in the protruding direction and the piston 8 moves to narrow the hydraulic oil outflow chamber R1 of the inner cylinder 7, hydraulic oil F flows out from the hydraulic oil outflow chamber R1 toward the damping valve unit 10.

[0032] The outflow pressure of the hydraulic oil F flowing out from the hydraulic oil outflow chamber R1 acts on the hydraulic oil inlet port P1, moving the valve body 14, which is biased by the pressure regulating spring 16, against the spring force of the pressure regulating spring 16, thereby opening the hydraulic oil inlet port P1.

[0033] When the hydraulic oil inlet port P1 is opened, the hydraulic oil F flows through the valve body 13 of the damping valve unit 10, through the gap between the inner surface of the valve body 13 and the valve element 14, toward the hydraulic oil outlet port P2, and then flows from the hydraulic oil outlet port P2 toward the hydraulic oil reservoir 6.

[0034] In the damping valve unit 10, the opening operation of the valve body 14 due to the outflow pressure of the hydraulic oil F from the hydraulic oil outflow chamber R1 is restricted by the pressure regulating spring 16, that is, by continuing to circulate the hydraulic oil F while maintaining the compressed state of the pressure regulating spring 16, the energy absorption function of the oil damper system 1 is exerted.

[0035] When the hydraulic oil outflow chamber R1 is narrowed and hydraulic oil F flows out of the hydraulic oil outflow chamber R1, the hydraulic oil F flows into the hydraulic oil inflow chamber R2, which is widened, from the hydraulic oil reservoir 6 through the first damper check valve 11.

[0036] On the other hand, when the piston rod 9 is pushed in the retracting direction toward the outer cylinder 5 and the piston 8 moves to expand the hydraulic oil outflow chamber R1 of the inner cylinder 7, thereby narrowing the hydraulic oil inflow chamber R2, because the first damper check valve 11 is closed and, as mentioned above, the pressure-receiving area on the hydraulic oil inflow chamber R2 side of the piston 8 is twice the pressure-receiving area on the hydraulic oil outflow chamber R1 side, the hydraulic oil F in the pressurized hydraulic oil inflow chamber R2 is sent into the hydraulic oil outflow chamber R1 through the second damper check valve 12 of the piston 8 in an amount twice that when the piston rod 9 is extended, and half of that amount of hydraulic oil F is further pushed out of the hydraulic oil outflow chamber R1 and flows out toward the damping valve unit 10.

[0037] In the hydraulic oil outflow chamber R1, the hydraulic oil F flows in at twice the amount from the hydraulic oil inflow chamber R2, and half of that amount is replenished and the hydraulic oil F is always filled.

[0038] During the retraction of the piston rod 9, as during the extension, the outflow pressure of the hydraulic oil F flowing out of the hydraulic oil outflow chamber R1 acts on the hydraulic oil inlet port P1, moving the valve body 14, which is biased by the pressure regulating spring 16, against the spring force of the pressure regulating spring 16, thereby opening the hydraulic oil inlet port P1.

[0039] When the hydraulic oil inlet port P1 is opened, the hydraulic oil F flows through the valve body 13 of the damping valve unit 10 toward the hydraulic oil outlet port P2, and further flows from the hydraulic oil outlet port P2 toward the hydraulic oil reservoir 6.

[0040] In the damping valve unit 10, even when the piston rod 9 is retracted, the opening operation of the valve body 14 due to the outflow pressure of the hydraulic oil F from the hydraulic oil outflow chamber R1 is restricted by the pressure regulating spring 16, that is, the hydraulic oil F continues to circulate while maintaining the compressed state of the pressure regulating spring 16, thereby achieving the energy absorption function of the oil damper system 1.

[0041] Whether the piston rod 9 is protruding or retracting, if the sliding amount of the piston 8 is the same, the amount of hydraulic oil F flowing into the damping valve unit 10 is the same, and therefore the amount of energy absorption is the same.

