JP2015224780A - Shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorber capable of being dispensed with a discharge pipe and capable of suppressing mixture of air with liquid in a reservoir chamber.SOLUTION: A shock absorber includes a cylinder 2 in which liquid is sealed, a piston 5 partitioning an inside of the cylinder into a rod side chamber R1 and a piston side chamber R2, a piston rod 4 connected to the piston, an outer cylinder 3 disposed on an outer peripheral side of the cylinder 2, a rod guide 24 closing one end of the cylinder 2 and the outer cylinder 3 and guiding the piston rod 4, a discharge passage 28 provided in the rod guide 24 and having a discharge port 13 for discharging the liquid in the cylinder 2 to the reservoir chamber 7, and an oil sump part forming member 12 provided in the reservoir chamber 7 and having at least a part arranged above the discharge port 13. An oil sump part is formed by one of the cylinder 2 and the outer cylinder 3, and the rod guide 24 and the oil sump part forming member 12, and the discharge port 13 faces the oil sump part.

Description

  The present invention relates to an improvement of a shock absorber installed horizontally.

  In the shock absorber, a cylinder in which liquid is sealed, a piston that is slidably inserted in the cylinder, a piston that divides the cylinder into a rod side chamber and a piston side chamber, and a cylinder that is inserted into the cylinder and connected to the piston. A piston rod disposed on the outer peripheral side of the cylinder and forming a reservoir chamber with the cylinder; a discharge passage for discharging the liquid in the cylinder to the reservoir chamber; and the liquid in the reservoir chamber as a piston There is a suction flow passage that flows into the side chamber, and is a uniflow type in which liquid flows in one direction in the cylinder, the discharge passage, and the reservoir chamber in either of the contraction stroke and the expansion stroke.

  During the contraction stroke of the shock absorber, the piston rod enters the cylinder, the liquid is pushed out from the cylinder into the reservoir chamber, and during the extension stroke, the piston rod moves out of the cylinder and sucks the liquid from the reservoir chamber into the cylinder. In addition, the reservoir chamber compensates for the volume change in the cylinder caused by the piston rod entering and exiting the cylinder.

  Further, the shock absorber is provided with a damping valve in a rod guide that passes through the piston rod and closes the opening end of the cylinder. Then, the liquid that has passed through the damping valve flows out to the reservoir chamber provided outside the cylinder through the discharge passage formed in the rod guide, but the downstream end of the discharge passage faces the reservoir chamber of the rod guide. Therefore, liquid is ejected vigorously from the downstream end of the discharge passage, and there is a concern that cavitation in which bubbles are generated in the liquid in the reservoir chamber may occur.

  Therefore, in the conventional shock absorber, a pipe is connected to the rod guide, this pipe is connected to the discharge passage, the flow of liquid flowing through the damping valve and flowing out to the reservoir chamber is rectified and the flow velocity is reduced. , Suppressing the occurrence of cavitation.

Japanese Patent Laid-Open No. 1002-349629 JP 2013-174274 A

  However, a structure in which a pipe is provided for rectifying the flow of liquid flowing into the conventional reservoir chamber, such as the buffer disclosed in Patent Document 1, is not preferable because the number of parts of the buffer increases.

  For this reason, in the proposal disclosed in Patent Document 2, the flow velocity can be reduced by providing a clearance for rectification on the downstream side of the damping valve provided in the middle of the passage communicating the rod side chamber and the reservoir chamber, The use of pipes can be omitted.

  Specifically, the gap is formed on the downstream side of a damping valve provided in the middle of the discharge passage. For this reason, in the structure disclosed in Patent Document 2, the shock absorber is vibrated and the liquid level in the reservoir chamber is inclined or waved, so that a gap serving as a discharge port for discharging liquid from the cylinder to the reservoir chamber is formed. If there is no hydraulic oil at the downstream end, when the liquid is discharged from the discharge port into the reservoir chamber in such a state, the liquid entrains the air in the reservoir chamber, and entrains the air during the extension stroke. There is a possibility that liquid is sucked into the cylinder. Thus, when air is mixed into the cylinder, there is a problem that the shock absorber cannot exhibit the damping force as set. Note that this problem may occur similarly even in a shock absorber having a rectifying passage.

  Accordingly, the present invention has been made to solve the above-described problem, and the object of the present invention is to prevent the liquid from entraining air in the reservoir chamber even if the discharge pipe is eliminated. Is to provide a shock absorber.

