JP5697706B2 - Hydraulic damper - Google Patents

Description

  The present invention relates to a hydraulic damper, and more particularly to a hydraulic damper suitable as a seismic isolation damper used to protect a structure such as a building or a detached house from an earthquake.

  Various seismic isolation devices have been developed and used so far in order to prevent propagation of ground vibrations, especially rolls, due to the occurrence of earthquakes to structures. The types of seismic isolation devices include, for example, those that support the upper structure from the bottom with laminated rubber with rubber plates stacked (or an iron plate in between), and those that absorb vibrations caused by earthquakes with dampers. In addition, what insulates between the ground and the upper structure has been proposed, and those in which these are combined are proposed. And the said damper absorbs seismic motion more than predetermined by the hydraulic resistance accompanying the movement of the piston arrange | positioned in a cylinder. However, these cylinders are filled with gas (gas) in addition to hydraulic oil, and the above gas often flows into and mixes in the suction port due to abrupt vibration caused by earthquake motion. The effect cannot be obtained. Therefore, in order to solve such a problem, the reservoir chamber containing the gas is provided with the first and second orifice plates for suppressing the fluctuation of the oil level (see Patent Document 1), the reservoir chamber is provided with a suction port and The thing (refer patent document 2) which arrange | positioned the cylindrical oil level fluctuation suppression pipe surrounding a discharge pipe is proposed.

Japanese Patent Laid-Open No. 9-42347 Japanese Patent No. 44567779

  However, the hydraulic damper disclosed in Patent Document 1 cannot be applied to a horizontal hydraulic damper. Further, in the hydraulic damper disclosed in Patent Document 2, when the oil is moved or expanded in the left-right direction due to a sudden earthquake motion, the oil level of the hydraulic oil fluctuates greatly, and the gas filled therein is sucked from the suction port. As a result, the hydraulic resistance is significantly reduced.

  Therefore, the present invention has been proposed to solve the above-described problems of the conventional hydraulic damper, and the hydraulic oil fluctuates in the hydraulic oil by moving and extending in the left-right direction due to a sudden earthquake motion. An object of the present invention is to provide a novel hydraulic damper that can prevent the gas from being sucked and can exhibit a desired damping effect as a seismic isolation damper even if it occurs.

The present invention has been proposed in order to solve the above-mentioned problems. The first invention (the invention according to claim 1) includes an inner cylinder in which a piston is slidably disposed, and an inner cylinder of the inner cylinder. An outer cylinder, which is disposed outside and sealed with gas, and is a reservoir chamber between the inner cylinder and the hydraulic oil in the reservoir chamber is guided into the inner cylinder and one end side of the inner cylinder And a suction port disposed on the other end side of the inner cylinder and having a length in the horizontal direction. The suction port is disposed below the axial center position of the inner cylinder, and the outer side of the inner cylinder is positioned above the inner cylinder from the upper position of the suction port. Regulating plate is mounted over the end side middle portion, the hydraulic oil passes through the lower side of the regulating plate with made is configured to be sucked into the suction port, the regulating plates, the inner cylinder An arc-shaped curved portion having a length in the length direction, and one regulating plate portion bent from one side of the curved portion and having a tip close to the inner peripheral surface of the outer cylinder, The other restriction plate portion bent from the other side of the curved portion and having a tip close to the inner peripheral surface of the outer cylinder, and the one and the other restriction plate portions are oil surfaces of the hydraulic oil. It is characterized in that it is located below .

In the hydraulic damper according to the first aspect of the present invention, when a sudden earthquake motion occurs, the piston slides in the inner cylinder, and the entire length of the hydraulic damper expands and contracts. As the hydraulic damper expands and contracts, the hydraulic oil in the reservoir chamber is sucked into the inner cylinder from the suction port, and the hydraulic oil in the inner cylinder is discharged from the discharge port into the reservoir chamber. And even if the hydraulic oil filled in the reservoir chamber fluctuates due to the entire hydraulic damper moving rapidly and repeatedly left and right simultaneously with the expansion and contraction operation due to the earthquake motion, the hydraulic oil is The suction is not sucked from above the suction port by the restriction plate, but is sucked by the suction port through the lower side of the restriction plate. Therefore, according to the hydraulic damper according to the first aspect of the present invention, gas does not flow into the suction port, and as a result, the expected damping effect can be effectively exhibited. In particular, in the hydraulic damper according to the first aspect of the invention, the one and the other restricting plate portions are positioned below the hydraulic oil surface, and the tips of the restricting plate portions are the inner peripheral surface of the outer cylinder. Therefore, the risk of the gas being sucked into the inner cylinder from the suction port can be avoided.