[0042] In the uniflow type cylinder unit 4 that constitutes the oil damper system 1 of this embodiment, as described above, the hydraulic oil F flows in one direction, flowing out only from the hydraulic oil outflow chamber R1 toward the hydraulic oil storage chamber 6 and flowing in only from the hydraulic oil storage chamber 6 to the hydraulic oil inflow chamber R2.

[0043] Between the hydraulic oil outflow chamber R1 and the hydraulic oil reservoir 6, a relief valve 17 is provided to release and control the hydraulic pressure of the hydraulic oil F in the hydraulic oil outflow chamber R1 when the piston rod 9 operates at high speed.

[0044] The cylinder unit 4 has an outer cylinder 5 connected to one of the vibration input side and the vibration attenuation target side, for example, the ground 2.

[0045] The cylinder unit 4 also has a piston rod 9 connected to the other of the vibration input side and the vibration attenuation target side, for example, a building 3 .

[0046] The cylinder unit 4 is installed by connecting it to, for example, the ground 2 and the building 3, and as shown in Figures 2 and 3, attachment portions 37 for these objects are provided on the piston rod 9 and outer cylinder 5 of the cylinder unit 4.

[0047] In addition, a bellows 51 that can expand and contract in accordance with the expansion and contraction stroke of the piston rod 9 is provided between the outer cylinder 5 and the mounting portion 37 as a cover that covers the transmission member 18 from the outside.

[0048] When an earthquake causes a relative displacement between the ground 2 and the building 3, the piston rod 9 of the cylinder unit 4 itself moves forward and backward by a stroke amount corresponding to the amount of the relative displacement.

[0049] In this specification, the "extension and retraction stroke of the piston rod 9" refers to the change in length of the cylinder unit 4, which occurs when the piston rod 9 is pulled out in a direction protruding outward from the outer cylinder 5 and the inner cylinder 7, or pushed in a direction retracting inward, accompanying the reciprocating movement of the piston 8, causing the length dimension of the cylinder unit 4 to become longer or shorter in the length direction of the piston rod 9.

[0050] Similarly, the "extending stroke of the piston rod 9" refers to the change in the length of the cylinder unit 4 as it lengthens in the longitudinal direction of the piston rod 9, and the "retracting stroke of the piston rod 9" refers to the change in the length of the cylinder unit 4 as it shortens in the longitudinal direction of the piston rod 9.

[0051] These strokes refer to the displacement of the piston rod 9 from the inoperative state of the cylinder unit 4 in which the piston rod 9 is stopped at the initial position.

[0052] Furthermore, the "protrusion" of the piston rod 9 means that, as the piston 8 reciprocates, the piston rod 9 is pulled out in a direction that protrudes outward from the outer cylinder 5 and the inner cylinder 7, and the length dimension of the cylinder unit 4 becomes longer in the length direction of the piston rod 9. The "recession" of the piston rod 9 means that the piston rod 9 is pushed in a direction that retracts into the outer cylinder 5 and the inner cylinder 7, and the length dimension of the cylinder unit 4 becomes shorter in the length direction of the piston rod 9.

[0053] As shown in FIGS. 1 to 3, the cylinder unit 4 is provided with a transmission member 18 that transmits the amount of extension and retraction stroke of the piston rod 9 that moves the piston 8.

[0054] The transmission member 18 is formed of a shaft that is long in the extension / retraction stroke direction of the piston rod 9. The transmission member 18 has a base end 18a, which is one end in the length direction, attached to the piston rod 9, and a tip end 18b, which is the other end in the length direction, supported outside the outer cylinder 5 so as to be freely movable.

[0055] The transmission member 18, whose base end 18a is attached to the piston rod 9, slides outside the cylinder unit 4 in accordance with the extension and retraction movement of the piston rod 9, and when the piston rod 9 performs an extension stroke, the tip 18b moves in the direction of the extension stroke by the same amount, and when the piston rod 9 performs a retraction stroke, the tip 18b moves in the direction of the retraction stroke by the same amount.

[0056] A pair of control cylinder units 19, 19 are provided outside the outer cylinder 5 of the cylinder unit 4, on both sides of the transmission member 18, along the extending / retracting stroke direction of the piston rod 9.