  A cylinder filled with liquid, a piston that is slidably inserted into the cylinder, and divides the cylinder into a rod side chamber and a piston side chamber, and a piston rod that is inserted into the cylinder and connected to the piston And an outer cylinder which is disposed on the outer peripheral side of the cylinder and forms a reservoir chamber between the cylinder and one end of the cylinder and the outer cylinder are closed, and the piston rod is moved in the axial direction. A rod guide for guiding, a discharge passage having a discharge port for discharging the liquid in the cylinder provided in the rod guide to the reservoir chamber, and at least a part of the discharge port disposed in the reservoir chamber A liquid reservoir member disposed at a higher position; one of the cylinder or the outer cylinder; the rod guide and the liquid reservoir member; Et sump portion is formed, the discharge port and wherein the overlooking to the sump portion.

  With the above configuration, even if the shock absorber is vibrated and the liquid level in the reservoir chamber undulates or the liquid level is inclined, the discharge port looks into the liquid reservoir, so there is no liquid in the discharge port. Therefore, it is possible to prevent the liquid from entraining air during the extension stroke of the piston rod and mixing the air into the cylinder.

  As a result, it is possible to provide a shock absorber capable of omitting the discharge pipe and suppressing the entrainment of air in the reservoir chamber.

It is a cross-sectional view of the shock absorber according to one embodiment. It is the longitudinal cross-sectional view which expanded and showed the DD arrow cross section of FIG. It is an expansion perspective view of the reservoir member of the buffer concerning one embodiment. It is a figure which shows the oil level fluctuation | variation in one Embodiment. It is a cross-sectional view of a shock absorber according to another embodiment. It is a longitudinal cross-sectional view of the buffer which concerns on other embodiment. It is a figure which shows the oil level fluctuation | variation in other embodiment. It is a longitudinal cross-sectional view of the shock absorber in the 1st modification of other embodiment. It is a figure which shows the oil level fluctuation | variation in the 1st modification of other embodiment. It is a figure which shows the oil level fluctuation | variation in the 2nd modification of other embodiment.

  The present invention will be described below based on the illustrated embodiments.

  The shock absorber 1 according to the present embodiment includes a cylinder 2 in which a liquid is sealed, and a piston 5 that is slidably inserted into the cylinder 2 and divides the cylinder 2 into a rod side chamber R1 and a piston side chamber R2. A piston rod 4 that is inserted into the cylinder 2 and connected to the piston 5; an outer cylinder 3 that is disposed on the outer peripheral side of the cylinder 2 and forms a reservoir chamber 7 between the cylinder 2; One end of the cylinder 2 and the outer cylinder 3 is closed to guide the piston rod 4 to move in the axial direction, and the liquid in the cylinder 2 provided on the rod guide 24 is removed. A discharge passage 28 having a discharge port 13 for discharging to the reservoir chamber 7, and a liquid reservoir member disposed in the reservoir chamber 7 and at least a part of which is disposed above the discharge port 13 2, a liquid reservoir portion is formed from either the cylinder 2 or the outer cylinder 3, the rod guide 24 and the liquid reservoir member 12, and the discharge port 13 looks into the liquid reservoir portion. Become.

  FIG. 1 shows a uniflow-type shock absorber 1 according to an embodiment of the present invention. This shock absorber 1 includes a cylinder 2 and a piston rod 4 inserted into the cylinder 2 from the head side. The piston rod 4 is made to be freely movable in and out of the cylinder 2 so as to expand and contract.

  Further, the shock absorber 1 according to the present embodiment is mainly used as a roll prevention damper in a railway vehicle, and exhibits a damping force during expansion and contraction to suppress vibration of the vehicle body. Naturally, the shock absorber 1 is not limited to the above-described railway vehicle, but can be used for other purposes.

  The cylinder 2 is filled with hydraulic oil as a liquid, and a piston 5 slidably inserted into the cylinder 2 forms a rod side chamber R1 and a piston side chamber R2 in the cylinder 2.

  As the liquid used in the shock absorber, it is possible to adopt a fluid applicable to the shock absorber, such as water, an aqueous solution, an electrorheological fluid, and a magnetic viscous fluid, in addition to the hydraulic oil.

  The piston 5 has a passage 31 that allows the piston-side chamber R2 and the rod-side chamber R1 to communicate with each other. The piston 5 opens and closes the passage 31 so that the hydraulic oil flows from the rod-side chamber R1 to the piston-side chamber R2. The first check valve 21 is provided that prevents the inflow of hydraulic oil and allows the hydraulic oil to flow from the piston side chamber R2 to the rod side chamber R1. Thereby, hydraulic fluid is set to one way flow.

  The piston 5 is connected to the piston rod 4 by being fitted to the tip portion of the piston rod 4 and screwing a piston nut 35 into a tip screw portion (not shown) of the piston rod 4.

  The cylinder 2 is provided with a rod guide 24 that fits into the opening end of the cylinder 2 that is the left end in FIG. 1 and closes the opening end. The base end portion of the piston rod 4 penetrates the shaft core portion of the rod guide 24 and protrudes outside the cylinder 2. The rod guide 24 guides the movement of the piston rod 4 in the axial direction.

