Shock absorber

Abstract

The invention provides a shock absorber which prevents air from entering a damping force adjusting mechanism. When the shock absorber is horizontally placed, an opening of a common communication path (a second communication path) for communicating the damping force adjusting mechanism with the storage chamber on the radial outer side (the storage chamber side) of a hole (a second hole) is lower than the liquid level of the storage chamber, so that air in the storage chamber can be prevented from entering the common communication path from the hole of the common communication path; furthermore, air in the storage chamber can be prevented from entering the damping force adjusting mechanism through the common communication path.

Description

Technical Field

[0001] This invention relates to a damper that adjusts damping force by controlling the flow of working fluid relative to the stroke of a piston rod. Background Technology

[0002] Patent document 1 discloses a buffer (hereinafter referred to as "existing buffer") in which the elongation-side damping force generating mechanism and the contraction-side damping force generating mechanism are separately configured along the axial direction of the cylinder.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2018 / 216716 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] In conventional damper designs, since one end of the passage connecting to the damping force generating mechanism (hereinafter referred to as the "damping force adjustment mechanism") opens to the storage chamber, air in the storage chamber may enter the damping force adjustment mechanism via this passage when the centerline of the cylinder block is configured horizontally. Therefore, after the air in the damping force adjustment mechanism is purged during the inspection process, it is necessary to maintain the vertical configuration of the centerline during transport and assembly on the vehicle to prevent air from entering the damping force adjustment mechanism.

[0008] The objective of this invention is to provide a buffer that prevents air from entering the damping force adjustment mechanism.

[0009] Technical solutions for solving technical problems

[0010] The buffer of the present invention is characterized by comprising: a cylinder having an outer cylinder and an inner cylinder disposed inside the outer cylinder and sealed with a working fluid; an annular storage chamber defined between the outer cylinder and the inner cylinder, and sealed with the working fluid and gas; a piston slidably inserted into the inner cylinder, dividing the inner cylinder into two liquid chambers; a piston rod axially connected to the piston on one side and protruding outward from the cylinder on the other side; a damping force adjustment mechanism provided to protrude radially outward from the outer cylinder, capable of adjusting the damping force; a first connecting passage connecting the damping force adjustment mechanism and the inner cylinder; and a second connecting passage having a passage component, one side of which is connected to the damping force adjustment mechanism, and the other side of which is connected to the storage chamber at a different position in the circumferential direction from the damping force adjustment mechanism, the second connecting passage connecting the damping force adjustment mechanism and the storage chamber.

[0011] According to one embodiment of the present invention, a buffer that prevents air from entering the damping force adjustment mechanism can be provided. Attached Figure Description

[0012] Figure 1 This is a conceptual diagram of the buffer in this embodiment.

[0013] Figure 2 It is Figure 1 The main part of the diagram is shown in magnification.

[0014] Figure 3 It is a conceptual diagram of a buffer with the centerline of the cylinder horizontally arranged, and a cross-sectional view of the cylinder's axial right-angled plane including the centerline of the bore (second bore) and port (first bore).

[0015] Figure 4 It is a conceptual diagram of a buffer with the centerline of the cylinder horizontally positioned. It is a cross-sectional view of the cylinder's axial right-angled plane, including the centerline of the hole (second hole) and the port (first hole), when the lower end of the cylinder and the lower end of the damping force adjustment mechanism are on the same plane. Detailed Implementation

[0016] An embodiment of the present invention will be described with reference to the accompanying drawings.

[0017] In this embodiment, a dual-flow vertical damper (hereinafter referred to as "buffer 1") installed between the car body and the bogie of a railway vehicle is illustrated. However, buffer 1 can also be used as a lateral motion damper or a yaw damper. Figure 1 This is a conceptual diagram of buffer 1, and a cross-sectional view of buffer 1 based on the axis plane. For convenience, [the following will be used]. Figure 1 The upper and lower sides are directly referred to as the upper and lower sides.

