Vibration suppression device

Abstract

To provide a vibration suppression device capable of preventing a seal material from being damaged by preventing excessive pressure in a viscous body chamber and suppressing a decrease in shear resistance of a viscous body due to repeated shear deformation.SOLUTION: According to the present invention, a vibration suppression device converts relative displacement between first and second parts occurring due to vibrations of a vibration control object into relative rotation of an outer cylinder 3 and an inner cylinder 4 connected to a screw shaft 2a and a nut 2b of a ball screw 2, and demonstrates a vibration suppression effect due to shear resistance of a viscous body VB filled in a viscous body chamber 5 between both cylinders 3, 4. An accumulator 6 includes a pressure accumulation chamber 34 for accumulating a portion of pressure in the viscous body chamber 5, first and second communication passages 31, 32 communicating with the viscous body chamber 5 and the pressure accumulation chamber 34, a relief valve 37 provided in the first communication passage 31 to open when pressure in the viscous body chamber 5 reaches relief pressure Prf, and a check valve 38 provided in the second communication passage 32 to prevent flow of the viscous body VB from the viscous body chamber 5 toward the pressure accumulation chamber 34.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration suppression device that converts linear motion into rotational motion using a ball screw and suppresses vibration of an object to be damped, such as a structure or a vehicle, by using a viscous damping effect due to the shear resistance of a viscous body. [Background technology]

[0002] A conventional vibration suppression device of this type is disclosed in, for example, Patent Document 1. This vibration suppression device is a viscous damper using a ball screw, and includes a non-rotatable outer cylinder, a rotatable inner cylinder arranged inside the outer cylinder and defining an annular viscous body chamber between the outer cylinder, a screw shaft, a ball screw having a nut screwed to the screw shaft via balls and fixed to the inner cylinder, a viscous body made of silicone oil or the like filled in the viscous body chamber, and a sealant arranged at both ends of the axial direction of the viscous body chamber for sealing the viscous body. In the viscous damper having the above configuration, for example, the outer cylinder is connected to a building as a vibration suppression target, and the screw shaft is connected to a foundation supporting the building.

[0003] In this configuration, when a building vibrates due to an earthquake, the relative displacement between the building and the foundation is transmitted to the ball screw, and the linear motion of the screw shaft is converted into the rotational motion of the nut, causing the inner cylinder to rotate, and the shear resistance of the viscous material filled in the viscous material chamber between the outer cylinder and the inner cylinder exerts a vibration suppression effect that suppresses the vibration of the building. In addition, the pressure change caused by the expansion and contraction of the viscous material due to temperature changes is absorbed by the buffer, preventing adverse effects such as damage to the sealing material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-132479 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the conventional viscous dampers described above, when the viscous body undergoes shear deformation, vibration energy is converted into thermal energy, and the temperature of the viscous body rises as the vibration progresses. Therefore, if the vibration speed exceeds the expected speed (e.g., 1.5 m / s or more), or if the cumulative displacement due to repeated vibration exceeds the expected speed (e.g., 50 m or more), the temperature and pressure of the viscous body may rise excessively and may not be fully absorbed by the buffer. In that case, the excessive pressure of the viscous body may exceed the allowable pressure of the sealing material, damaging the sealing material and causing the viscous body to leak out of the viscous body chamber.

[0006] In addition, the shear resistance of viscous bodies such as silicone oil has the characteristic of decreasing as shear deformation is repeated. This is because silicone oil and other such materials are polymeric materials, and repeated shear deformation causes the entanglement of polymer chains to become loose. For this reason, when a viscous body undergoes shear deformation for a long period of time, such as in long-period earthquake motion, the performance of the viscous damper decreases, and there is a risk that the vibration suppression effect will not be fully exerted.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a vibration suppression device that can prevent damage to the sealing material in the viscous material chamber by preventing excessive pressure in the viscous material chamber even in the event of seismic motion that exceeds expectations, and that can suppress the decrease in shear resistance of the viscous material due to repeated shear deformation, thereby maintaining an excellent vibration suppression effect. [Means for solving the problem]

[0008] In order to achieve this object, the invention according to claim 1 provides a vibration suppression device that is provided between a first portion and a second portion in a system including a vibration-damping target that undergoes relative displacement when vibrating, in order to suppress vibration of the vibration-damping target, the vibration suppression device comprising: a screw shaft connected to the first portion, and a ball screw having a nut that is screwed onto the screw shaft via balls and converts linear motion of the screw shaft into rotational motion; an outer cylinder; an inner cylinder that is disposed inside the outer cylinder and defines a viscous body chamber between the outer cylinder and the inner cylinder; a viscous body filled in the viscous body chamber; and a sealant for sealing the viscous body within the viscous body chamber, one of the outer cylinder and the inner cylinder being connected to the second portion, and the other of the outer cylinder and the inner cylinder being connected to the nut, the vibration suppression device comprising: The pressure regulator further includes an accumulator for storing a portion of the pressure of the viscous material in the viscous material chamber, the accumulator having a casing communicating with the viscous material chamber, a piston slidably provided within the casing and defining a pressure accumulator chamber on the viscous material chamber side within the casing, a set spring for biasing the piston toward the pressure accumulator chamber, a first communication passage and a second communication passage in parallel with each other and communicating with the viscous material chamber side and the pressure accumulator chamber, a relief valve provided in the first communication passage that opens when the pressure in the viscous material chamber reaches a predetermined relief pressure to release the pressure in the viscous material chamber to the pressure accumulator chamber, and a check valve provided in the second communication passage for preventing the flow of viscous material from the viscous material chamber to the pressure accumulator chamber side.