  On the other hand, the shock absorber 1 has a cylindrical outer cylinder 3 that covers the cylinder 2 on the outer peripheral side of the cylinder 2, and an annular reservoir chamber 7 is formed between the outer cylinder 3 and the cylinder 2. The opening end of the outer cylinder 3 which is the left end in FIG. 1 is also closed by the rod guide 24 being fitted. That is, the opening end which is the left end in FIG. 1 of the cylinder 2 and the outer cylinder 3 is closed by the rod guide 24. Further, the opening end of the cylinder 2 which is the right end in FIG. 1 is closed by the bottom member 29.

  The bottom member 29 includes a fitting portion 29a fitted to the inner periphery of the cylinder 2 and a pedestal portion 29b that contacts the right end of the cylinder 2 in FIG. The fitting portion 29a is formed in a columnar shape, and prevents the hydraulic oil from flowing from the piston side chamber R2 to the reservoir chamber 7 on the inner side, and allows the hydraulic oil to flow from the reservoir chamber 7 to the piston side chamber R2. 2 The check valve 30 is accommodated. Thereby, hydraulic fluid is set to one way flow.

  The pedestal portion 29 b has a larger outer diameter than the fitting portion 29 a and protrudes in the radial direction of the cylinder 2. In the pedestal 29b, there is a through-hole 33 that opens inside the fitting portion 29a and opens in the axial direction, a recess 34 that extends in the radial direction from the right end of the through-hole 33 in FIG. Three suction passages 42 communicating with the chamber 7 are formed (see FIG. 6). The flow path 32 is configured by the through hole 33, the recess 34, and the suction passage 42. The number of the suction passages 42 is not limited to three, and any number may be used as long as the hydraulic oil in the reservoir chamber 7 can be sufficiently sucked when the hydraulic oil in the reservoir chamber 7 is guided to the piston side chamber R2.

  Further, the suction pipe 11 is connected to a suction port 46 which is an end portion of the suction passage 42 facing the reservoir chamber 7 side of the flow path 32, and the reservoir chamber is connected by the suction pipe 11 and the flow path 32. 7 communicates with the piston side chamber R2. Then, the hydraulic oil in the reservoir chamber 7 when the shock absorber 1 extends is sucked from the suction passage 42 through the suction pipe 11, passes through the recess 34 and the through hole 33, and opens the second check valve 30. , Flows into the piston side chamber R2.

  In the present embodiment according to FIG. 1, the suction pipe 11 is provided so that its tip is arranged near the lower center of the reservoir chamber 7, so that it always operates at the tip of the suction pipe 11 even if the oil level O is inclined. It is expected that there will be oil, and the suction of air into the cylinder 2 can be prevented.

  In addition, the rod guide 24 is provided with a discharge passage 28 that allows the rod-side chamber R1 to communicate with the reservoir chamber 7. A valve hole 22 is formed in the middle of the discharge passage 28, and the damping valve 6 is accommodated in the valve hole 22.

  The damping valve 6 is provided so as to open and close the discharge passage 28, and allows only hydraulic oil to flow from the rod side chamber R1 to the reservoir chamber 7. Moreover, resistance is given to the flow of the hydraulic oil which passes, and predetermined damping force is exhibited. Therefore, the damping valve 6 only needs to perform a check valve function and exhibit a predetermined damping action.

  Further, in the present embodiment, a rectifying unit 36 that exhibits a rectifying action is provided on the reservoir chamber 7 side in the middle of the discharge passage 28 and downstream of the damping valve 6. The rectifying unit 36 includes a chamber 36a in the middle of the discharge passage 28, and rectifies the hydraulic oil that flows vigorously from the rod side chamber R1 through the discharge passage 28, and reduces the flow velocity.

  By providing the above-described configuration, a uniflow type structure in which hydraulic oil flows in one direction in the order of the rod side chamber R1, the rod side chamber R1, and the reservoir chamber 7 during the expansion stroke, from the rod side chamber R1 to the reservoir chamber 7, during the contraction stroke. It has become.

  Further, the rod guide 24 is fitted to the opening end of the cylinder 2 as described above, and the discharge port 13 which is the end of the discharge passage 28 on the side of the reservoir chamber 7 when the shock absorber 1 is installed horizontally. It is fitted and fixed in the outer cylinder 3 so as to be located in the hydraulic oil in the reservoir chamber 7.

  The outer end of the rod guide 24 which is the left end in FIG. 1 is a reduced diameter portion (not shown), and the ring nut 25 engages with the reduced diameter portion. The ring nut 25 has a male screw portion (not shown) formed on the outer periphery, and is screwed into a female screw portion (not shown) formed on the inner periphery of the opening end portion of the outer cylinder 3. Thus, by screwing the ring nut 25 into the outer cylinder 3, the cylinder 2 and the bottom member 29 are pressed to the bottom side of the outer cylinder 3 via the rod guide 24, and these are fixed in the outer cylinder 3. Is done. Further, the rod guide 24 is stabilized by being pressed toward the cylinder 2 by the ring nut 25.