[0057] One control cylinder unit 19 is provided to act on the extension stroke of the piston rod 9 and the other control cylinder unit 19 is provided to act on the retraction stroke.

[0058] As shown in FIG. 5, each of these control cylinder units 19, 19 comprises a cylinder case 20, a control piston 21 that is slidably provided in the cylinder case 20 in an airtight state and divides the interior of the cylinder case 20 into an oil chamber 20a filled with control oil f and an air chamber 20c that is maintained at atmospheric pressure through an air hole 20b provided in the cylinder case 20, and a control piston rod that is connected at one end to the control piston 21 from the oil chamber 20a side and at the other end that protrudes outward from the cylinder case 20 in a liquid-tight state and is slidably operable to move in and out. 22, and a control oil inlet / outlet port P4 which is provided in the cylinder case 20 and discharges control oil f from an oil chamber 20a narrowed by a control piston 21 which is slid by the protruding operation of the control piston rod 22 toward the damping valve unit 10, and which, as will be described later, allows control oil f returned from the damping valve unit 10 to flow into the oil chamber 20a when the cylinder unit 4 has finished operating and is in a non-operating state, thereby narrowing the air chamber 20c and pushing back the control piston 21 together with the control piston rod 22.

[0059] In this specification, "the control piston rod 22 protrudes or retracts" refers to a change in length in which the control piston rod 22 is pulled out in a direction protruding outward from the cylinder case 20 or pushed in a direction retracting inward, accompanied by the reciprocating movement of the control piston 21, causing the length dimension of the control cylinder unit 19 to become longer or shorter in the length direction of the control piston rod 22.

[0060] An operating part 24 is provided at the tip 18b of the transmission member 18, and a passive part 25 with which the operating part 24 can be freely engaged and disengaged is provided at the protruding tip of the other end of the control piston rod 22 of the pair of control cylinder units 19 on both sides of the transmission member 18.

[0061] As shown in Figures 1 and 2, the pair of control cylinder units 19, 19 are installed so that the protruding directions of their control piston rods 22, 22 are opposite to each other, and so that the operating part 24 of the transmission member 18 is located between their passive parts 25, 25 in the direction of the extending and retracting stroke of the piston rod 9.

[0062] Furthermore, when the piston rod 9 of the cylinder unit 4 is in a neutral position in the direction of the protruding and retracting stroke (in other words, when the cylinder unit 4 is in its initial non-operating state) and the air chamber 20c is narrowed and the protruding stroke amount of the control piston rods 22 and 22 is positioned at its initial position of "0", the passive parts 25 and 25 of these control cylinder units 19 and 19 are spaced apart from the operating part 24 by a distance equal to the predetermined protruding and retracting stroke amount set for the piston rod 9.

[0063] The predetermined extension / retraction stroke amount refers to the extension stroke amount S and retraction stroke amount S that are set equal in the extension stroke direction and retraction stroke direction, respectively, with the neutral position N of the piston rod 9 as a reference, as shown in FIG.

[0064] That is, the operating portion 24 and each of the passive portions 25, 25 are equally spaced apart by a distance corresponding to the predetermined stroke amount S of the piston rod 9.

[0065] When the piston rod 9 is extended or retracted within a predetermined stroke amount S, the operating part 24 of the transmission member 18 moves accordingly, but the operating part 24 does not engage with the passive part 25 of any of the control cylinder units 19, and the control cylinder units 19 are not operated.

[0066] When the piston rod 9 experiences an excessive protruding stroke exceeding the predetermined retraction stroke amount S, for example, an excessive protruding stroke, the operating portion 24 engages with the passive portion 25 of the control piston rod 22 of one of the control cylinder units 19 .

[0067] The passive portion 25 then causes the control piston rod 22 to protrude by an excess protruding stroke amount that exceeds the predetermined protruding / retracting stroke amount S.

