JP2018071570A - Hydraulic circuit and hydraulic pressure type damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic circuit having a low flow passage resistance including a check valve and provide a hydraulic pressure type damper using this hydraulic circuit.SOLUTION: A hydraulic circuit 1 is constituted by a main body 3, a valve body 5 and an elastic member 7 and the like. The valve body 5 is stored in the main body 3. At the front side of the valve body 5 where a hole 8 is formed at a location positioned at an outer side of the hole 8a to pass through the valve body 5. In addition, at the rear side of a space where the elastic member 7 of the main body 3 is stored, there is provided a hole 8b. Partial oil flows at a first flow passage 9a. The flow passage 9a acting as a first flow passage becomes a flow passage similar to that of the prior art in-line type check valve. At the hydraulic circuit 1, there is further provided a hole 8c facing toward a side part at a space where the valve body 5 of the main body 3 is stored in respect to the prior art in-line type check valve. The partial oil flows at a flow passage 9b acting as a second flow passage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydraulic circuit and a hydraulic damper using the same.

  Conventionally, a check valve is used in a hydraulic circuit to regulate the flow direction of oil. By arranging the check valve in the flow path, the flow of oil from one side is allowed, but the oil can be prevented from flowing from the other side.

  On the other hand, hydraulic dampers are used to reduce the shaking of buildings due to earthquakes and winds. The hydraulic damper uses the fluid resistance of oil to generate a resistance force (damping force) against the shaking of the building, absorbs the shaking of the building, and improves earthquake resistance and habitability. That is, the hydraulic oil filled in the cylinder of the hydraulic damper generates a damping force by the fluid resistance when passing through the hydraulic valve and absorbs the shaking of the building.

  As such a hydraulic damper, for example, there is a hydraulic damper in which a check valve is provided behind the pressure regulating valve and an accumulator is connected to a flow path that flows to the check valve (for example, Patent Document 1).

  The accumulator absorbs the volume expansion caused by changes in the oil temperature due to changes in the outside air temperature and the heat generated during operation, and stabilizes the performance of the hydraulic damper by replenishing hydraulic oil when the volume shrinks. It is to make it. That is, the accumulator has a role of temporarily storing excess hydraulic oil from the hydraulic circuit (hydraulic chamber) and releasing the oil to the circuit when the hydraulic oil is insufficient.

JP 2004-36677 A

  FIG. 8 is a diagram showing the relationship between the damping force generated in the hydraulic damper and the displacement of the piston when a vibration such as an earthquake occurs using the hydraulic damper as in Patent Document 1. The displacement and damping force change clockwise with respect to the circle in the figure. For example, as shown in FIG. 8 (a), ideally, the site where the change in displacement is the largest (that is, the state where the moving speed of the piston is the largest), the site where the damping force becomes the largest and the direction of displacement changes ( That is, at the moment when the direction of shaking changes, the damping force becomes the smallest. At this time, ideally, the change in the damping force continues even when the direction of displacement is reversed.

  On the other hand, when the direction of displacement changes, the check valve that has been opened so far is closed inside the hydraulic damper, and the check valve that has been closed so far is opened, so that the direction of oil flow changes. However, due to the flow resistance of the oil flowing through the check valve, it takes a short time for the oil to flow sufficiently after the check valve is opened.

  However, as described above, if the hydraulic oil does not flow out smoothly from the check valve, the hydraulic oil will exceed the pressure applied by the accumulator spring for a short time before the oil flows out from the check valve. Inflow. If the hydraulic oil in the pressure chamber on the low pressure side is insufficient in this way, the hydraulic oil amount in the hydraulic circuit is insufficient, and a damping force is generated at the moment when the direction of displacement is reversed, as shown in FIG. The phenomenon that the piston slides slightly may occur. When such slip occurs, the damping performance of the hydraulic damper becomes unstable.

  In order to prevent such a phenomenon, it is necessary to reduce the flow path resistance of the check valve. In this case, there is a method of increasing the size of the valve body of the check valve. However, when the size of the check valve is increased, a piston for accommodating the check valve becomes large, and the apparatus becomes large.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a hydraulic circuit having a small flow path resistance including a check valve and a hydraulic damper using the hydraulic circuit.

