GB2544245A - Hydraulic shock-absorbing device - Google Patents
Hydraulic shock-absorbing device Download PDFInfo
- Publication number
- GB2544245A GB2544245A GB1704079.1A GB201704079A GB2544245A GB 2544245 A GB2544245 A GB 2544245A GB 201704079 A GB201704079 A GB 201704079A GB 2544245 A GB2544245 A GB 2544245A
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- United Kingdom
- Prior art keywords
- inner tube
- fitting portion
- end plate
- tube
- passage
- Prior art date
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
- F16F9/3207—Constructional features
- F16F9/3235—Constructional features of cylinders
- F16F9/3242—Constructional features of cylinders of cylinder ends, e.g. caps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/10—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using liquid only; using a fluid of which the nature is immaterial
- F16F9/14—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect
- F16F9/16—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts
- F16F9/18—Devices with one or more members, e.g. pistons, vanes, moving to and fro in chambers and using throttling effect involving only straight-line movement of the effective parts with a closed cylinder and a piston separating two or more working spaces therein
- F16F9/185—Bitubular units
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
- F16F9/32—Details
- F16F9/3207—Constructional features
- F16F9/3235—Constructional features of cylinders
- F16F9/3257—Constructional features of cylinders in twin-tube type devices
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Fluid-Damping Devices (AREA)
- Actuator (AREA)
Abstract
[Problem] To provide a double tube-type transverse hydraulic shock-absorbing device in which an air venting structure can be simplified. [Solution] An air venting structure configured to discharge air accumulated in the upper corner part (35) of a first liquid chamber (13A) to a reservoir (6) through a communicating passage (37), an annular passage (36), an orifice (41), and a channel (40) together with an actuating fluid, wherein the inside mating part (31) of an end plate (4) is caused to mate with the inside of an inner tube (3) and the left end part (33) of the inner tube (3) is closed. This makes it possible to cause the annular gap formed between the outside mating part (32) of the end plate (4) and the outside of the inner tube (3) to serve as the annular passage (36) of the air venting structure, and simplify the air venting structure.
Description
DESCRIPTION HYDRAULIC'DAMPER
TECHNICAL FIELD
. [0001] The present invention relates to a horizontal double-tube hydraulic damper for a railroad car or the like. BACKGROUND ART
[0002] Patent Document 1, for example, discloses a horizontal double-tube hydraulic damper designed to allow air present in an upper corner of a fluid chamber to discharge through an annular passage and an orifice into a lower portion o f a r e s e r v o i r.
PRIOR ART REFERENCES PATENT LITERATURE
[0003] Patent Document 1: JP-A-2009-243634 SUMMARY OF THE INVENTION
TECHNICAL PROBLEM
[0004] This hydraulic damper has the outside (outer' circumferential surface) of an inner: tube fitted in an end plate. It is thus required to give precision to the outer diameter of the inner tube, normally having general tolerances. In other words, machining (finishing) of the outer circumference of the inner tube is required.
In view of this, the present invention is made. An object of the present invention is to provide a horizontal double-tube hydraulic damper having a degassing structure that can be formed in a simplified manner.
SOLUTION TO PROBLEM
[0005] To solve the above-described problem, the hydraulic damper of the present invention is a horizontal double-tube hydraulic damper including: an annular reservoir containing liquid and gas sealed between end plates closing opposite ends of an outer tube and an inner tube disposed coaxially; and an annular passage formed in a fitting portion where one end portion of the inner tube is fitted in one of the end plates, so as to permit any gas present in a corner, on an upper side when the damper is mounted, of a fluid chamber in the inner tube, to escape, via the annular passage and an orifice for generating damping force into the reservoir, wherein: the one of the end plates includes an inner fitting portion fitted in an inside of the inner tube and an outer fitting portion fitted on an outside of the inner tube; a clearance between the outer fitting portion and the outside of the inner tube is set larger than a clearance between the inner fitting portion and the inside of the inner tube to form the annular passage; and a communication passage that communicates between an upper portion of the corner of the fluid chamber in the inner tube and the annular passage is formed in the one of the end plates or the inner tube.
