JP6491568B2 - Accumulator and damper - Google Patents

Description

  The present invention relates to an accumulator and a damper.

  Among dampers used for seismic isolation or damping of buildings or large machines, a cylinder and a piston that is slidably inserted into the cylinder and divides the cylinder into an extension side chamber and a compression side chamber A rod connected to the piston, a flow path communicating the extension side chamber and the pressure side chamber, a damping valve that provides resistance to the flow of liquid moving through the flow path, and an accumulator connected to the pressure side chamber. There are dampers (for example, Patent Documents 1 and 2). The accumulator includes a liquid chamber that communicates with the cylinder and an air chamber that compensates for a change in the amount of liquid in the liquid chamber. When the volume of the liquid in the cylinder changes, the liquid moves back and forth between the liquid chamber and the pressure side chamber.

  Specifically, the liquid chamber and the air chamber of the accumulator are formed in the packing round integrated with the cylinder and the inside of the cylinder end in the cited document 1, and are formed in the rod in the cited document 2. Further, the liquid chamber and the air chamber in the accumulators of the cited documents 1 and 2 are partitioned by a free piston that can move in the axial direction of the cylinder or rod. If an urging spring for urging the free piston toward the liquid chamber is provided, the liquid can be quickly supplied from the accumulator into the cylinder when the liquid is insufficient in the cylinder.

JP 2006-77800 A JP 2014-95454 A

  Here, when the damper including the conventional accumulator is used in a severe low temperature environment such as a cold district or a freezing warehouse, such as below -30 ° C., the force that biases the free piston toward the liquid chamber is high. There may be a shortage. This is because the pressure in the air chamber usually acts in the direction of urging the free piston toward the liquid chamber, but the air chamber is sealed in the conventional accumulator, so that the damper is exposed to severe low temperatures after it is assembled at room temperature. When this is done, the temperature in the air chamber decreases, the air chamber becomes negative pressure, and a force that draws the free piston toward the air chamber side acts.

  When the pressure in the air chamber decreases excessively and the force that pulls the free piston toward the air chamber increases, the force that urges the free piston toward the liquid chamber is insufficient, so that sufficient liquid can flow from the accumulator into the cylinder. There is a possibility that the damper cannot be supplied and the damper cannot exhibit a desired damping force. In particular, as in the damper described in FIGS. 4 and 6 of Japanese Patent Laid-Open No. 2006-77800, when the change in the cylinder volume corresponding to the volume of the rod in and out of the cylinder is compensated by the accumulator, the extension stroke in which the rod retracts from the cylinder. If sufficient liquid is not supplied to the pressure side chamber, the pressure increase in the pressure side chamber is delayed in the subsequent compression stroke, and the damping force generation responsiveness is lowered. Such a problem may occur not only when the air chamber and the liquid chamber of the accumulator are partitioned by the free piston.

  Accordingly, an object of the present invention is to provide an accumulator and a damper that can prevent the pressure in the air chamber from being excessively lowered even when used in a severe low temperature environment.

  The accumulator according to claim 1, which solves the above problem, includes a suction valve that sucks gas into the air chamber when the pressure in the air chamber is lower than the external pressure of the case. For this reason, it can prevent that the pressure in an air chamber falls from the external pressure of a case.

  An accumulator according to a second aspect includes the structure according to the first aspect and a free piston that divides the inside of the case into a liquid chamber and an air chamber. For this reason, the liquid in the liquid chamber and the gas in the air chamber can be separated to prevent bubbles from entering the liquid, and the change in the liquid volume in the liquid chamber can be compensated in the air chamber.

  An accumulator according to a third aspect includes the configuration according to the first aspect or the second aspect, and further includes an elastic member that is provided in the air chamber and biases the free piston toward the liquid chamber. In an accumulator provided with an elastic member, it is particularly effective to provide the suction valve of the present invention because the pressure in the air chamber tends to decrease.

  The accumulator according to claim 4 is provided with the structure according to any one of claims 1 to 3, and the suction valve opens and closes a suction passage that communicates the air chamber with the outside of the case. And a spring for biasing the valve body in the closing direction, and the spring constant of the spring is set to open the valve body when the pressure in the air chamber becomes negative. . For this reason, the valve opening pressure of the suction valve can be lowered.

