US20020046651A1 - Piston for a piston-cylinder arrangement, in particular a shock absorber piston - Google Patents

Piston for a piston-cylinder arrangement, in particular a shock absorber piston Download PDF

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Publication number
US20020046651A1
US20020046651A1 US09/834,322 US83432201A US2002046651A1 US 20020046651 A1 US20020046651 A1 US 20020046651A1 US 83432201 A US83432201 A US 83432201A US 2002046651 A1 US2002046651 A1 US 2002046651A1
Authority
US
United States
Prior art keywords
piston
piston body
collar
peripheral
web
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09/834,322
Other languages
English (en)
Inventor
Antonio Casellas
Ewald May
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GKN Sinter Metals GmbH
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Assigned to GKN SINTER METALS GMBH reassignment GKN SINTER METALS GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CASELLAS, ANTONIO, MAY, EWALD
Publication of US20020046651A1 publication Critical patent/US20020046651A1/en
Priority to US10/988,954 priority Critical patent/US7178237B2/en
Abandoned legal-status Critical Current

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Classifications

    • 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
    • F16J15/164—Sealings between relatively-moving surfaces the sealing action depending on movements; pressure difference, temperature or presence of leaking fluid
    • 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
    • F16F9/368—Sealings in pistons
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49229—Prime mover or fluid pump making
    • Y10T29/49249—Piston making
    • Y10T29/49252—Multi-element piston making
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49229—Prime mover or fluid pump making
    • Y10T29/49249—Piston making
    • Y10T29/49256—Piston making with assembly or composite article making
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49229—Prime mover or fluid pump making
    • Y10T29/49249—Piston making
    • Y10T29/49256—Piston making with assembly or composite article making
    • Y10T29/49261—Piston making with assembly or composite article making by composite casting or molding

