CN111757996B - Reciprocating fluid pressure device - Google Patents
Reciprocating fluid pressure device Download PDFInfo
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- CN111757996B CN111757996B CN201980014960.4A CN201980014960A CN111757996B CN 111757996 B CN111757996 B CN 111757996B CN 201980014960 A CN201980014960 A CN 201980014960A CN 111757996 B CN111757996 B CN 111757996B
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- outer peripheral
- peripheral surface
- cylinder
- lip
- peripheral lip
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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
- F16F9/32—Details
- F16F9/36—Special sealings, including sealings or guides for piston-rods
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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
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/16—Sealings between relatively-moving surfaces
- F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
- F16J15/3204—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip
Abstract
The shock absorber (100) comprises a cylinder (10), a piston rod (20), a rod guide (60), and a seal member (70) that closes the space between the cylinder (10) and the piston rod (20), wherein the seal member (70) comprises a base (71) and an outer peripheral lip (74) that extends from the base (71) in the axial direction and is disposed in a compressed state between the inner peripheral surface of the cylinder (10) and the outer peripheral surface of the rod guide (60), the outer peripheral surface of the outer peripheral lip (74) comprises an outer pressing portion (74 a) that is disposed apart from the base (71) in the axial direction and is pressed by the inner peripheral surface of the cylinder (10), and the outer pressing portion (74 a) is formed to bulge in a curved shape as a whole in a state in which the outer peripheral lip (74) is not compressed.
Description
Technical Field
The present invention relates to a reciprocating fluid pressure device.
Background
In reciprocating fluid pressure devices such as dampers and fluid pressure cylinders, annular seal members for closing a space between a cylinder tube and a piston rod are known (JP 2007-155078A and JP 2001-173797A). In the dampers disclosed in JP2007-155078A and JP2001-173797A, the seal member has a metal ring supported by a rod guide fixed to the inner periphery of the cylinder tube and an outer peripheral lip portion vulcanization-bonded to the metal ring. The outer peripheral lip is provided in a compressed state between the inner peripheral surface of the cylinder and the outer peripheral surface of the rod guide, thereby sealing the cylinder.
Disclosure of Invention
In the shock absorber disclosed in JP2007-155078A, the outer peripheral lip portion of the seal member is formed to expand relatively sharply toward the radial outside in an uncompressed state. Therefore, when the shock absorber is assembled and the outer peripheral lip is compressed by the cylinder and the rod guide, local internal stress is generated in the outer peripheral lip, and a part of the outer peripheral lip may be broken, thereby degrading the sealing performance of the seal member.
In the damper disclosed in JP2001-173797A, the outer peripheral lip portion of the seal member has an outer periphery bent from the outer periphery of the metal ring toward the tip end. Therefore, when the cylinder tube is crimped and the seal member is fixed to the cylinder tube, a portion of the outer peripheral lip portion that is bonded to the outer periphery of the metal ring is sandwiched between the cylinder tube made of metal and the metal ring, and is subjected to excessive stress. This promotes a creep phenomenon of the outer peripheral lip portion, which may cause a premature decrease in sealing performance, thereby resulting in oil leakage.
The invention aims to improve the sealing performance of a sealing component of a buffer.
According to one aspect of the present invention, a reciprocating fluid pressure apparatus includes: a cylinder barrel; a piston rod inserted into the cylinder so as to be movable in the axial direction; a rod guide provided on an inner periphery of the cylinder tube and supporting the piston rod; and a seal member that is supported by the rod guide and closes a gap between the cylinder tube and the piston rod, the seal member including: a base portion formed in a ring shape and through which the piston rod passes; and an outer peripheral lip portion that extends in the axial direction from the base portion and is provided in a compressed state between an inner peripheral surface of the cylinder tube and an outer peripheral surface of the rod guide, the outer peripheral lip portion having an outer pressing portion that is provided apart from the base portion in the axial direction and is pressed by the inner peripheral surface of the cylinder tube, the outer pressing portion being formed to bulge in a curved shape as a whole in a state where the outer peripheral lip portion is not compressed.