  According to a fifth aspect of the present invention, there is provided a damper according to any one of the first to fourth aspects. A partitioning piston, a partition partitioning the one chamber and the liquid chamber, and a flow path communicating the one chamber and the liquid chamber are provided. For this reason, the volume change in a cylinder and the volume change of the liquid in a cylinder can be compensated with an accumulator through a flow path.

  A damper according to a sixth aspect includes an accumulator according to any one of the first to fourth aspects, a cylinder, and a cylinder that is movably inserted into the cylinder so that the inside of the cylinder is moved into one chamber and the other chamber. The partitioning piston is provided, and the one chamber and the liquid chamber are integrated. For this reason, the volume change in a cylinder and the volume change of the liquid in a cylinder can be compensated with an accumulator.

  A damper according to a seventh aspect includes the structure according to the fifth or sixth aspect, and is interposed between a column and a beam of the structure or between the structure and the ground. For this reason, the damper can be used for vibration control or seismic isolation. When the damper is used for vibration control or seismic isolation as described above, the damper standby time (non-operation time) becomes longer, and the damper is in a harsh low-temperature environment such as in a refrigerated warehouse or a cold district. The situation used in is assumed. Therefore, it is particularly effective to use the accumulator according to the present invention for such a damper.

  According to the accumulator and the damper of the present invention, it is possible to prevent the pressure in the air chamber from excessively decreasing even when used in a severe low temperature environment.

It is the longitudinal cross-sectional view which simplified and showed the damper provided with the accumulator which concerns on one embodiment of this invention. It is the longitudinal cross-sectional view which simplified and showed the modification of the damper provided with the accumulator which concerns on one embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  As shown in FIG. 1, the accumulator A1 which concerns on one embodiment of this invention is utilized for the damper D1 which comprises a seismic isolation apparatus. The seismic isolation device is interposed between the seismic isolation floor of the refrigerated warehouse to be controlled and the foundation on the fixed side. The damper D1 suppresses the floor from shaking continuously.

  The damper D1 includes a cylindrical cylinder 1, a piston 2 that is slidably inserted into the cylinder 1, a rod 3 having one end connected to the piston 2 and the other end protruding outside the cylinder 1, and the cylinder 1 And the valve case 4 fixed to the opposite rod side of the piston 2. The accumulator A 1 is connected to the opposite cylinder side of the valve case 4. The accumulator A1 includes a cylindrical case 5 aligned with the cylinder 1 in the axial direction, a free piston 6 that is slidably inserted into the case 5, and an elastic member that urges the free piston 6 toward the valve case 4 side. The urging spring 7 is provided.

  And the attachment part 30 is provided in the left end part in FIG. 1 of the rod 3 which protrudes from the cylinder 1, and the rod 3 is connected to one of the seismic isolation floor and foundation of a freezer warehouse through the attachment part 30 concerned. Moreover, the attachment part 50 is provided also in the right end part in FIG. 1 of the accumulator A1, and the cylinder 1 is connected with the seismic isolation floor and the other foundation of a freezer warehouse through the said attachment part 50 and the accumulator A1. Therefore, when the seismic isolation floor is shaken due to the occurrence of an earthquake, the rod 3 moves in and out of the cylinder 1, the damper D1 expands and contracts, and the piston 2 moves in the cylinder 1 in the axial direction.

  The cylinder 1 and the case 5 are respectively screwed into one end and the other end of the valve case 4, and are integrated in a state of being connected in the axial direction via the valve case 4. The valve case 4 is a partition wall and partitions the cylinder 1 and the case 5. In the cylinder 1, a head member 10 is provided on the opposite side of the valve case 4, and the head member 10 pivotally supports the rod 3 so as to be movable in the axial direction and closes the left side opening of the cylinder 1 in FIG. 1. . In the other case 5, a bottom cap 51 is provided on the opposite side of the valve case 4, and the bottom cap 51 closes the right opening in FIG. 1 of the case 5. Further, the cylinder 1 and the case 5 and the valve case 4 are respectively closed by seals (not shown). Therefore, the inside from the cylinder 1 to the case 5 becomes a sealed space and is separated from the outside air.