  A first invention for achieving the above-described object is a hydraulic circuit using an in-line type check valve, wherein the check valve includes a main body, a valve body accommodated in the main body, and the valve body. An elastic member that presses, the check valve is disposed in the flow path, and when oil presses the valve body against the elastic member from the front of the check valve and flows into the main body, The oil passes through the inside of the valve body and flows to the rear of the check valve, and the oil passes through the outside of the valve body through a hole or slit formed in the main body. A hydraulic circuit comprising: a second flow path that can merge with the oil flowing through the first flow path.

  According to the first invention, in the hydraulic circuit using the inline type check valve, the second flow path is provided outside the main body in which the valve body is accommodated, separately from the first flow path that flows from the front to the rear of the valve body. Since it is formed, the flow path resistance can be reduced as compared with the conventional check valve having only the first flow path.

  A second invention is a hydraulic damper comprising the hydraulic circuit according to the first invention, wherein the hydraulic damper moves in the cylinder and moves in the cylinder filled with hydraulic oil. A piston that is divided into a first pressure chamber and a second pressure chamber; and piston rods provided on both sides of the piston; wherein the hydraulic circuit is housed in the piston; The flow path is provided between the first pressure chamber and the second pressure chamber, and the second flow path includes the hole or slit formed in the piston, and the piston. The hydraulic damper is characterized by a gap between the cylinder and the cylinder.

  A first check valve which is connected to the second pressure chamber and the outflow side is connected to the third flow path, the inflow side is connected to the first pressure chamber, and the outflow side is connected to the third flow path. A second check valve that is connected to the third flow path and the outflow side is connected to the fourth flow path, and generates a fluid resistance in the hydraulic fluid that passes from the third flow path to the fourth flow path side. One pressure regulating valve, a third check valve whose inflow side is connected to the fourth flow path and an outflow side connected to the second pressure chamber, an inflow side connected to the fourth flow path, and an outflow side connected to the first pressure chamber. When the first pressure chamber is higher in pressure than the second pressure chamber, the hydraulic oil in the first pressure chamber is supplied to the second check valve, the third flow valve, and the fourth check valve. Through the passage, the pressure regulating valve, the fourth flow path, the third check valve in order, The first check valve blocks the hydraulic oil from flowing from the third flow path to the second pressure chamber, and the fourth check valve moves to the first pressure chamber. When the second pressure chamber is higher than the first pressure chamber, the hydraulic oil in the second pressure chamber is prevented from flowing in the first check valve, The first check chamber flows into the first pressure chamber through the third flow path, the pressure regulating valve, the fourth flow path, and the fourth check valve in order, and the second check valve is connected to the first flow path from the third flow path. The hydraulic oil is prevented from flowing into the pressure chamber, and the third check valve prevents the hydraulic oil from flowing from the second pressure chamber into the fourth flow path, and the piston moves in either direction. A damping force is generated, and at least the third check valve and the fourth check valve are connected to the hydraulic circuit. Kicking may be the check valve.

  According to the second invention, the hydraulic circuit according to the first invention is formed in the piston, and separately from the first flow path that flows from the front to the rear of the valve body of the check valve accommodated in the piston, Since the gap is used as the second flow path, the flow path resistance can be further reduced as compared with the conventional check valve having only the first flow path.

  In particular, when an accumulator is connected upstream of the check valve, the check valve opens and the flow resistance of the check valve prevents the hydraulic oil from flowing into the accumulator due to a delay in the flow of hydraulic oil from the check valve. can do.

  ADVANTAGE OF THE INVENTION According to this invention, the hydraulic circuit with small flow path resistance including a check valve and a hydraulic damper using the same can be provided.

The figure which shows the hydraulic circuit 1. FIG. 1 is a configuration diagram of a hydraulic damper 10. FIG. 1 is a hydraulic circuit diagram of a hydraulic damper 10. FIG. 1 is a hydraulic circuit diagram of a hydraulic damper 10. FIG. The figure which shows the structure of the hydraulic circuit 1 in the hydraulic damper. (A) is a figure which shows the hole 8c provided in the piston 40, (b) is a figure which shows the slit 8d provided in the piston 40. The hydraulic circuit diagram of the hydraulic damper 10a. The figure which shows the characteristic of the displacement and damping force of a hydraulic damper.