ADVANTAGEOUS EFFECT OF INVENTION
[0006] The present invention facilitates the formation of the degassing structure of the horizontal double-tube hydrau1ic damper.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Fig. 1 is a cross-sectional view taken along an axial plane to schematically show the structure of a hydraulic damper of first embodiment. fig. 2 is an on larged mew of the main portion of Fig. 1.
Fig. 3 shows a variation of the first embed:merit.
Fig. 4 shows another vari.a tioof th:e frisr embodiment.
Fig. 5 is an enlarged view of the main portion of a second embodiment.
EMBODIMENTS
[00081 nFirst embodiments
The first embodiment of the present irn/enrion writ now be described with reference to Figs** 1 and 2. This embodiment relates to a horizon Lai double ~ t ube hyotauire damper 1 , a Iaieral-vi brati on damper, disposed in generally horizontal direction between a body and undercarriage or a railroad car hereinafter simply referred L o as '"hydraulic damper >/ } . In the following description, the tορ~bo11om/upper-Iower direction and left-right direction as v.Lowed in Fig. 1 are defined for convenience as the top-faottom/upper~;ower direction arid left-right directi on of the hydraulic clamper 1 in a mounted state.
[000¾ is shown in Fig. 1, the hydraulic damper 1 includes an outer tube 2 and an inner tube 3 that are coaxial >.y disposed to have an axis in common. The outer tube 2 and the inner tube 3 are closed at left and right ends by an end plate I and an end plate 5. As such, an annular reservoir 6 is formed between the outer tube 2; and the inner tube 3. The end plate 5 is divided into two separate members:: an end plate 7 for closing the right end of the outer tube 2; and an end plate 8 for closing the right end oi the inner tube 3. To the end plate 7 is fixed a bracket 9 that is to be coupled to the body side of the railroad car. The end plate 5 is so structured that the end plate 7 and the end plate 8 are integrated by fitting an axial portion 10, formed on the right-side of the end plate 8, into a recess 11 formed in an (left) end surface of the end plate 7 opposite from the bracket 9. A spigot joint portion 29 is formed between the outer circumference of the end plate 7 and the right end of the outer tube 2, [0010] A piston 12 is slidably fitted in the inner tube 3.
An interior of the inner tube 3 is divided by the piston 12 into left and right chambers, namely, a first fluid chamber 13A and a second fluid chamber 133. The first and second fluid chambers 13A and 13B have working fluid sealed therein. The reservoir 6 has working fluid and air sealed therein. A left end of a piston rod 14 is coupled to the piston 12, The left end side of the piston rod 14 extends through the first fluid chamber 13A and the end plate 4 out of the inner tube 3. A bracket 15 to be coupled to the undercarriage of the railroad car is fixed to the left side of the piston rod 14, A cylindrical cover IScovering a portion of the piston rod 14 extending out of the end plate 4 is attached to the bracket 15.
[0011] The piston 12 is provided with a compression-side relief valve 17 that, during the compression stroke of the piston rod 14, prevents working fluid from flowing from the second fluid chamber 13B into the first fluid chamber 13A, and allows the pressure of fluid in the second fluid chamber 133 to escape into the first fluid chamber 13A when the fluid in the second fluid chamber 1333 has reached a predetermined pressure. The piston 12 is also provided with an expansion-side relief valve 18 that, during the expansion stroke of the piston rod 14, prevents working fluid from flowing from the first fluid chamber 13Ά into the second fluid chamber 13B, and allows the pressure of fluid in the first fluid chamber 13Ά to escape into the second fluid chamber 13B when the fluid in the first fluid chamber 13A has reached a predetermined pressure. The end plate 8 is provided with a relieve valve 19 that opens in accordance with the pressure of fluid in the second fluid chamber 13B to allow the pressure of fluid in the second fluid chamber 13B to escape into the reservoir 6. The end plate 8 is also provided with a-; check valve 20 that admits only a flow of working fluid from the reservoir 6 to the second fluid chamber 133.