  Subsequently, the cylinder 1 is partitioned by the piston 2 into an extension side chamber L1 on the head member 10 side and a pressure side chamber L2 on the valve case 4 side. The other case 5 is partitioned by a free piston 6 into a liquid chamber L3 on the valve case 4 side and an air chamber G on the bottom cap 51 side. The extension side chamber L1, the pressure side chamber L2, and the liquid chamber L3 are filled with a liquid, and the gas chamber G is filled with gas. In the present embodiment, the pressure side chamber L2 is one chamber, the expansion side chamber L1 is the other chamber, the pressure side chamber L2 and the liquid chamber L3 are partitioned by the valve case 4, and the pressure side chamber L2 is provided in the valve case 4. The fluid chamber L3 communicates with a flow path described later.

  As the liquid accommodated in the extension side chamber L1, the pressure side chamber L2, and the liquid chamber L3, there is a liquid that can maintain a viscosity suitable for generating a damping force without excessively increasing the viscosity even in an environment that is greatly below the freezing point. Selected. As long as the liquid is suitable for use in such a low-temperature environment, the type of liquid and additives are not limited. For example, as the liquid, aircraft oil or the like can be used.

  Subsequently, the piston 2 that partitions the extension side chamber L1 and the compression side chamber L2 is formed with an extension side flow channel 2a and a pressure side flow channel 2c that communicate the extension side chamber L1 and the pressure side chamber L2. The extension side flow path 2a is provided with an extension side valve V1 that provides resistance to the flow of liquid from the extension side chamber L1 toward the compression side chamber L2. The other pressure side channel 2c is provided with a pressure side valve V2 that provides resistance to the flow of liquid from the pressure side chamber L2 toward the expansion side chamber L1.

  The expansion side valve V1 includes a valve body 20 that causes a valve head to be attached to and detached from an annular valve seat 2b provided in the middle of the expansion side flow path 2a, and a spring 21 that urges the valve body 20 toward the valve seat 2b. And the valve body 20 is disposed with the valve head directed toward the extension side chamber L1. When the pressure in the expansion side chamber L1 becomes higher than the pressure in the compression side chamber L2 by a predetermined amount or more, the valve body 20 moves backward against the biasing force of the spring 21 and opens the expansion side flow path 2a.

  The other pressure side valve V2 includes a valve body 22 that allows the valve head to be attached to and detached from an annular valve seat 2d provided in the middle of the pressure side flow path 2c, and a spring 23 that biases the valve body 22 toward the valve seat 2d. And the valve body 22 is disposed with the valve head directed toward the compression side chamber L2. Then, when the pressure in the pressure side chamber L2 becomes higher than the pressure in the expansion side chamber L1 by a predetermined amount or more, the valve body 22 moves backward against the urging force of the spring 23 and opens the pressure side flow path 2c.

  In addition, although the valve bodies 20 and 22 of the expansion side valve V1 and the pressure side valve V2 are poppet types, the configuration of the expansion side valve V1 and the pressure side valve V2 can be appropriately changed. Further, the valve opening pressures of the expansion side valve V1 and the pressure side valve V2 can be freely changed according to the characteristics of the desired damping force, and the pressure side valve V2 may be a check valve.

  Subsequently, in the valve case 4 that divides the inside of the cylinder 1 and the case 5, a suction passage 4a and a damping passage 4b, which are passages that communicate the pressure side chamber L2 and the liquid chamber L3, are formed. The suction flow path 4a is provided with a suction valve V3 that is a check valve that allows only the flow of liquid from the liquid chamber L3 toward the pressure side chamber L2. The other damping flow path 4b is provided with a damping valve V4 that provides resistance to the flow of liquid from the pressure side chamber L2 toward the liquid chamber L3.

  The suction valve V3 has an annular valve body 40 that can open and close the outlet of the suction flow path 4a, and a spring 41 that urges the valve body 40 in the closing direction, and the valve body 40 is a pressure side chamber of the valve case 4. It is laminated on the L2 side. When the pressure in the liquid chamber L3 exceeds the pressure in the pressure side chamber L2, the valve body 40 moves backward against the urging force of the spring 41 and opens the suction flow path 4a.

  The other damping valve V4, like the expansion side valve V1 and the pressure side valve V2, has a valve body 42 that allows the valve head to be attached to and detached from an annular valve seat 4c provided in the middle of the damping flow path 4b. A spring 43 that biases toward the valve seat 4c, and the valve body 42 is disposed with the valve head directed toward the compression side chamber L2. Then, when the pressure in the pressure side chamber L2 becomes higher than the pressure in the liquid chamber L3 by a predetermined amount or more, the valve body 42 moves backward against the urging force of the spring 43 and opens the damping flow path 4b.

  The valve body 40 of the suction valve V3 is an annular plate, and the valve body 42 of the damping valve V4 is a poppet type, but this is not restrictive, and the configurations of the suction valve V3 and the damping valve V4 can be changed as appropriate. Further, the valve opening pressure of the damping valve V4 can be freely changed according to the desired damping force characteristics.

  Subsequently, the free piston 6 that divides the liquid chamber L3 and the air chamber G is urged toward the valve case 4 by the urging spring 7 as described above. The biasing spring 7 exerts an elastic force when it is interposed between the free piston 6 and the bottom cap 51 and compressed. Therefore, the free piston 6 is urged toward the liquid chamber L3 by the urging spring 7 and pressurizes the liquid chamber L3. Then, the pressure in the liquid chamber L3 increases and the pressure in the cylinder 1 increases. This is because the liquid chamber L3 is in communication with the compression side chamber L2 through the flow path of the valve case 4, and the pressure side chamber L2 is in communication with the expansion side chamber L1 through the flow path of the piston 2.

  The air chamber G communicates with the outside air through the gas suction passage 5a. The suction flow path 5a is provided with a suction valve V5 which is a gas check valve. When the pressure in the air chamber G falls below the external air pressure of the case 5, the suction flow path 5a is opened, and the outside air enters the air chamber G. Inhale. The outside air is air existing around the case 5. The external pressure of the case 5 is the pressure of the air around the case 5, and when the damper D1 is used in the freezer warehouse as in this embodiment, the pressure in the freezer warehouse (use environment). It corresponds to. Although the inside of the freezer warehouse is a highly sealed space, the pressure in the freezer warehouse becomes substantially equal to the atmospheric pressure due to opening and closing of the entrance accompanying loading and unloading. Therefore, even if the temperature in the air chamber G decreases and the pressure decreases, the air chamber G does not drop below the pressure in the freezer warehouse, and the negative pressure increases and the force that pulls the free piston 6 toward the air chamber G is increased. It can be prevented from becoming large.

  The suction valve V5 includes a poppet-type valve body 52 and a spring 53 that biases the valve body 52 in the closing direction, but is not limited thereto and can be changed as appropriate. Furthermore, even if a cover is provided at the inlet on the outside side of the gas suction flow path 5a and dust and dust are prevented from entering the suction flow path 5a by the cover, the suction flow path 5a can be prevented from being clogged. Good.

  Hereinafter, the operation of the damper D1 including the accumulator A1 according to the present embodiment will be described.

  In the extension stroke of the damper D1 in which the rod 3 is retracted from the cylinder 1, the piston 2 moves in the cylinder 1 to the left in FIG. 1, the extension side chamber L1 is compressed, and the pressure side chamber L2 expands. Then, the pressure in the expansion side chamber L1 to be compressed rises, and the liquid in the expansion side chamber L1 pushes open the expansion side valve V1, passes through the expansion side flow path 2a, and moves to the compression side chamber L2. In the cylinder 1, the liquid corresponding to the retracted rod volume is insufficient, but the suction valve V3 is opened and the liquid corresponding to the shortage is supplied from the liquid chamber L3 of the accumulator A1 to the pressure side chamber L2 through the suction flow path 4a.

  Since resistance is given to the flow of the liquid from the extension side chamber L1 to the pressure side chamber L2 by the extension side valve V1, the pressure in the extension side chamber L1 rises. On the other hand, since the pressure side chamber L2 receives the supply of the liquid from the accumulator A1, it becomes substantially equal to the pressure in the case 5. Therefore, a differential pressure is generated in the pressures of the extension side chamber L1 and the compression side chamber L2, and this differential pressure acts on the piston 2 to generate a damping force that suppresses the extension operation of the damper D1. Further, when the liquid for the volume of the rod that has retreated is supplied from the liquid chamber L3 to the pressure side chamber L2, the liquid in the liquid chamber L3 decreases, but the free piston 6 moves to the left in FIG. Expands to compensate for the decrease in liquid in the case 5.