[0009] The vibration suppression device of the present invention is composed of a viscous damper using a ball screw, and is provided between a first part and a second part in a system including a vibration-suppression target such as a structure or a vehicle. When the vibration-suppression target vibrates, the relative displacement between the first and second parts is transmitted between the screw shaft of the ball screw and one of the outer cylinder and the inner cylinder (e.g., the outer cylinder), and is converted into rotational motion by the ball screw, causing the nut of the ball screw and one of the outer cylinder and the inner cylinder (e.g., the inner cylinder) connected thereto to rotate relative to the outer cylinder. As a result, a vibration suppression effect is exerted that suppresses the vibration of the vibration-suppression target by a viscous damping effect due to the shear resistance of the viscous body filled in the viscous body chamber between the outer cylinder and the inner cylinder.

[0010] Furthermore, when the vibration suppression device operates for a long time, for example, in response to a long-period earthquake motion input of the vibration control target, the viscous body undergoes repeated shear deformation, causing the temperature of the viscous body to rise, and the temperature expansion causes the pressure in the viscous body chamber to rise. Until the pressure in the viscous body chamber reaches the relief pressure of the relief valve provided in the first communication passage, the relief valve is kept closed, thereby maintaining the high pressure state in the viscous body chamber. This suppresses the disentanglement of the polymer chains that make up the viscous body during repeated deformation, and suppresses the decrease in the shear resistance of the viscous body, thereby maintaining a good vibration suppression effect.

[0011] From this state, as the vibration of the controlled object continues, the pressure of the viscous material in the viscous material chamber increases further, and when it reaches the relief pressure of the relief valve, the relief valve opens. This causes the viscous material to flow from the viscous material chamber through the first communication passage into the pressure accumulation chamber of the accumulator, compressing the set spring via the piston, and a portion of the pressure in the viscous material chamber is accumulated in the accumulator. As a result, it is possible to prevent the pressure in the viscous material chamber from becoming excessive, and to prevent damage to the seal material provided in the viscous material chamber.

[0012] Then, when the vibration of the controlled object ends and the pressure in the accumulator chamber exceeds the pressure in the viscous material chamber, the check valve in the second communication passage opens, causing the viscous material to be returned from the accumulator chamber to the viscous material chamber via the second communication passage, and the pressure accumulated in the accumulator is released to the viscous material chamber, restoring the original state.

[0013] The invention according to claim 2 is characterized in that in the vibration suppression device according to claim 1, the accumulator is disposed inside the inner cylinder.

[0014] According to this configuration, the entire accumulator, including the first and second communication passages, is built into the inner cylinder and does not appear on the outside of the outer cylinder, thereby ensuring a compact vibration suppression device and excellent design.

[0015] The invention of claim 3 is characterized in that, in the vibration suppression device described in claim 1, the first communication passage is composed of a plurality of first communication passages arranged in parallel with each other, one end of which is connected to a different position in the viscous chamber and the other end of which is connected to a different position in the pressure accumulator chamber, and a relief valve is provided in each of the plurality of first communication passages.

[0016] According to this configuration, the first communication passage with a relief valve, which communicates with the viscous material chamber and the pressure accumulator chamber, is composed of multiple first communication passages in parallel with each other. Therefore, it is possible to ensure a large distance between the multiple points in the viscous material chamber where the viscous material flows out to the accumulator side and the point where the viscous material flows in from the accumulator side. This makes it possible to suppress variations in shear resistance caused by turbulence in the flow of the viscous material in the viscous material chamber, and to obtain a stable vibration suppression effect.

[0017] The invention of claim 4 is characterized in that, in the vibration suppression device described in claim 3, the sealing material is composed of a pair of sealing materials provided at both axial ends of the viscous chamber, and the multiple first communication passages are composed of two first communication passages each having one end connected to a position close to the pair of sealing materials in the viscous chamber.

[0018] According to this configuration, the points at which the viscous material flows from the viscous material chamber to the accumulator side through the two first communication passages are each located near a pair of sealing materials, so that the pressure in the viscous material chamber can be accurately and appropriately controlled while effectively reflecting the pressure near the sealing materials.

[0019] The invention of claim 5 is characterized in that, in the vibration suppression device described in claim 1, the first communication passage and the second communication passage are connected at one end to different positions in the viscous chamber, and are connected to the accumulator chamber via a common third communication passage connected at the other end.

[0020] According to this configuration, when the pressure in the viscous material chamber rises and the relief valve opens, the viscous material flows from the viscous material chamber through the first and third communication passages in this order to the accumulator chamber. On the other hand, when the pressure in the accumulator chamber becomes relatively high and the check valve opens, the viscous material flows from the accumulator chamber through the third and second communication passages in this order to the viscous material chamber. As described above, the functions required of the first and second communication passages, the relief valve, and the check valve are ensured, while the third communication passage is shared, making it possible to simplify the overall configuration of the communication passages.

[0021] The invention according to claim 6 is characterized in that, in the vibration suppressing device according to claim 1, it further comprises a pressurizing mechanism for applying a predetermined initial pressure to the viscous material in the viscous material chamber.

[0022] According to this configuration, a predetermined initial pressure is applied to the viscous body in the viscous body chamber by the pressurizing mechanism, so that a higher pressure of the viscous body is ensured from the initial stage when the vibration damping target vibrates. As a result, a larger shear resistance is obtained by the viscous body, and a decrease in shear resistance due to the loosening of entanglements of the polymer chains of the viscous body is suppressed, thereby achieving a greater vibration damping effect.

[0023] The invention of claim 7 is characterized in that, in the vibration suppression device described in claim 1, it further comprises a storage chamber provided downstream of the relief valve in the first communication passage, for temporarily storing the viscous material flowing in from the viscous material chamber.

[0024] According to this configuration, when the relief valve opens during vibration of the vibration damping target, the viscous material flows from the viscous material chamber to the accumulator side through the first communication passage, and the viscous material flows into the storage chamber and is temporarily stored there. This reduces and stabilizes the flow of the viscous material and pressure fluctuations in the storage chamber, thereby achieving a more stable vibration damping effect.