Drawings
Fig. 1 is a partial sectional view of a damper according to an embodiment of the present invention.
Fig. 2 is an enlarged sectional view of the periphery of the sealing member.
Fig. 3 is an enlarged sectional view of the seal member, showing a state before being assembled to the cylinder tube.
Fig. 4 is an enlarged view of the portion IV shown in fig. 3, showing a state before being assembled to the cylinder tube.
Fig. 5 is a sectional view taken along line V-V shown in fig. 2.
Detailed Description
Hereinafter, a description will be given of a shock absorber 100 as a reciprocating fluid pressure device according to an embodiment of the present invention with reference to the drawings.
Fig. 1 is a partial cross-sectional view of a bumper 100. The shock absorber 100 is provided, for example, between a vehicle body and an axle of a vehicle (not shown), and generates a damping force to suppress vibration of the vehicle body.
The damper 100 includes a cylinder 10, a piston rod 20 movably inserted into the cylinder 10, and a piston 30 connected to the piston rod 20. The piston rod 20 extends from the cylinder 10, and the damper 100 is contracted by the piston rod 20 entering the cylinder 10, and the damper 100 is extended by the piston rod 20 retreating from the cylinder 10.
Hereinafter, the direction along the piston rod 20 is referred to as "axial direction", and the radial direction around the piston rod 20 is referred to as "radial direction".
The piston 30 is slidably housed in the cylinder 10, and divides the inside of the cylinder 10 into a compression-side chamber 11a and an extension-side chamber 11b. Working oil as a working fluid is sealed in the compression-side chamber 11a and the extension-side chamber 11b. The piston 30 is provided with a compression-side passage 31a and an extension-side passage 31b that communicate between the compression-side chamber 11a and the extension-side chamber 11b. The compression-side passage 31a and the expansion-side passage 31b are opened and closed by a compression-side damping valve 40a and an expansion-side damping valve 40b, which are damping force generating portions provided in the piston 30, respectively.
When the shock absorber 100 contracts, the piston 30 moves in a direction to contract the compression-side chamber 11a and expand the expansion-side chamber 11b. The compression-side damping valve 40a opens and opens the compression-side passage 31a due to the pressure difference between the compression-side chamber 11a and the expansion-side chamber 11b, and the hydraulic oil flows from the compression-side chamber 11a into the expansion-side chamber 11b through the compression-side passage 31 a. At this time, the compression side damping valve 40a applies resistance to the flow of the hydraulic oil, and the shock absorber 100 generates a damping force.
When the shock absorber 100 extends, the piston 30 moves in a direction to reduce the extension side chamber 11b and expand the compression side chamber 11 a. The expansion side damping valve 40b opens by the pressure difference between the expansion side chamber 11b and the compression side chamber 11a to open the expansion side passage 31b, and the working oil flows from the expansion side chamber 11b into the compression side chamber 11a through the expansion side passage 31b. At this time, resistance is applied to the flow of the hydraulic oil by the extension side damping valve 40b, and the shock absorber 100 exerts a damping force.
As described above, the compression-side damping valve 40a and the extension-side damping valve 40b generate a damping force by applying resistance to the flow of the hydraulic oil in accordance with the movement of the piston rod 20.
The change in volume in the cylinder 10 accompanying the movement of the piston rod 20 is compensated by the air chamber 12 formed by the free piston 50 in the cylinder 10.
A rod guide 60 that supports the piston rod 20 via a bush 61 is provided on the inner periphery of the cylinder 10. The rod guide 60 is supported by a retainer ring 62 provided on the inner periphery of the cylinder tube 10.
The open end 13 of the cylinder tube 10 is bent inward by the crimping process, and a seal member 70 that closes the space between the cylinder tube 10 and the piston rod 20 is provided between the open end 13 and the rod guide 60. That is, the seal member 70 and the rod guide 60 are sandwiched between the open end 13 of the cylinder 10 and the retainer ring 62 and fixed to the cylinder 10.