Further, according to a second invention (the invention according to claim 2 ), in the first invention, one or a plurality of openings are formed on the discharge port side of the one and the other regulation plate portions. It is characterized by.

In the hydraulic damper according to the second aspect of the present invention, even if gas enters the lower surface on the tip side (the other end direction of the inner cylinder) of the one and the other restriction plate portions due to the occurrence of an earthquake, the opening is not provided. Pass through and escape upwards. Therefore, according to the hydraulic damper according to the second aspect of the present invention, it is possible to avoid the risk that the gas staying on the lower surfaces of the one and the other regulating plate portions flows into the suction port.

In the hydraulic damper according to the first aspect of the invention (invention of claim 1), the oil level of the hydraulic oil fluctuates when the entire hydraulic damper suddenly repeatedly moves left and right simultaneously with the expansion and contraction operation due to the earthquake motion. However, the restriction plate prevents the gas in the reservoir chamber from being sucked from the suction port, and as a result, the desired damping effect can be effectively exhibited. In particular, in the hydraulic damper according to the first aspect of the invention, the one and the other restricting plate portions are positioned below the hydraulic oil surface, and the tips of the restricting plate portions are the inner peripheral surface of the outer cylinder. Therefore, the risk of the gas being sucked into the suction port can be avoided.

Further, in the hydraulic damper according to the second invention (the invention according to claim 2 ), due to the occurrence of an earthquake, gas is generated on the lower surface on the distal end side (in the other end direction of the inner cylinder) of the one and the other restriction plate portions. Even if it has penetrated, it can pass through the opening and escape upward, so that it is possible to avoid the danger that the gas staying on the lower surface of one and the other regulating plate will flow into the suction port It becomes.

It is a sectional side view which shows the hydraulic damper which concerns on embodiment. FIG. 2 is an enlarged side sectional view showing one end side of the hydraulic damper shown in FIG. 1. It is a front view of a blocking member. It is a front view of a hydraulic damper. FIG. 2 is a hydraulic circuit diagram of the hydraulic damper shown in FIG. 1. It is a perspective view which shows a control plate. It is a graph which shows the change of resistance and stroke of a hydraulic damper in which a restriction plate is not arranged. It is a graph which shows the change of resistance and stroke of a hydraulic damper in which a control plate is arranged.

  Hereinafter, the best mode for carrying out the hydraulic damper according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the hydraulic damper 1 according to this embodiment includes an outer cylinder 2, an inner cylinder 3 disposed inside the outer cylinder 2, and a base end side slidable within the inner cylinder 3. And a piston rod 4 housed in the housing. The outer cylinder 2 is formed in a cylindrical shape, and a lid 6 is fixed to one end (right end in FIG. 1) of the outer cylinder 2, and a cylinder head is connected to the other end of the outer cylinder 2. 7 is fixed. The lid body 6 and the cylinder head 7 are both formed into a rectangular parallelepiped shape in the front shape, and through holes (not shown) are formed at the corners of the facing surfaces of the lid body 6 and the cylinder head 7. The tie rods 10 with screws threaded on the outer peripheral surfaces at both ends are inserted into these through holes, and nuts 11 are screwed into the respective tie rods 10. Therefore, the lid 6 and the cylinder head 7 are firmly in close contact with the outer cylinder 2 by screwing the nuts 11 at both ends closer to each other. As shown in FIG. 2, the outer surface of the lid body 6 is used when the hydraulic damper 1 is fixed to either the structure side or the ground side, and has one opening formed in the center. A fixed piece 6a is formed, and a spherical bearing 14 is disposed in the opening. Further, a disc-shaped fitting ring portion (reference numeral is omitted) having an outer diameter to be fitted in the outer cylinder 2 is formed on the inner side surface of the lid body 6. One end of the outer cylinder 2 is closed by being fitted into the outer cylinder 2.

  The inner cylinder 3 is formed in a cylindrical shape having an outer diameter smaller than that of the outer cylinder 2, and one end of the inner cylinder 3 is closed by a closing member 13. A disc-like fitting portion (reference numeral is omitted) having an outer diameter fitting into the inner cylinder 3 is formed on the inner side surface of the closing member 13, and this fitting portion is the inner cylinder. The one end of the inner cylinder 2 is closed by being fitted into the inner part 2. A plurality of ports 13 a are formed in the closing member 13. These ports 13a have a length in the horizontal direction, and communicate with a reservoir chamber described later via left and right suction ports 13b and 13c. These left and right suction ports 13b and 13c are formed below the axis of the closing member 13 (or inner cylinder 3) as shown in FIG. 3 or FIG. When installed, it is formed on both the left and right sides of the lowermost end of the closing member 13. Further, these ports 13a are formed with discharge ports (reference numerals are omitted) communicating with the inside of the inner cylinder 3, and a first check valve 15 is disposed in this discharge port. The first check valve 15 includes a valve body (symbol is omitted) that closes the discharge port, and a spring (symbol is omitted) that urges the valve body in a direction that always closes the discharge port. And.