[0012] In the first embodiment, the end plate 8 is a cast-iron component of generally cap shape. The axial portion 10, described above, is formed on the right end of the end plate 8, An annular outer fitting portion 21 is formed on the opposite end of the end plate 8 to the axial portion 10. The annular outer fitting portion 21 forms part of a side wall of the end plate 8. The outer fitting portion 21 has an inner circumferential surface 21B that fits on an outer circumferential surface 22A of a right, end portion 22 of the inner tube 3. An annular seal groove 23 is formed on the inner circumferential surface 213 of the outer fitting portion 21. A sealing member 24 fitted in the seal groove 23 seals between the inner tube 3 and the end plate 8. The inner tube 3 abuts, at its right end (an end surface of the right end portion 22), on a bottom 25 of the end plate 8, The inner tube 3 is formed with a general tolerance for its outer diameter. The outer fitting portion 21 of the end plate 8 and the right end portion 22 of the inner tube 3 are fitted t o ge t h e r w i t b a p r e de t e mined f i t t ole r a nee, [0013] On the other hand, in the first embodiment, the end plate 4 is a cast-iron component of generally cylindrical shape. As shown in Fig. 2, the end plate 4 has an outer circumferential surface 26 on the bracket 15 side (left side). The outer circumferential surface 26 is fitted in an end-plate fitting portion 28 formed on the inside of a left end portion 27 of the outer tube 2, The end-plate fitting portion 28 is formed by machining the inside of the left end portion 27 of the outer tube 2. The outer tube 2 and the end plate 4 are fitted together with a predetermined fit. tolerance. The end plates 8 and 4 may be sintered components, instead of cast-iron ones.
[0014] An inner fitting portion 31 fitted in the inner tube 3, and an outer fitting portion 32 fitted on the outside of the inner tube 3are provided on the right, end side of the end plate 4 or on the opposite side to the bracket 15. To put it another way, the tip of a left end portion 33 of the inner tube 3 is inserted in an annular groove 34 formed between the inner and outer fitting portions 31 and 32 of the end plate 4. The outer fitting portion 32 of the end plate 4 extends to the right beyond the inner fitting portion 31. In this manner, an outer circumferential surface 33A of the left end portion 33 or the inner Luse 3 is covered by the octet:: fitting poftibh 3?, The tip of the Lett end portion 33 of the inner tube 3 abuts on the bottom of the groove 34 of the end plate 4. This determines the relative axial (left--right) position of the inner tube 3 and the end plate 4.
[0015] In the first embodiment, the clearance between the outer fitting portion 32 of the end plate 4 and the outside of the inner tube 3, or the clearance between an inner circumferential surface 32B Of the outer fitting pert ion 32 and the outer circumferential surface 33A of the left end portion.....31 Of the inner tube 3, is set larger than the clearance between the inner fitting portion 31 of the end plate 4 and the inside of the inner plate 3, or the clearance; between the outer circumferential surface 31¾ of the inner fitting portion 31 and the inner cifcumferehtial surface 33B of the .1 eft end portion 33 of the inner tube 31 Pop example, the: inner fitting portion :31 and the inside of the; inner tube 3 are transition-fitted together, and the outer fitting portion 32 and the outside of the ;nre.r tube 3 are clearance-fitted. together. This permits the clearance between the outer fitting port, ton 32 and the outside of' the inner tube; 3 to be made larger than that: between: the inner pitting portion 31 and the inside of the inner tube 3» [0016] The hydraulic damper 1 is provided with a degassing struct:ure that allows any air present in an upper corner 35 of the first fluid chamber 13¾ to discharge int.o the reservoir 6. in the first embodiment, the clearance between the surer fitting portion 32 and the outside of the inner tube 3,: described above, functions as an annular passage 36 that forms part of the degassing structure. The degassing structure includes a communication passage 37 that communicates between the annular passage 36 and the upper corner 35 of the first fluid chamber 13A. In the first embodiment, the communication passage 37 is formed by cutting out an upper portion of the inner fitting portion 31 of the end plate 4, In other words, the communication passage 37 is formed by cutting an upper portion (topmost) of the groove 34 in the end plate 4 farther to the left and downward. The right end of the annular passage 36 is defined by a sealing member 38. The sealing member 38 is fitted in a seal groove 39 formed in the inner circumferential surface 32B of the outer fitting portion 32 of the end plate 4.
[0017] In the first embodiment, the degassing structure includes a flow passage 40. The flow passage 40 communicates between a leftmost lower region of the reservoir 6, that is, a region surrounding the outer circumferential surface 32A of the outer fitting portion 32 in the reservoir 6 and a lower portion (bottommost) of the annular passage 36. The flow passage 40 is located below the outer fitting portion 32 of the end plate 4. The flow passage 40 is provided with an orifice 41 that opens at its top end to the bottom of the annular passage 36, In this way, the degassing structure communicates the upper corner 35 of the first fluid chamber 13A and the leftmost lower region of the reservoir 6 via the communication passage 37, the annular passage 36, the orifice 41, and the flow passage 40. The corner 35 is preferably located on the upper side, more preferably at. uppermost, when the hydraulic damper 1 is mounted. The upper side does pot necessar 11 y have fee be the top, arid the corner 35 may res located,; for exarnpIe, anywhere above midpoint. This still permits air to discharge under the pressure in the rifest and second: fluid chambers .13A and 131.
[C018j Between the left end portion of the end plate 4, or the portion fitted in the end^piafe fitting portion z8 of the outer tube 2, and the right end portion of the end plate 4, or the portion where the inner and outer fitting portions 3 L and 3:2 ere located, is formed ar: intermediate portion Id navinq a predetermined clearance from the inner circumferential s;.itrace 2B of the outer tube 2. The intermediate portion 42. is formed so as not to produce a case in which a step 4:¾ i-oca ted between the intermediate: portion 42 and the portion of tne outer tube 2 that fits on the encfo-plate fitting portion 28, interferes with a step 44, formed between the inner circumferential surface 21 of the outer tube: 2 and the end-plate fitting portion 28, and thereby: the lap of tne left end portion 3 3 of the inner tube 3 cannot be abutted a g a j. n s 1 fhd bottom of the groove 34 in the end plate 4. The end plate 4 has a cutout; ^5 (at the position of 12 ψ olmfa. as viewed along the· M:ft-rigIt direction) at all upper portion: of: the intermediate portion 42, The eutogf 4 5 engaqe5¾ with a uw.-jged portion 4,6 fpfmed at a left1 end portion 23 of the outer foe 2. In this way, ar:. anti-iotation mechanism is formed that prevents movement of the end plate 4: relative to the: outer tube 2 around its axis. The: anti-rotation mechanism may be provided with a projection on the inner circumference of the outer tube 2, instead of the swaged portion 46* [0019] An operation of the first embodiment will now be described.
As the body and the undercarriage of the railroad car-move horizontally relative to each other, the piston rod 14 of the hydraulic damper 1, disposed horizontally, extends and contracts. During the extension stroke of the piston rod 14, the working fluid in the first fluid chamber 13A flows through the expansion-side relief valve 18 in the piston 12 into the second fluid chamber 13B. At the same time, the working fluid in the first fluid chamber 13A flows via the communication passage 37, the annular passage 36, and the orifice 41, and the flow passage 40 into the reservoir 6, Working fluid passing from the first fluid chamber 13A through the relief valve 18 and the orifice 41 in this manner creates an expansion-side damping force.
[0020] If any air is present in the upper corner 35 of the first fluid chamber 13A during the expansion stroke of the piston rod 14 described above, the air is discharged with working fluid through the communication passage 37, the annular passage 36, the orifice 41, and the flow passage 40 into the reservoir 6. During the expansion stroke of the piston rod 14, the same volume of working fluid as that of the portion of the piston rod 14 has contracted from the first fluid chamber 13A is introduced from the reservoir 6 via the check valve 20 in the end plate 8 into the second fluid chamber 13B.
[0021] On the other hand, during the compression, stroke of the piston rod 14, the working fluid flows from the second fluid chamber 13B through the compression-side relief valve 17 in the piston 12 into the first fluid chamber 13A. At the same time, the same volume of working fluid as that of the portion of the piston rod 14 has moved into the first fluid chamber 13A is released from the second fluid chamber 13B through the relieve value 19 in the end plate 8 into the reservoir 6, The passage of working fluid from the second fluid chamber 1.3B through the relief valves 17 and 19 in this manner creates a compression-side damping force.
[0022] According to the first embodiment, the annular passage 36 communicates with the upper corner 35 located at the topmost of the first fluid chamber 13A to form the degassing structure. This ensures that any air present in the upper corner 35 of the first fluid chamber 13Ά will be discharged 'with 'working fluid through the communication passacje 37, the annular passage 36, the orifice 41, and the flow passage 40 into the reservoir 6 even when the hydraulic damper 1 operates in such a manner that the piston rod 14 extends and contracts (vibrates) with a relatively short amplitude. Air present in the upper corner 35 of the first fluid chamber 13A moves smoothly through the communication passage 37 to the topmost of the annular passage 36 located at higher position. This prevents air, once it reaches the top of the annular passage 36 through the communication passage 37, from returning to the first fluid chamber 13A. As such, damping is surely performed even against an input of small amplitude, and thereby reliability of the horizontal doubletube hydraulic damper i can be improved.
[0023] For conventional hydraulic dampers that have the left end portion 33 of the inner tube 3 closed by fitting the end plate 4 on the outside only of the inner tube 3 without fitting the end plate 4 on the inside of the inner tube 3, the outer circumferential surface 3A of the inner tube 3 is machined, since the inner cylinder 3 is required to be formed with a narrower tolerance for outer diameter than a general tolerance, This is one of the factors that contribute to an increase in manufacturing cost in combination with the fact that a thick-walled material (for the inner tube 3) is selected in view of machining margin.
In contrast, in the first, embodiment, the left end portion 33 of the inner tube 3 is closed by fitting the inner fitting portion 31 of the end plate 4 on the inside of the inner tube 3, which allows use of a general tolerance for the outer diameter of the inner tube 3, without the need for a narrower tolerance. This reduces the manufacturing cost as compared with conventional hydraulic dampers as describe above, [0024] Since in the first embodiment, the left end portion 33 of the inner tube 3 is closed by fitting the inner fitting portion 31 of the end plate 4 on the inside of the inner tube 3, the annular clearance formed between the outer fitting portion 32 of the end plate 4 and the outside of the inner tube 3 (the inner circumference 33B of the left end portion 33) can be used as the annular passage 36 of the degassing structure. As such, the degassing structure can be formed in a simplified manner.
Further., in the first embodiment, the cutout 45 formed at the topmost of the intermediate portion 42 of the end plate 4 is engaged with the swaged portion 46 formed by swaging the side wall of the outer tube 2. This prevents movement (rotation) of the end plate 4 relative to the outer cuoe 2 around its axis and also prevents the hydraulic damper 1 from being disposed upside down on a railroad car, that is, prevents inverted arrangement of communication passage 37 and the o rifice 41.
[0025] The first embodiment, is not limited to the one described above and can be modified, for example, in the f ο11owi n g way.
The end plates 4 and 8 of the first embodiment are made of casting iron by die casting or the like but can be formed instead, for example, by sintering or cuttincj.
In the first embodiment, the communication passage 37 is formed in the end plate 4 to form the degassing structure. Instead, for example, a cutout (slit) can be formed at an upper portion (at the topmost position) of the left end of the inner tube 3 to serve as the communication passage 37, thereby forming the degassing structure.