  On the contrary, in the contraction stroke of the damper D1 in which the rod 3 enters the cylinder 1, the piston 2 moves rightward in FIG. 1 in the cylinder 1, the compression side chamber L2 is compressed, and the expansion side chamber L1 expands. Then, the pressure in the compression side chamber L2 to be compressed rises, and the liquid in the compression side chamber L2 pushes open the compression side valve V2, passes through the compression side channel 2c, and moves to the expansion side chamber L1. In the cylinder 1, the liquid for the volume of the rod that has entered becomes surplus, but this surplus liquid pushes and opens the damping valve V4 and is discharged from the pressure side chamber L2 to the liquid chamber L3 of the accumulator A1 through the damping channel 4b. .

  With respect to the flow of the liquid from the pressure side chamber L2 to the extension side chamber L1 and the liquid chamber L3, resistance is given by the pressure side valve V2 and the damping valve V4, so the pressure in the pressure side chamber L2 increases. On the other hand, the pressure in the expansion side chamber L1 which expands falls. Therefore, a differential pressure is generated between the pressure side chamber L2 and the extension side chamber L1, and this differential pressure acts on the piston 2 to generate a damping force that suppresses the contraction operation of the damper D1. Further, when the liquid for the volume of the rod that has entered is discharged from the pressure side chamber L2 to the liquid chamber L3, the liquid in the liquid chamber L3 increases, but the free piston 6 moves to the right in FIG. Shrink to compensate for the increase in liquid in case 5.

  Moreover, since the free piston 6 is urged toward the liquid chamber L3 by the elastic force of the urging spring 7, the pressure in the cylinder 1 can be increased via the liquid chamber L3, and the damping force generation response can be improved.

  Further, when the outside air temperature of the damper D1 decreases due to an environmental change outside the damper D1, the temperature in the air chamber G decreases and the pressure decreases. When the pressure in the air chamber G falls below the external pressure of the case 5, the suction valve V5 opens the suction flow path 5a, and the air outside the case 5 flows into the air chamber G. In addition, as long as the pressure in the air chamber G exceeds the external pressure of the case 5, the suction valve V5 is not opened, so that the pressure in the air chamber G can be kept higher than the external pressure of the case 5, that is, the pressure in the freezer. That is, even if the temperature in the air chamber G decreases and the pressure decreases, it is possible to prevent the negative pressure in the air chamber G from increasing and the force that pulls the free piston 6 toward the air chamber G from increasing. Therefore, the force for urging the free piston 6 toward the liquid chamber L3 is not insufficient, and the damping force generation response in the damper D1 is maintained well.

  Hereinafter, the effect of damper D1 provided with accumulator A1 and accumulator A1 of this embodiment is explained.

  In the present embodiment, the damper D1 is interposed between the seismic isolation floor of the refrigeration warehouse, which is a structure, and the ground.

  Thus, when the damper D1 is used for seismic isolation, the standby time (non-operating time) of the damper D1 becomes longer, and the damper D1 is used in a severe low temperature environment such as in a freezer warehouse or outdoors in a cold district. A situation is assumed. Therefore, it is particularly effective to use the accumulator according to the present invention for the damper D1. Moreover, in this Embodiment, although the damping object is a seismic isolation floor of a freezing warehouse, you may interpose a damper D1 between another structure and the ground. Further, the damper D1 may be interposed between the pillar and the beam of the structure body and used for damping. As described above, even when the damper D1 is used for vibration control, it is assumed that the damper D1 is used in a severe low-temperature environment as in the case of using it for vibration isolation. It is also effective to use the accumulator according to the present invention for this damper.

  Further, in the present embodiment, the damper D1 is inserted into the accumulator A1, the cylinder 1, and the cylinder 1 so as to be movable so that the inside of the cylinder 1 becomes a compression side chamber (one chamber) L2 and an extension side chamber (other chamber) L1. Piston 2 to be partitioned, valve case (partition wall) 4 for partitioning pressure side chamber L2 and liquid chamber L3, and suction flow path and damping flow paths (flow paths) 4a, 4b communicating pressure side chamber L2 and liquid chamber L3 With.