[0018] like Figure 1 As shown, the buffer 1 has a cylinder 2 coaxially arranged with an outer cylinder 3 and an inner cylinder 4. The cylinder 2 has a storage chamber 5 formed between the outer cylinder 3 and the inner cylinder 4. A piston 6 is slidably inserted into the inner circumference of the inner cylinder 4. The piston 6 divides the interior of the inner cylinder 4 into two chambers: an upper liquid chamber 2A and a lower liquid chamber 2B. The lower end (axial side) of the piston rod 7 is connected to the piston 6. The upper end (axial side) of the piston rod 7 is inserted through a rod guide 8 mounted at the upper end of the cylinder 2 and protrudes to the outside of the cylinder 2. The rod guide 8 closes the opening at the upper end of the cylinder 2.

[0019] During its extension stroke, the piston 6 opens a valve when the pressure in the upper liquid chamber 2A of the cylinder 2 reaches a set pressure, and has an overflow valve 9 that releases the pressure in the upper liquid chamber 2A to the lower liquid chamber 2B. The piston 6 also has an overflow valve 10, which opens during its retraction stroke when the pressure in the lower liquid chamber 2B of the cylinder 2 reaches a set pressure, releasing the pressure in the lower liquid chamber 2B to the upper liquid chamber 2A. Furthermore, the piston 6 has a throttling passage 11 that always connects the upper liquid chamber 2A and the lower liquid chamber 2B of the cylinder 2.

[0020] The upper end 19 of the inner cylinder 4 engages with the annular recess 17 formed in the rod guide 8. A bottom valve 13 is provided at the lower end 12 of the inner cylinder 4 to divide the lower liquid chamber 2B of the cylinder 2 and the storage chamber 5. The bottom valve 13 has a check valve 14 that allows the working fluid to flow only from the storage chamber 5 to the lower liquid chamber 2B of the cylinder 2. The bottom valve 13 also has an overflow valve 15 that opens when the pressure in the lower liquid chamber 2B of the cylinder 2 reaches a set pressure, releasing the pressure in the lower liquid chamber 2B to the storage chamber 5. Furthermore, the upper liquid chamber 2A and lower liquid chamber 2B of the cylinder 2 are sealed with working fluid, and the storage chamber 5 is sealed with both working fluid and gas.

[0021] The buffer 1 has a damping force adjustment mechanism 30, which is radially outward from the outer cylinder 3. Figure 1 The damping force is adjusted by controlling the flow of the working fluid relative to the stroke of the piston rod 7 (the "right side" is highlighted in the text). The damping force adjustment mechanism 30 has a frame 31 fixed to a base block 18 disposed radially outside the outer cylinder 3, an extension-side mechanism 32 housed in the frame 31, and a contraction-side mechanism 33. Furthermore, the basic structure of the extension-side mechanism 32 and the contraction-side mechanism 33 is the same as that of the extension-side damping force generating mechanism and the contraction-side damping force generating mechanism in conventional buffers. Therefore, for the sake of simplicity, the description related to the details of the extension-side mechanism 32 and the contraction-side mechanism 33 is omitted.

[0022] The elongation-side mechanism 32 is connected to the upper liquid chamber 2A of the cylinder 2 via the elongation-side connecting passage 34 (first connecting passage). The elongation-side connecting passage 34 has a passage 64 and an annular passage 66 formed in the elongation-side passage member 36, and a plurality of ( ) formed in the upper end portion 19 of the inner cylinder 4. Figure 1 The text indicates that there are only "two" holes 20. The holes 20 are arranged at equal intervals in the circumferential direction of the cylinder block 2.

[0023] like Figure 1 or Figure 2As shown, the elongated side passage component 36 has a straight pipe 38 and a separation pipe 40. The radially outer end 42 of the straight pipe 38 is connected to a port 46 formed in the outer cylinder 3 and the base block 18, and the radially inner end 44 is connected to a port 48 formed in the separation pipe 40. The radially outer end 42 and port 46 of the straight pipe 38 are sealed by a sealing member 50 (O-ring), and the radially inner end 44 and port 48 of the straight pipe 38 are sealed by a sealing member 52 (O-ring).