As shown in fig. 2, the seal member 70 includes an annular base portion 71 through which the piston rod 20 passes, oil seal lips 72 and dust seal lips 73 that are inner peripheral lips extending in the axial direction from the inner periphery of the base portion 71, and an outer peripheral lip 74 extending in the axial direction from the outer periphery of the base portion 71. The base 71 is formed of metal. The oil seal lip 72, the dust lip 73, and the outer peripheral lip 74 are integrally formed of a rubber material as an elastic body. That is, the oil seal lip 72 and the dust lip 73 are coupled to each other by a coupling portion 75 extending between the inner peripheral surface of the base portion 71 and the outer peripheral surface of the piston 20 in the axial direction, and the oil seal lip 72 and the outer peripheral lip 74 are coupled to each other by a coupling portion 76 extending between the base portion 71 and the rod guide 60 in the radial direction. The oil seal lip 72, the dust lip 73, the outer peripheral lip 74, the coupling portion 75, and the coupling portion 76 are bonded to the base portion 71 by vulcanization adhesion.
The oil seal lip 72 is formed to protrude radially inward from the base 71 and in the direction in which the piston rod 20 enters the cylinder 10, and is in sliding contact with the outer periphery of the piston rod 20. When the shock absorber 100 extends, the working oil adhering to the outer periphery of the piston rod 20 is scraped off by the oil seal lip 72 and remains in the cylinder tube 10. That is, the oil seal lip 72 prevents the working oil from leaking out of the cylinder tube 10.
An annular groove portion 72a is formed in the outer periphery of the oil seal lip portion 72, and an annular garter spring 72b is attached to the groove portion 72 a. The fastening of the oil seal lip 72 with respect to the piston rod 20 is secured by the garter spring 72b.
The dust lip 73 is formed to protrude radially inward from the base 71 and in a direction in which the piston rod 20 retreats from the cylinder 10, and is in sliding contact with the outer periphery of the piston rod 20. When the damper 100 contracts, foreign matter adhering to the outer periphery of the piston rod 20 is scraped off by the dust lip 73. That is, the dust lip 73 prevents foreign matter from entering the cylinder 10. Further, a garter spring may be attached to the outer periphery of the dust lip 73 in the same manner as the oil lip 72.
The outer peripheral lip 74 extends annularly along the inner periphery of the cylinder 10 from the base 71, and is provided in a compressed state between the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the rod guide 60. Specifically, the rod guide 60 is provided with a projection 60a projecting in the axial direction toward the seal member 70 at a distance from the inner circumferential surface of the cylinder 10, and the outer circumferential lip 74 is provided in a compressed state between the outer circumferential surface of the projection 60a and the inner circumferential surface of the cylinder 10. Therefore, the outer peripheral lip 74 is pressed against the inner peripheral surface of the cylinder tube 10 by the protrusion 60a, and leakage of the working oil and entry of foreign matter between the outer peripheral lip 74 and the cylinder tube 10 can be prevented.
The outer peripheral surface of the projection 60a includes an inclined portion 60b inclined with respect to the inner peripheral surface of the cylinder tube 10. Therefore, when assembling the shock absorber 100, the outer peripheral lip 74 of the seal member 70 can be easily inserted between the outer peripheral surface of the protrusion 60a and the inner peripheral surface of the cylinder tube 10.
The distal end surface 60c of the projection 60a abuts against the coupling portion 76 of the seal member 70. In other words, the coupling portion 76 has an abutment surface 76a that abuts against the distal end surface 60c of the projection 60 a.
Fig. 3 is an enlarged sectional view of the seal member 70, which shows a state before assembly to the cylinder 10, i.e., a state in which the outer peripheral lip 74 of the seal member 70 is not compressed by the cylinder 10 and the rod guide 60. Fig. 3 shows a cross section of the cylinder 10, the piston rod 20, and the rod guide 60 in a two-dot chain line.