  Further, as shown in FIG. 3, one restricting plate attaching groove 13 d and the other restricting plate attaching groove 13 e are formed on the outer periphery of the closing member 13. The one and other restricting plate mounting grooves 13d and 13e are formed below the axis of the closing member 13 (or the inner cylinder 3).

  Therefore, as will be described later, when the cylinder rod 4 is extended from the outer cylinder 2, the hydraulic oil filled in the reservoir chamber flows into the port 13a from the left and right suction ports 13b and 13c. The first check valve 15 opens against the elastic force of the spring, thereby flowing into the inner cylinder 3.

  In addition, as shown in FIG. 1, one end side of the piston rod 4 is inserted into the inner cylinder 3. The piston rod 4 is formed to have an outer diameter thinner than the inner diameter of the inner cylinder 3, and a reduced diameter portion 4a having a shorter outer diameter is formed on the tip side (the right end in FIG. 1). A stepped portion 4b is formed in a direction opposite to the distal end side of the reduced diameter portion 4a. Then, a screw (reference numeral is omitted) is threaded on the outer periphery on the distal end side of the reduced diameter portion 4a, and a nut 17 is screwed on the screw. The reduced diameter portion 4a is mounted in the order of the piston 18, the second check valve 19, and a spring (reference numerals are omitted) between the nut 17 and the stepped portion 4b. The piston 18 is formed with an insertion hole (reference numeral is omitted) through which the reduced diameter portion 4a is inserted at the center, and the outer diameter is formed to have the same inner diameter as the inner diameter of the inner cylinder 3. Yes, when the piston rod 4 moves, the outer peripheral surface of the piston 18 is in sliding contact with the inner peripheral surface of the inner cylinder 3. A ring-shaped recess (reference numeral is omitted) is formed on the outer periphery of the piston 18, and an O-ring (not shown) is accommodated in the recess. The piston 18 is formed with a plurality of flow paths (reference numerals are omitted) in the moving direction of the piston 18. These flow paths are provided in the inner cylinder 3 and the hydraulic oil stored in a space (hereinafter referred to as “A chamber”) on one end side (tip side) of the inner cylinder 3 with the piston 18 as a boundary. It is a flow path that moves to a space on the other end side of the inner cylinder 3 (hereinafter referred to as B chamber).

  The second check valve 19 is movable in the direction of closing the flow path and in the direction opposite to the direction, and the middle part of the reduced diameter portion 4a is inserted in the center. An insertion hole (not shown) is formed. In addition, the spring is a coil spring in which the reduced diameter portion 4a is inserted inside, and one end is in contact with the second check valve 19 and the other end is in contact with the step portion 4b. The check valve 19 is pressed and biased to one end of the piston rod 4. Therefore, as will be described later, when the piston rod 4 moves to one end side of the inner cylinder 3, the second check is performed against the elastic force of the spring by the pressure of the hydraulic oil contained in the chamber A. The valve 19 moves to the other end side of the inner cylinder 3, and by the movement of the second check valve 19, the hydraulic oil in the A chamber passes through the flow path and moves to the B chamber.

  Further, as shown in FIG. 1, the cylinder head 7 has a cylindrical outer fitting portion 7a fitted into the inner diameter of the outer cylinder 2 and an inner side of the outer fitting portion 7a. A cylindrical inner fitting portion 7b fitted into the inner cylinder 3, and a sliding surface in which the outer peripheral surface of the piston rod 4 slides on the inner peripheral surface inside the inner fitting portion 7b. A hole 7c is formed.