  Hereinafter, a hydraulic damper according to an embodiment of the present invention will be described. As shown in FIG. 1A, the hydraulic circuit 1 includes a main body 3, a valve body 5, an elastic member 7, and the like. A valve body 5 is accommodated in the main body 3. A hole 8 a is provided in the main body 3 in front of the valve body 5. The valve body 5 is pressed from behind by the elastic member 7, and the front surface (tapered surface) of the valve body 5 is in contact with the edge of the hole 8a. That is, the valve body 5 is pressed by the elastic member 7 and closes the hole 8a.

  A hole 8 is formed on the front surface side of the valve body 5 and on the outer peripheral side of the contact portion with the edge of the hole 8 a, and penetrates the valve body 5. That is, the valve body 5 communicates between the front and the rear through the hole 8 on the outer peripheral side of the contact portion with the hole 8a. A hole 8b is provided on the rear side of the space in which the elastic member 7 of the main body 3 is accommodated.

  As shown in FIG. 1B, when oil presses the valve body 5 against the elastic member 7 from the front of the valve body 5 through the hole 8a, the valve body 5 moves rearward, and the valve body 5 And a gap between the edge of the hole 8a. From this gap, when oil flows into the main body 3 from the hole 8a, a part of the oil passes through the inside of the valve body 5 through the hole 8 and flows out from the hole 8b. That is, as illustrated, a part of the oil flows through the flow path 9a that is the first flow path. The flow path 9a is the same flow path as a conventional in-line type check valve.

  In the hydraulic circuit 1, a hole 8 c is provided to the side in a space in which the valve body 5 of the main body 3 is accommodated in addition to the conventional inline type check valve. In the illustrated example, in a state where the valve body 5 is closed, a hole 8 c that penetrates from the space surrounded by the valve body 5 and the main body 3 to the outside of the main body 3 from the outer periphery side of the hole 8 a is provided.

  The hole 8c merges with the hole 8b described above via the outside of the main body 3. More specifically, when the oil flows into the main body 3 from the hole 8a from the gap formed between the valve body 5 and the edge of the hole 8a when the valve body 5 moves rearward, a part of the oil is It is possible to merge with the hole 8b through the outside of the main body 3 (that is, outside of the valve body 5) through the hole 8c. That is, as shown in the drawing, part of the oil flows through the flow path 9b that is the second flow path.

  In the conventional in-line type check valve, since oil flows only through the flow path 9a, it is necessary to increase the cross-sectional area of the flow path 9a in order to reduce the flow resistance of the check valve. However, in order to increase the flow path cross-sectional area of the flow path 9a, it is necessary to increase the size of the valve body 5, which increases the size of the entire hydraulic circuit.

  On the other hand, according to the hydraulic circuit 1, since the flow path 9b is further formed with respect to the conventional in-line type check valve, the total flow path cross-sectional area can be increased. Moreover, since it is not necessary to increase the size of the valve body 5, a conventional small check valve can be used. In the illustrated example, the flow path 9b is formed by connecting a tubular flow path to the outside of the main body 3. However, it is only necessary that oil can flow outside the main body 3. Etc. are not required.

  Next, a hydraulic damper 10 using the hydraulic circuit 1 according to the present invention will be described. As shown in FIG. 2, the hydraulic damper 10 mainly includes a cylinder 20, piston rods 30a and 30b, a piston 40, and the like, a pressure regulating valve 13, an accumulator 23, and the like.

  A piston 40 is movably provided in the cylindrical cylinder 20. On both sides of the piston 40, cylindrical piston rods 30a and 30b are provided. A joint 25 a is connected to the cylinder 20. A joint 25b is connected to the piston rod 30b. The joints 25a and 25b are fixed to a brace or base of a building.

  The inside of the cylinder 20 is divided into a first pressure chamber 50 and a second pressure chamber 51. The first pressure chamber 50 and the second pressure chamber 51 are filled with hydraulic oil. The cylinder 20, the piston 40, the piston rods 30a and 30b, etc. are made of metal.