  According to the above configuration, the accumulator A1 can compensate for the volume change in the cylinder 1 and the volume change of the liquid in the cylinder 1 through the suction flow path and the attenuation flow paths (flow paths) 4a and 4b. In the present embodiment, the pressure side chamber L2 and the liquid chamber L3 are separated from each other with the valve case 4 as a boundary. However, the liquid chamber may be integrated with the pressure side chamber L2 as in the damper D2 shown in FIG. In this case, the same effect as described above can be obtained. Further, in the damper D2 shown in FIG. 2, the cylinder and the case of the accumulator A2 are seamlessly integrated as one component 8. Such a change is also possible with the damper D1.

  In the present embodiment, the accumulator A1 is connected to the pressure side chamber L2 of the damper D1, but this is not restrictive. For example, the accumulator A1 may be connected in the middle of a hydraulic circuit that constitutes a cylinder device or the like.

  In the present embodiment, the suction valve V5 includes a valve body 52 that opens and closes the suction flow path 5a that communicates the air chamber G with the outside of the case 5, and a spring 53 that biases the valve body 52 in the closing direction. Have. The spring constant of the spring 53 is preferably set so that the valve body 52 is opened when the pressure in the air chamber G becomes negative.

  Thus, when the valve body 52 is opened in a state in which the pressure in the air chamber G is negative (pressure lower than atmospheric pressure), the pressure in the air chamber G is atmospheric pressure or higher. However, since there is no problem, it is not necessary to increase the airtightness when the valve body 52 closes the suction flow path 5a. Accordingly, since the force for urging the valve body 52 in the closing direction can be reduced, it is possible to employ the spring 53 having a small spring constant, and the valve opening pressure of the suction valve V5 can be lowered. When the valve opening pressure of the suction valve V5 is lowered, the suction valve V5 opens even if the pressure difference between the inside and outside of the air chamber G is small, so that the pressure inside the air chamber G can be kept high.

  The configuration of the suction valve V5 is not limited to the above, and can be changed as appropriate. For example, according to the said structure, since the airtightness by the valve body 52 may be low, what does not have the spring 53 as the suction valve V5 is employable. In addition, the spring constant of the spring 53 is increased to increase the airtightness of the valve body 52, and the pressure in the air chamber G at the time of assembly of the damper D1 is increased so that the damper D1 is kept in a low temperature environment. Even if it is used, the air chamber G may be set so as not to become lower than the external pressure of the case 5. In such a case, an inert gas such as nitrogen can be sealed in the air chamber G to prevent the generation of rust, and there is no concern that outside air will be taken into the air chamber G after assembly. The cover to prevent can be omitted. Such a change is also possible in the accumulator A2, and is possible regardless of the type and configuration of the connection target to which the accumulators A1 and A2 are connected.

  When the suction valve V5 having a low valve opening pressure is used, the humidity in the freezer warehouse is low. Therefore, the suction valve V5 is opened in the freezer and the air in the freezer warehouse is taken into the air chamber G. Although there is no concern about rust or the like, outside air with high humidity may be taken into the air chamber G in the process of assembling the damper D1, transporting it to the freezer warehouse, and attaching it to the freezer warehouse. Therefore, even when the suction valve V5 as described above is used, in order to suppress the valve opening during this time, an inert gas such as nitrogen is injected into the air chamber G when the damper D1 is assembled, The pressure in the air chamber G may be increased to some extent.

  In the present embodiment, the accumulator A1 includes an urging spring (elastic member) 7 that is provided in the air chamber G and urges the free piston 6 toward the liquid chamber L3.

  According to the above configuration, the damping force generation response can be improved by pressurizing the inside of the cylinder 1 via the liquid chamber L3. Further, it is particularly effective to provide the suction valve V5 in the accumulator A1 including the biasing spring 7. This is because the urging spring 7 acts in the direction in which the air chamber G is enlarged, and therefore, if the urging spring 7 is provided, the pressure in the air chamber G tends to decrease. Then, the inside of the air chamber G becomes negative pressure, and when the negative pressure increases, the force that draws the free piston 6 toward the air chamber G increases, so the effect of providing the biasing spring 7 is impaired. On the other hand, when the suction valve V5 is provided, the pressure in the air chamber G is not significantly reduced, so that the damping force generation response can be maintained well.