[0025] The invention of claim 8 is characterized in that, in the vibration suppression device described in claim 1, the accumulator has an intermediate wall fixed within the casing and dividing the inside of the casing into a first space including an accumulator chamber and in which a piston and a set spring are provided, and a second space on the viscous body chamber side, and a second piston slidably provided within the second space and dividing the second space into a first fluid chamber communicating with the viscous body chamber and a second fluid chamber on the intermediate wall side, the first fluid chamber is filled with a viscous body, and the second fluid chamber and the accumulator chamber are filled with hydraulic oil having a lower viscosity than the viscous body, the first and second communication passages are formed to penetrate the intermediate wall and communicate with the second fluid chamber and the accumulator chamber, and a relief valve and a check valve are provided in the first and second communication passages, respectively.

[0026] According to this configuration, when the pressure of the viscous body in the viscous body chamber increases due to repeated shear deformation of the viscous body during vibration of the vibration damping target, this pressure is transmitted to the hydraulic oil in the second fluid chamber via the viscous body in the first fluid chamber and the second piston. The relief valve is opened and closed by the hydraulic oil in the second fluid chamber, and is kept closed until the pressure reaches the relief pressure, thereby maintaining the viscous body chamber at the previous high pressure state.

[0027] When the pressure of the hydraulic oil in the second fluid chamber reaches the relief pressure from this state, the relief valve opens. As a result, the hydraulic oil flows from the second fluid chamber through the first communication passage into the accumulator chamber, and a part of the pressure in the viscous body chamber is released to the accumulator and stored. Thereafter, as the vibration of the vibration-damping target ends, the pressure of the hydraulic oil in the accumulator chamber exceeds the pressure of the hydraulic oil in the second fluid chamber, and the check valve opens. As a result, the hydraulic oil flows from the accumulator chamber into the second fluid chamber through the second communication passage. As a result, the second piston is pushed down, and the viscous body is returned from the first fluid chamber to the viscous body chamber, and the pressure stored in the accumulator is released to the viscous body chamber, and the original state is restored.

[0028] As described above, in the present invention, by opening and closing the relief valve and check valve at appropriate times in response to an increase or decrease in the pressure of the viscous material in the viscous material chamber when the object to be damped vibrates, and by appropriately controlling the pressure in the viscous material chamber, the viscous damping effect due to the shear resistance of the viscous material can be effectively exerted, and the pressure in the viscous material chamber can be suppressed to below the allowable pressure of the sealing material, thereby preventing damage to the sealing material.

[0029] Furthermore, according to the present invention, like the other inventions described above, the viscous damping effect of the vibration suppression device is obtained by the shear resistance of the viscous body, but unlike the other inventions, the relief valve and the check valve are opened and closed by a lower viscosity hydraulic oil, not by a viscous body. This allows the relief valve and the check valve to operate smoothly with high responsiveness without being affected by the large flow resistance that occurs when a high-viscosity viscous body is used, and allows the pressure in the viscous body chamber to be controlled more accurately and appropriately.

[0030] The invention according to claim 9 is characterized in that, in the vibration suppressing device according to claim 1, the relief pressure of the relief valve is set to be equal to or lower than the allowable pressure of the sealing material.

[0031] According to this configuration, the pressure in the viscous material chamber can be reliably suppressed to the allowable pressure of the sealing material or less by opening the relief valve, thereby preventing damage to the sealing material and leakage of the viscous material from the viscous material chamber. [Brief description of the drawings]

[0032] [Figure 1] 1 is a longitudinal sectional view, partly cut away, of a viscous damper according to a first embodiment of the present invention. [Diagram 2] FIG. 1 is a diagram showing two types of installation conditions of viscous dampers on a structure. [Diagram 3] FIG. 11 is a longitudinal sectional view showing a viscous damper according to a second embodiment, with a portion cut away. [Figure 4] FIG. 11 is a longitudinal sectional view showing a part of a viscous damper according to a third embodiment, with a cutaway view. [Diagram 5]FIG. 11 is a vertical cross-sectional view showing a viscous damper according to a fourth embodiment, with a portion cut away. [Figure 6] FIG. 13 is a vertical cross-sectional view showing a viscous damper according to a first modified example of the fourth embodiment, with a portion cut away. [Figure 7] FIG. 13 is a longitudinal sectional view, partly cut away, of a viscous damper according to a second modified example of the fourth embodiment. [Figure 8] FIG. 13 is a vertical cross-sectional view showing a part of a viscous damper according to a first modified example of the fifth embodiment. [Figure 9] 11A and 11B are diagrams showing modified examples of the first and second communication passages. [Figure 10] FIG. 13 is a partially cutaway longitudinal sectional view of a viscous damper according to a sixth embodiment. [Figure 11] 13 is a diagram showing an example in which a flow rate adjustment valve is attached to a communication passage to an accumulator. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 shows a viscous damper 1A according to a first embodiment of the present invention. The viscous damper 1A constitutes a vibration suppression device that suppresses vibrations of a structure such as a building or a vehicle as a vibration damping target.

[0034] As shown in FIG. 1, a viscous damper 1A includes a ball screw 2, an outer cylinder 3, an inner cylinder 4, a viscous body VB filled in a viscous body chamber 5, an accumulator 6, and the like.

[0035] The ball screw 2 has a screw shaft 2a and a nut member 2b that is rotatably engaged with the screw shaft 2a via a number of balls (not shown). Most of the screw shaft 2a and the nut member 2b are coaxially housed in an outer cylinder 3, and the remaining part of the screw shaft 2a protrudes outside the outer cylinder 3.

[0036] The outer cylinder 3 is made of a cylindrical steel material. A first support 11a and a second support 11b are provided at one end and the other end of the outer cylinder 3, respectively. The first and second supports 11a and 11b are both short cylindrical with holes and different diameters. The first support 11a is fitted inside the outer cylinder 3, and the second support 11b is provided integrally with the outer cylinder 3, in a state of contacting the end face of the outer cylinder 3.