  Further, a damping valve 21 and a needle valve 22 are built in the cylinder head 7. Hereinafter, these members will be described with reference to FIG. In FIG. 5, the A chamber and the B chamber are as described above, and the space A compressed when the piston rod 4 moves rightward in FIG. 5 and the piston rod 4 are illustrated in FIG. The space B compressed when moving to the left in the middle 5 is formed in the inner cylinder 3 on the left and right sides with the piston 18 as a boundary. The C chamber is a space formed between the inner cylinder 3 and the outer cylinder 2, and is filled with hydraulic oil O and gas (reference numerals are omitted). When the hydraulic cylinder 1 is installed horizontally, the liquid level of the hydraulic oil O is located above the axis of the hydraulic cylinder 1 as shown in FIG. In the cylinder head 7, a first discharge passage 7d and a second discharge passage 7e connecting the B chamber and the C chamber are formed, respectively, and in the middle of the first discharge passage 7d. The damping valve 21 is disposed, and the needle valve 22 is disposed in the middle of the second discharge passage 7e. The first discharge pipe 7d into which the hydraulic oil discharged from the first discharge passage 7d flows into the first discharge passage 7d and discharges the hydraulic oil from the tip into the C chamber is provided in the C chamber. The second discharge pipe 24 is connected to the second discharge passage 7e. The second discharge pipe 24 into which the hydraulic oil discharged from the second discharge passage 7e flows and discharges the hydraulic oil from the tip into the C chamber is provided in the C chamber. It is connected to. The space in the B room is a narrower space than the space in the A room.

  Therefore, when the piston rod 4 is moved to one end side (the right side in FIG. 5) of the inner cylinder 3 and the hydraulic oil filled in the A chamber is pressurized, the second check valve 19 is opened, The hydraulic oil in the A chamber flows into the B chamber, and the damping valve 21 and the needle valve 22 are also opened. The hydraulic oil that flows into the B chamber passes through the first discharge passage 7d and the second discharge passage 7e. The first exhaust pipe 23 and the second exhaust pipe 24 are then discharged into the C chamber.

  And in the hydraulic damper 1 which concerns on this embodiment, as shown in FIG. 1 or FIG. 2, the control plate 31 is arrange | positioned on the outer side of the said inner cylinder 3. As shown in FIG. As shown in FIG. 6, the restricting plate 31 includes a curved portion 31a having an end surface curved in an arc shape, one restricting plate portion 31b bent from one side of the curved portion 31a, and the curved portion. The other restricting plate part 31c bent from the other side of the part 31a is provided. The curvature of the bending portion 31 a is the same as the curvature of the outer periphery of the inner cylinder 3, and the upper surface of the bending portion 31 a is in contact with or close to the outer periphery of the inner cylinder 3. Further, the restriction plate 31 has a length from the suction ports 13b, 13c side to the cylinder head 7 side. In the hydraulic damper 1 according to the present embodiment, the length of the inner cylinder 3 is increased. On the other hand, the length is about 1/3 to 1/4. A notch 31d is formed on the base end side of the curved portion 31a. The widths of the one restricting plate portion 31 b and the other restricting plate portion 31 c are equal to the distance from the outer peripheral surface of the inner cylinder 3 to the inner peripheral surface of the outer cylinder 2. Furthermore, in the regulation plate 31 according to this embodiment, circular shapes are provided on the tip side (the discharge port side and the other end side of the inner cylinder 3) of the one and the other regulation plate portions 31b and 31c, respectively. A plurality of (three) openings 31e and 31f are formed. The restriction plate 31 is press-fitted into one restriction plate mounting groove 13d shown in FIG. 3 at the end (on the side where the notch 31d is formed) of the one restriction plate 31b. The other restricting plate portion 31c (on the side where the notch portion 31d is formed) is press-fitted into the other restricting plate attaching groove 13e so that the other restricting plate portion 31c is attached above the suction ports 13b and 13c. ing. When the restriction plate 31 configured in this way is placed in the C chamber (reservoir chamber) by being press-fitted into the one and the other restriction plate mounting grooves 13d and 13e, the one and the other As shown in FIG. 1 or FIG. 4, the restricting plate portions 31 b and 31 c are not only below the level of the hydraulic oil O filled in the C chamber (reservoir chamber), but also the shaft core of the hydraulic damper 1. Is located below.

  Therefore, when the hydraulic damper 1 according to this embodiment is installed and used as a seismic isolation damper used to protect a structure such as a building or a detached house from an earthquake, an earthquake occurs. Thus, even when the hydraulic damper 1 moves suddenly and repeatedly left and right, and the liquid level of the hydraulic oil O in the C chamber (reservoir chamber) drops downward, the hydraulic oil O The one and the other restricting plate portions 31b and 31c constituting the plate 31 are not sucked from above the suction ports 13b and 13c, and as shown by the arrows in FIG. Since the gas is sucked after passing the lower side of 31b, 31c, the risk of the gas being sucked from the suction ports 13b, 13c can be effectively avoided. In particular, in the hydraulic damper 1 according to the present embodiment, the restriction plate 31 has a length of about 1/3 to 1/4 with respect to the total length of the inner cylinder 3, so that the gas is sucked into the suction port. The danger of flowing into 13b, 13c can be largely avoided.