  In the piston 40, flow paths 33, 35, 37, 39, 41, 43 are provided. The first check valve 15 and the second check valve 17 are provided in the flow path 33 that is the third flow path. Further, the third check valve 19 and the fourth check valve 21 are provided in the flow path 35 that is the fourth flow path. The flow path 33 and the flow path 35 are connected via a single pressure regulating valve 13. The pressure regulating valve 13 generates fluid resistance in the hydraulic oil that passes from the flow path 33 to the flow path 35 side. A first relief valve 27 is provided between the flow path 37 and the flow path 39. A second relief valve 29 is provided between the flow path 41 and the flow path 43.

  The inflow side of the first check valve 15 is connected to the second pressure chamber 51, and the inflow side of the second check valve 17 is connected to the first pressure chamber 50. The outflow sides of the first check valve 15 and the second check valve 17 are connected to the flow path 33. The flow path 33 is connected to the inflow side of the pressure regulating valve 13.

  The outflow side of the third check valve 19 is connected to the second pressure chamber 51, and the outflow side of the fourth check valve 21 is connected to the first pressure chamber 50. The outflow side of the pressure regulating valve 13 is connected to the flow path 35, and the flow path 35 is connected to the inflow side of the third check valve 19 and the fourth check valve 21. Further, an accumulator 23 is connected between the inflow side of the third check valve 19 and the inflow side of the fourth check valve 21 via a throttle valve 31.

  The flow path 37 connects the first pressure chamber 50 and the inflow side of the first relief valve 27. The flow path 39 connects the outflow side of the first relief valve 27 and the second pressure chamber 51. The flow path 41 connects the first pressure chamber 50 and the outflow side of the second relief valve 29. The flow path 43 connects the inflow side of the second relief valve 29 and the second pressure chamber 51.

  When the first pressure chamber 50 has a higher pressure than the second pressure chamber 51, the second check valve 17 is opened, allowing hydraulic oil to flow from the first pressure chamber 50. Further, the hydraulic oil passes through the pressure regulating valve 13, the third check valve 19 is opened, and flows out to the second pressure chamber 51 side. At this time, the fourth check valve 21 prevents the hydraulic oil from flowing from the first pressure chamber 50 into the flow path in the piston 40, and the first check valve 15 moves from the flow path in the piston 40 to the second pressure chamber 51. Prevents hydraulic fluid from flowing out.

  When the second pressure chamber 51 has a higher pressure than the first pressure chamber 50, the first check valve 15 is opened, allowing hydraulic oil to flow from the second pressure chamber 51. Further, the hydraulic oil passes through the pressure regulating valve 13, the fourth check valve 21 is opened, and the hydraulic oil flows out to the first pressure chamber 50 side. At this time, the third check valve 19 prevents the hydraulic oil from flowing from the second pressure chamber 51 into the flow path in the piston 40, and the second check valve 17 moves from the flow path in the piston 40 to the first pressure chamber 50. Prevents hydraulic fluid from flowing out.

  The first relief valve 27 opens when the pressure of the hydraulic oil in the first pressure chamber 50 exceeds a certain value, and allows the hydraulic oil to flow from the first pressure chamber 50 side to the second pressure chamber 51 side. . The second relief valve 29 opens when the pressure of the hydraulic oil in the second pressure chamber 51 exceeds a certain value, and allows the hydraulic oil to flow from the second pressure chamber 51 side to the first pressure chamber 50 side. .

  The accumulator 23 is provided in the flow path on the outflow side from the pressure regulating valve 13 in the piston 40, and is accommodated, for example, inside the piston rod 30a. The accumulator 23 has a function of absorbing the thermal expansion of the hydraulic oil. In addition, the hydraulic oil is supplied to the low-pressure side pressure chamber to prevent the hydraulic oil from becoming negative pressure and to stabilize the performance of the hydraulic damper. The accumulator 23 may be housed inside the piston rod 30b or the piston 40.

  Next, the operation of the hydraulic damper 10 will be described in detail with reference to FIGS. 3 to 4 show the hydraulic damper 10 shown in FIG. 1 as a hydraulic circuit diagram.

  FIG. 3 shows a case where a force such as an earthquake or wind acts on the building and an external force in the direction A acts on the piston 40. When the piston 40 moves in the A direction, the hydraulic oil filled in the second pressure chamber 51 is compressed. The hydraulic oil compressed in the second pressure chamber 51 flows from the first check valve 15 into the flow path 33 (in the direction of arrow B in the figure). At this time, the second check valve 17 and the third check valve 19 are closed.