As shown in fig. 3 and 4, the outer peripheral lip 74 bulges radially outward in a state (non-compressed state) where it is not compressed by the cylinder 10 and the projecting portion 60a of the rod guide 60. Specifically, the outer peripheral surface of the outer peripheral lip 74 has an outer pressing portion 74a pressed by the inner peripheral surface of the cylinder tube 10, and the outer pressing portion 74a bulges in a non-compressed state so that the maximum outer diameter thereof is larger than the inner diameter of the cylinder tube 10.
The outer peripheral lip 74 is formed so that its outer peripheral surface is not sharply curved in a non-compressed state. Therefore, in the state where the seal member 70 is assembled to the cylinder tube 10, the local internal stress of the outer peripheral surface of the outer peripheral lip 74 can be made smaller as compared with the case where the outer peripheral surface is sharp in the non-compressed state, and the creep phenomenon of the outer peripheral lip 74 can be reduced. Therefore, the outer periphery of the outer peripheral lip 74 can be prevented from being damaged. This can improve the sealing performance of the sealing member 70.
The outer pressing portion 74a of the outer peripheral lip 74 is provided so as to be axially spaced apart from the base portion 71. Specifically, the outer pressing portion 74a is provided between the 1 st position 74b axially spaced from the base portion 71 and the 2 nd position 74c where the outer peripheral surface of the outer peripheral lip portion 74 starts to be spaced from the inner peripheral surface of the cylinder tube 10. In a state where the outer peripheral lip 74 is not compressed, the outer pressing portion 74a is formed to bulge in a curved shape as a whole. Therefore, the radius of curvature of the outer pressing portion 74a can be made larger than in the case where only a part of the outer pressing portion 74a is bent. Therefore, the local internal stress of the outer peripheral surface of the outer peripheral lip 74 can be made smaller, and the creep phenomenon of the outer peripheral lip 74 can be further reduced. This can further improve the sealing performance of the sealing member 70.
As shown in fig. 4, the 1 st position 74b is located in a retreating direction (upward in fig. 3 and 4) in which the piston rod 20 is retreated from the cylinder 10, with respect to a virtual extended surface 76b obtained by extending the contact surface 76a of the coupling portion 76 radially outward.
In addition, the outer peripheral surface of the outer peripheral lip 74 may be curved not only at the outer pressing portion 74a but also between the 1 st position 74b and the tip 74d of the outer peripheral lip 74 as a whole in the non-compressed state. In this case, the radius of curvature of the outer peripheral surface of the outer peripheral lip 74 can be made larger. Therefore, local internal stress on the outer peripheral surface of the outer peripheral lip 74 can be reduced, and the creep phenomenon of the outer peripheral lip 74 can be further reduced. This can further improve the sealing performance of the sealing member 70.
The entire outer pressing portion 74a may be provided in a range from the 1 st position 74b located above the contact surface 76a of the coupling portion 76 to the distal end 74 d. That is, the outer peripheral lip 74 may be formed to be pressed by the inner peripheral surface of the cylinder 10 in a range from the 1 st position 74b to the tip 74 d.
An inner pressing portion 74e pressed by the inclined portion 60b of the rod guide 60 is provided on the inner peripheral surface of the outer peripheral lip 74. The inner pressing portion 74e includes a flat surface portion 74f along the axial direction and a bent portion 74g bent from the flat surface portion 74f toward the distal end 74d in a non-compressed state. Therefore, in the state where the seal member 70 is assembled to the cylinder tube 10, the local internal stress of the inner peripheral surface of the outer peripheral lip 74 can be made smaller than in the case where the outer peripheral lip 74 is relatively sharp from the flat surface portion 74f toward the tip end 74d in the non-compressed state, and the creep phenomenon of the outer peripheral lip 74 can be reduced. This prevents the pressing force applied from the protrusion 60a to the cylinder tube 10 against the outer peripheral lip 74 from being weakened, and improves the sealing performance of the sealing member 70.