Definitions

  • shock absorber piston known from EP-A-0 658 611 that has a piston body that is provided with a peripheral web at its peripheral surface. A number of webs running in the axial direction attach to this peripheral web on one side of it. A seal made of thermoplastic synthetic is sprayed onto this piston body in an injection molding process. The webs extending in the axial direction and the notches between them, which are filled in with sealing material, serve to reliably anchor the sealing material.
  • the seal applied by injection molding enables close tolerancing, which prevents “blow-by” and thus provides a reliable seal of the cylindrical spaces facing one another. The process to produce these types of injection-molded seals is relatively expensive.
  • the grooves are completely filled with the sealant material so as to provide a form-locked solid connection of the seal to the peripheral surface of the piston body.
  • shock absorber piston known from EP-A-682 190 whose only essential difference from the processes described above in its manufacture is in that to apply the seal, instead of a cup-shaped preliminary mold, a stamped circular sleeve is used. This circular sleeve is placed on one end of the piston body. The piston body prepared thusly is then pressed into a heated forming and calibrating cylinder, wherein the circular sleeve is placed around the peripheral surface of the piston body as a strip and then pressed into the grooves running in the peripheral direction of the piston body under the influence of heat. Then, the piston with its pressed-on seal is guided through a cooling tube.
  • the sealant material fills the grooves practically completely so that the seal is solidly connected to the peripheral surface of the piston body in form-locked fashion.
  • the objective of this invention is to produce a piston, in particular a shock absorber piston, in which the disadvantages described above are avoided.
  • a piston for a piston-cylinder arrangement in particular a shock absorber piston
  • a piston body that is provided with at least one peripherally running web on its peripheral surface.
  • a collar-shaped seal made of a thermoformable plastic material is formed onto the peripheral surface of the piston body such that the web presses into the material of the seal only along a portion of its height.
  • a useful embodiment of the invention provides that at least two peripheral webs are located on the peripheral surface, the peripheral webs being located on both sides of a notch. This results in a reliable form-locked connection even at higher working pressures. An arrangement with one, or even two peripheral webs can still be produced cost-effectively through machining.
  • each of the edges of the collar-shaped seal extends beyond the end surface of the piston body associated with it. Since the collar-shaped seal is produced according to a known process from a circular sleeve, the phenomenon of “back memory” of the sealant material described in EP-A-0 682 190 can be used to cause the edge around the inner diameter of the circular sleeve to pull inward after it is applied to the piston body, and to cause the edge of the collar-shaped seal produced from the external edge of the circular sleeve to move back outward and in this way to protrude above the rest of the peripheral surface of the collar-shaped seal as a lip seal.
  • the piston body is installed such that, when used as a shock absorber piston, the piston surface provided with the lip-shaped edge extending outward faces the pressurized side, i.e. the side subjected to the high load, and if the piston surface with the edge that springs back inward is located on the so-called suction side, this results in an improved seal of the piston in the shock absorber cylinder during a pressure load since the hydraulic fluid in the lip-shaped edge presses against the cylinder wall. When it springs back, i.e. for suction loads, the hydraulic fluid can then enter the intermediate space between the piston wall and the cylinder wall to some degree as a result of the minimal play between the two.
  • the fluid can thus find its way up to the edge where the lip-shaped edge of the collar-shaped seal sits against the cylinder wall for the purposes of lubrication.
  • acceptable lubrication is provided, preventing wear of the seal. Since the flow resistance due to this minimum gap between the sealing surface of the piston and the cylinder wall is considerably higher than the flow resistance through the flow channels in the piston body, practically no drop in performance results.
  • At least one web is located in an area adjacent to one end surface of the piston body.
  • the webs can be dimensioned to be relatively wide; the notch laterally bordered by the webs can then be twice to three times as wide as the width of a web. This simplifies the contour of the peripheral surface of the piston body considerably.
  • the piston body is pieced together from at least two element sections, each of which has a plane of separation that runs perpendicular to the piston axis.
  • This type of piston body design is suited for manufacture using a powder-metallurgy process, i.e. as a sintered metal part.
  • the form of the two element sections is particularly favorable if each element section has only one peripheral web so that the mirror-imaged element sections pieced together border a notch with their webs. This allows cost-effective manufacture of an [undercut] notch since machining work is not necessary.
  • FIG. 1 a partial section in the axial direction through a piston-cylinder arrangement for a shock absorber
  • FIG. 2 an enlarged partial section through the piston of the arrangement according to FIG. 1,
  • FIG. 3 an enlarged partial section through a piston with one web.
  • FIG. 1 shows an axial section through a shock absorber that connects two parts that are movable relative to one another, for example a vehicle axis and a vehicle frame.
  • the shock absorber has a cylindrical part 1 that is connected to one of the two parts that are movable with respect to one another.
  • a piston 2 is guided inside cylinder 1 that is fastened to a piston rod 3 whose free end is fixed to the other part of the parts moving relative to one another.
  • the cylinder 1 is closed on both sides and is filled with a hydraulic fluid so that the piston-cylinder arrangement is designed to be dual-acting, with the piston separating two cylinder spaces 4 , 5 from one another.
  • the piston body 6 of the piston 2 has a number of penetration channels 7 , 8 running alongside one another.
  • a throttle valve 7 . 1 and 8 . 1 covers the exit side of each of the penetration channels 7 , 8 .
  • This arrangement is designed such that, for example, three penetration channels 7 and three penetration channels 8 are arranged in the shape of a star in alternating fashion around the cylinder axis.
  • the peripheral surface of the piston 2 is provided with a collar-shaped seal 9 that seals off cylinder space 4 against cylinder space 5 .
  • the fluid is pushed through the penetration channels 7 against the return force of the throttle valve 7 . 1 .
  • the penetration openings 8 are held shut by the pressure of the fluid space 4 acting on the throttle valve 8 . 1 .
  • the penetration channels 7 are closed by throttle valve 7 . 1 , with the fluid now able to flow back through the flowing channels 8 out of cylinder space 5 into cylinder space 4 .
  • FIG. 2 shows a piston 2 in an enlarged representation without the arrangement of the throttle valves 7 . 1 and 8 . 1 .
  • the piston body 6 is provided with two webs 10 on its peripheral surface, which are arranged in the embodiment example shown here such that they also contain a portion of the respective end surface 4 . 1 or 5 . 1 of the piston body 6 .
  • the two webs border a notch 11 on the peripheral surface of the piston body 6 .
  • the arrangement can also be designed such that at least one of the webs 10 is set back somewhat with respect to its associated end surface 4 . 1 and/or 5 . 1 .
  • the collar-shaped seal 9 arranged on the peripheral surface of the piston body 6 consists of a thermoplastic synthetic material, preferably PTFE.
  • the collar-shaped seal 9 was formed onto the peripheral surface of the piston body 6 by heat forming a circular sleeve, with edge 9 . 1 of the seal 9 being formed by the inner edge of the circular sleeve and edge 9 . 2 being formed by the outer edge of the circular sleeve.
  • the width of the circular sleeve was dimensioned such that it was wider than the thickness of the piston body 6 in the axial direction. By doing so, edge 9 . 1 produced by the inner edge of the circular sleeve is pulled inward after it deforms, whereas edge 9 . 2 produced by the outer edge of the circular sleeve is bent outward, thus forming a functioning lip seal.
  • the webs 10 press into the material of the collar-shaped seal 9 over only a portion of their height so that a certain amount of free space remains between the material of the seal 9 and the bottom of the notch 11 . This allows the sealing material to freely flow into the notch 11 without being squeezed when the seal 9 is formed.
  • the cylindrical exterior surface 13 of the seal 9 is simultaneously calibrated so that the desired tolerances to the inner diameter of the cylinder 1 can be maintained.
  • this remaining free space in the base of the notch also allows the sealing material to expand into the notch within certain limits so that the wear of the seal on the peripheral surface of the seal 9 adjacent to the edges is reduced.
  • the piston body 6 is produced from two element sections 6 . 1 and 6 . 2 .
  • the shape of the contours of the penetration channels 7 and 8 in one section is identical with that in the other section in the embodiment example shown so that regardless of the arrangement of a bushing 6 . 3 on element section 6 . 1 and a corresponding recess 6 . 4 in element section 6 . 2 , both element sections have the identical external form and are designed without back tapering [undercutting], which hinders the press process.
  • FIG. 3 an embodiment form is shown differing in comparison to FIG. 2.
  • the same references apply to the same elements so that reference can be made to FIG. 2 accordingly.
  • FIG. 3 The embodiment form shown in FIG. 3 is provided for cases of minimal suction-pressure load so that the piston body 6 is provided with only one peripheral web 10 .
  • the end surface 4 . 1 of the piston body 6 is subjected to the higher pressure so that the web 10 is located close to this end surface in this case.
  • the collar-shaped seal 9 is formed onto the piston body 6 in the manner described above, wherein here, as well, the peripheral web 10 presses into the material of the collar-shaped seal 9 only over a portion of its height.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Sealing Devices (AREA)
US09/834,322 1998-10-14 2001-04-13 Piston for a piston-cylinder arrangement, in particular a shock absorber piston Abandoned US20020046651A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/988,954 US7178237B2 (en) 1998-10-14 2004-11-15 Piston for a piston-cylinder arrangement, in particular a shock absorber piston