  An annular seal member 26 is attached to the rod guide 24, and the seal member 26 is in sliding contact with the outer periphery of the piston rod 4, thereby preventing leakage of hydraulic oil in the cylinder 2.

  When the piston 5 moves to the right in FIG. 1 due to the contraction stroke of the shock absorber 1, the first check valve 21 provided in the piston 5 opens and the piston side chamber R <b> 2 compressed by the piston 5 is opened. The hydraulic oil moves from the rod side chamber R1. Since the piston rod 4 penetrates into the cylinder 2, the damping valve 6 is opened by the excess hydraulic oil in the piston rod 4 and the excess hydraulic oil passes through the discharge passage 28 and is discharged. It flows from the outlet 13 to the reservoir chamber 7. The damping valve 6 increases the pressure of the rod side chamber R1 and the piston side chamber R2 by giving resistance to the flow of hydraulic oil, and the shock absorber 1 exhibits a damping force during the contraction operation.

  Returning, in the reservoir chamber 7 of the shock absorber 1, at least a part of the reservoir 11 is disposed above the discharge port 13 which is the end of the discharge passage 28 on the side of the reservoir chamber 7 in addition to the suction pipe 11. The oil sump portion forming member 12 is provided.

  As shown in FIGS. 2 and 3, the oil sump forming member 12 has an annular shape having notches 14 and 18 at the upper end and the lower end, and is mounted on the outer periphery of the cylinder 2. An upper end notch 18 is provided at the upper end of the oil sump portion forming member 12, and an upper end gap for avoiding the pin 23 between the oil sump portion forming member 12 and the outer cylinder 3 by providing the upper end notch 18. 16 is formed. The pin 23 is used for positioning when the shock absorber 1 is assembled. Further, a lower end notch 14 is provided at the lower end of the oil sump forming member 12, and by providing the lower end notch 14, the discharge port 13 looks into an oil sump part as a liquid sump part to be described later. ing.

  Further, as shown in FIG. 4A, the oil sump portion forming member 12 forms an oil sump portion between the outer cylinder 3, the rod guide 24, and the oil sump portion forming member 12. In FIG. 4, the cylinder 2 is not shown in order to avoid making the figure complicated. The same applies to FIGS. 7, 9, and 10 described later.

  By forming the oil sump portion, as shown in FIG. 4A, even if the shock absorber 1 is vibrated and the hydraulic oil is inclined to the bottom side, the discharge port 13 that looks into the oil sump portion is operated. Oil will be present and air entrainment can be prevented.

  Further, as shown in FIG. 3, the oil sump portion forming member 12 is provided with a flange 15 extending from the side end opposite to the rod guide 24 to the outer periphery. In this case, as shown in FIG. 4B, the outer periphery of the convex portion 17, which is a portion other than the flange 15 of the oil sump portion forming member 12, and a gap between the flange 15 and the rod guide 24. Is formed. Since the hydraulic oil is stored in the gap, even if the hydraulic oil between the oil sump forming member 12 and the outer cylinder 3 flows to the bottom side due to vibration or the like, the gap Since the hydraulic oil stored in the tank flows down along the oil reservoir forming member 12, the oil reservoir is compensated, so that the discharge port 13 is not exposed to the air more reliably.

  2 indicates the outer periphery of the convex portion 17 that is formed when the flange 15 is provided on the oil sump portion forming member 12.

  Further, the oil sump portion forming member 12 is mounted on the cylinder 2 by forming a small diameter portion with the outer periphery of the left end portion in FIG. 1 of the cylinder 2 having a small diameter and fitting the small diameter portion. When the rod guide 24 is assembled to the cylinder 2 as described above, the oil sump forming member 12 is sandwiched and fixed between the rod guide 24 and the cylinder 2. The oil sump portion forming member 12 may be fixed to the outer periphery of the cylinder 2 or the inner periphery of the outer cylinder 3 with an O-ring or a snap ring as long as it can be fixed in the reservoir chamber 7, and the fixing method is not limited to these methods. . In the case of this embodiment, an annular groove is provided on the inner periphery of the oil sump portion forming member 12, and a rubber ring 19 is mounted in the annular groove. The rubber ring 19 biases the outer periphery of the cylinder 2 to be tightened. As a result, the oil sump forming member 12 is mounted on the cylinder 2 without shifting.

  Next, operation | movement of the buffer 1 in this embodiment is demonstrated.