[0026] In the first embodiment, the inner fitting portion 31 of the end. plate 4 is cut. out to form the communication passage 37. In other words, the end plate 4 and the communication passage 37 are formed at the same time, and the upper corner 35 of the first fluid chamber 13A and the annular passage 36 are communicated with each other to form the degassing structure, Instead, as shown in Fig, 3, an inclined bore extending upward to the left may be drilled toward above the groove 34 to form the communication passage 37.
In this case, the topmost of the drilled communication passage 37 (see Fig. 3} is located above the topmost, of the communication passage 37 (see Fig, 2} that would otherwise be formed by the cutout. This more reliably prevents air that has reached the top of the annular passage 36 through the communication passage 37 from returning to the first fluid chamber 13A.
[0027] In the first embodiment, the clearance between the outer fitting portion 32 of the end plate 4 and the outside of the inner tube 3, that is, between the inner circumferential surface 32B of the outer fitting portion 32 and the outer circumferential surface 33A of the left end portion 33 of the inner tube 3, is used as the annular passage 36 to form the degassing structure. In the case that there are relatively wide deviations in the outer diameter of the inner tube 3, as shown in Fig. 4, an auxiliary annular groove 47 may be formed on the inner circumferential surface 323 of the outer fitting-portion 32 of the end plate 4 to form a flow passage for a degassing structure .
In this case, such an auxiliary annular groove can be formed with a cross-sectional area smaller than that of the annular groove of a conventional degassing structure which groove alone forms a flow passage. This prevents the axial (left-right) dimension of the end plate 4 (the outer fitting portion 32) from becoming too large.
[0028] <Seoond Embodiment:»
The second embodiment o.t the present invent i or· will how be described with reference to Fig. 5. Detailed description of elements the: same as or corresponding to those ol the first embodiment will: be omitted by assigning the same terms and: the same numerals to therm
In tip second embodiment, the degassing structure of first embodiment,: formed between the left end portion 83 of the inner tube 3 and the end plate 1 closing: the lift end portion 33, is Ideated between the right end portion φβ or ^ inner tube 3 and: the end plate # closing the: right end por-:12:, [00291 ©n the left side of the: end plate 8, or on the opposite end of the end plate: 8 to the shaft .10, is formed ^ inner fitting portion 51 fitted in the: inside: of the inner tube: 3 and an outer fitting portion 52 fitted on the oatsfr^ of the inner tube 3. In other words, the tip of the right ^ portion 22 of the inner tube 3 is inserted in an annular groove 54 formed: between the inner fitting portion 5:1 and ^ outer fitting portion 52 of the end plate 8. The outer fitting portion 52 of the end plate 8 extends to the left beyond the inner fitting portion 51. in this manner, the outer fitting portion 52 covers the outer circumferential surface 22A of the right end portion 22 of the inner tube -<
^ V
The tip of the right end portion 22. of the inner tube 3 afo^ against the bottom of a groove 54 of the end plate *. This determines the: relative axial (left-right): position of the inner tube 3 and the end plate: 8 and hence the relative aχ: ^ (left-right) position of the inner and outer tabes 3 and 2.
[0030] The clearance between the outer fitting portion 52 of the end plate 8 and the outside of the inner tube 3, or the clearance between an inner circumferential surface 52B of the outer fitting portion 52 and the outer circumferential surface 22A of the right end portion 22 of the inner tube 3, is set larger than the clearance between the inner fitting portion 51 of the end plate 8 and the inside of the inner plate 3, or the clearance between the outer circumferential surface 51A of the inner fitting portion 51 and the inner circumferential surface 22B of the right end portion 22 of the inner tube 3. For example, the inner fitting portion 51 and the inside of the inner tube 3 are transition-fitted together, and the outer fitting portion 52 and the outside of the inner tube 3 are clearance-fitted together. This permits the clearance between the outer fitting portion 52 and the outside of the .inner tube 3 to be made larger than that between the inner fitting portion 51 and the inside of the inner tube 3.