[0037] A first cover plate 12a is provided integrally with the outer cylinder 3 and the first support 11a to cover the outer cylinder 3 and a second cover plate 12b is provided integrally with the second support 11b to cover the outer cylinder 3 and the first support 11a. The screw shaft 2a of the ball screw 2 penetrates the first cover plate 12a and extends to the outside, and a clevis 14 and a first flange plate 15a are connected to the end of the screw shaft 2a in this order. The clevis 14 and a second flange plate 15b are connected to the second cover plate 12b in this order.

[0038] The inner cylinder 4 is made of a cylindrical steel material, is disposed inside the outer cylinder 3 and the second support 11b, and extends in the axial direction. An annular space having a predetermined gap is defined between the outer cylinder 3 and the inner cylinder 4, and this annular space serves as the viscous body chamber 5. The viscous body chamber 5 is filled with a viscous body VB. The viscous body VB is made of a material having a relatively high viscosity, such as silicone oil.

[0039] In addition, O-ring-shaped seals 21, 21 are provided at both ends of the viscous body chamber 5 to seal the viscous body VB inside the viscous body chamber 5. The seals 21 are, for example, made of a Rotovariseal. While a Rotovariseal has the advantage of being able to suppress leakage of the viscous body while allowing rotation, it also has the characteristic of being damaged when pressure exceeding the allowable pressure is applied, making it unable to suppress leakage of the viscous body.

[0040] One end side (the left end side in FIG. 1) of the inner cylinder 4 is integrally connected to the nut member 2b of the ball screw 2. The nut member 2b is supported by the first support body 11a, and the inner cylinder 4 is supported by the second support body 11b, respectively, via a radial bearing 22 and a thrust bearing 23. With the above configuration, the inner cylinder 4 and the nut member 2b are supported by the outer cylinder 3 so as to be rotatable but immovable in the axial direction.

[0041] The accumulator 6 is for storing a part of the pressure of the viscous body VB in the viscous body chamber 5. The accumulator 6 includes a casing 33 that communicates with the viscous body chamber 5 via a first communication passage 31 and a second communication passage 32 that are parallel to each other, a piston 35 that is slidably provided in the casing 33 and defines a pressure accumulation chamber 34 on the viscous body chamber 5 side in the casing 33, and a coil spring 36 that biases the piston 35 toward the pressure accumulation chamber 34.

[0042] A relief valve 37 is provided in the first communication passage 31 near the viscous body chamber 5. The relief valve 37 closes until the pressure of the viscous body VB in the viscous body chamber 5 reaches a predetermined relief pressure Prf, and opens when the relief pressure Prf is reached to release the pressure in the viscous body chamber 5 to the pressure accumulator chamber 34. In this embodiment, the relief pressure Prf is set to a value equal to the allowable pressure of the Rotovariseal constituting the sealing material 21, for example, 30 MPa.

[0043] In addition, by setting the spring constant of the coil spring 36 of the accumulator 6, it is possible to adjust the amount of viscous body VB flowing into the pressure accumulator chamber 34 and the pressure accumulated in the pressure accumulator chamber 34. For example, in this embodiment, the spring constant of the coil spring 36 is set so that the pressure in the pressure accumulator chamber 34 becomes 0.3 MPa when the coil spring 36 is compressed and deformed by several centimeters.

[0044] A check valve 38 is provided in the second communication passage 32 near the pressure accumulator chamber 34. The check valve 38 is configured to block the flow of the viscous body VB from the viscous body chamber 5 to the accumulator 6. The opening pressure of the check valve 38 is set to, for example, 0.01 MPa, and when the pressure in the pressure accumulator chamber 34 exceeds this opening pressure and the pressure in the viscous body chamber 5, the check valve 38 opens, and the viscous body VB flows from the pressure accumulator chamber 34 into the viscous body chamber 5.

[0045] When the viscous damper 1A having the above configuration is used as a vibration suppression device for a structure, it is installed between two parts of the structure that are displaced relative to each other due to vibration, via the first and second flange plates 15a, 15b. For example, in the example of FIG. 2(a), the viscous damper 1A is arranged in a portal frame consisting of upper and lower beams BU, BL and left and right columns PL, PR of the structure S, and is installed between a V-shaped brace BR connected to the upper beam BU and the left and right beams PL, PR. In the example of FIG. 2(b), the viscous damper 1A is arranged in a similar portal frame of the structure S, and is installed diagonally on a diagonal brace BD extending between the corner of the upper beam BU and the right column PR and the corner of the lower beam BL and the left column PL.

[0046] In the above configuration, when the structure S vibrates, the relative displacement between the two portions where the viscous damper 1A is installed is transmitted between the screw shaft 2a and the outer cylinder 3 and converted into rotational motion by the ball screw 2, causing the nut member 2b and the inner cylinder 4 connected thereto to rotate relative to the outer cylinder 3. As a result, a vibration suppression effect that suppresses the vibration of the structure S is achieved by the viscous damping effect due to the shear resistance of the viscous body VB filled in the viscous body chamber 5 between the outer cylinder 3 and the inner cylinder 4.

[0047] Furthermore, for example, when the viscous damper 1A operates for a long time in response to the response of the structure S to a long-period earthquake motion input, the viscous body VB undergoes repeated shear deformation, causing the temperature of the viscous body VB to rise, and the temperature expansion causes the pressure in the viscous body chamber 5 to rise. Until the pressure in the viscous body chamber 5 reaches the relief pressure Prf of the relief valve 37, the relief valve 37 is kept closed, thereby maintaining the viscous body chamber 5 at the high pressure state that has been increased up to that point. This suppresses the untangling of the polymer chains that make up the viscous body VB during repeated deformation, and suppresses the decrease in the shear resistance of the viscous body VB, thereby making it possible to maintain the vibration suppression effect of the viscous damper 1A in an excellent manner.