[0068] The control piston 21 is slid by the control piston rod 22 that is actuated to protrude, and control oil f is discharged from the inlet / outlet port P4 of the cylinder case 20 in an amount corresponding to the excess protruding stroke.

[0069] When the piston rod 9 repeating the extending and retracting strokes moves to the retracting stroke, the operating portion 24 of the transmission member 18 disengages from the passive portion 25 that has engaged to operate the control piston rod 22 to extend.

[0070] If the excess protrusion stroke amount during the next protrusion stroke does not exceed the previous excess protrusion stroke amount, the control piston rod 22 that had been protruding during that time will remain in the same position and no control oil f will be discharged.On the other hand, if the excess protrusion stroke amount increases beyond the previous excess protrusion stroke, the operating part 24 will again engage with the passive part 25, causing the control piston rod 22 to protrude again by the newly increased excess protrusion stroke amount, and as a result, control oil f will be discharged from the control cylinder unit 19 in an amount corresponding to the increased excess protrusion stroke.

[0071] When an excessive plunger stroke that exceeds the specified plunger stroke occurs in the piston rod 9, the operating part 24 of the transmission member 18 causes the control piston rod 22 of the other control cylinder unit 19 to protrude in the same manner as the control piston rod 22 of the one control cylinder unit 19 described above, and control oil f for the excess plunger stroke and the increased excess plunger stroke is discharged from the inlet / outlet port P4 of the cylinder case 20.

[0072] In this way, when the extension / retraction stroke amount of the piston rod 9 of the cylinder unit 4 exceeds the predetermined extension / retraction stroke amount S, the control cylinder unit 19 first discharges control oil f in an amount corresponding to the excess extension / retraction stroke amount when it exceeds the predetermined extension / retraction stroke amount S, and then repeats this process of discharging control oil f in an amount corresponding to the excess extension / retraction stroke amount that exceeds the previous excess extension / retraction stroke amount.

[0073] That is, when the predetermined extension / retraction stroke amount S is exceeded, and thereafter, each time the excess extension / retraction stroke amount increases, both of the pair of control cylinder units 19, 19 discharge an increased amount of control oil f.

[0074] As shown in FIGS. 1 to 3, a control oil supply system 26 is provided between the pair of control cylinder units 19, 19 and the damping valve unit 10.

[0075] The control oil supply system 26 is composed of a piping system and has a communication section 27 that connects the inlet / outlet ports P4, P4 of a pair of control cylinder units 19, 19, and also connects the communication section 27 to the inlet port P3 of the damping valve unit 10.

[0076] The control oil supply system 26 is provided with a check valve 28 disposed between the communication portion 27 and the introduction port P3 of the damping valve unit 10.

[0077] The check valve 28 allows the control oil f to flow from the communication portion 27 toward the introduction port P3, and prevents backflow.

[0078] Then, hydraulic pressure is generated at the back surface of the spring seat 15 by the control oil f flowing into the valve body 13 from the inlet port P3, and this hydraulic pressure acts on the check valve 28 as back pressure.

[0079] Unlike the valve element 14, the spring seat 15 is provided in the valve body 13 so as to be movable in a liquid-tight manner.

[0080] Therefore, the control oil f flowing in from the inlet port P3 remains inside the valve body 13, pressing and displacing the spring seat 15, and therefore the control oil f does not mix with the hydraulic oil F and flow into the hydraulic oil reservoir 6 from the hydraulic oil outlet port P2.

[0081] That is, in the control oil supply system 26 equipped with the check valve 28, the control oil f discharged from each of the inlet / outlet ports P4, P4 flows back and forth between these pairs of inlet / outlet ports P4, P4, or passes through the check valve 28 and the inlet port P3 and flows onto the back surface of the spring seat 15 in the damping valve unit 10, generating oil pressure on the back surface of the spring seat 15 that changes the spring force of the pressure regulating spring 16.

[0082] The piston rod 9 of the cylinder unit 4 alternately protrudes and retracts, and as a result, when the control piston rods 22, 22 of a pair of control cylinder units 19, 19 are alternately protruded, control oil f is alternately and intermittently discharged from each inlet / outlet port P4, P4.