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19847341A DE19847341A1 (de) 1998-10-14 1998-10-14 Kolben für eine Kolben-Zylinder-Anordnung, insbesondere Stoßdämpferkolben
DE198473419 1998-10-14
PCT/EP1999/007642 WO2000022319A1 (de) 1998-10-14 1999-10-12 Kolben für eine kolben-zylinder-anordnung, insbesondere stossdämpferkolben

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1999/007642 Continuation WO2000022319A1 (de) 1998-10-14 1999-10-12 Kolben für eine kolben-zylinder-anordnung, insbesondere stossdämpferkolben

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US10/988,954 Continuation US7178237B2 (en) 1998-10-14 2004-11-15 Piston for a piston-cylinder arrangement, in particular a shock absorber piston

Publications (1)

Publication Number Publication Date
US20020046651A1 true US20020046651A1 (en) 2002-04-25

Family

ID=7884434

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/834,322 Abandoned US20020046651A1 (en) 1998-10-14 2001-04-13 Piston for a piston-cylinder arrangement, in particular a shock absorber piston
US10/988,954 Expired - Fee Related US7178237B2 (en) 1998-10-14 2004-11-15 Piston for a piston-cylinder arrangement, in particular a shock absorber piston

Family Applications After (1)

Application Number Title Priority Date Filing Date
US10/988,954 Expired - Fee Related US7178237B2 (en) 1998-10-14 2004-11-15 Piston for a piston-cylinder arrangement, in particular a shock absorber piston

Country Status (9)

Country Link
US (2) US20020046651A1 (enExample)
EP (1) EP1121544B1 (enExample)
JP (1) JP2002527692A (enExample)
AT (1) ATE231953T1 (enExample)
AU (1) AU1035200A (enExample)
BR (1) BR9914434A (enExample)
DE (2) DE19847341A1 (enExample)
ES (1) ES2190261T3 (enExample)
WO (1) WO2000022319A1 (enExample)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6591948B2 (en) * 1998-10-14 2003-07-15 Gkn Sinter Metals Gmbh Piston with support webs for a piston-cylinder arrangement, in particular a shock absorber piston
US20040079599A1 (en) * 2001-02-21 2004-04-29 Ewald May Piston with supporting connector elements for a piston-cylinder arrangement, in particular a shock absorber piston
US20080289491A1 (en) * 2002-09-28 2008-11-27 Gkn Sinter Metals Gmbh Powder-Metallurgically Produced Piston Body Comprising Support Webs
US20110308383A1 (en) * 2010-06-17 2011-12-22 Carl Freudenberg Kg Piston accumulator
US9327797B2 (en) 2011-10-04 2016-05-03 Yamaha Hatsudoki Kabushiki Kaisha Vehicle shock absorber
US20220275847A1 (en) * 2019-10-02 2022-09-01 Hitachi Astemo, Ltd. Shock absorber