The outer peripheral lip 74 has a radius of curvature of the outer pressing portion 74a larger than that of the curved portion 74g of the inner pressing portion 74e in the non-compressed state. Therefore, in a state where the seal member 70 is assembled to the cylinder tube 10, the local internal stress of the outer peripheral surface of the outer peripheral lip 74 is smaller than the local internal stress of the inner peripheral surface. Therefore, the creep phenomenon of the outer periphery of the outer peripheral lip 74 can be further reduced, and the outer periphery of the outer peripheral lip 74 can be prevented from being damaged. This can improve the sealing performance of the sealing member 70.
The pressing amount a of the inner periphery of the cylinder 10 against the outer peripheral lip 74 is smaller than the pressing amount B of the inclined portion 60B of the rod guide 60 against the outer peripheral lip 74. Here, the pressing amount a of the inner peripheral surface of the cylinder 10 against the outer peripheral lip 74 is represented as a maximum dimension a in a direction orthogonal to the inner peripheral surface of the cylinder 10 between the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the outer peripheral lip 74 in a non-compressed state. In addition, a pressing amount B of the inclined portion 60B of the rod guide 60 to the outer peripheral lip 74 is expressed as a maximum dimension B between the inclined portion 60B and the inner peripheral surface of the outer peripheral lip 74 in a direction orthogonal to the inclined portion 60B of the rod guide 60 in a non-compressed state.
The pressing amounts a and B may be the amounts of swelling of the outer pressing portion 74a and the inner pressing portion 74e of the outer peripheral lip 74 in the non-compressed state, respectively. That is, in the shock absorber 100, the amount of swelling of the outer pressing portion 74a is smaller than the amount of swelling of the inner pressing portion 74e in a state where the outer lip portion 74 is not compressed.
In the seal member 70, since the pressing amount a of the inner peripheral surface of the cylinder 10 is smaller than the pressing amount B of the inclined portion 60B of the rod guide 60, the internal stress in the vicinity of the outer peripheral surface of the outer peripheral lip 74 is smaller than the internal stress in the vicinity of the inner peripheral surface in a state where the seal member 70 is assembled to the cylinder 10. Therefore, the creep phenomenon of the outer periphery of the outer peripheral lip 74 can be further reduced, and the outer periphery of the outer peripheral lip 74 can be prevented from being damaged. This can improve the sealing performance of the sealing member 70.
The portion of the inner pressing portion 74e that is pressed the most (the portion pressed by the pressing amount B in fig. 4) is arranged at a position closer to the direction in which the piston rod 20 enters the cylinder 10 (downward in fig. 3 and 4) than the portion of the outer pressing portion 74a that is pressed the most (the portion pressed by the pressing amount a in fig. 4). Therefore, the pressing force of the inclined portion 60b of the lever guide 60 is more likely to act on the outer pressing portion 74a. Therefore, the sealing performance of the sealing member 70 can be further improved.
The inner pressing portion 74e may be disposed below a part of the outer pressing portion 74a in fig. 3 and 4, or may be disposed below the entire outer pressing portion 74a in fig. 3 and 4. That is, the inner pressing portion 74e may be disposed below at least a part of the outer pressing portion 74a in fig. 3 and 4. In this case as well, the pressing force of the inclined portion 60b of the rod guide 60 is likely to act on the outer pressing portion 74a, and the sealing property of the sealing member 70 can be improved.
The cylinder 10 is formed by a so-called electric welded pipe. An electric-welded pipe is manufactured by rolling a steel plate into a tubular shape so that edges abut each other and welding the seam. Since the weld portion is formed to protrude toward the inside of the electric welded pipe, when the electric welded pipe is used as the cylinder tube 10, the weld portion 10a (see fig. 5) is cut from the inside of the electric welded pipe to cut off the weld portion.