[0024] The separator tube 40 is formed as a cylinder coaxial with the cylinder body 2 and is disposed on the outer periphery of the upper part of the inner cylinder 4. An annular passage 66 is formed between the separator tube 40 and the inner cylinder 4. The separator tube 40 has an inner flange-shaped fitting portion 54 that fits into the upper end portion 19 of the inner cylinder 4 and an inner flange-shaped fitting portion 56 that fits into the middle portion (notation omitted) of the inner cylinder 4. The fitting portion 54 of the separator tube 40 and the inner cylinder 4 are sealed by a sealing member 58 (O-ring), and the fitting portion 56 of the separator tube 40 and the inner cylinder 4 are sealed by a sealing member 60 (O-ring).

[0025] like Figure 1 As shown, the contraction-side mechanism 33 is connected to the lower liquid chamber 2B of the cylinder 2 via the contraction-side connecting passage 35 (first connecting passage). The contraction-side connecting passage 35 has a passage 65 and an annular passage 67 formed in the contraction-side passage component 37, and a plurality of passages (in) formed in the lower end 12 of the inner cylinder 4. Figure 1 The text indicates that there are two holes 21. The holes 21 are arranged at equal intervals around the circumference of the cylinder block 2.

[0026] like Figure 1 or Figure 2 As shown, the contraction-side passage component 37 has a straight pipe 39 and a separation pipe 41. The radially outer end 43 of the straight pipe 39 is connected to a port 47 formed in the outer cylinder 3 and the base block 18, and the radially inner end 45 is connected to a port 49 formed in the separation pipe 41. The radially outer end 43 and port 47 of the straight pipe 39 are sealed by a sealing member 51 (O-ring), and the radially inner end 45 and port 49 of the straight pipe 39 are sealed by a sealing member 53 (O-ring).

[0027] The separator tube 41 is formed as a cylinder coaxial with the cylinder body 2 and is disposed on the outer periphery of the lower end 12 of the inner cylinder 4. An annular passage 67 is formed between the separator tube 41 and the inner cylinder 4. The separator tube 41 has an inner flange-shaped fitting portion 55 that fits into the outer periphery of the inner cylinder 4 and an inner flange-shaped fitting portion 57 that fits into the lower end 12 of the inner cylinder 4. The fitting portion 55 of the separator tube 41 and the inner cylinder 4 are sealed by a sealing member 59 (O-ring), and the fitting portion 57 of the separator tube 41 and the inner cylinder 4 are sealed by a sealing member 61 (O-ring).

[0028] like Figure 1As shown, the attenuation force adjustment mechanism 30 includes: a mechanism section connecting passage 70 that connects the elongation side mechanism section 32 and the contraction side mechanism section 33; a common passage 71 connected to the mechanism section connecting passage 70; and a common connecting passage 72 (second connecting passage) that connects the common passage 71 to the storage chamber 5, thereby connecting the elongation side mechanism section 32 and the contraction side mechanism section 33 to the storage chamber 5. The common connecting passage 72 has a passage 74, an annular passage 75, and a hole 76 (second hole) formed in the common passage member 73 (passage member).

[0029] like Figure 1 or Figure 2 As shown, the common passage component 73 has a straight pipe 77 and a separation pipe 78. The radially outer end 79 of the straight pipe 77 is connected to a port 81 formed in the outer cylinder 3 and the base block 18, and the radially inner end 80 is connected to a port 82 (first hole) formed in the separation pipe 78. The radially outer end 79 and port 81 of the straight pipe 77 are sealed by a sealing member 83 (O-ring), and the radially inner end 80 and port 82 of the straight pipe 77 are sealed by a sealing member 84 (O-ring).