[0048] From this state, as the vibration of the structure S continues, the pressure of the viscous body VB in the viscous body chamber 5 further increases, and when it reaches the relief pressure Prf of the relief valve 37, the relief valve 37 opens. As a result, the viscous body VB flows from the viscous body chamber 5 through the first communication passage 31 into the pressure accumulation chamber 34 of the accumulator 6, and compresses the coil spring 36 through the piston 35, so that a part of the pressure in the viscous body chamber 5 is stored in the accumulator 6. As described above, the relief pressure Prf of the relief valve 37 is set to a value equal to the allowable pressure of the seal material 21. Therefore, by opening the relief valve 37, the pressure in the viscous body chamber 5 is suppressed to be equal to or lower than the allowable pressure of the seal material 21, thereby preventing damage to the seal material 21 and preventing leakage of the viscous body VB from the viscous body chamber 5 due to the damage.

[0049] Thereafter, as the vibration of the structure S ends, the pressure in the pressure accumulator chamber 34 exceeds the pressure in the viscous body chamber 5, and the check valve 38 opens. As a result, the viscous body VB is returned from the pressure accumulator chamber 34 to the viscous body chamber 5 via the second communication passage 32, and the pressure accumulated in the accumulator 6 is released to the viscous body chamber 5, restoring the original state.

[0050] Next, a viscous damper 1B according to a second embodiment of the present invention will be described with reference to Fig. 3. In the figure, components that are the same as or equivalent to those of the viscous damper 1A of the first embodiment are given the same reference numerals. This also applies to Figs. 4 to 8 and 10, which show other embodiments and modified examples, respectively.

[0051] 1, the viscous damper 1B differs from the viscous damper 1A of the first embodiment in that the accumulator 6 is disposed inside the inner cylinder 4, rather than outside the outer cylinder 3. Specifically, the accumulator 6, like the first embodiment, has a piston 35 and a coil spring 36 built into a casing 33, and the casing 33 is coaxially fitted integrally into the end of the inner cylinder 4 on the second cover plate 11b side, and is installed inside the inner cylinder 4 with the accumulator chamber 34 facing inward in the axial direction.

[0052] The first communication passage 31 communicates with the viscous body chamber 5 at one end, extends radially inward, and communicates with the pressure accumulator chamber 34 at the other end. The second communication passage 32 is disposed radially opposite the first communication passage 31, communicates with the viscous body chamber 5 at one end, extends radially inward, and communicates with the pressure accumulator chamber 34 at the other end. A relief valve 37 is provided in the first communication passage 31 near the viscous body chamber 5, and a check valve 38 is provided in the second communication passage 32 near the pressure accumulator chamber 34.

[0053] The viscous damper 1B having the above-mentioned configuration can achieve the same operation and effects as the viscous damper 1A of the first embodiment described above. Moreover, the entire accumulator 6 including the first and second communication passages 31, 32 is built into the inner cylinder 4 and does not appear at all outside the outer cylinder 3, so that the viscous damper can be made compact and has excellent design.

[0054] Next, a viscous damper 1C according to a third embodiment of the present invention will be described with reference to Fig. 4. As is clear from a comparison with Fig. 1, the viscous damper 1C differs from the viscous damper 1A of the first embodiment in that the first communication passage 11 with the relief valve 37 communicating with the viscous body chamber 5 and the pressure accumulation chamber 34 of the accumulator 6 is composed of two first communication passages 31, 31 in parallel with each other.

[0055] 4, the two first communication passages 31, 31 are arranged symmetrically to each other on both sides of the second communication passage 32, and specifically, one end of each of them is connected immediately inside the seal materials 21 arranged at both axial ends of the viscous body chamber 5, and the other end is connected to both sides of the second communication passage 32 of the pressure accumulator chamber 34. The second communication passage 32 is connected to the axial center of the viscous body chamber 5. A relief valve 37 is provided in each first communication passage 31, and its relief pressure Prf is set to the same value as in the first embodiment.

[0056] According to the viscous damper 1C configured as above, in the viscous body chamber 5, a large distance is ensured between the two outlet points of the viscous body VB to the accumulator 6 side through the first communication passage 31 and the inflow point of the viscous body VB from the accumulator 6 side through the second communication passage 32. This makes it possible to suppress variations in shear resistance due to turbulence in the flow of the viscous body VB in the viscous body chamber 5, and obtain a stable vibration suppression effect. In addition, since the two outlet points of the viscous body VB to the accumulator 6 side are respectively disposed near the seal materials 21, 21, the pressure in the viscous body chamber 5 can be accurately and appropriately controlled while favorably reflecting the pressure near the seal material 21.

[0057] In the third embodiment, the number of the first communication passages 31 is two, but it may be three or more. This allows the outflow location of the viscous material VB from the viscous material chamber 5 to the accumulator 6 to be set more precisely, and the pressure in the viscous material chamber 5 can be controlled more accurately.

[0058] Alternatively, the first and second communication passages 31, 32 may be configured as shown in Fig. 9. In this example, there are only one each of the first and second communication passages 31, 32, and one end thereof is connected to different positions of the viscous body chamber 5. The other end side is connected to a common third communication passage 39, and communicates with the pressure accumulator chamber 34 via the third communication passage 39. A relief valve 37 and a check valve 38 are provided in each of the first and second communication passages 31, 32.

[0059] In this configuration, when the pressure in the viscous body chamber 5 rises and the relief valve 37 opens, the viscous body VB flows from the viscous body chamber 5 through the first communication passage 31 and the third communication passage 39 in this order to the accumulator chamber 34. On the other hand, when the pressure in the accumulator chamber 34 becomes relatively high and the check valve 38 opens, the viscous body VB flows from the accumulator chamber 34 through the third communication passage 39 and the second communication passage 32 in this order to the viscous body chamber 5. As described above, the basic functions required of the first and second communication passages 31, 32, the relief valve 37, and the check valve 38 are ensured, while the third communication passage 39 is shared, making it possible to simplify the overall configuration of the communication passages.