  When the shock absorber 1 is extended and the piston 5 moves to the left in FIG. 1, the hydraulic oil is compressed in the rod side chamber R1, opens the damping valve 6, passes through the discharge passage 28, and passes from the discharge port 13 to the reservoir chamber. It flows to 7. The rod side chamber R1 is pressurized by giving resistance to the flow of the hydraulic oil by the damping valve 6, and the shock absorber 1 exhibits a damping force that suppresses the extension operation. In this extension operation, the piston 5 moves to the left in FIG. 1 to increase the volume of the piston side chamber R2, but the second check valve 30 is driven by the hydraulic oil sucked into the suction pipe 11 from the reservoir chamber 7. Is opened, and the hydraulic oil corresponding to the increased volume is supplied to the piston side chamber R2. At this time, when the shock absorber 1 is vibrated, the oil level O in the reservoir chamber 7 undulates and the oil level O tilts, but even if the oil level O tilts, the oil level O remains on the oil reservoir forming member 12. By colliding, an oil sump portion is formed by the outer cylinder 3, the rod guide 24, and the oil sump portion forming member 12, and therefore hydraulic oil is always present in the discharge port 13 that is seen in the oil sump portion. As a result, the hydraulic oil discharged from the discharge port 13 is not discharged into the air, but is discharged into the oil. Therefore, when the piston rod 4 is extended, the hydraulic oil entrains air and mixes the air into the cylinder 2. Is prevented.

  Next, effects according to the present embodiment will be described.

  The shock absorber 1 having the above-described configuration has a discharge port formed by the outer cylinder 3, the rod guide 24, and the oil sump portion forming member 12 even if the oil level O in the reservoir chamber 7 is waved or inclined due to vibration. 13 forms an oil sump portion that is desired, so that there is no loss of hydraulic oil around the discharge port 13, preventing the hydraulic oil from entraining air into the cylinder 2 when the piston rod 4 is extended. it can.

  Further, the oil sump portion forming member 12 of the shock absorber 1 is formed in an annular shape and attached to the cylinder 2 or the outer cylinder 3, so that the oil sump portion forming member 12 can be easily provided in the reservoir chamber 7.

  The oil sump forming member 12 may be formed integrally with the rod guide 24 or may be formed on the cylinder 2 or the outer cylinder 3.

  Further, the oil reservoir forming member 12 of the shock absorber 1 is provided with a flange 15 extending from the end opposite to the rod guide 24 side to the outer periphery, so that the outer periphery of the convex portion 17 A gap is provided between 15 and the rod guide 24 for storing hydraulic oil. As a result, the hydraulic oil is stored in the gap above the sump part, so even if the hydraulic oil in the sump part flows to the bottom side due to vibration or the like, it is stored in the gap. Since the hydraulic oil that has been filled is supplemented in the oil sump portion, the discharge port 13 is not exposed to the air more reliably.

  Further, the hydraulic oil that has been in contact with the upper end of the oil reservoir forming member 12 flows down along the oil reservoir forming member 12, so that the hydraulic oil is more easily collected in the oil reservoir.

  Therefore, the effect of preventing the working oil from entraining air and causing air to enter the cylinder 2 when the piston rod 4 is extended is improved.

  Further, a rubber ring 19 that urges the outer periphery of the cylinder 2 to be tightened is attached to the inner periphery of the oil reservoir forming member 12, and the oil reservoir forming member 12 is attached to the cylinder 2 by the rubber ring 19. By fixing, rotation of the oil sump portion forming member 12 and the like are prevented, and the oil sump portion forming member 12 is attached to the cylinder 2 without being displaced.

  In the above description, the example in which the oil sump portion forming member 12 is applied to the shock absorber provided with the rectifying portion 36 has been described. However, the present invention provides a shock absorber other than the shock absorber provided with the rectifying portion 36. It is also applicable to.

  In addition, the lower end notch 14 includes a configuration in which a hole is provided in the oil sump forming member 12 so as to face the discharge port 13. The discharge port 13 only needs to be seen in the oil reservoir and not exposed to the air. Therefore, a hole-like notch may be provided in the oil reservoir forming member 12 to make the inside of the hole an oil reservoir. Further, instead of providing the flange 15 on the outer periphery of the oil sump portion forming member 12, an annular groove is provided, and working oil is stored in the annular groove so that the oil sump portion does not cause oil shortage. Good.

  Further, the oil sump portion forming member 12 is provided in contact with the rod guide 24. However, the oil sump portion forming member 12 is separated from the rod guide 24 so as to provide a gap therebetween, and the gap itself is used as the oil sump portion. Is also possible.

  Next, other embodiments will be described below. In this embodiment, the suction pipe 11 of the above-described embodiment is changed to a configuration in which a partition plate 41 as a partition member is provided in the reservoir chamber 7, and the same configuration is only given the same reference numeral. Therefore, detailed description is omitted.

  FIG. 5 is a cross-sectional view of a shock absorber 100 according to another embodiment.