[0030] The separator tube 78 is formed as a cylinder coaxial with the cylinder body 2 and is disposed on the outer periphery of the inner cylinder 4. An annular passage 75 is formed between the separator tube 78 and the inner cylinder 4. The separator tube 78 has an inner flange-shaped fitting portion 85 formed on the upper end side and fitted into the outer periphery of the inner cylinder 4, and an inner flange-shaped fitting portion 86 formed on the lower end side and fitted into the inner cylinder 4. The fitting portion 85 of the separator tube 78 and the inner cylinder 4 are sealed by a sealing member 87 (O-ring), and the fitting portion 86 of the separator tube 78 and the inner cylinder 4 are sealed by a sealing member 88 (O-ring).

[0031] like Figure 1 As shown, the separator 78 has a boss 89 protruding radially outward. A side facing the attenuation force adjustment mechanism 30 is provided on the inner circumference (inner side) of the boss 89. Figure 1 The port 82 is an opening on the "right side" of the connector 72. The hole 76 of the common connection path 72 is formed on the opposite side of the separator 78 to port 82. Figure 1 The side wall of the "left side" of the cylinder 2. In other words, the hole 76 (second hole) is configured to be opposite the port 82 (first hole) across the center line of the cylinder 2. The center line of the hole 76 (second hole) and the center line of the port 82 (first hole) are aligned on the same straight line.

[0032] like Figure 1 or Figure 2As shown, the separator 78 of the common passage component 73 has an upper end face 90 that is parallel to a plane orthogonal to the centerline of the cylinder 2 (hereinafter referred to as the "axial right-angled plane of the cylinder 2"), and a lower end face 91 that is parallel to the axial right-angled plane of the cylinder 2. On the other hand, the separator 40 of the extended side passage component 36 is parallel to the axial right-angled plane of the cylinder 2 and has an end face 92 that contacts the upper end face 90 of the separator 78 of the common passage component 73.

[0033] Furthermore, the separation tube 41 of the contraction side passage component 37 has an end face 93 that is parallel to the right-angle plane of the cylinder body 2 and contacts the end face 91 of the lower side of the separation tube 78 of the common passage component 73. In addition, the center lines of the port 48 of the separation tube 40, the port 49 of the separation tube 41, and the port 82 (first hole) of the separation tube 78 are arranged on the same plane and are parallel to each other.

[0034] Next, the function of this embodiment will be explained.

[0035] During the retraction stroke of the piston rod 7, the working fluid in the lower liquid chamber 2B of the cylinder 2 flows into the retraction side mechanism 33 of the damping force adjustment mechanism 30 via the retraction side connecting passage 35 (first connecting passage), thereby generating a damping force on the retraction side. The working fluid flowing out of the retraction side mechanism 33 flows into the storage chamber 5 via the mechanism connecting passage 70, the common passage 71, and the common connecting passage 72 (second connecting passage).

[0036] During the contraction stroke, the volume of working fluid moved by the piston 6 flows from the lower liquid chamber 2B through the contraction-side connecting passage 35 (first connecting passage), the mechanism connecting passage 70, and the extension-side connecting passage 34 (first connecting passage) to the upper liquid chamber 2A of the cylinder body 2. Here, when the pressure in the lower liquid chamber 2B of the cylinder body 2 reaches the opening pressure of the overflow valve 10 of the piston 6, the overflow valve 10 opens, releasing the pressure in the lower liquid chamber 2B to the upper liquid chamber 2A, thereby suppressing excessive pressure rise in the lower liquid chamber 2B. Furthermore, when the pressure in the lower liquid chamber 2B of the cylinder body 2 reaches the opening pressure of the overflow valve 15 of the base valve 13, the overflow valve 15 opens, releasing the pressure in the lower liquid chamber 2B to the storage chamber 5, thereby suppressing excessive pressure rise in the lower liquid chamber 2B.

[0037] During the extension stroke of the piston rod 7, the working fluid in the upper liquid chamber 2A of the cylinder 2 flows into the extension side mechanism 32 of the damping force adjustment mechanism 30 via the extension side connecting passage 34 (first connecting passage), thereby generating a damping force on the extension side. The working fluid flowing out of the extension side mechanism 32 flows to the storage chamber 5 via the mechanism connecting passage 70, the common passage 71, and the common connecting passage 72 (second connecting passage).

[0038] During the extension stroke, the volume of working fluid moved by the piston 6 flows from the storage chamber 5 through the common connecting passage 72 (second connecting passage), the common passage 71, the mechanism connecting passage 70, and the contraction side connecting passage 35 (first connecting passage) to the lower liquid chamber 2B of the cylinder 2. Here, when the pressure in the upper liquid chamber 2A of the cylinder 2 reaches the opening pressure of the overflow valve 9 of the piston 6, the overflow valve 9 opens, releasing the pressure in the upper liquid chamber 2A to the lower liquid chamber 2B, thereby suppressing excessive pressure rise in the upper liquid chamber 2A.

[0039] Figure 3 This is a conceptual diagram of a buffer 1 with the centerline of the cylinder 2 horizontally positioned. It is a cross-sectional view of the buffer 1 cut along a right-angled plane from the centerline of the cylinder 2, including the hole 76 (second hole) and port 82 (first hole) of the separator 78 formed in the common passage component 73. Figure 3 For convenience, the lower end of the damping force adjustment mechanism 30 is positioned lower than the lower end of the cylinder 2 (outer cylinder 3).

[0040] like Figure 3 As shown, in this embodiment, when the lower end of the opening 95 on the radially outer side (storage chamber 5 side) of the hole 76 (second hole) is at the liquid level height H1 of the storage chamber 5, the upper end of the opening 96 on the radially inner side (annular passage 75 side) of the hole 76 is set to be lower than the liquid level height H1 of the storage chamber 5. Furthermore, when the piston rod 7 is extended to its maximum length, i.e., when the amount of working fluid in the storage chamber 5 is at its minimum, working fluid is injected into the storage chamber 5 such that the liquid level height H1 of the storage chamber 5 is higher than half the height H2 of the storage chamber 5.

[0041] In conventional damper designs, since one end of the passage connecting to the damping force adjustment mechanism opens into the storage chamber, air in the storage chamber may enter the damping force adjustment mechanism via this passage when the damper is installed laterally (with the cylinder's centerline horizontally aligned). Therefore, after the air in the damping force adjustment mechanism is purged during the inspection process, the conventional damper needs to be maintained longitudinally (with the centerline vertically aligned) during transport and assembly onto the vehicle to prevent air from entering the damping force adjustment mechanism.

[0042] In contrast, in this embodiment, when the buffer 1 is placed laterally such that the lower end of the damping force adjustment mechanism 30 and the lower end of the cylinder 2 are on the same horizontal plane, as... Figure 4 As shown, the opening 95 of the radially outer side (storage chamber 5 side) of the common connecting path 72 (second connecting path) that connects the attenuation force adjustment mechanism 30 and the storage chamber 5 is lower than the liquid level height H1 of the storage chamber 5.

[0043] According to this embodiment, when the buffer 1 is placed horizontally, the hole 76 (second hole) of the common connecting passage 72 (second connecting passage) is open in the working fluid sealed in the storage chamber 5. Therefore, it is possible to prevent air in the storage chamber 5 from entering the common connecting passage 72 through the hole 76, and further prevent air in the storage chamber 5 from entering the damping force adjustment mechanism 30 via the common connecting passage 72. Thus, in this embodiment, it is not necessary to maintain the buffer 1 in a longitudinal position, thereby facilitating operation during the transport of the buffer 1 and during assembly operations for vehicle assembly.

[0044] In this embodiment, the upper end face 90 of the separation tube 78 of the common passage component 73 (passage component) contacts the lower end face 92 of the separation tube 40 of the extension side passage component 36, and the lower end face 91 of the separation tube 78 contacts the upper end face 93 of the separation tube 41 of the contraction side passage component 37.

[0045] Therefore, the error in the axial relative position of the cylinder 2 between port 82 (first hole) of separator 78, port 48 of separator 40, and port 49 of separator 41 depends on the machining error of each separator 78, 40, and 41. In other words, the relative position between separator 78, separator 40, and separator 41 is positioned with high precision.