  The hydraulic oil that has flowed into the flow path 33 from the first check valve 15 flows into the pressure regulating valve 13. When hydraulic oil having a predetermined pressure or higher flows into the pressure regulating valve 13, the hydraulic oil flows out into the flow path 35 through the pressure regulating valve 13. The hydraulic oil that has flowed out of the pressure regulating valve 13 flows into the first pressure chamber 50 through the fourth check valve 21 (in the direction of arrow C in the figure).

  Since the second pressure chamber 51 is higher in pressure than the hydraulic oil after passing through the pressure regulating valve 13, the third check valve 19 does not open. Further, since the throttle valve 31 is provided, resistance is given to the inflow of the hydraulic oil into the accumulator 23. Therefore, the hydraulic oil flowing through the flow path 35 immediately flows out from the fourth check valve 21 into the first pressure chamber 50 and can be prevented from flowing into the accumulator 23.

  Thus, by adjusting the spring or the like accommodated in the pressure regulating valve 13 with respect to the speed at which the piston 40 moves in the A direction, a damping force is generated in the piston 40 in a direction to cancel the force in the A direction. . That is, the damping force characteristic of the hydraulic damper 10 can be adjusted by adjusting the pressure regulating valve 13.

  Further, when the moving speed of the piston 40 in the A direction exceeds a certain value and the pressure in the second pressure chamber 51 becomes equal to or higher than a predetermined pressure, the second relief valve 29 is opened, and the hydraulic oil is supplied from the second pressure chamber 51 to the first pressure chamber 51. It flows to the pressure chamber 50 (arrow D in the figure). That is, when the damping force generated in the piston 40 exceeds a certain value, the second relief valve 29 is opened to suppress the increase of the damping force with respect to the speed increase.

  Next, a case where the direction of force such as earthquake or wind acting on the building is reversed will be described. FIG. 4 shows a case where a force such as an earthquake or wind acts on the building and an external force in the E direction acts on the piston 40.

  When the piston 40 moves in the E direction, the hydraulic oil filled in the first pressure chamber 50 is compressed. The hydraulic oil compressed in the first pressure chamber 50 flows from the second check valve 17 into the flow path 33 (in the direction of arrow F in the figure). At this time, the first check valve 15 and the fourth check valve 21 are closed.

  The hydraulic oil that has flowed into the flow path 33 from the second check valve 17 flows into the pressure regulating valve 13. When hydraulic oil having a predetermined pressure or higher flows into the pressure regulating valve 13, the hydraulic oil flows out into the flow path 35 through the pressure regulating valve 13. The hydraulic fluid that has flowed out of the pressure regulating valve 13 flows into the second pressure chamber 51 through the third check valve 19 (in the direction of arrow G in the figure). At this time, since the first pressure chamber 50 is higher than the pressure of the hydraulic oil after passing through the pressure regulating valve 13, the fourth check valve 21 does not open.

  Further, as described above, since the throttle valve 31 is provided, resistance is given to the inflow of the hydraulic oil from the flow path 35 to the accumulator 23. Therefore, the hydraulic oil flowing through the flow path 35 immediately flows out from the third check valve 19 into the second pressure chamber 51 and can be prevented from flowing into the accumulator 23.

  Thus, when the piston 40 moves in the E direction, a damping force having the same characteristics as that when the piston 40 moves in the A direction is generated. That is, by adjusting one pressure regulating valve 13, the hydraulic damper 10 can be adjusted so as to generate the same damping force characteristic with respect to the left-right swing.

  Note that when the moving speed of the piston 40 in the E direction exceeds a certain value and the pressure in the first pressure chamber 50 becomes equal to or higher than a predetermined pressure, the first relief valve 27 is opened, and the hydraulic oil flows from the first pressure chamber 50 to the second pressure. It flows to the pressure chamber 51 (in the direction of arrow H in the figure). That is, when the damping force generated in the piston 40 exceeds a certain value, the first relief valve 27 is opened to suppress the increase of the damping force with respect to the speed increase.

  FIG. 5 is a diagram illustrating a hydraulic circuit disposed in the piston 40, and is a diagram illustrating the state of FIG. In other words, the second pressure chamber 51 is on the high pressure side, and the hydraulic oil flows into the flow path 33 through the first check valve 15. An O-ring 49 is provided on the outer periphery of the piston 40 to seal between the piston 40 and the cylinder 20. In the present embodiment, the hydraulic circuit 1 described above is formed in the third check valve 19 and the fourth check valve 21. That is, the hydraulic circuit 1 is accommodated in the piston 40.