The electric welded pipe is inexpensive as compared with a pipe member having no welded portion, but as shown in fig. 5, a recessed portion 10b is formed inside the welded portion 10a as the welded portion is cut off.
If the space between the cylinder tube 10 and the piston rod 20 is closed by using a seal member having an outer circumferential lip that sharply bulges in the radial direction, a sufficient area of close contact with the recess 10b cannot be obtained, and there is a possibility that the working oil leaks from the cylinder tube 10.
As shown in fig. 3, in the seal member 70, since the outer pressing portion 74a of the outer peripheral lip portion 74 is formed to bulge in a curved shape as a whole, sufficient sealing performance can be maintained even when an inexpensive electric welding pipe is used.
In the shock absorber 100, the volume of the outer peripheral lip 74 is smaller than the volume of the space 63 defined by the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the rod guide 60. That is, the filling ratio, which is the ratio of the volume of the outer peripheral lip 74 to the volume of the space 63, is less than 100%. Therefore, a retreat space of the outer peripheral lip 74 is formed between the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the rod guide 60. Therefore, when the seal member 70 is assembled to the cylinder 10, the cylinder 10 can be prevented from expanding.
The structure, operation, and effects of the embodiments of the present invention are summarized below.
The buffer 100 has: a cylinder barrel 10; a piston rod 20 inserted into the cylinder 10 to be movable in the axial direction; a rod guide 60 which is provided on the inner periphery of the cylinder tube 10 and supports the piston rod 20; and a seal member 70 supported by the rod guide 60 and closing a gap between the cylinder 10 and the piston rod 20, the seal member 70 including: a base portion 71 formed in an annular shape and through which the piston rod 20 passes; and an outer peripheral lip 74 that extends in the axial direction from the base 71 and is provided in a compressed state between the inner peripheral surface of the cylinder tube 10 and the outer peripheral surface of the rod guide 60, the outer peripheral surface of the outer peripheral lip 74 having an outer pressing portion 74a that is provided apart from the base 71 in the axial direction and is pressed by the inner peripheral surface of the cylinder tube 10, the outer pressing portion 74a being formed so as to bulge in a curved shape as a whole in a state where the outer peripheral lip 74 is not compressed.
In this structure, local internal stress in the outer peripheral surface of the outer peripheral lip 74 is smaller than in the case where the outer peripheral surface is sharp in a non-compressed state. Breakage of the outer peripheral lip 74 can be prevented. Further, the outer peripheral lip 74 can be prevented from being clamped in a state of receiving excessive stress between the cylinder tube 10 and the base 71. Therefore, the creep phenomenon of the outer peripheral lip 74 can be suppressed. This can improve the sealing performance of the sealing member 70 of the shock absorber 100.
In the damper 100, the outer peripheral surface of the rod guide 60 has the inclined portion 60B inclined with respect to the inner peripheral surface of the cylinder 10, the inner peripheral surface of the outer peripheral lip 74 has the inner pressing portion 74e pressed by the inclined portion 60B, the inner pressing portion 74e is bent in a state where the outer peripheral lip 74 is not compressed, and the pressing amount a of the inner peripheral surface of the cylinder 10 against the outer peripheral lip 74 is smaller than the pressing amount B of the inclined portion 60B of the rod guide 60 against the outer peripheral lip 74.
In this configuration, the local internal stress of the outer peripheral surface of the outer peripheral lip 74 is smaller than the local internal stress of the inner peripheral surface of the outer peripheral lip 74. Therefore, the damage of the portion near the outer peripheral surface of the outer peripheral lip 74 can be prevented, and the sealing performance of the sealing member 70 of the shock absorber 100 can be further improved.