[0060] Next, a viscous damper 1D according to a fourth embodiment of the present invention will be described with reference to Fig. 5. As is clear from a comparison with Fig. 1, the viscous damper 1D differs from the viscous damper 1A of the first embodiment in that a pressurizing mechanism 41 is newly provided.

[0061] The pressurizing mechanism 41 is for applying an initial pressure to the viscous body VB in the viscous body chamber 5. In this embodiment, the pressurizing mechanism 41 has an injection hole 41a that communicates with the viscous body chamber 5 and opens to the outer circumferential surface of the outer cylinder 3, a check valve 41b for preventing backflow that is provided in the injection hole 41a, and a cap 41c that closes the injection hole 41a.

[0062] In this configuration, the cap 41c is removed, and the viscous material VB is injected into the injection hole 41a in a pressurized state, thereby opening the check valve 41b and injecting the viscous material VB into the viscous material chamber 5. As a result, an initial pressure corresponding to the pressurized state and injection amount of the viscous material VB is applied in advance to the viscous material VB in the viscous material chamber 5. In this embodiment, the initial pressure is set to, for example, 2 MPa.

[0063] When an initial pressure is applied in this manner, a higher pressure from the viscous body VB is ensured from the initial stage when the structure S vibrates. As a result, a larger shear resistance is obtained from the viscous body VB, and a decrease in shear resistance due to the untangling of the polymer chains of the viscous body VB is suppressed, thereby achieving a greater vibration suppression effect.

[0064] Next, a viscous damper 1E according to a first modified example of the above-mentioned fourth embodiment will be described with reference to Fig. 6. The viscous damper 1E differs from the pressurizing mechanism 41 of the fourth embodiment in the configuration of the pressurizing mechanism 51.

[0065] The pressurizing mechanism 51 has a second piston 51a and a pressurizing screw 51b provided in the accumulator 6. The second piston 51a is disposed between the coil spring 36 and the top wall of the casing 33 in the accumulator 6, and is provided so as to be able to slide freely. The pressurizing screw 51b is screwed into the top wall of the casing 33 from above, and its tip abuts against the upper surface of the second piston 51a.

[0066] In this configuration, by rotating the pressure screw 51b and moving it downward, the viscous body VB in the pressure accumulator chamber 34 is pressurized in a state in which the coil spring 36 is compressed via the second piston 51a, and the check valve 38 opens, causing the viscous body VB to flow into the viscous body chamber 5. As a result, an initial pressure according to the amount of screwing of the pressure screw 51b and the like is applied to the viscous body VB in the viscous body chamber 5. Therefore, as in the above-mentioned fourth embodiment, from the initial stage of vibration, the pressure of the viscous body VB in the viscous body chamber 5 becomes high, thereby obtaining a larger shear resistance due to the viscous body VB, and suppressing a decrease in shear resistance due to the untangling of the polymer chains of the viscous body VB, thereby obtaining a larger vibration suppression effect.

[0067] Next, a viscous damper 1F according to a second modified example of the fourth embodiment will be described with reference to Fig. 7. In the viscous damper 1F, a pressurizing mechanism 61 having the same configuration as in the first modified example is provided separately from the accumulator 6.

[0068] 7, the second modified example includes an accumulator 6 having the same configuration as that of the first embodiment, and a pressurizing mechanism 61 that is separate from the accumulator 6. The configuration of the pressurizing mechanism 61 is basically the same as that of the pressurizing mechanism 51 of the first modified example that is incorporated into the accumulator 6.

[0069] Specifically, the pressurizing mechanism 61 has a communicating passage 61a that communicates with the viscous material chamber 5 and opens to the outer peripheral surface of the outer cylinder 3, a casing 61b that communicates with the communicating passage 61a, a piston 61d that is slidably arranged within the casing 61b and defines a pressurizing chamber 61c on the viscous material chamber 5 side, a coil spring 61e that urges the piston 61d toward the pressurizing chamber 61c, a second piston 61f that is slidably arranged between the coil spring 61e and the top wall of the casing 61b, a pressurizing screw 61g that is screwed from above into the top wall of the casing 61b and whose tip abuts against the upper surface of the second piston 61f, and an opening / closing valve (not shown) that opens and closes the communicating passage 61a.

[0070] In this configuration, the on-off valve is opened, and the pressure screw 61g is rotated and moved downward in the same manner as in the first modified example, whereby the viscous body VB in the pressure chamber 61c is pressurized and flows into the viscous body chamber 5 in a state in which the coil spring 61e is compressed via the second piston 61f. The on-off valve is then closed. As a result, an initial pressure according to the amount of screwing of the pressure screw 61g and the like is applied to the viscous body VB in the viscous body chamber 5. Therefore, similar to the fourth embodiment described above, a larger shear resistance is obtained by the viscous body VB, and a decrease in shear resistance due to the untangling of polymer chains is suppressed, thereby obtaining a larger vibration suppression effect.

[0071] Next, a viscous damper 1G according to a fifth embodiment of the present invention will be described with reference to Fig. 8. As is clear from a comparison with Fig. 1, the viscous damper 1G differs from the viscous damper 1A of the first embodiment in that a storage chamber 71 is provided in the middle of the first communication passage 31.

[0072] The storage chamber 71 has a housing 71a that communicates with the first communication passage 31 via an inlet and an outlet. The housing 71a is taller than the first communication passage 31, and the viscous material VB is stored therein with an air layer 71b remaining at the top. A check valve 71c for preventing backflow of the viscous material VB is provided at the outlet of the housing 71a.

[0073] In this configuration, when the relief valve 37 opens during vibration of the structure S, the viscous material VB flows from the viscous material chamber 5 to the accumulator 6 side via the first communication passage 31, and the viscous material VB flows into the storage chamber 71 and is temporarily stored therein. This reduces and stabilizes the flow and pressure fluctuations of the viscous material VB within the storage chamber 71, thereby achieving a more stable vibration suppression effect.