  In the shock absorber 100 according to another embodiment, the oil sump portion forming member 12 is provided on the rod guide 24 side, and as shown in FIG. In addition, a partition plate 41 is provided vertically as a partition member.

  The partition plate 41 will be described in detail with reference to FIG.

  6 shows a cross-sectional view taken in a direction perpendicular to the axial direction of the cylinder 2 of the shock absorber 100 in FIG. As shown in FIG. 6, a partition plate 41 is provided in the reservoir chamber 7 between the outer cylinder 3 and the cylinder 2. The partition plate 41 has an inner peripheral surface along the outer periphery of the cylinder 2 and an outer peripheral surface along the inner peripheral surface of the outer cylinder 3, and is provided perpendicular to the axial direction of the cylinder 2. . Further, the partition plate 41 is on the bottom member 29 side with respect to the sump forming member 12, and at least a part thereof is disposed above the suction port 46 in the reservoir chamber 7.

  Further, as shown in FIG. 6, the partition plate 41 is provided with two bolts 44 at both ends thereof, and the partition plate 41 is fixed in the reservoir chamber 7 by screwing the bolts 44 to the bottom member 29. The position and the number of bolts are not limited to the above, and it is sufficient that the partition plate 41 can be fixed in the reservoir chamber 7. The fixing method is not limited to bolt fixing, and may be fixed to the cylinder 2 or the outer cylinder 3 with a snap ring or an O-ring, for example. The partition plate 41 may be provided so as to be inclined with respect to the axial direction of the cylinder 2, but it is advantageous that the partition plate 41 is provided vertically so as to be screwed into the bottom member 29.

  In addition, a suction gap 43 is opened to the lower portion of the partition plate 41 with respect to the suction port 46 so that the suction port 46 does not cause insufficient suction of the hydraulic oil. The suction gap 43 may be opened so that the suction port 46 does not cause insufficient suction, and the shape thereof may be, for example, a notch, a groove, or a hole.

  A gap (not shown) is provided between the partition plate 41 and the cylinder 2 and the outer cylinder 3, and the space between the right direction and the left direction of the partition plate 41 always communicates with each other. Is prevented. 6, an assembling notch 45 is provided at the upper end, but this assembling notch 45 is provided to avoid the pin 23 as a positioning when the shock absorber 100 is assembled. By providing the mounting notch 45 as described above, the space in the right direction and the space in the left direction of the partition plate 41 can always communicate with each other. In this case, the partition plate 41 and the cylinder 2 and the outer cylinder 3 The vacuum phenomenon can be prevented without providing a gap between them.

  As described above, at least a part of the partition plate 41 is disposed above the suction port 46 in the reservoir chamber 7. By arranging the partition plate 41 in this way, it is possible to suppress oil level fluctuations when the shock absorber 100 is vibrated, and at the same time, hydraulic oil is formed in the space formed between the partition plate 41 and the suction port 46. Can exist. Details will be described below with reference to FIG.

  FIG. 7 shows the oil level fluctuation of the hydraulic oil when the partition plate 41 is provided in the reservoir chamber 7 of the shock absorber 100. In addition, a continuous line shows the oil level fluctuation | variation when the partition plate 41 is provided, and a dashed-dotted line shows the oil level fluctuation | variation when the partition plate 41 is not provided. The oil sump forming member 12 is not shown.

  First, when the partition plate 41 is not provided, when the shock absorber 1 is vibrated from the bottom side, the oil level is inclined to the rod guide 24 side, and air exists on the upper side indicated by the alternate long and short dash line. In this way, when air is present on the upper side of the alternate long and short dash line, air is sucked from the suction port 46, and the air is guided to the piston side chamber R2.

  On the other hand, when the partition plate 41 is provided, a space is formed between the partition plate 41 and the suction port 46. When the shock absorber 100 is vibrated, the hydraulic oil existing in this space comes into contact with the partition plate 41 and the oil level fluctuation is suppressed. That is, the hydraulic oil present in the right space in FIG. 3 tends to flow toward the rod guide 24, but the flow is blocked by the partition plate 41. Thereby, even if the shock absorber 100 is vibrated, the hydraulic oil is always present in the suction port 46. Further, by disposing at least a part of the partition plate 41 above the suction port 46, more hydraulic oil can be present in the space between the partition plate 41 and the suction port 46.

  From the above, air is prevented from being sucked from the suction port 46 during the expansion stroke of the shock absorber 100. Therefore, the suction pipe provided for preventing the suction of air as in the prior art can be eliminated. Thereby, by combining the oil sump forming member 12 and the partition plate 41, both the discharge pipe and the suction pipe can be eliminated from the reservoir chamber 7, and the outer periphery of the shock absorber can be reduced.