In the damper 100, the pressing amount a of the inner peripheral surface of the cylinder 10 against the outer peripheral lip 74 is the maximum dimension in the direction orthogonal to the inner peripheral surface of the cylinder 10 between the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the outer peripheral lip 74 in the non-compressed state, and the pressing amount B of the inclined portion 60B of the rod guide 60 against the outer peripheral lip 74 is the maximum dimension in the direction orthogonal to the inclined portion 60B of the rod guide 60 between the inclined portion 60B and the inner peripheral surface of the outer peripheral lip 74 in the non-compressed state.
In this configuration, the local internal stress of the outer peripheral surface of the outer peripheral lip 74 is smaller than the local internal stress of the inner peripheral surface of the outer peripheral lip 74. Therefore, the damage of the portion near the outer peripheral surface of the outer peripheral lip 74 can be prevented, and the sealing performance of the seal member 70 of the shock absorber 100 can be further improved.
In the shock absorber 100, the cylinder tube 10 is formed of an electric welded pipe having a welded portion 10a at a joint, and the electric welded pipe has a recessed portion 10b inside the welded portion 10 a.
In this structure, sufficient sealing performance can be maintained even when an inexpensive electric welding pipe is used.
In the shock absorber 100, the volume of the outer peripheral lip 74 is smaller than the volume of the space 63 defined by the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the rod guide 60.
In this configuration, a relief space of the outer peripheral lip 74 is formed between the inner peripheral surface of the cylinder 10 and the outer peripheral surface of the rod guide 60. Therefore, the cylinder tube 10 can be prevented from expanding.
The embodiments of the present invention have been described above, but the above embodiments are merely some of application examples of the present invention, and the scope of the present invention is not intended to be limited to the specific configurations of the above embodiments.
In the above embodiment, the working oil is used as the working fluid, but a non-compressible fluid such as water or an aqueous solution may be used instead of the working oil.
In the above embodiment, the single-cylinder shock absorber in which the compression-side chamber 11a, the extension-side chamber 11b, and the air chamber 12 are formed in the cylinder 10 has been described as the shock absorber 100, but the shock absorber 100 may be a multi-cylinder shock absorber in which an outer cylinder is provided on the outer periphery of an inner cylinder and a receiver is formed between the inner cylinder and the outer cylinder.
Further, although the damper 100 has been described in the above embodiment, the present invention can be applied to a reciprocating fluid pressure device such as a fluid pressure cylinder.
This application claims priority based on patent application 2018-058027 filed on 3/26/2018 to the office of this franchise, the entire contents of which are incorporated herein by reference.
Claims (5)
1. A reciprocating fluid pressure apparatus, wherein,
the reciprocating fluid pressure apparatus has:
a cylinder barrel;
a piston rod inserted into the cylinder so as to be movable in an axial direction;
a rod guide provided on an inner periphery of the cylinder tube and supporting the piston rod; and
a seal member supported by the rod guide and occluding between the cylinder tube and the piston rod,
the sealing member has:
a base portion formed in a ring shape and through which the piston rod passes; and
an outer peripheral lip portion that extends from the base portion in the axial direction and is provided in a compressed state between an inner peripheral surface of the cylinder tube and an outer peripheral surface of the rod guide,
an outer peripheral surface of the outer peripheral lip has an outer pressing portion that is provided apart from the base portion in the axial direction and is pressed by an inner peripheral surface of the cylinder tube,
the outer pressing portion is formed to bulge in a curved shape as a whole in a state where the outer peripheral lip portion is not compressed,
the outer peripheral surface of the rod guide has an inclined portion inclined with respect to the inner peripheral surface of the cylinder,
the inner peripheral surface of the outer peripheral lip portion has an inner pressing portion pressed by the inclined portion,
the amount of pressing of the inner peripheral surface of the cylinder against the outer peripheral lip is smaller than the amount of pressing of the inclined portion of the rod guide against the outer peripheral lip.
2. The reciprocating fluid pressure apparatus according to claim 1,
the inner pressing portion is bent in a state where the outer peripheral lip portion is not compressed.