[0083] The check valve 28 introduces the control oil f into the inlet / outlet port P3 when the oil pressure of the control oil f discharged from the inlet / outlet port P4 of either of the control cylinder units 19 during the protruding operation and acting through the communicating part 27 exceeds its valve opening pressure, and on the other hand, when the oil pressure of the control oil f is below its valve opening pressure, the check valve 28 prevents the control oil f from flowing into the inlet port P3.

[0084] The control oil f, whose flow is blocked by the check valve 28, flows through the communicating section 27 into the inflow / outflow port P4 of the other control cylinder unit 19 (in a state where no oil pressure is generated in the oil chamber 20a and the control piston rod 22 can move toward the air chamber 20c).

[0085] This communication section 27 functions as a relief circuit when the control oil f cannot pass through the check valve 28, such as when the oil pressure generated at the back of the spring seat 15 (back pressure of the check valve 28) reaches the set upper limit value.

[0086] An excess protruding stroke amount and an excess retracting stroke amount occur, and then as these stroke amounts increase sequentially, the hydraulic pressure of the control oil f generated by a pair of control cylinder units 19, 19 which are alternately operated to protrude repeatedly acts on the check valve 28, and the check valve 28 causes the control oil f to flow into the inlet port P3 of the damping valve unit 10 each time the pressure exceeds the valve opening pressure.

[0087] As a result, within the valve body 13 of the damping valve unit 10, the control oil f is introduced from the inlet port P3 to the back surface of the spring seat 15, and the amount of control oil f gradually increases, causing the pressure regulating spring 16 to gradually contract between itself and the valve body 14, and this contraction causes the spring force of the pressure regulating spring 16 that biases the valve body 14 to change so that it becomes larger.

[0088] That is, the spring seat 15 is moved so as to compress the pressure regulating spring 16 by the hydraulic pressure of the control oil f introduced from the inlet port P3, thereby causing a change in the spring force of the pressure regulating spring 16 according to the amount of excess protruding stroke or excess retracting stroke.

[0089] As shown in FIG. 1, the control oil supply system 26 is provided with a bypass path 29 that bypasses the check valve 28 in order to return the control oil f to the pair of control cylinder units 19, 19, and this bypass path 29 is provided with a return valve (e.g., a needle valve) 30 in parallel with the check valve 28, which has a throttling function that can be opened and closed freely and has an adjustable opening.

[0090] This return valve 30 is opened, for example, when an earthquake subsides and the cylinder unit 4 finishes operating and becomes inactive (the piston rod 9 returns to the neutral position N in the direction of the extending and retracting stroke), and returns the control oil f that has been sent to the damping valve unit 10 sequentially from the inlet port P3 through the communication part 27 to the inlet / outlet ports P4, P4 of the pair of control cylinder units 19, 19.

[0091] On the other hand, the return valve 30 restricts the outflow of the control oil f from the back surface of the spring seat 15 while the cylinder unit 4 is in operation.

[0092] In the oil damper system 1 of this embodiment, unlike the background art, the damping valve unit 10 is provided with a return means for returning the control oil f from the damping valve unit 10 to the inlet / outlet ports P4, P4 of each control cylinder unit 19, 19 in order to return each control piston rod 22, 22 to its initial position with a protruding stroke amount of "0" when, for example, an earthquake has subsided as described above, the cylinder unit 4 has ceased operation and is in an inoperative state, and the flow of hydraulic oil F that moves the valve body 14 has ceased.

[0093] In the example of the damping valve unit 10 shown in Figure 4, the return means is configured so that the pressure adjustment spring 16 is set to have a spring force that presses the spring seat 15 so as to cause the control oil f to flow out to the control oil supply system 26.

[0094] In other words, when the cylinder unit 4 transitions from an operating state to a non-operating state, only a slight hydraulic pressure acts on the valve body 14 of the damping valve unit 10 at the hydraulic oil inlet port P1, which is connected to the hydraulic oil outflow chamber R1, and the operating part 24 does not engage with the passive part 25 to cause the control piston rod 22 to protrude.