  The partition plate 41 is disposed closer to the suction port 46 than the half of the reservoir chamber 7 in the axial direction of the cylinder 2. This is preferable because the oil level becomes high.

  Next, a first modification of another embodiment will be described with reference to FIGS. FIG. 8 shows a cross-sectional view of the shock absorber 200 in a first modification of the other embodiment cut in a direction perpendicular to the axial direction of the cylinder 2. Note that, in the first modification example described below, points different from the above-described embodiment will be mainly described, and components having similar functions are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 8, the partition plate 101 is disposed in the reservoir chamber 7 formed between the cylinder 2 and the outer cylinder 3, and is provided in the horizontal direction with respect to the axial direction of the cylinder 2.

  The partition plate 101 is formed in a semi-cylindrical shape along the outer peripheral surface of the cylinder 2, and its both ends are bent so as to extend over the outer peripheral surface with the cylinder 2 and the outer cylinder 3. This bent portion can suppress oil level fluctuation when the shock absorber 200 is vibrated. Details will be described below with reference to FIG.

  FIG. 9 shows the oil level fluctuation of the hydraulic oil when the partition plate 101 is provided in the horizontal direction with respect to the axial direction of the cylinder 2. Note that the oil sump forming member 12 is not shown in FIG. When the shock absorber 200 is vibrated, the oil level O of the hydraulic oil tends to tilt toward the bottom side. However, the inclination of the hydraulic oil in the lower space divided by the partition plate 101 is suppressed, and hydraulic oil exists in the space between the partition plate 101 and the suction port 46. Thereby, even if the shock absorber 200 is vibrated, the hydraulic oil is always present in the suction port 46. Further, by disposing at least a part of the partition plate 101 above the suction port 46, more hydraulic oil can be present in the space between the partition plate 101 and the suction port 46.

  From the above, air is prevented from being sucked from the suction port 46 during the expansion stroke of the shock absorber 200. Therefore, the suction pipe provided for preventing the suction of air as in the prior art can be eliminated. Thereby, by combining the oil sump forming member 12 and the partition plate 41, both the discharge pipe and the suction pipe can be eliminated from the reservoir chamber 7, and the outer periphery of the shock absorber can be reduced.

  Returning, as described above, the partition plate 101 is formed in a semi-cylindrical shape along the outer peripheral surface of the cylinder 2 (see FIG. 8), and a portion where the cylinder 2 and the partition plate 101 are in contact is bolted (not shown). Z)). Thereby, the partition plate 101 is fixed. The fixing method is not limited to bolts.

  In addition, the partition plate 101 may be provided so as to contact the outer cylinder 3, or a groove is provided in the outer peripheral surface of the cylinder 2 and the inner peripheral surface of the outer cylinder 3, and the partition plate 101 is provided in the groove. May be inserted. Further, the partition plate 101 may be sandwiched between the rod guide 24 and the bottom member 29. In this case, it is necessary to connect the upper side and the lower side of the partition plate 101. Further, the portion of the partition plate 101 to be bent is a space between the partition plate 101 and the suction port 46 when the shock absorber 200 is vibrated, and a position where hydraulic oil is always present with respect to the suction port 46. If it is.

  Furthermore, the 2nd modification of other embodiment is demonstrated using FIG. FIG. 10 shows the oil level fluctuation when the partition plate 201 in the second modification is provided. In FIG. 10, the oil sump portion forming member 12 is not shown as in FIGS. Further, in the second modification shown below, differences from the other embodiments and the first modification will be mainly described, and components having similar functions are denoted by the same reference numerals and description thereof is omitted. .

  As shown in FIG. 10, the partition plate 201 of the second modified example is provided at two locations perpendicular to the axial direction of the cylinder 2, and oil when a shock absorber (not shown) is vibrated. Surface fluctuation can be suppressed.

  With these two partition plates 201, three spaces are formed in the reservoir chamber 7, and compared with the case where only one partition plate 201 is provided, the oil level of the hydraulic oil with respect to the suction port 46. It is possible to reduce the height difference of the fluctuation and to make it difficult to suck air. Further, by disposing at least a part of the partition plate 201 above the suction port 46, more hydraulic oil can be present in the space between the partition plate 201 and the suction port 46.

  From the above, air is prevented from being sucked from the suction port 46 during the expansion stroke of the shock absorber. Therefore, the suction pipe provided for preventing the suction of air as in the prior art can be eliminated.

  Two or more partition plates 201 may be provided. Further, the partition plate 201 may be provided to be inclined with respect to the axial direction of the cylinder 2.

  According to another embodiment, the following effects can be obtained.

  In the reservoir chamber 7 between the cylinder 2 and the outer cylinder 3, partition plates 41, 101, 201 are provided, at least a part of which is disposed above the suction port 46. As a result, even if the shock absorber is vibrated and the oil level of the hydraulic oil fluctuates, the hydraulic oil is always present in the suction port 46, so that air can be prevented from being sucked.