  Here, the main body 3 in the hydraulic circuit 1 shown in FIG. That is, the valve body 5 is accommodated in the piston 40. Further, the hole 8a is a flow path 35 and is a portion into which hydraulic oil that has passed through the pressure regulating valve 13 flows.

  The third check valve 19 and the fourth check valve 21 are disposed in the vicinity of the outer peripheral side of the piston 40. Further, the third check valve 19 and the fourth check valve 21 are formed with holes 8 c toward the outer peripheral surface of the piston 40.

  In the example shown in FIG. 5, the fourth check valve 21 is open. At this time, the hydraulic oil flowing in from the flow path 35 (hole 8a) flows outside the piston 40 via the flow path 9a flowing to the first pressure chamber 50 via the valve body 5 (see FIG. 1) and the hole 8c. A flow path 9b that flows out toward the first pressure chamber 50 through a gap between the piston 40 and the cylinder 20 is formed. An O-ring is formed on the outer periphery of the piston 40 between the first pressure chamber 50 and the second pressure chamber 51, and the hole 8 c of the third check valve 19 is located in the second pressure chamber 51 rather than the O-ring 49. The hole 8 c of the fourth check valve 21 is provided closer to the first pressure chamber 50 than the O-ring 49.

  Thus, compared with the case of only the conventional channel 9a, the channel resistance can be reduced by the channel 9b. For this reason, it is possible to suppress the hydraulic oil from flowing more smoothly through the fourth check valve 21 and flowing into the accumulator 23.

  Further, even when the operation direction of the piston 40 is reversed, the third check valve 19 is opened, and similarly, the hydraulic oil flows not only through the flow path 9a but also through the flow path 9b. Inflow of hydraulic oil can be suppressed.

  In addition, although the clearance gap between piston 40 and cylinder 20 is small, since the perimeter of piston 40 becomes a flow path, sufficient flow-path cross-sectional area can be ensured. Further, as shown in FIG. 6A, a plurality of holes 8c may be arranged in the circumferential direction of the piston 40 in order to increase the channel cross-sectional area of the hole 8c that becomes a part of the channel 9b. Further, as shown in FIG. 6B, a slit 8d may be formed instead of the hole 8c.

  As mentioned above, according to 1st Embodiment, since the hydraulic circuit 1 is accommodated in the piston 40, the resistance at the time of the 3rd check valve 19 and the 4th check valve 21 opening and flowing hydraulic fluid can be made small. . For this reason, it can suppress that hydraulic fluid flows in into the accumulator 23, and can obtain the stable attenuation | damping characteristic.

  Moreover, in this Embodiment, since the pressure regulation valve 13 is one, the piston 40 which accommodates the pressure regulation valve 13 can be reduced in size. That is, the hydraulic damper 10 itself can be reduced in size. Moreover, the adjustment time of the pressure regulating valve 13 can be shortened. Further, since the same characteristic of the pressure regulating valve 13 is used for the movement of the piston 40 in the left-right direction, the hydraulic damper 10 can obtain the same damping force characteristic for the left-right swing.

  Note that the same hydraulic circuit 1 may be formed for the first check valve 15 and the second check valve 17, but in order to simplify the structure and increase the degree of freedom of the layout, in particular, the accumulator 23. It is desirable to form the hydraulic circuit 1 only for the third check valve 19 and the fourth check valve 21 in which the inflow of hydraulic oil into the engine becomes a problem.

  Next, a hydraulic damper 10a according to a second embodiment will be described. In the following description, components having the same functions as those of the hydraulic damper 10 are denoted by the same reference numerals as those in FIG.

  The hydraulic damper 10 a has substantially the same configuration as the hydraulic damper 10, but a check valve 47 is provided in parallel with the throttle valve 31 between the accumulator 23 and the first pressure chamber 50 and the second pressure chamber 51. . In the present embodiment, for the sake of simplicity, the relief valve is not shown, and an example in which the pressure regulating valve 13 is arranged in each direction is shown.