[0031] In the second embodiment, the clearance between the outer fitting portion 52 and the outside of the .inner tube 3, described above, functions as an annular passage 56 that forms part of the degassing structure. In the second embodiment, the degassing structure includes a communication passage 57 for communicating between the annular passage 56 and an upper corner 55 of the second hydraulic chamber 13B, The communication passage 57 is formed by cutting out an upper portion of the inner fitting portion 51 of the end plate 8.
In other words, the communication passage 57 is formed by cutting an upper portion (topmost) of the groove 54 formed in the end plate 8 farther to the right and downward. The left end of the annular passage 56 is defined by a sealing member 58. The sealing member 58 is fitted in a seal groove 59 formed in the inner: circumferential surface 52B of the outer fitting portion 52 of the end plate 8, [0032] In the second embodiment, the degassing structure includes a flow passage 60. The flow passage 60 communicates between a rightmost lower region of the reservoir 6, that is, a region surrounding the outer circumferential surface 52A of the outer fitting portion 52 in the reservoir 6 and a lower portion (bottommost) of the annular passage 56. The flow passacfe 60 is located in a lower part of the outer fitting portion 52 of the end plate 8. The flow passage 40 is provided with an orifice 61 that opens at its top end to the bottom of the annular passage 56. In this way, the degassing structure communicates between the upper corner 55 of the second fluid chamber 13B and the rightmost lower region of the reservoir 6 via the communication passage 57, the annular passage 56, the orifice 61, and the flow passage 60. A sealing member 81 is fitted in a seal groove 80 formed in the inner circumferential surface 52B of the outer fitting portion 52. With such a backup seal, the second embodiment can be used as a hydraulic damper for high pressure.
[0033] An operation of the second embodiment will now be described,
As the body and the undercarriage of the railroad car move horizontally relative to each other, the piston rod 14 of the hydraulic damper 1, disposed horizontally., extends and contracts. During the contraction stroke of the piston rod 14, the working fluid in the second fluid chamber 13B flows through the contraction-side relief valve 17 in the piston 12 into the first fluid chamber 13A. During this flow, if any air is present in the upper corner 55 of the second chamber 13B, the air is discharged with the working fluid via the communication passage 57, the annular passage 565, the orifice 61, and the flow passage 60 into the reservoir 6.
[0034] The second embodiment brings about the same effect as that of the first embodiment. The degassing structure of the second embodiment may be combined with that of the first embodiment or may be formed alone in the hydraulic damper 1. REFERENCE NUMERALS
[0035] 1. hydraulic damper 2, outer tube 3, inner tube 4, 5. end plates 6, reservoir 13Ά, 13B. hydraulic chambers 31. inner fitting portion 32. outer fitting portion 33. left end portion (an end portion of inner tube) 35, upper corner 36, annular passage 37, communication passage 41. orifice
Claims (4)
1. A horizontal double-tube hydraulic damper comprising: an annular reservoir containing liquid and gas sealed between end plates closing opposite ends of an outer tube and an inner tube disposed coaxially; and an annular passage formed in a fitting portion where one end portion of the inner tube is fitted in one of the end plates, so as to permit any gas present in a corner, on an upper side when the damper is mounted, of a fluid chamber in the inner tube, to escape via the annular passage and an orifice for generating damping force into the reservoir, wherein the one of the end plates includes an inner fitting portion fitted in an inside of the inner tube and an outer fitting portion fitted on an outside of the inner tube, a clearance between the outer fitting portion and the outside of the inner tube is set larger than a clearance between the inner fitting portion and the inside of the inner tube to form the annular passage, and a communication passage that communicates between an upper portion of the corner of the fluid chamber in the inner tube and the annular passage is formed in the one of the end plates or the inner tube,