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4898563B2 (ja) * 2007-06-06 2012-03-14 カヤバ工業株式会社 ピストン
DE102007036017A1 (de) 2007-07-30 2009-02-19 Gkn Sinter Metals Holding Gmbh Kolben für eine Kolben-Zylinder-Anordnung und Herstellungsverfahren
DE102010050868B4 (de) 2010-11-09 2013-09-26 Gkn Sinter Metals Holding Gmbh Herstellung mehrteiliger, gefügter Ventilbauteile in hydraulischen Anwendungen mit Fügedichtprofilen
KR101288613B1 (ko) * 2011-08-11 2013-07-22 주식회사 만도 쇽업소버의 피스톤 어셈블리
KR101374875B1 (ko) * 2011-12-30 2014-03-18 주식회사 만도 쇽업소버의 피스톤 어셈블리
JP7465163B2 (ja) 2020-07-03 2024-04-10 カヤバ株式会社 緩衝器および緩衝器の組み立て方法

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4110023A1 (de) * 1991-03-27 1992-10-01 Ringsdorff Werke Gmbh Stossdaempferkolben aus ungleichen, gefuegten teilen
DE3429474A1 (de) * 1984-08-10 1986-02-20 Fichtel & Sachs Ag, 8720 Schweinfurt Kolben mit einem kolbenring fuer schwingungsdaempfer oder federbeine
JPS61116137A (ja) 1984-11-12 1986-06-03 Toyota Motor Corp 液圧緩衝器およびその製造方法
JPS61116138A (ja) 1984-11-13 1986-06-03 Toyota Motor Corp 液圧緩衝器
DE3812574A1 (de) * 1988-04-15 1989-10-26 Boge Ag Kolben mit einem kolbenring
EP0345561A3 (de) * 1988-06-04 1990-09-19 Manfred Fietz Teleskopierende Vorrichtung sowie Verfahren zu deren Herstellung
DE4343428A1 (de) 1993-12-18 1995-06-22 Ringsdorff Sinter Gmbh Spritzgegossene Führungs- und Dichtelemente an Sinterteilen für Stoßdämpfer
DE4421968C2 (de) * 1994-06-23 1997-09-11 Bilstein August Gmbh Co Kg Dichtung für Dämpfungskolben
DE29623140U1 (de) * 1996-11-20 1997-11-13 Mannesmann Sachs AG, 97422 Schweinfurt Schwingungsdämpfer für ein Kraftfahrzeug
DE19707633C1 (de) * 1997-02-26 1998-07-09 Mannesmann Sachs Ag Dichtung zwischen zwei axialen Bauteilen

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6591948B2 (en) * 1998-10-14 2003-07-15 Gkn Sinter Metals Gmbh Piston with support webs for a piston-cylinder arrangement, in particular a shock absorber piston
US20040079599A1 (en) * 2001-02-21 2004-04-29 Ewald May Piston with supporting connector elements for a piston-cylinder arrangement, in particular a shock absorber piston
US6928923B2 (en) 2001-02-21 2005-08-16 Gkn Sinter Metals Gmbh Piston with supporting connector elements for a piston-cylinder arrangement, in particular a shock absorber piston
US20080289491A1 (en) * 2002-09-28 2008-11-27 Gkn Sinter Metals Gmbh Powder-Metallurgically Produced Piston Body Comprising Support Webs
US20110308383A1 (en) * 2010-06-17 2011-12-22 Carl Freudenberg Kg Piston accumulator
US9327797B2 (en) 2011-10-04 2016-05-03 Yamaha Hatsudoki Kabushiki Kaisha Vehicle shock absorber
US20220275847A1 (en) * 2019-10-02 2022-09-01 Hitachi Astemo, Ltd. Shock absorber
US12222018B2 (en) * 2019-10-02 2025-02-11 Hitachi Astemo, Ltd. Shock absorber

Also Published As

Publication number Publication date
EP1121544A1 (de) 2001-08-08
DE19847341A1 (de) 2000-04-20
ATE231953T1 (de) 2003-02-15
JP2002527692A (ja) 2002-08-27
BR9914434A (pt) 2001-07-03
WO2000022319A1 (de) 2000-04-20
AU1035200A (en) 2000-05-01
US7178237B2 (en) 2007-02-20
ES2190261T3 (es) 2003-07-16
EP1121544B1 (de) 2003-01-29
US20050145457A1 (en) 2005-07-07
DE59904189D1 (de) 2003-03-06

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AS Assignment

Owner name: GKN SINTER METALS GMBH, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CASELLAS, ANTONIO;MAY, EWALD;REEL/FRAME:011995/0623;SIGNING DATES FROM 20010605 TO 20010618

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION