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
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D25/00—Fluid-actuated clutches
  • F16D25/08—Fluid-actuated clutches with fluid-actuated member not rotating with a clutching member
  • F16D25/082—Fluid-actuated clutches with fluid-actuated member not rotating with a clutching member the line of action of the fluid-actuated members co-inciding with the axis of rotation
  • F16D25/083—Actuators therefor

Definitions

• the invention relates to a slave cylinder of a release system for clutch or brake systems of a motor vehicle according to the preamble of the first claim.
• CSCs concentric slave cylinders
• CSCs Generic concentric slave cylinders
• a housing designed as an annular cylinder, which is arranged around a clutch or transmission input shaft an axially displaceable annular piston is guided, which carries a release bearing which is supported on a clutch, an energy accumulator designed as a helical compression spring surrounds the piston ,
• such a slave cylinder is known from DE 1 1 2005 000 619 T5, which comprises a plastic body which defines an annular bore in which an annular piston is slidably mounted.
• the piston is sealed to the bore by an annular seal.
• a pressure chamber is defined, in which a pressure medium is introduced.
• the pressure medium comes from a master cylinder, which can be actuated by a clutch pedal.
• the piston of the slave cylinder acts on a release bearing, by which in turn the clutch is actuated.
• the piston contacts a circlip located on the housing which limits the piston stroke.
• the retaining ring has a circular cross-section and is seated in a groove in the outer circumference of the radially inwardly located wall region of the piston, which limits the pressure chamber inwards.
• the task is to develop a slave cylinder, which has a reliable stop for the piston stroke and absorbs a high impact force, even at high temperatures.
• the slave cylinder is preferably formed in the form of a CSC and has a housing arranged concentrically about a transmission input shaft made of plastic and an axially movable annular piston, which with a pressure of a pressure medium
• the housing is provided a stop which limits a stroke of the piston towards the release bearing and the stop according to the invention at least partially from a plastic material of a base body of the housing different plastic material and / or a metallic sleeve.
• the metallic sleeve is preferably attached by encapsulation with plastic on the housing and is molded in particular as an insert in the manufacture of the housing from the plastic and is thereby integrated into the housing.
• the sleeve is made of steel or aluminum. It has one or more openings / holes through which the plastic the base material of the housing is sufficient so that a good clamping of the sleeve is ensured in the housing.
• the sleeve is facing radially outward
• Edge area provided. This can be done after assembly of the piston by a forming process e.g. be generated by a radially outward beading and in this case even without further components form the stop for the piston.
• the radially outwardly facing edge region of the sleeve may be spaced from an end face of the housing facing it, whereby a groove-like recess is formed.
• a conventional snap ring may then be arranged, which forms the stop for the piston in connection with the sleeve.
• the substantially cylindrical wall portion of the sleeve is arranged radially inwardly of the piston, so that the running surface of the piston is not affected.
• the stop may also be made from the second plastic material that differs from the plastic material of the main body of the housing via a two-component injection molding process and have a radially outwardly facing edge region which serves as a stop or which is spaced from the end face of the housing facing thereon, wherein then in the recess formed thereby also a snap ring is arranged, which forms the stop for the piston in conjunction with the second plastic material
• the second plastic material has higher strength properties than the base material of the housing.
• the second plastic material has a high temperature resistance. To achieve the required properties of the second plastic material, this may be fiber-reinforced or contain other strength-increasing additives.
• the existing of metallic material (especially steel) existing sleeve or the second plastic material has a higher strength than the plastic of the housing (especially at high temperatures), it is possible to produce a much higher impact force, since it can be assumed that the sleeve will not be the weak spot. Due to the fixed connection between sleeve and housing via the bore matrix, the maximum impact force will depend on the complete wall thickness of the housing.
• a positive connection with a snap ring or a clip ensures both when sending a stopper from a metallic sleeve (in particular a steel sleeve) as well as a second plastic material made of a high-strength plastic, the inclusion of higher forces than in a conventional plastic housing, since the stress concentration on the steel ring or on radially outwardly facing paragraph of the second plastic material is much less critical.
• FIG. 1 shows the region of a housing arranged radially on the inside, in which a steel sleeve is arranged,
• Figure 4 shows a portion of a housing made of a plastic material which is combined with a second plastic material by a 2K injection molding process.
• FIG. 1 shows an end of a radially inner first wall region 1.1 of a plastic housing 1 of a slave cylinder.
• a steel sleeve 2 is used, which has a plurality of openings 2.1 and the end face 1.2 of the first wall portion 1 .1 projects beyond a crimping 2.2.
• the steel sleeve 2 was molded with plastic to the housing 1, wherein the plastic flows into the openings 2.1 and thereby an intimate connection between the housing 1 and steel sleeve 2 is produced, which withstands high loads in the axial direction.
• the piston 3 After injection molding of the steel sleeve 2, the piston 3 is mounted with the piston seal 4 in the annular space 5 of the housing 1, which is formed by the first wall portion 1 .1 and a second wall portion 1 .3 of the housing 1 according to Figure 2.
• the annular space 5 opens a pressure medium bore 6, so that between the first wall portion 1 .1, second wall portion 1.3 and piston seal 4, a pressure chamber D is formed.
• the flaring region 2.2 is deformed radially outward, so that it protrudes circumferentially beyond the outer diameter 1 .1 'of the first wall region 1.1 by a region a.
• the piston 3 acts upon pressurization of the pressure chamber D on a release bearing 7 and it is a preload spring 8 is provided.
• the region a forms a stop a for a radially inner end region 3.1 of the piston 3, by which it is ensured that no pressure medium can escape from the pressure chamber D even at high temperatures.
• the steel sleeve 2 according to FIG. 3 has no flaring region 2.2. It is only provided a collar 2.3, which is axially spaced from the end face 1.2 of the first wall portion 1.1 and the radially does not protrude beyond the outer diameter of the first wall portion 1 .1 ', so that the piston 3 and the piston seal 4 mounted in the annular space 5 can be. Between the end face 1.2 of the first wall portion 1 .1, the collar 2.3 and the outer diameter 1 .1 ', a groove N is formed, in which after the assembly of piston 3 and piston seal 4, a snap ring 9 is inserted and, like the crimping 2.2 in Fig.
• the stop formed by the snap ring 9 a cooperates in this case with the collar 2.3 of the sleeve 2, because the snap ring 9 is by the front side 3.1 of the piston 3 at a high pressure in the pressure chamber D in the groove N against the collar 2.3 and thus pressed against the steel sleeve 2. Because the steel sleeve 2 is substantially stronger than the plastic of the housing 1, higher axial forces can also be absorbed with this solution.
• FIG. 1 An end region of the first wall region 1 .1 of a housing 1 made of plastic with a second plastic material 10 injection-molded in the 2K injection molding process is shown in FIG.
• the radially outwardly facing edge region is formed by a collar 10. 1 of the second plastic material 10, which is spaced from a facing end face 1 .2 of the housing 1.
• a snap ring 9 is arranged, which protrudes radially beyond the outer diameter 1.1 'of the first wall region 1 .1 and thereby forms a stop a which, in conjunction with the collar 10.1 and thus with the second plastic material 10, limits the stroke of the piston 3 (not shown here).

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)
• Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49765244

Family Applications (1)

Country Status (5)

Families Citing this family (7)

Family Cites Families (9)

• 2013
  • 2013-10-28 DE DE112013005612.7T patent/DE112013005612B4/de active Active
  • 2013-10-28 WO PCT/DE2013/200250 patent/WO2014079428A1/de active Application Filing
  • 2013-10-28 DE DE102013221840.0A patent/DE102013221840A1/de not_active Withdrawn
  • 2013-10-28 EP EP13805260.0A patent/EP2923101A1/de not_active Withdrawn
  • 2013-10-28 CN CN201380060178.9A patent/CN104797837B/zh active Active
• 2015
  • 2015-04-14 IN IN3092DEN2015 patent/IN2015DN03092A/en unknown

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events