  In the hydraulic damper 1 according to this embodiment, the restriction plate 31 has a plurality of openings 31e and 31f formed in the one and the other restriction plate portions 31b and 31c. This is a case where a part of the gas moves to the lower surface on the front end side of the one and the other restricting plate portions 31b and 31c due to the generation, and moves to the bottom surface of the one and the other restricting plate portions 31b and 31c from the specific gravity. However, the gas can be moved upward (escape) through the openings 31e and 31f, and thus the gas staying on the bottom surface moves on the bottom surfaces of the one and the other restricting plate portions 31b and 31c and moves to the suction port. It can prevent flowing into 13b, 13c. The restriction plate 31 has an end portion of the one restriction plate portion 31b press-fitted into the restriction plate attachment groove 13d, and an end portion of the other restriction plate portion 31c in the other restriction plate attachment groove 13e. Since it is attached above the suction ports 13b and 13c, it is possible to prevent a situation in which it is detached due to an earthquake or rotates in the C room.

  7 and 8 are graphs showing the relationship between the resistance force and stroke of the hydraulic damper according to the above configuration, respectively, and FIG. 7 is a test result regarding the hydraulic damper in which the restriction plate 31 is not arranged. FIG. 8 shows a test result relating to the hydraulic damper 1 in which the regulating plate 31 is arranged. As is clear from the graph shown in FIG. 7, when the piston rod 4 moves in the + direction (the direction in which the pressure in the A chamber is pressurized), the resistance is greatly reduced because the gas flows into the A chamber. Compared with this, in FIG. 8 which shows the test result concerning the hydraulic damper 1 in which the regulating plate 31 is arranged, the resistance force does not decrease at all according to the change of the stroke of the piston rod 4. This is because gas is sucked from the suction ports 13b and 13c and does not flow into the chamber A due to the arrangement of the regulation plate 31. As is clear from these respective graphs, according to the hydraulic damper 1 according to this embodiment, even when the level of the hydraulic oil O in the reservoir chamber (C chamber) is lowered due to the earthquake, Thus, it can be seen that the gas does not flow into the suction ports 13b and 13c, and that the originally intended damping effect is exhibited.

  In the hydraulic damper 1 according to the above-described embodiment, the example in which the restriction plate 31 is disposed horizontally with respect to the one and the other restriction plate portions 31b and 31c has been described. However, the one and the other restriction plate portions 31b are described. , 31c are not only horizontally arranged in this way, but also, for example, are made horizontal from the suction ports 13b, 13c side, and incline so that they gradually turn downward from the middle to the tip. In addition, an opening (not shown) for allowing the gas to escape upward may be formed between the inclined portion and the horizontal portion.

DESCRIPTION OF SYMBOLS 1 Hydraulic damper 2 Outer cylinder 3 Inner cylinder 13b, 13c Suction port 31 Restriction plate 31b One restriction plate part 31c The other restriction plate part 31e, 31f Opening O Hydraulic oil

Claims (2)

An inner cylinder in which a piston is slidably disposed, an outer cylinder disposed outside the inner cylinder and filled with hydraulic oil together with a gas, and a reservoir chamber between the inner cylinder and the reservoir A suction port disposed on one end side of the inner cylinder while guiding the hydraulic oil in the chamber to the inner cylinder, and is disposed on the other end side of the inner cylinder while discharging the hydraulic oil in the inner cylinder into the reservoir chamber. A hydraulic damper provided with a discharge port and having a length in the horizontal direction,
The suction port is disposed below the axial center position of the inner cylinder, and a regulating plate is provided on the outer side of the inner cylinder from the upper position of the suction port to the middle portion on the other end side of the inner cylinder. The hydraulic oil is attached so that the hydraulic oil passes through the lower side of the restriction plate and is sucked into the suction port . The restriction plate has a length in the length direction of the inner cylinder. Arc-shaped curved part, one restriction plate part that is bent from one side of the curved part and the tip is close to the inner peripheral surface of the outer cylinder, and the other side of the curved part. The other end of the outer cylinder is adjacent to the inner peripheral surface of the outer cylinder, and the one and the other restricting plate are located below the oil level of the hydraulic oil. Features hydraulic damper. 2. The hydraulic damper according to claim 1, wherein one or a plurality of openings are formed on the discharge port side of the one and the other regulating plate portions .