[0074] Next, a viscous damper 1H according to a sixth embodiment of the present invention will be described with reference to Fig. 10. The viscous damper 1H differs from the viscous dampers of the other embodiments in that a relief valve 37 and a check valve 38 are built into the accumulator casing, and that these valves 37 and 38 are opened and closed by hydraulic oil HF having a lower viscosity instead of the viscous body VB.

[0075] 10, in this embodiment, a casing 82 of an accumulator 81 is formed to be longer and thinner than those of the other embodiments, is attached directly to the outer cylinder 3 so as to protrude upward, and is connected to the viscous material chamber 5. In the casing 82, a slidable piston 35, a fixed intermediate wall 83, and a slidable second piston 84 are provided in this order from the top.

[0076] The intermediate wall 83 divides the inside of the casing 82 into an upper first space and a lower second space. In the first space, the piston 35 and the intermediate wall 83 define the pressure accumulator chamber 34, and the coil spring 36 is disposed on the opposite side of the pressure accumulator chamber 34. The second space is divided by the second piston 84 into a lower first fluid chamber 85 communicating with the viscous body chamber 5 and an upper second fluid chamber 86. The first fluid chamber 85 is filled with the viscous body VB, and the second fluid chamber 86 and the pressure accumulator chamber 34 are filled with hydraulic oil HF. The hydraulic oil HF is a normal hydraulic oil having an appropriate viscosity lower than that of the viscous body VB.

[0077] First and second communication passages 31, 32 are formed penetrating the intermediate wall 83, and both communication passages 31, 32 are in communication with the second fluid chamber 86 and the pressure accumulator chamber 34. A relief valve 37 is provided in the first communication passage 31, and a check valve 38 is provided in the second communication passage 32.

[0078] In this configuration, when the pressure of the viscous body VB in the viscous body chamber 5 increases due to repeated shear deformation of the viscous body VB during vibration of the structure S, this pressure is transmitted to the hydraulic oil HF in the second fluid chamber 86 via the viscous body VB in the first fluid chamber 85 and the second piston 84. The relief valve 37 is opened and closed by the hydraulic oil HF in the second fluid chamber 86, and is kept in a closed state until the pressure reaches the relief pressure Prf, thereby maintaining the viscous body chamber 5 at the previous high pressure state.

[0079] From this state, when the pressure of the hydraulic oil HF in the second fluid chamber 86 reaches the relief pressure Prf, the relief valve 37 opens. As a result, the hydraulic oil HF flows from the second fluid chamber 86 through the first communication passage 31 into the pressure accumulator chamber 34, and a part of the pressure in the viscous body chamber 5 is released to the accumulator 81 and stored. Thereafter, as the vibration of the structure S ends, the pressure of the hydraulic oil HF in the pressure accumulator chamber 34 exceeds the pressure of the hydraulic oil HF in the second fluid chamber 86, and the check valve 38 opens. As a result, the hydraulic oil HF flows from the pressure accumulator chamber 34 into the second fluid chamber 86 through the second communication passage 32. As a result, the second piston 84 is pushed down, and the viscous body VB is returned from the first fluid chamber 85 to the viscous body chamber 5, so that the pressure stored in the accumulator 81 is released to the viscous body chamber 5, and the original state is restored.

[0080] As described above, in this embodiment, as in the other embodiments, by opening and closing the relief valve 37 and the check valve 38 at appropriate timing in response to an increase or decrease in the pressure of the viscous material VB in the viscous material chamber 5 when the structure S vibrates, and appropriately controlling the pressure in the viscous material chamber 5, the viscous damping effect due to the shear resistance of the viscous material VB can be effectively exerted, and the pressure in the viscous material chamber 5 can be suppressed to below the allowable pressure of the sealing material 21, thereby preventing damage to the sealing material 21.

[0081] Furthermore, according to this embodiment, like the other embodiments described above, the viscous damping effect of the viscous damper is obtained by the shear resistance of the viscous body VB, but unlike the other embodiments, the relief valve 37 and the check valve 38 are opened and closed by the lower viscosity hydraulic oil HF, not by the viscous body VB. This makes it possible to operate the relief valve 37 and the check valve 38 smoothly with high responsiveness without being affected by the large flow resistance that would occur if a high-viscosity viscous body VB were used, and the pressure in the viscous body chamber 5 can be controlled more accurately and appropriately.

[0082] Furthermore, in this embodiment, the accumulator 81 can be easily installed by simply assembling the accumulator 81 shown in Fig. 10 in advance and then attaching the casing 82 to the outer cylinder 3 of the viscous damper, and unlike the other embodiments, there is an advantage that only one mounting hole needs to be formed in the outer cylinder 3. Also, multiple accumulators 81 may be installed for one viscous body chamber 5, or the casing 82 can be installed so as to extend horizontally.

[0083] The present invention is not limited to the embodiments described above, and can be implemented in various ways. For example, in all the embodiments, the viscous damper is of a type in which the outer cylinder 3 is fixed and the inner cylinder 4 is rotating, but the present invention can also be applied to a viscous damper of the opposite type, in which the inner cylinder is fixed and the outer cylinder is rotating. In this case, it is particularly advantageous to use the second embodiment in which the accumulator is built into the inner cylinder.

[0084] In the embodiment, the vibration control target is mainly a structure such as a building, but the present invention can be applied to any vibration control target as long as vibration can be controlled by the vibration control device. For example, as described briefly in the text, a vehicle can be the vibration control target, and a vibration control device can be installed between parts that vibrate during driving as a damper to suppress vibration.

[0085] Furthermore, in the embodiment, the diameters of the first to third communication passages 31, 32, and 39 are not mentioned, but each diameter may be set arbitrarily. Also, for example, as shown in FIG. 11, a flow rate adjustment valve 91 for adjusting the flow rate of the viscous material VB may be provided in a communication passage (the third communication passage 39 in this case) from the viscous material chamber 5 to the pressure accumulation chamber 34 of the accumulator 6. In this case, a globe valve or a butterfly valve can be used as the flow rate adjustment valve 91. By adjusting the flow rate of the viscous material VB with the flow rate adjustment valve 91 in this manner, the pressure in the viscous material chamber 5 and, ultimately, the damping force of the vibration suppression device can be appropriately adjusted.