2. A hydraulic damper according to Claim 1, wherein the communication passage is formed in the one of the end plates by casting or sintering,
3. A hydraulic damper according to Claim 1 or 2, wherein the communication passage is a bore formed in the one of the end plates,, the bore being inclined relative to an axis of the inner tube,
4. A hydraulic damper according to any one of Claims 1 to 3, wherein an annular groove communicating with the communication passage is formed in the outer fitting portion,
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2014201647 | 2014-09-30 | ||
| PCT/JP2015/073862 WO2016052008A1 (en) | 2014-09-30 | 2015-08-25 | Hydraulic shock-absorbing device |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201704079D0 GB201704079D0 (en) | 2017-04-26 |
| GB2544245A true GB2544245A (en) | 2017-05-10 |
| GB2544245B GB2544245B (en) | 2020-06-24 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1704079.1A Active GB2544245B (en) | 2014-09-30 | 2015-08-25 | Hydraulic damper |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP6250185B2 (en) |
| CN (1) | CN106715953B (en) |
| GB (1) | GB2544245B (en) |
| WO (1) | WO2016052008A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3690275A4 (en) * | 2017-09-27 | 2021-06-30 | KYB Motorcycle Suspension Co., Ltd. | Front fork and method for manufacturing front fork |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0861416A (en) * | 1994-08-23 | 1996-03-08 | Kayaba Ind Co Ltd | Air bleeder structure in oil damper |
| JPH11344068A (en) * | 1998-05-29 | 1999-12-14 | Kayaba Ind Co Ltd | Oil damper |
| JP2009243634A (en) * | 2008-03-31 | 2009-10-22 | Hitachi Ltd | Hydraulic shock absorber |
| JP2011007287A (en) * | 2009-06-26 | 2011-01-13 | Hitachi Automotive Systems Ltd | Transverse cylinder device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101793273B (en) * | 2009-01-30 | 2017-05-17 | 日立汽车***株式会社 | Cylinder apparatus |
| CN101857039B (en) * | 2009-04-10 | 2012-07-25 | 萱场工业株式会社 | Linear shock absorber for railway vehicles |
| JP2011052732A (en) * | 2009-08-31 | 2011-03-17 | Hitachi Automotive Systems Ltd | Cylinder device |
| CN202326886U (en) * | 2011-11-10 | 2012-07-11 | 浙江森森汽车零部件有限公司 | Self gas exhaust device of dual-drum hydraulic shock absorber |
| CN102606667B (en) * | 2012-04-01 | 2014-10-08 | 常州朗锐凯迩必减振技术有限公司 | Transverse shock absorber for locomotives |
-
2015
- 2015-08-25 WO PCT/JP2015/073862 patent/WO2016052008A1/en active Application Filing
- 2015-08-25 GB GB1704079.1A patent/GB2544245B/en active Active
- 2015-08-25 JP JP2016551638A patent/JP6250185B2/en active Active
- 2015-08-25 CN CN201580050644.4A patent/CN106715953B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0861416A (en) * | 1994-08-23 | 1996-03-08 | Kayaba Ind Co Ltd | Air bleeder structure in oil damper |
| JPH11344068A (en) * | 1998-05-29 | 1999-12-14 | Kayaba Ind Co Ltd | Oil damper |
| JP2009243634A (en) * | 2008-03-31 | 2009-10-22 | Hitachi Ltd | Hydraulic shock absorber |
| JP2011007287A (en) * | 2009-06-26 | 2011-01-13 | Hitachi Automotive Systems Ltd | Transverse cylinder device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3690275A4 (en) * | 2017-09-27 | 2021-06-30 | KYB Motorcycle Suspension Co., Ltd. | Front fork and method for manufacturing front fork |
| US11400999B2 (en) | 2017-09-27 | 2022-08-02 | Kyb Motorcycle Suspension Co., Ltd. | Front fork and front fork manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2544245B (en) | 2020-06-24 |
| WO2016052008A1 (en) | 2016-04-07 |
| CN106715953A (en) | 2017-05-24 |
| JPWO2016052008A1 (en) | 2017-04-27 |
| GB201704079D0 (en) | 2017-04-26 |
| JP6250185B2 (en) | 2017-12-20 |
| CN106715953B (en) | 2019-03-15 |
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