  In the present embodiment, when the piston 40 moves, the hydraulic oil is supplied from the accumulator 23 to the low pressure side pressure chamber in order to prevent the supply of the hydraulic oil to the low pressure side from being delayed. At this time, if the flow path resistance of the check valve 47 is large, the supply of hydraulic oil is delayed.

  Therefore, in the present embodiment, the hydraulic circuit 1 described above is configured for the check valve 47. That is, the hydraulic circuit 1 having a part of the check valve 47 is formed in the piston 40. By doing so, the movement of the hydraulic oil via the check valve 47 becomes smoother. Thus, the hydraulic circuit 1 can be applied to other than the hydraulic damper 10 configured as described above.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ......... Hydraulic circuit 3 ......... Main body 5 ......... Valve 7 ......... Elastic members 8, 8a, 8b, 8c ......... Hole 8d ......... Slits 9a, 9b ......... Flow paths 10, 10a ...... Hydraulic damper 13 ......... Pressure adjustment valve 15 ......... First check valve 17 ......... Second check valve 19 ......... Third check valve 20 ......... Cylinder 21 ......... Fourth check valve 23 ... ...... Accumulators 25a, 25b ......... Joint 27 ......... First relief valve 29 ......... Second relief valve 30a, 30b ......... Piston rod 31 ......... Throttle valves 33, 35, 37, 39, 41, 43 ......... Flow path 40 ......... Piston 45 ......... Low pressure part 47 ......... Fifth check valve 50 ......... First pressure chamber 51 ......... Second pressure chamber

Claims (3)

A hydraulic circuit using an inline type check valve,
The check valve includes a main body, a valve body accommodated in the main body, and an elastic member that presses the valve body,
The check valve is disposed in the flow path, and when oil presses the valve body against the elastic member from the front of the check valve and flows into the main body, the oil passes through the inside of the valve body. A first flow path that flows behind the check valve, and the oil that flows through the first flow path through the outside of the valve body through a hole or slit formed in the body. A second flow path capable of joining,
A hydraulic circuit comprising: A hydraulic damper comprising the hydraulic circuit according to claim 1,
The hydraulic damper includes a cylinder filled with hydraulic oil, a piston that moves in the cylinder and divides the cylinder into a first pressure chamber and a second pressure chamber, and pistons provided on both sides of the piston. A rod, and
The hydraulic circuit is housed in the piston, and the body is part of the piston;
The flow path is provided between the first pressure chamber and the second pressure chamber, and the second flow path is formed between the hole or the slit formed in the piston, the piston, and the cylinder. A hydraulic damper characterized by a gap. The piston or the piston rod,
A first check valve having an inflow side connected to the second pressure chamber and an outflow side connected to a third flow path;
A second check valve having an inflow side connected to the first pressure chamber and an outflow side connected to the third flow path;
A single pressure regulating valve having an inflow side connected to the third flow path and an outflow side connected to the fourth flow path, and generating a fluid resistance in the hydraulic oil passing from the third flow path to the fourth flow path;
A third check valve having an inflow side connected to the fourth flow path and an outflow side connected to the second pressure chamber;
A fourth check valve having an inflow side connected to the fourth flow path and an outflow side connected to the first pressure chamber;
An accumulator,
When the first pressure chamber is higher in pressure than the second pressure chamber,
The hydraulic oil in the first pressure chamber flows into the second pressure chamber through the second check valve, the third flow path, the pressure regulating valve, the fourth flow path, and the third check valve in this order. ,
The first check valve prevents the hydraulic oil from flowing from the third flow path into the second pressure chamber;
The fourth check valve prevents the hydraulic oil from flowing into the fourth flow path from the first pressure chamber;
When the second pressure chamber is higher than the first pressure chamber,
The hydraulic oil in the second pressure chamber flows into the first pressure chamber through the first check valve, the third flow path, the pressure regulating valve, the fourth flow path, and the fourth check valve in this order. ,
The second check valve prevents the hydraulic oil from flowing from the third flow path into the first pressure chamber;
The third check valve prevents the hydraulic oil from flowing into the fourth flow path from the second pressure chamber;
No matter which direction the piston moves, it generates a damping force,
The hydraulic damper according to claim 2, wherein at least the third check valve and the fourth check valve are the check valves in the hydraulic circuit.

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