[0095] At this time, as the pressure regulating spring 16 expands from its contracted state due to the control oil f through the spring seat 15 and returns to its original state, it presses the spring seat 15 to block the inlet port P3, and pushes almost all of the control oil f from the valve body 13 back through the return valve 30 to the control oil supply system 26 and ultimately to the inlet / outlet port P4 of each control cylinder unit 19, 19.

[0096] The spring force of the pressure regulating spring 16 is preferably such that the control oil f gradually flows out and returns to the control oil supply system 26 when the cylinder unit 4 is in an inoperative state where the flow of the hydraulic oil F has ceased.

[0097] The pressure adjustment spring 16 is preferably installed in such a way that no or only a small deformation load is applied to the pressure adjustment spring 16, while the valve body 14 can close the hydraulic oil inlet port P1 and the spring seat 15 can close the introduction port P3.

[0098] In FIG. 1, reference numeral 31 denotes a hydraulic pressure gauge that displays the hydraulic pressure in the control oil supply system 26, and reference numeral 32 denotes an on-off valve for draining the control oil f.

[0099] The operation of the oil damper system 1 according to this embodiment will be described below. The cylinder unit 4 is set between the ground 2 and the building 3 so that the piston rod 9 is in the neutral position N in the extending / retracting stroke direction.

[0100] For example, when an earthquake occurs and the cylinder unit 4 begins to operate, if the piston rod 9 does not have an excessive protruding stroke or excessive retracting stroke, the pair of control cylinder units 19, 19 will not be operated, and the cylinder unit 4 will absorb the earthquake energy by having the valve body 14 of the damping valve unit 10 open and close in response to the outflow pressure of the hydraulic oil F with the initial spring characteristics set in the pressure regulating spring 16.

[0101] When an excess extension / retraction stroke amount exceeding the predetermined extension / retraction stroke amount S occurs in the piston rod 9, the operating portion 24 of the transmission member 18 operates the control cylinder units 19, 19.

[0102] When the control piston rod 22 of one of the control cylinder units 19 is extended by either the initial excessive protruding stroke or excessive retracting stroke and the control oil f is introduced from the inlet / outlet port P4 through the check valve 28 to the back of the spring seat 15 of the damping valve unit 10, the pressure regulating spring 16 is compressed, and as a result, the damping valve unit 10 opens and closes the valve body 14 against the outflow pressure of the working oil F due to the spring characteristics of the pressure regulating spring 16, which have been changed to a spring force greater than the initial spring characteristics, thereby increasing the absorption of earthquake energy.

[0103] When the excess extension / retraction stroke is within the initial excess extension / retraction stroke amount and does not exceed this amount, the pair of control piston rods 19, 19 are not operated to extend further by the transmission member 18.

[0104] On the other hand, whenever an excess protruding stroke or excess retracting stroke occurs that exceeds the previous excess protruding stroke, the check valve 28 is opened by the oil pressure of the control oil f discharged from each of the pair of control cylinder units 19, 19, and each time this occurs, the control oil f is introduced into the damping valve unit 10, causing the spring force of the pressure regulating spring 16 to change increasingly significantly.

[0105] Therefore, the larger the extension / retraction stroke of the piston rod 9 caused by an earthquake, the greater the spring force of the pressure adjustment spring 16 of the damping valve unit 10 can be made to change the energy absorption performance to a greater extent.

[0106] Thereafter, for example, when the earthquake subsides and the cylinder unit 4 finishes operating and becomes inoperative (the piston rod 9 returns to the neutral position N in the extending / retracting stroke direction), in the damping valve unit 10, the pressure regulating spring 16, which had been in a contracted state until then, begins to expand with the valve body 14 side as the base point and elastically restores, thereby pressing the spring seat 15 toward the inlet port P3, and the control oil f introduced into the valve body 13 can be gradually returned to the control oil supply system 26.

[0107] In the control oil supply system 26, the control oil f flows from the bypass path 29 through the return valve 30 into the communicating section 27, and is then returned to the oil chambers 20a, 20a through the inlet / outlet ports P4, P4 of each control cylinder unit 19, 19.As a result, the control pistons 21, 21 slide to narrow the air chambers 20c, 20c, the control cylinder rods 22, 22 are retracted into the cylinder cases 20, 20, and the control cylinder units 19, 19 are returned to their initial state.

[0108] In the oil damper system 1 of this embodiment, when the flow of hydraulic oil F that moves the valve body 14 ceases, in order to return each of the control piston rods 22, 22 to their initial positions, a return means that returns the control oil f to each of the control cylinder units 19, 19 is configured as a pressure regulating spring 16 and is provided in the damping valve unit 10.Therefore, there are no points where foreign matter such as dirt can get mixed into the control oil f between the control cylinder unit 19 where the control oil f circulates and the control oil supply system 26, and premature deterioration of the control oil f can be prevented.

[0109] Furthermore, by providing the damping valve unit 10 with the pressure adjusting spring 16 as the return means, maintenance work relating to the spring characteristics for adjusting performance can be performed on the damping valve unit 10 alone.

[0110] As a result, the maintainability of the oil damper system 1 can be improved.

[0111] A bypass path 29 that bypasses the check valve 28 is provided in the control oil supply system 26, and a return valve 30 is provided in the bypass path 29 in parallel with the check valve 28 to sequentially return the control oil f from the inlet port P3 of the damping valve unit 10 to the inlet / outlet ports P4, P4 of the pair of control cylinder units 19, 19 via the communicating part 27.Therefore, after the end of an earthquake, the cylinder unit 4 and the pair of control cylinder units 19, 19 can be smoothly returned to the neutral state they were in before operation.

[0112] A modification of the above embodiment is shown in Figure 6. In this modification, the return means is provided between the spring seat 15 and the valve body 14, overlapping with the pressure adjustment spring 16, and is configured as a shim 33 that causes the pressure adjustment spring 16 to press the spring seat 15 so as to cause the control oil f to flow into the control oil supply system 26.

[0113] The shim 33 is a well-known component for adjusting a gap. By placing this shim 33 on top of the pressure regulating spring 16 and performing fine adjustments, the initial spring characteristics of the pressure regulating spring can be set or changed by the thickness of the shim 33, without having to change to a pressure regulating spring 16 with different spring characteristics. This allows the control oil f to be appropriately returned to the control oil supply system 26, and the control cylinder unit 19 to be restored to its initial state.

[0114] In the illustrated example, three shims 33 are stacked between the valve body 14 and the pressure adjustment spring 16, but they may also be placed between the spring seat 15 and the pressure adjustment spring 16, and the number of shims is not important.

[0115] The shim 33 may be provided in combination with the pressure adjusting spring as the return means in the above embodiment. Even in such a modified example, the same effects as those in the above embodiment can be achieved.

[0116] Another modified example of the above embodiment is shown in Figure 7. In this modified example, the return means is formed with a spring constant smaller than that of pressure adjustment spring 16, is provided in parallel with pressure adjustment spring 16 between spring seat 15 and valve body 14, and is composed of return spring 34 that presses spring seat 15 from the valve body 14 side so as to cause control oil f to flow into control oil supply path 26.

[0117] The return spring 34 has a spring constant smaller than that of the pressure adjustment spring 16, i.e., a spring with weak spring force, so as not to interfere with the energy absorption function of the pressure adjustment spring 16 itself.

[0118] While the cylinder unit 4 is in operation, the return spring 34 expands and contracts and deforms almost independently of the action of the pressure regulating spring 16. However, after the operation of the cylinder unit 4 has ceased and the cylinder unit 4 has entered a non-operating state, for example after an earthquake has subsided, the spring seat 15, which is returned by the elastic restoration of the pressure regulating spring 16, has not yet returned to a position that completely blocks the introduction port P3. Therefore, when the control piston rod 22 has not yet returned completely to its original position, the return spring 34 gradually presses the spring seat 15 toward the introduction port P3 with a weak spring force, appropriately returning the control oil f to the control oil supply system 26, and returning the control cylinder unit 19 to its initial state.

[0119] The return spring 34 may be provided in combination with the pressure adjustment spring 16 as the return means in the above embodiment, or may further be combined with the shim 33. Even in such a modified example, the same effects as those in the above embodiment can be achieved, as a matter of course.

[0120] The return valve 30 may be set to allow a small amount of control oil f to flow at all times, so that even while the control oil f is flowing toward the inlet port P3, that small amount is returned to the control cylinder unit 19.

[0121] It is desirable to set this minute amount so that all of the control oil f can be returned to the control cylinder unit 19 in a short time, for example, 5 to 10 minutes after the earthquake has subsided, and so that an appropriate oil pressure can be generated within the valve body 13 when the oil damper system 1 is operating. [Explanation of symbols]

[0122] 1 Oil damper system 2 Ground 3. Building 4 Uniflow type cylinder unit 5 outer cylinder 7 Inner Cylinder 8 pistons 9 Piston rod 10 Damping valve unit 14 Valve body 15 Spring seat 16 Pressure adjusting spring 18 Transmission components 19 Control cylinder unit 22 Control piston rod 26 Control oil supply system 33 Sim 34 Return spring F Hydraulic oil f Control oil S: Predetermined stroke amount R1 hydraulic oil outflow chamber R2 hydraulic oil inlet chamber

Claims

1. a uniflow type cylinder unit in which an outer cylinder is connected to one of the vibration input side and the vibration damping target side, and a piston rod is connected to the other of the vibration input side and the vibration damping target side, and an inner cylinder is provided inside the outer cylinder in which hydraulic oil is stored, and an hydraulic oil outflow chamber and a hydraulic oil inflow chamber are partitioned by a piston to which the piston rod is connected, and when the piston reciprocates, the hydraulic oil in the hydraulic oil outflow chamber flows out into the outer cylinder and flows in one direction from the outer cylinder to the hydraulic oil inflow chamber; a damping valve unit having a valve body biased by a spring member, wherein the hydraulic oil flowing from the hydraulic oil outflow chamber to the outer cylinder moves the valve body against the spring force, thereby absorbing energy; a transmission member that transmits a stroke amount of the piston rod that moves the piston; a pair of control cylinder units respectively provided along the extending / retracting stroke direction of the piston rods, and when an excessive protruding stroke or excessive retracting stroke exceeding a predetermined extending / retracting stroke occurs in the piston rods, the control piston rods are respectively extended by the excessive protruding stroke or excessive retracting stroke amount by the transmission member, thereby discharging control oil; a control oil supply system that supplies control oil discharged from each of the pair of control cylinder units to the damping valve unit, The damping valve unit is provided with a spring seat that is located on the opposite side of the valve body across the spring member, and is moved to compress the spring member with control oil supplied from the control oil supply system, thereby increasing the spring force of the spring member according to the amount of excess protrusion stroke and the amount of excess retraction stroke, and a return means that returns control oil to each of the control cylinder units to return each of the control piston rods to their initial positions.

2. 2. The oil damper system according to claim 1, wherein the return means is set to a spring force that presses the spring seat so that the spring member causes the control oil to flow out to the control oil supply system.

3. 3. The oil damper system according to claim 1, wherein the return means is a shim that is provided between the spring seat and the valve body and overlaps with the spring member, and that causes the spring member to press the spring seat so as to cause the control oil to flow out into the control oil supply system.

4. The oil damper system according to any one of claims 1 to 3, characterized in that the return means is a return spring formed with a spring constant smaller than the spring constant of the spring member, provided in parallel with the spring member between the spring seat and the valve body, and pressing the spring seat from the valve body side so as to cause the control oil to flow out into the control oil supply system.

5. An oil damper system as described in any one of claims 1 to 4, characterized in that the return means returns control oil to each of the control cylinder units when the flow of hydraulic oil that moves the valve body ceases.

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