[0086] Furthermore, the number and arrangement of components of the vibration suppression device shown in the embodiments are merely examples and may be changed as appropriate depending on the size of the functions required of the components, the layout, etc. For example, in an embodiment in which the accumulator is disposed outside the outer cylinder 3, two or more accumulators 6 or 81 may be installed.

[0087] In the embodiment, the viscous body VB is silicone oil, the seal material is Rotovariseal, and the hydraulic oil HF is a normal oil with a suitable viscosity, but as long as the conditions of the present invention are met, other suitable materials may be used. In addition, the detailed configuration may be changed as appropriate within the scope of the present invention. [Explanation of symbols]

[0088] 1A Viscous damper (vibration suppression device) according to the first embodiment 1B Viscous damper (vibration suppression device) according to the second embodiment 1C Viscous damper (vibration suppression device) according to the third embodiment 1D Viscous damper (vibration suppression device) according to the fourth embodiment 1E Viscous damper (vibration suppression device) according to a first modified example of the fourth embodiment 1F Viscous damper (vibration suppression device) according to the second modified example of the fourth embodiment 1G Viscous damper (vibration suppression device) according to the fifth embodiment 1H Viscous damper (vibration suppression device) according to the sixth embodiment 2. Ball screw 2a Screw shaft 2b Nut material (nut) 3. Outer cylinder 4 Inner cylinder 5 Viscous chamber 6 Accumulator 21 Sealing material 31 1st communication passage (1st communication passage) 32 2nd communication passage (2nd communication passage) 33 Casing 34 Pressure accumulator 35 Piston 36 Coil spring (set spring) 37 Relief valve 38 Check valve 39 Third communication passage 41 Pressurizing mechanism 51 Pressurizing mechanism 61 Pressurizing mechanism 71 Storage chamber 81 Accumulator 82 Casing 83 Intermediate Wall 84 Second piston 85 1st fluid chamber 86 Second fluid chamber S Structure (vibration control target) VB Viscous body Prf Relief Pressure HF hydraulic oil

Claims

1. A vibration suppression device provided between a first portion and a second portion in a system including a vibration-suppression target that undergoes relative displacement upon vibration in order to suppress vibration of the vibration-suppression target, A ball screw having a screw shaft connected to the first portion and a nut screwed to the screw shaft via a ball and converting a linear motion of the screw shaft into a rotational motion; An outer cylinder, an inner cylinder disposed inside the outer cylinder and defining a viscous material chamber between the inner cylinder and the outer cylinder; A viscous body filled in the viscous body chamber; a seal material for sealing the viscous material in the viscous material chamber, one of the outer cylinder and the inner cylinder is connected to the second portion, and the other of the outer cylinder and the inner cylinder is connected to the nut, The vibration suppression device further includes an accumulator for storing a portion of the pressure of the viscous material in the viscous material chamber, The accumulator is a casing communicating with the viscous material chamber; a piston slidably provided within the casing and defining a pressure accumulator chamber on the viscous body chamber side within the casing; a set spring that biases the piston toward the pressure accumulator chamber; a first communication passage and a second communication passage which are in parallel with each other and communicate with the viscous body chamber and the pressure accumulator chamber; a relief valve provided in the first communication passage, the relief valve opening when the pressure in the viscous material chamber reaches a predetermined relief pressure to release the pressure in the viscous material chamber to the pressure accumulator chamber; a check valve provided in the second communication passage for preventing a flow of viscous material from the viscous material chamber toward the pressure accumulator chamber.

2. 2. The vibration suppression device according to claim 1, wherein the accumulator is disposed inside the inner cylinder.

3. 2. The vibration suppression device according to claim 1, wherein the first communication passage is composed of a plurality of first communication passages arranged in parallel with each other, each of which has one end connected to a different position in the viscous material chamber and the other end connected to a different position in the pressure accumulator chamber, and the relief valve is provided in each of the plurality of first communication passages.

4. The vibration suppression device described in claim 3, characterized in that the sealing material is composed of a pair of sealing materials provided at both axial ends of the viscous material chamber, and the multiple first communication passages are composed of two first communication passages each having one end connected to a position close to the pair of sealing materials in the viscous material chamber.

5. 2. The vibration suppression device according to claim 1, wherein the first communication passage and the second communication passage are connected at one end to different positions in the viscous chamber, and are connected to the accumulator chamber via a common third communication passage connected at the other end.

6. 2. The vibration suppressing device according to claim 1, further comprising a pressurizing mechanism for applying a predetermined initial pressure to the viscous material in the viscous material chamber.

7. 2. The vibration suppression device according to claim 1, further comprising a storage chamber provided in the first communication passage downstream of the relief valve, for temporarily storing the viscous material that has flowed in from the viscous material chamber.

8. the accumulator includes an intermediate wall fixed within the casing and dividing the interior of the casing into a first space including the accumulator chamber and in which the piston and the set spring are provided, and a second space on the viscous body chamber side; and a second piston slidably provided within the second space and dividing the second space into a first fluid chamber communicating with the viscous body chamber, and a second fluid chamber on the intermediate wall side; The first fluid chamber is filled with the viscous material, and the second fluid chamber and the pressure accumulator chamber are filled with hydraulic oil having a lower viscosity than the viscous material, 3. The vibration suppression device according to claim 1, wherein the first and second communication passages are formed to pass through the intermediate wall and communicate with the second fluid chamber and the accumulator chamber, and the relief valve and the check valve are provided in the first and second communication passages, respectively.

9. 2. The vibration suppressing device according to claim 1, wherein the relief pressure of the relief valve is set to be equal to or lower than an allowable pressure of the sealing material.

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