  Conventionally, the suction pipe is fixed by silver brazing, but the partition plates 41, 101, 201 can be fixed by bolts. Therefore, the suction pipe can be eliminated, and a fixing method that is easier and less expensive than the silver brazing used when fixing the suction pipe can be selected. For this reason, processing man-hours and costs can be reduced.

  Furthermore, since the partition plates 41, 101, 201 can be arranged in a relatively narrow space like the reservoir chamber 7, they can be fixed easily. As a result, the conventional shock absorber can be replaced without changing other components, and is compatible with the conventional product.

  By providing the partition plates 41, 101, 201 in a direction perpendicular to the axial direction of the cylinder 2, the bolts 44 can be inserted straight in the axial direction of the cylinder 2 and fixed to the bottom member 29, so that the fixing is easy. can do.

  In the first modification, the partition plate 101 is provided in the horizontal direction with respect to the axial direction of the cylinder 2. As a result, the interior of the reservoir chamber 7 can be divided into upper and lower parts, and even if the shock absorber 200 is vibrated and the hydraulic oil in the reservoir chamber 7 undergoes oil level fluctuations, the oil level fluctuations below the partition plate 101. Since the hydraulic oil is always present in the suction port 46, the suction of air can be prevented.

  Furthermore, in the second modification, a plurality of partition plates 201 are provided. As a result, a plurality of chambers are formed in the reservoir chamber 7, so that the difference in level of the oil level fluctuation of the hydraulic oil can be reduced as compared with the case where only one partition plate 201 is provided, and air is sucked in. Can be difficult.

  By combining with the oil sump forming member 12, both the discharge pipe and the suction pipe can be eliminated from the reservoir chamber 7, and the outer periphery of the shock absorber can be reduced.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

  The partition member is not limited to a plate-like member, and a block member may be used. That is, what is necessary is just to be able to suppress the oil level fluctuation of the hydraulic oil. The partition member may be provided integrally with the cylinder 2, the outer cylinder 3, or the bottom member 29.

  Furthermore, although this invention demonstrated as a buffer which suppresses the vibration in the vehicle body of a railway vehicle, it is possible to apply not only to this but to the shock absorber arrange | positioned horizontally and suppressing a vibration.

1, 100, 200 Shock absorber 2 Cylinder 3 Outer cylinder 4 Piston rod 5 Piston 6 Damping valve 7 Reservoir chamber 11 Suction pipe 12 Oil sump forming member
13 Discharge port 14 Lower end notch 15 鍔 16 Upper end clearance 17 Protruding portion 18 Upper end notch 19 Rubber ring 21 First check valve 22 Valve hole 23 Pin 24 Rod guide 25 Ring nut 26 Seal member 28 Discharge passage 29 Bottom member 29a Fitting portion 29b Pedestal part 30 Second check valve 31 Passage 32 Flow path 33 Through hole 34 Recess 35 Piston nut 36 Rectifier 36a Chamber 41, 101, 201 Partition plate (partition member)
42 Suction passage 43 Suction gap 44 Bolt 45 Assembly notch 46 Suction port R1 Rod side chamber R2 Piston side chamber O Oil level

Claims (5)

A cylinder filled with liquid;
A piston that is slidably inserted into the cylinder and divides the cylinder into a rod side chamber and a piston side chamber;
A piston rod inserted into the cylinder and connected to the piston;
An outer cylinder disposed on the outer peripheral side of the cylinder and forming a reservoir chamber with the cylinder;
A rod guide that closes one end of the cylinder and the outer cylinder and guides the piston rod to move in the axial direction;
A discharge passage having a discharge port for discharging the liquid in the cylinder provided in the rod guide to the reservoir chamber;
A reservoir member disposed in the reservoir chamber and having at least a portion disposed above the discharge port;
A liquid reservoir portion is formed from either one of the cylinder or the outer cylinder, the rod guide and the liquid reservoir member,
The shock absorber characterized in that the discharge port looks into the liquid reservoir.   2. The shock absorber according to claim 1, wherein the liquid reservoir member is provided with a flange extending from the end opposite to the rod guide side to the outer periphery.   The shock absorber according to claim 1 or 2, wherein a rubber ring is attached to an inner periphery of the liquid reservoir member.   The shock absorber according to any one of claims 1 to 3, wherein the liquid reservoir member is annular and is mounted on the cylinder or the outer cylinder. A bottom member having a suction port for closing the other end of the cylinder and allowing the liquid in the reservoir chamber to flow into the piston-side chamber; and a partition member in the reservoir chamber;
The said partition member is the said bottom member side from the said liquid reservoir member, Comprising: At least one part is arrange | positioned above the said suction inlet, The any one of Claims 1-4 characterized by the above-mentioned. Shock absorber.