[0046] Therefore, in this embodiment, when the damping force adjustment mechanism 30 is assembled onto the cylinder 2, that is, when the end 79 of the straight tube 77 protruding from the cylinder 2 is connected to the port 81 on the side of the damping force adjustment mechanism 30, and the ends 44 and 45 of the straight tubes 38 and 39 protruding from the damping force adjustment mechanism 30 are connected to the ports 48 and 49 on the side of the cylinder 2, each straight tube 77, 38, and 39 can be easily inserted into the corresponding ports 81, 48, and 39, thereby improving the assemblability of the buffer 1.

[0047] In addition, during the assembly process of the buffer 1, when the rod guide 8 is inserted into the cylinder 2, the straight tube 77 is pre-inserted into the port 82 (first hole) of the separation tube 78 installed on the outer periphery of the inner cylinder 4 and the port 81 formed in the outer cylinder 3 and the base block 18, thereby ensuring the coaxiality of the inner cylinder 4 relative to the outer cylinder 3. Therefore, the upper end 19 of the inner cylinder 4 can be easily fitted into the annular recess 17 formed in the rod guide 8, which can improve the assemblability of the buffer 1.

[0048] Furthermore, the present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are detailed embodiments for the purpose of easily understanding and illustrating the present invention, and are not limited to having all the structures described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of another embodiment, and it is also possible to add the structure of another embodiment to the structure of a certain embodiment. Furthermore, regarding a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0049] This application claims priority based on Japanese Patent Application No. 2023-166111, filed on September 27, 2023. The entire disclosure of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2023-166111, filed on September 27, 2023, is incorporated herein by reference in its entirety.

[0050] Explanation of reference numerals in the attached figures

[0051] 1: Buffer

[0052] 2: Cylinder block

[0053] 2A: Upper liquid chamber (liquid chamber)

[0054] 2B: Lower liquid chamber (liquid chamber)

[0055] 3: Outer cylinder

[0056] 4: Inner cylinder

[0057] 5: Storage room

[0058] 6: Piston

[0059] 7: Piston rod

[0060] 30: Attenuation force adjustment mechanism

[0061] 34: Extended side connecting path (first connecting path)

[0062] 35: Contraction-side connecting path (first connecting path)

[0063] 72: Public Connector (Second Connector)

[0064] 73: Common access components (access components)

Claims

1. A buffer, characterized in that, The buffer has the following features: A cylinder having an outer cylinder and an inner cylinder located inside the outer cylinder and sealed with working fluid. An annular storage chamber, defined between the outer cylinder and the inner cylinder, is sealed with the working fluid and gas; A piston that is slidably inserted into the inner cylinder divides the inner cylinder into two liquid chambers; The piston rod is connected to the piston on one axial side and protrudes outward from the cylinder body on the other axial side. The damping force adjustment mechanism is provided in such a way that it protrudes radially outward from the outer cylinder, and is capable of adjusting the damping force; The first connecting path connects the attenuation force adjustment mechanism to the inner cylinder. The second connecting path has a passage component, one side of which is connected to the attenuation force adjustment mechanism, and the other side is connected to the storage chamber at a different position in the circumferential direction from the attenuation force adjustment mechanism. The second connecting path connects the attenuation force adjustment mechanism and the storage chamber.

2. The buffer according to claim 1, characterized in that, The passage component has a first hole opening on the side of the attenuation force adjustment mechanism and a second hole opening on the side of the storage chamber. The second hole is located at a position opposite to the first hole, separated by the centerline of the cylinder body.

3. The buffer according to claim 2, characterized in that, The passage component has an annular passage located on the outer periphery of the inner cylinder, connecting the first hole and the second hole. When the cylinder is horizontally positioned along its centerline and the lower end of the opening on the storage chamber side of the second hole is at the liquid level of the working fluid in the storage chamber, the opening on the annular passage side of the second hole is formed at a position lower than the liquid level.

4. The buffer according to claim 2, characterized in that, When the centerline is horizontal and the piston rod is extended to its maximum length, the working fluid is injected such that the liquid level in the storage chamber is higher than half the height of the storage chamber.

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