  Note that the accumulator A1 does not necessarily have to include the urging spring 7. In the present embodiment, the urging spring 7 is a coil spring, but the free piston 6 may be urged by a spring other than the coil spring or an elastic member such as rubber. Such a change is also possible in the accumulator A2, and is possible regardless of the type and configuration of the connection target to which the accumulators A1 and A2 are connected and the configuration of the suction valve V5.

  In the present embodiment, the accumulator A1 includes a free piston 6 that is movably inserted into the case 5 and partitions the liquid chamber L3 and the air chamber G.

  According to the above configuration, the liquid in the liquid chamber L3 and the gas in the gas chamber G can be separated to prevent bubbles from entering the liquid, and the change in the liquid volume in the liquid chamber L3 can be compensated by the gas chamber G. Further, when the liquid chamber L3 and the air chamber G are partitioned by the free piston 6, the free piston 6 can be biased toward the liquid chamber L3 by the biasing spring 7, so that the liquid chamber L3 is easily pressurized. The configuration for partitioning the liquid chamber L3 and the air chamber G is not limited to this, and an extendable bladder or bellows may be used. Such a change is also possible in the accumulator A2, and is possible regardless of the type and configuration of the connection target to which the accumulators A1 and A2 are connected and the configuration of the suction valve V5.

  Further, in the present embodiment, the cylinder 1 and the case 5 are connected side by side in the axial direction, but a case is provided on the outer periphery of the cylinder 1 to form a cylindrical space between the case and the cylinder 1. The liquid chamber L3 and the air chamber G may be formed. In this case, the liquid chamber L3 and the air chamber G may be separated from the liquid surface of the liquid chamber L3, and the liquid in the liquid chamber L3 and the gas in the air chamber G may be in contact with each other at the liquid surface. Such a change is also possible in the accumulator A2, and is possible regardless of the type and configuration of the connection target to which the accumulators A1 and A2 are connected and the configuration of the suction valve V5.

  Further, in the present embodiment, the accumulator A1 is arranged in the case 5 when the pressure in the air chamber G is lower than the case 5, the liquid chamber L3 and the air chamber G provided in the case 5, and the external pressure of the case 5. And a suction valve V5 for sucking gas into the air chamber G from the outside.

  According to the above configuration, the inside of the air chamber G can be prevented from becoming lower than the external pressure of the case 5. As a result, according to the accumulator A1, even if the accumulator A1 is used in a severe low temperature environment, the pressure in the air chamber G can be prevented from excessively decreasing.

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

A1, A2 ... Accumulator, D1, D2 ... Damper, G ... Air chamber, L1 ... Extension side chamber (other chamber), L2 ... Pressure side chamber (one chamber), L3 ... Liquid Chamber, V5 ... Suction valve, 1 ... Cylinder, 2 ... Piston, 5 ... Case, 5a ... Suction flow path, 4 ... Valve case (partition), 4a, 4b ...・ Suction flow path and damping flow path (flow path), 6 ... free piston, 7 ... energizing spring (elastic member), 8 ... component in which the case of the cylinder and accumulator is seamlessly integrated, 52 ... Valve, 53 ... Spring

Claims (7)

Case and
A liquid chamber and an air chamber provided in the case;
An accumulator comprising: a suction valve that sucks gas from outside the case into the air chamber when the pressure in the air chamber is lower than the outside air pressure of the case. The accumulator according to claim 1, further comprising a free piston that is movably inserted into the case and partitions the liquid chamber and the air chamber. The accumulator according to claim 2, further comprising an elastic member that is provided in the air chamber and biases the free piston toward the liquid chamber. The suction valve has a valve body that opens and closes a suction flow path that communicates the air chamber outside the case, and a spring that biases the valve body in a closing direction,
4. The spring constant of the spring is set to open the valve body when the pressure in the air chamber becomes negative. 5. Accumulator. The accumulator according to any one of claims 1 to 4,
A cylinder,
A piston that is movably inserted into the cylinder and divides the cylinder into one chamber and the other chamber;
A partition partitioning the one chamber and the liquid chamber;
A damper comprising: a flow path communicating with the one chamber and the liquid chamber. The accumulator according to any one of claims 1 to 4,
A cylinder,
A piston that is movably inserted into the cylinder and divides the cylinder into one chamber and the other chamber;
The damper, wherein the one chamber and the liquid chamber are integrated. The damper according to claim 5 or 6, wherein the damper is interposed between a column and a beam of the structure or between the structure and the ground.

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