3. The reciprocating fluid pressure apparatus according to claim 1,
the pressing amount of the inner peripheral surface of the cylinder tube to the outer peripheral lip is a maximum dimension between the inner peripheral surface of the cylinder tube and the outer peripheral surface of the outer peripheral lip in a direction orthogonal to the inner peripheral surface of the cylinder tube in a non-compressed state,
the amount of pressing of the outer peripheral lip by the inclined portion of the rod guide is a maximum dimension between the inclined portion and the inner peripheral surface of the outer peripheral lip in a direction orthogonal to the inclined portion of the rod guide in a non-compressed state,
the range of the outer peripheral lip portion between the outer periphery of the base portion and the outer pressing portion is at the same radial position.
4. The reciprocating fluid pressure apparatus according to claim 1,
the inner pressing portion is disposed at a position closer to the direction in which the piston rod enters the cylinder than the outer pressing portion.
5. The reciprocating fluid pressure apparatus according to claim 1,
the volume of the outer circumferential lip is smaller than the volume of a space defined by the inner circumferential surface of the cylinder and the outer circumferential surface of the rod guide.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2018-058027 | 2018-03-26 | ||
| JP2018058027 | 2018-03-26 | ||
| PCT/JP2019/012962 WO2019189236A1 (en) | 2018-03-26 | 2019-03-26 | Reciprocating fluid compressor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111757996A CN111757996A (en) | 2020-10-09 |
| CN111757996B true CN111757996B (en) | 2023-02-28 |
Family
ID=68062110
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201980014960.4A Active CN111757996B (en) | 2018-03-26 | 2019-03-26 | Reciprocating fluid pressure device |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP7222979B2 (en) |
| CN (1) | CN111757996B (en) |
| WO (1) | WO2019189236A1 (en) |
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| JPH11132338A (en) * | 1997-10-28 | 1999-05-21 | Nok Corp | Sealing device |
| JP2007107550A (en) * | 2005-10-11 | 2007-04-26 | Nok Corp | Sealing device for reciprocating shaft |
| CN204004152U (en) * | 2014-06-11 | 2014-12-10 | 无锡恩福油封有限公司 | Seal arrangement |
| CN204164252U (en) * | 2014-06-11 | 2015-02-18 | 无锡恩福油封有限公司 | Seal arrangement |
| CN106233026A (en) * | 2014-05-19 | 2016-12-14 | Ｋｙｂ株式会社 | Buffer |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4491818B2 (en) | 2003-05-30 | 2010-06-30 | 日立オートモティブシステムズ株式会社 | Single cylinder type shock absorber |
| JP2010281373A (en) | 2009-06-04 | 2010-12-16 | Nok Corp | Seal for absorber |
| CN105042077A (en) * | 2015-07-07 | 2015-11-11 | 青岛睿辰密封科技有限公司 | High-performance multi-purpose tooth-shaped Y-shaped combined seal device |
-
2019
- 2019-03-26 WO PCT/JP2019/012962 patent/WO2019189236A1/en active Application Filing
- 2019-03-26 CN CN201980014960.4A patent/CN111757996B/en active Active
- 2019-03-26 JP JP2020510948A patent/JP7222979B2/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11132338A (en) * | 1997-10-28 | 1999-05-21 | Nok Corp | Sealing device |
| JP2007107550A (en) * | 2005-10-11 | 2007-04-26 | Nok Corp | Sealing device for reciprocating shaft |
| CN106233026A (en) * | 2014-05-19 | 2016-12-14 | Ｋｙｂ株式会社 | Buffer |
| CN204004152U (en) * | 2014-06-11 | 2014-12-10 | 无锡恩福油封有限公司 | Seal arrangement |
| CN204164252U (en) * | 2014-06-11 | 2015-02-18 | 无锡恩福油封有限公司 | Seal arrangement |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2019189236A1 (en) | 2019-10-03 |
| JP7222979B2 (en) | 2023-02-15 |
| JPWO2019189236A1 (en) | 2021-03-25 |
| CN111757996A (en) | 2020-10-09 |
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